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Hello and welcome to Noon Conference, hosted by modality

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Noon Conference connects the global radiology community

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through free live educational webinars that are accessible

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for all and is an opportunity

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to learn alongside top radiologists from around the world.

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Today we are honored to welcome Dr.

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Anup Shetty for a lecture entitled Pi RR

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standardizing prostate MRI Post-treatment reporting.

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Dr. Shetty completed his internal medicine residency,

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radiology residency

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and body MRI fellowship at Washington University.

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He currently serves as associate professor of radiology,

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advanced Abdominal Imaging Fellowship director

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and service director of Body MRI at Mallinckrodt

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Institute of Radiology.

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At the end of the lecture, please join him in a q

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and a session where he will address questions you may

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have on today's topic.

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Please remember to use that q

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and a feature to submit your questions so we can get to

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as many as we can before our time is up.

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With that, we are ready to begin today's lecture. Dr.

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Shetty, please take it from here.

0:57

Thank you so much, Ashley, for the invitation

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and modality for getting

1:00

to speak on PI rrr standardizing prostate MRI

1:04

post-treatment reporting.

1:06

Um, so I think we're all aware

1:07

that there is a growing alphabet soup

1:10

of different ways in which to assess, uh, the prostate,

1:13

including PI rrr.

1:14

Uh, we won't be talking about focal ablation today, uh,

1:17

but that that is a, a somewhat adjacent topic.

1:21

Okay, so first we'll discuss the rationale why have another

1:24

yet another imaging system.

1:26

So, uh, the, the whole gland treatment such

1:29

as radical prostatectomy

1:30

and radiation are really designed for curative intent

1:32

for localized prostate cancer.

1:35

And after biochemical recurrence, distinguishing

1:38

between local and systemic recurrence really guides the

1:41

decision making in terms of salvage radiation therapy versus

1:44

systemic therapy or both.

1:46

So the PY RAD system, which hopefully everyone is familiar

1:49

with, is really not intended

1:50

to be applied following radical

1:52

prostatectomy or radiotherapy.

1:55

And so the PI RRR system,

1:57

or prostate imaging for recurrence reporting system was

2:01

developed in 2021 to create standards

2:03

for reporting pelvic MRI following these treatments

2:06

and has gained acceptance, uh, in Europe as referenced

2:09

by the 2024 EAU guidelines.

2:13

So this is a five point Likert scoring system similar

2:16

to PI rads to convey the likelihood

2:18

of recurrent prostate cancer.

2:21

And there are different criteria which we'll discuss in some

2:23

depth following prostatectomy versus radiation therapy.

2:27

And the emphasis unlike, uh, PY rads

2:30

with PI rrr is really on T one weighted dynamic

2:33

contrast enhanced imaging.

2:34

That is one of the, the key points of this

2:36

as the enhancement may be seen in the setting

2:38

of recurrence without a corresponding finding on diffusion

2:41

or T two, and we'll, you'll get

2:42

to see some examples of this.

2:45

PI RRR does take into account the location

2:47

of the primary tumor on pre-treatment imaging

2:50

or on, uh, histopathology report.

2:53

So having a, either a prior study

2:56

or histology is very useful.

2:58

It is not mandatory.

2:59

We will see that we can still apply pi RR without that,

3:03

but it allows us to be more precise.

3:06

So the development of this, um,

3:07

these are consensus guidelines that are formulated

3:10

by members of the European Society

3:11

of Euro Genital Radiology, uh, disclosure.

3:14

I'm not one of those members as well as the European Society

3:16

of Urologic Imaging and the PI Rad Steering Committee.

3:19

This was based upon a non systematic review

3:22

of the literature that was available at the time

3:24

with consensus formed through discussion.

3:26

Uh, I'm not gonna belabor the data supporting this,

3:29

but as you can see, there have been a number

3:31

of studies looking at the performance

3:33

of PI RRR using different thresholds, three

3:36

or more being the most common, uh,

3:38

others looking at a more specific

3:40

threshold of four or higher.

3:42

There was a meta-analysis from 2024,

3:44

and this kind of supports the, the general, uh,

3:47

takeaway from all of the various data within these tables

3:50

that the sensitivity and specificity are around 80%.

3:55

So we'll touch briefly on the differences in technical

3:58

standards for performing a pelvic MRI

4:01

to apply pi rrr the similarities

4:03

with PI RADS version 2.1 and what's different.

4:06

So these are, um, the, the, the technical standards here,

4:10

and I'm really going to focus your attention on a few

4:13

things that are different.

4:14

So specifically for T two weighted imaging for PI rr,

4:17

it is advantageous to have all three planes.

4:20

Axial, sagittal and coronal pi rads version 2.1 only asks

4:24

for two separate planes.

4:26

The field of view for T two should also include sites

4:28

where we expect to encounter, uh, relapse disease such

4:32

as the vesco urethral anastomosis,

4:34

if there's any residual seminal vesical tissue, as well

4:37

as covering the complete posterior wall of the bladder.

4:39

So potentially a larger or not larger,

4:42

but a more encompassing cranial coddle field of view

4:44

for T two weighted imaging compared

4:46

to just a standard prostate MRI.

4:49

And then additionally, pi RR does

4:52

recommend obtaining at least one pulse sequence

4:54

of the larger field of view, either T one

4:56

or diffusion weighted imaging.

4:59

So I will just briefly touch on this now,

5:01

and then if there are questions about protocol, um,

5:03

we can certainly discuss that, uh, during the q and a.

5:06

Uh, so this is our protocol for, for prostate, MRI,

5:09

whether it is for initial staging or follow up

5:12

or looking for occurrence.

5:14

We run the same protocol on every patient.

5:16

It's simpler, I think, for both the technologist

5:18

as well as our radiologist.

5:19

So we perform a full field

5:21

of view T two weighted imaging in the coronal

5:24

and sagittal plane, faster

5:25

sequences, a single shot sequence.

5:27

Then we have the small field of view, axial coronal.

5:31

We run a 3D axial T two from which we create a

5:34

sagittal multiplanar.

5:35

The main purpose of that,

5:36

that 3D axial T two is really for fusion biopsy.

5:39

And then we perform two different types of small field

5:42

of view diffusion weighted imaging.

5:44

One is a, a zoomed

5:45

or selective excitation, uh, diffusion weighted image.

5:48

Another is a, a technique to reduce susceptibility,

5:52

a readout segmented EPI sequence,

5:54

and then a relatively fast full field of view,

5:57

really looking for bone metastases, lymph nodes, uh,

6:00

the deep, the dynamic contrast imaging,

6:02

small field of view of the prostate.

6:04

And then we also perform full field

6:06

of view T one weighted imaging using the Dixon method,

6:08

where we get both fat suppressed as well as, uh,

6:11

fat only imaging, which is helpful

6:13

for assessing bone lesions.

6:14

And then after the dynamic imaging,

6:16

we obtain this post contrast including a subtraction,

6:19

which is really nice for looking for bone metastases.

6:22

Uh, this protocol takes a little bit under

6:24

30 minutes to run.

6:27

So some of those additional protocol considerations, um,

6:29

that pyr specifically highlights is the value

6:32

of subtraction imaging.

6:33

Certainly you are still able to identify, um,

6:37

small lesions using dynamic contrast

6:39

enhancement without subtraction.

6:41

But let me just rewind a little bit

6:43

and I can show you that with subtraction.

6:46

Certainly seeing that focal early enhancement

6:49

and the timing is important, uh, can be easier.

6:51

So whether you do that in software such as we do

6:54

or your, your reconstructions include subtraction images,

6:58

um, it is very helpful to have that for applying pi rr.

7:04

Okay, so let's get into the scoring system.

7:06

So we'll start first with radiation therapy.

7:09

It's important to recognize the common findings that we see

7:12

after radiation, which include generalized atrophy

7:15

of the gland, diffuse T two hypo intensity,

7:17

not really being able to

7:19

distinctly separate the transition zone and peripheral zone.

7:22

Those are all expected changes.

7:24

So we're using the same type of scoring system

7:26

as PY rads a one through five from very low

7:29

to very high suspicion.

7:31

Uh, and you'll note that T two does not have a role in the

7:34

overall score, both for radiation as well as, uh,

7:37

for radical prostatectomy radiation incorporates both

7:41

diffusion and DCE.

7:43

And so we will look at some individual

7:46

details, uh, regarding this.

7:48

So most local recurrence is going to be at the site

7:51

of the primary tumor

7:52

after radiation therapy, and it makes sense.

7:54

Uh, T two as we mentioned, it's useful

7:56

for anatomic localization,

7:58

but it is often hard

7:59

to distinctly see an abnormality on T two

8:01

for recurrent prostate cancer.

8:03

Really, we're looking for focal early enhancement and

8:05

or diffusion restriction.

8:07

And the grading is the same, whether it's in the peripheral

8:10

or the transition zone.

8:11

So that is an important distinction from pyres.

8:14

The original

8:16

or new location of the tumor,

8:17

peripheral versus transition zone really doesn't matter.

8:21

And ideally, when, uh, looking for recurrence,

8:23

the imaging should occur at least three months

8:24

after radiation to avoid, uh, treatment related inflammation

8:28

that may alter the dynamic contrast Enhancement

8:31

characteristics, brachytherapy seeds

8:34

and fiducial markers can create susceptibility artifacts.

8:37

So it's important to use all of your sequences.

8:39

It's possible that one may be degraded more than others,

8:41

and that is why it is also helpful to have, uh,

8:44

diffusion weighted imaging

8:45

or a T two weighted sequence, uh,

8:47

that is more robust against susceptibility artifact.

8:51

So let's look at the scoring system now for each

8:53

of the key components.

8:54

So for diffusion, a score

8:56

of one is no abnormality, score of two.

8:59

You may see diffuse moderate diffusion,

9:01

but nothing that is focal.

9:03

A score of three. You can see this is very

9:05

similar to PY rads.

9:06

You can either have focal marked diffusion hyperintensity

9:09

or a DC hyperintensity, but not both.

9:11

So here's an example where we see a focus

9:13

that is dark on the A DC,

9:15

but it's really not correspondingly

9:17

that bright on the high B value diffusion weighted image.

9:20

A score of four is when you have a focal abnormality on both

9:24

a, D, C and diffusion, but either not at the primary site

9:27

or you don't know the primary site.

9:30

And then a score of five is going to be having both

9:32

of those corresponding abnormalities at the

9:34

site of the primary tumor.

9:36

So whether that's awareness

9:37

because you have prior imaging showing the tumor there,

9:40

or potentially from a path report

9:42

or a clinical note for A DCE, pretty similar.

9:46

Um, a score of one is basically no discreet

9:48

abnormality on enhancement.

9:50

A score of two is if there's just diffuse enhancement,

9:52

but it's really not focal in this case,

9:54

you can see the brachytherapy seeds that are here.

9:56

If the enhancement is late, uh,

9:58

then it gets a score of three.

10:00

We're really looking for that early focal enhancement

10:03

to get a score of four.

10:04

Again, if you don't know the primary tumor site, um,

10:07

and here we can see some BPH nodules

10:08

that are still enhancing,

10:09

that we distinguish from this peripheral zone recurrence.

10:13

And then a score of five is focal

10:14

or mass, like early enhancement at the PR

10:17

primary tumor site.

10:19

T two we'll talk about for completeness,

10:21

but again, not really used from a scoring perspective

10:24

as a primary feature.

10:25

So a score of one is no discreet abnormality.

10:28

A score of two is kind of what we expect to see

10:30

after radiation, that the peripheral zone is diffusely

10:33

t you hypo I intense, but really not a focal abnormality.

10:36

A score of three is focal or mass, like mild hypo intensity.

10:40

What does mild mean? I think

10:41

it's kind of in the eye of the beholder.

10:43

Um, a score of four, similar to if you were applying py rads

10:47

as focal or mass, like moderate hypo intensity.

10:49

Again, either not at the same site

10:51

as a primary tumor or we don't know.

10:53

And then a score of five is if it's at the same site

10:56

as the primary tumor.

10:57

So let's look at a few cases

10:59

that will hopefully illustrate applying, uh,

11:01

pi rrr in practice.

11:04

So our first case is a 66-year-old man

11:06

who initially had a right lateral peripheral zone prostate

11:09

cancer after radiation.

11:11

And I've structured these slides,

11:12

so you have all the information here.

11:14

Um, you can kind of see it at a glance,

11:15

but I, I'll go through kind of each of these points.

11:18

So this is what we typically expect to see after radiation.

11:22

Um, we really don't see a discreet signal abnormality.

11:25

Uh, in this case. You actually can still distinguish the

11:28

zones despite the hypo intensity of the peripheral zone,

11:31

but you would really get a score of two, uh,

11:33

for T two weighted imaging if you've lost

11:35

that zonal distinction on dynamic contrast enhancement,

11:39

we don't see a discreet abnormality on our A DC map

11:42

and diffusion weighted imaging.

11:44

We don't see a discreet abnormality.

11:45

So this is what we're ideally hoping

11:47

for when we're scanning these patients

11:49

that there is no discrete abnormality.

11:51

We can give a PI RR score of one

11:53

to imply a very low likelihood of recurrence.

11:56

And from a reporting standpoint, I think it's helpful, um,

12:00

for your templates for post, uh,

12:03

post-treatment recurrence reporting

12:05

to be different than the PI rads template.

12:07

So in our templates for standard prostates,

12:10

we reference using the PI RADS version 2.1 scoring system

12:14

for, uh, recurrence reporting.

12:15

We have a separate, a separate template

12:17

that references PI RR

12:19

and has some other changes just to make sure

12:21

that we're really reporting this, um,

12:23

using this system rather than defaulting to PI rads.

12:28

Our second case is a patient

12:29

who underwent external beam and brachytherapy.

12:32

72-year-old man had Gleason four plus four left-sided

12:35

prostate cancer, underwent both external beam as well

12:38

as high dose rate brachytherapy.

12:39

Androgen deprivation now has a PSA of 13.3.

12:44

So if we look at his imaging on T two weighted imaging,

12:46

we do have this, uh,

12:48

this lesion within the left peripheral zone along

12:51

with diffuse hypo intensity.

12:53

This was the, um,

12:54

the original tumor we can see on our post-treatment imaging.

12:59

You can maybe hallucinate a mass here.

13:01

I think it's probably easier after you find the DCE

13:03

and diffusion abnormalities to say, oh yeah,

13:05

of course there is an abnormality here,

13:07

but this just illustrates T two.

13:09

I think it's extremely challenging

13:11

to see these masses in many cases.

13:14

Um, the focal enhancement on DCEI think is much easier

13:18

to recognize in this case also has corresponding

13:21

hyperintensity on a high B value diffusion weighted image in

13:24

this case B 2000, as well as corresponding A DC.

13:28

I think the A DC is really hard

13:29

to interpret here in isolation, you can see some

13:33

of the susceptibility artifact from brachytherapy sees.

13:36

So the DCE as well

13:37

as this high high B value diffusion are really the easiest

13:40

to use, uh, in identifying this recurrence.

13:44

So this gets a score of five

13:45

because we do know

13:46

where the primary tumor was located in this case by imaging

13:50

and the recurrences at the same site.

13:53

So we are able to get a score of five for both diffusion

13:56

and DCE, but you end up

13:58

with a PI RADS five from either of those.

14:00

You don't need a score of both of those to get

14:02

to a PI RR score of five.

14:07

Our next case is a 66-year-old man had Gleason four plus

14:10

three prostate cancer in 2018,

14:13

underwent a whole pelvis intensity modulated radiation

14:16

and androgen deprivation therapy has a rising PSA of 1.5.

14:20

So this was their right sided tumor

14:23

that we can see at the time of diagnosis.

14:26

And now this is the imaging that we are looking at

14:29

for suspected recurrence with

14:30

that biochemical recurrence that we see here.

14:33

And we do have an abnormality

14:34

that is diffusely hypot intense,

14:36

maybe slightly brighter than the left.

14:37

Again, this is where T two is just difficult to,

14:40

to really use in isolation.

14:42

But the diffuse asymmetric enhancement early enhancement

14:46

that we see on DCE is helpful

14:48

because that was going to give us a DCE score of five.

14:51

And then there is also focal, uh, DWI hyperintensity as well

14:55

as a DC hypo intensity.

14:58

Um, this patient also happened to have A-P-S-M-A PET CT

15:01

where we can see it looks like there's probably bilateral

15:03

disease based on the PSMA pet.

15:05

We really only see the DC characteristics on

15:08

the, on the right side.

15:10

And I will say that, um, you know, many

15:12

of our patients will either have A-P-S-M-A PET CT prior

15:16

to getting an MRI, they've identified

15:18

or either found some systemic sites of disease,

15:21

maybe something abnormal in their prostate,

15:23

or they really didn't find much at all.

15:24

Maybe there's too much bladder activity that's obscuring

15:27

the, uh, the, the prostate on the PSMA PET ct.

15:31

And then an MRI is ordered more for local staging.

15:34

But certainly you want to, there's no formal way

15:36

to integrate the, uh, PSMA PET data into the PI RR score.

15:40

Uh, and we'll discuss this in a bit more detail later,

15:43

but you certainly want to use all of your resources in sort

15:46

of guiding your attention.

15:48

So in this case, we have that T two score.

15:50

Uh, we have a diffuse hypo intensity, a DC score of five,

15:54

a diffusion score of five.

15:55

Either of these would give us an overall PI

15:58

RRR classification of five.

16:03

Our next case is a 72-year-old man

16:05

who had prostate cancer status post brachytherapy

16:08

androgen deprivation.

16:09

Now with the PSA of of almost 22.

16:12

So on T two we can see focal mass like hypo intensity, uh,

16:17

below the right apex.

16:18

We don't know. We did not have

16:19

prior imaging for this patient.

16:21

We can see that there is this, uh,

16:23

focal mass like early enhancement

16:25

that essentially corresponds to the entirety

16:28

of this slightly T two hyperintense soft tissue.

16:31

And in this case, I think the diffusion is even more useful

16:34

than the dc the DC you, you might wonder is this just the,

16:39

the diffuse enhancement that would correspond

16:41

to a DC score of two?

16:43

But we can see that the diffusion abnormality really

16:46

highlights the, uh, the, um, the recurrent cancer here

16:48

that hyperintensity on DW corresponding A DC,

16:53

and of course, a, a large corresponding abnormality on

16:55

PSMA PET ct.

16:57

So in a case like this, we don't have the original tumor

17:00

site, so we cannot reach a score of five

17:03

for either diffusion weighted imaging

17:04

or dynamic contrast enhancement.

17:06

But because both of these are a score of four,

17:10

we reach an overall PI RR score of five highly likely

17:14

to represent recurrent prostate cancer.

17:18

Our next case is an 84-year-old man had Gleason three plus

17:22

four prostate cancer in the left lateral peripheral zone.

17:24

This was the T two diffusion and DCE at diagnosis.

17:29

So kind of checks all the boxes

17:31

for a RADS five prostate cancer.

17:35

They underwent radiation, androgen deprivation therapy,

17:38

had a subsequent rising PSA from a NA of 0.24 to 2.68.

17:43

So that's biochemical recurrence.

17:45

And they had a recent PSMA PET CT showing uptake at

17:48

the original site.

17:50

So on our recurrence, uh, imaging pelvic MRI, we can see

17:54

that there's focal hypo intensity in the left lateral

17:57

peripheral zone corresponding to the site

17:58

of the original tumor corresponding DCE, uh,

18:02

hyperintensity diffusion hyperintensity,

18:05

A DC hypo intensity.

18:07

Just a reminder again, that most of your occurrences

18:09

after radiation are going to be at the side

18:12

of primary tumor, though certainly you can see, uh,

18:14

multifocal disease or just new disease that is, um,

18:17

remote from the, the side of the primary tumor.

18:21

Okay, so this is an older case.

18:23

Um, if you happen to be doing endo recal, uh, uh, prostate,

18:27

MRI, um, you, you might find this appearance more familiar.

18:30

This is a 66-year-old man had Gleason four plus four,

18:33

right lateral peripheral zone prostate cancer underwent

18:36

radiation or hormonal therapy.

18:38

We can see on T two.

18:40

And again, I think it's easier to work backwards from DC

18:42

to see that there's an abnormality here on T two focal mild

18:46

hypo intensity, not at the primary tumor site.

18:49

There is focal mass like early enhancement.

18:51

Um, and we really don't see much on DWI.

18:54

You can maybe convince yourself

18:56

that there's some focal A DC hypo intensity.

18:58

Um, so this is the situation

19:00

that I think you will encounter not infrequently

19:04

that the diffusion doesn't really help you.

19:07

I diffusion and DCE are sort of co-dominant parameters

19:11

for PI RR scoring after radiation therapy.

19:14

But really the DCE is, is the key, uh, in my, my experience.

19:18

Um, so if you are encountered with a situation where

19:23

the refer has ordered a pelvic MRI to assess

19:25

for recurrent prostate cancer

19:27

and they've ordered it without contrast,

19:29

or, you know, the patient shows up and doesn't want contrast

19:33

or they can't get an iv

19:34

and they're calling me to ask, do you wanna still do it?

19:36

I will usually say no, that I don't.

19:38

The value I think is not there

19:40

for doing this study without contrast

19:42

because of, of the primacy of DC and scoring and,

19:45

and just my own own experience seeing how many

19:48

of these you really don't see well on a DC and DWI.

19:51

So again, your, your mileage may vary,

19:54

but, um, DCE is really much more important

19:57

for PI RR than it is for PY rads.

19:59

And I think studies have shown the, the increasing relevance

20:03

of doing by parametric prostate MRI

20:05

for detecting prostate cancer with just diffusion and T two

20:09

and not, uh, and no contrast enhanced imaging.

20:11

And I think you can do pretty well with that

20:13

for prostate cancer, but not so much

20:15

for recurrence reporting.

20:19

Okay, uh, our next case is a

20:20

64-year-old man had brachytherapy.

20:22

So we can see the brachytherapy sees the diffuse T two hypo

20:25

intensity within the prostate gland, um,

20:28

also at androgen deprivation now has a

20:31

markedly elevated PSA.

20:33

And so we can see again this DCE focal early enhancement.

20:37

We don't really see much on a DC, it's quite bright,

20:39

but it is also bright on DWI.

20:42

So the DWI score here is only a three,

20:45

but the DC score is

20:46

for giving us an overall PI RRR classification of four.

20:50

And again, a patient who had a,

20:51

a subsequent PSMA PET CT looking

20:54

for additional sites of disease.

20:55

Just kind of confirming, um, the involvement

20:58

of the prostate gland here.

20:59

So this patient underwent salvage focal cryoablation.

21:02

Our last, uh,

21:04

radiation case example here is a 50-year-old man Gleason

21:08

three plus four underwent brachytherapy treated with cell,

21:11

and sorry, you'll eventually get to the focal cryoablation,

21:14

but we don't really see much on T two.

21:16

Um, you can kind of work backwards again from DCE to see

21:19

that there's maybe mild focal hypo intensity here.

21:22

The DC shows us the enhancement,

21:24

really in this case it's the diffusion.

21:26

So the diffusion is really a more conspicuous abnormality

21:29

of a DC, hypo intensity, diffusion hyperintensity,

21:33

and then corresponding, uh, early enhancement

21:36

and PSMA pet ct, again,

21:38

showing a corresponding finding as well.

21:41

So to summarize for radiation therapy, diffusion

21:43

and DCE are co-dominant,

21:46

but I think you'll find in doing this

21:47

that DC is really your key sequence.

21:51

Um, and if you do find an abnormality on diffusion,

21:54

then work backwards because maybe it's just something

21:56

that is not quite as apparent for

21:58

that particular patient on dc,

21:59

but in my experience, DC will really be the,

22:02

the most useful sequence for most of these patients.

22:06

Okay, we're going to switch gears now to, uh,

22:09

patients who've undergone a radical prostatectomy.

22:11

And now it actually gets even simpler, uh,

22:13

because you'll note that DCE is really the dominant feature

22:17

that it dictates the pi RR score with the exception

22:21

of potentially upgrading with a DC score of two or three.

22:25

If the diffusion score is four

22:26

or more, we still have those same Likert scale from one

22:30

to five, either very low to very high likelihood

22:32

of recurrent prostate cancer.

22:35

So it's important to note that in a small, uh,

22:39

but significant minority patients,

22:40

you may have some residual seminal vesical

22:42

or prostatic tissue that could be present.

22:45

So the presence of residual seminal vesical tissue does not

22:48

mean the patient necessarily

22:50

has residual or recurrent tumor.

22:51

However, if the enhancement is abnormal,

22:54

then you should be raising suspicion for

22:56

that as a side of disease.

22:58

The vesco urethral anastomosis

23:00

or VUA we will abbreviate it is the most common site

23:03

of recurrence after radical prostatectomy.

23:05

So when I'm reading these cases, that is

23:07

where I'm looking first, uh, to look

23:10

for recurrent prostate cancer.

23:12

Um, you may also see recurrence in the vesco rectal space if

23:15

they have re remnant seminal vesicles

23:17

or potentially abutting the levator a nine.

23:20

And, uh, as we alluded to, DCE is the key sequence

23:23

for imaging after radical prostatectomy.

23:26

And recurrence should look in general like the primary tumor

23:29

with early enhancement kind

23:30

of plus minus diffusion restriction.

23:32

And you really wanna see that early enhancement.

23:35

If it is late enhancement

23:36

or diffuse, then potentially, you know,

23:38

there's some fibrous tissue scarring,

23:40

something else going on,

23:41

but not something where we can raise a high degree

23:44

of suspicion for recurrent prostate cancer.

23:47

And similar to radiation, ideally, um,

23:50

you should be performing this no earlier than three months

23:53

after radical prostatectomy.

23:54

Hopefully they're not having recurrence that fast,

23:56

but it does happen on occasion, particularly

23:58

with more aggressive tumors.

24:00

And with the recurrence at the vesco urethral anastomosis,

24:04

ideally, you, uh,

24:05

should be reporting this using a clock face position

24:08

to describe where the recurrence is.

24:12

So let's look at the scoring and the rubric using DCE.

24:16

So a score of one is no discreet early enhancement at the

24:20

vesco urethral anastomosis.

24:22

Two is if there's diffuse or heterogeneous enhancement.

24:25

So this arrow head is kind of pointing out where is the VUA,

24:28

that little darker spot in the center,

24:30

and there's diffuse enhancement if you have focal

24:33

or mass, like late enhancement.

24:35

This is a patient who had residual, uh,

24:37

seminal vesicle tissue.

24:38

We can see there is asymmetric enhancement

24:40

of the right seminal, but this was late,

24:42

so it only gets a score

24:44

of three rather than being early enhancement.

24:47

Um, a score of four is focal

24:49

or mass, like early enhancement, either not on the same side

24:53

as the primary tumor or the site is unknown.

24:55

So this differs a bit from patients who had radiation, where

24:58

that's really looking at the primary site for,

25:02

for radical prostatectomy,

25:03

since they no longer have a prostate, you're looking for it

25:06

to be on the same side.

25:07

That is how the system was formulated.

25:10

So if you don't know, uh, the side

25:12

or the side is unknown, uh, you give it a score of four.

25:15

So here we see focal early enhancement at the 11 o'clock

25:19

position relative to this cul urethral anastomosis in a

25:22

patient who had an unknown primary tumor side.

25:26

And then a score of five is going to be focal

25:28

or mass like early enhancement on the same

25:31

side as a primary tumor.

25:32

So this patient had a predominantly left sided cancer,

25:35

and we can see here's the VUA,

25:37

this is mostly on the left side.

25:39

Midline tumors and midline enhancement are not specifically

25:43

addressed by PI rr.

25:45

So I think you, uh, you can take the liberty

25:47

to tell the story that make that is the most compelling, uh,

25:51

with regards to the side when you

25:53

encounter those situations.

25:55

Okay, so for diffusion weighted imaging, it's a useful,

25:58

can be a useful adjunct,

25:59

but um, you may have surgical material clips, other sources

26:03

of susceptibility that may limit its value.

26:06

So here we can, we can nicely see the vesco urethral

26:09

anastomosis and no abnormality on either high B value

26:13

DWI or a DC.

26:15

Here's an example of a score of two for diffusion,

26:18

where there's diffuse moderate hyperintensity.

26:20

You can see that it's like slightly bright here,

26:22

not super dark on the A DCA score of three again is an

26:27

or so focal marked TWI hyperintensity

26:30

or a DC hyperintensity, but not both.

26:32

So we can see that there is this focus kind

26:34

of about the seven o'clock position of a DC hypo intensity,

26:39

but we really don't see corresponding DW hyper intensity.

26:43

And then a score of four is going

26:45

to be a focal marked abnormality on both, again,

26:48

either not on the same side, um,

26:50

as a primary tumor or site unknown.

26:52

And then a score of five is going

26:54

to be a focal abnormality on both DWI

26:57

and a DC on the same side as the primary tumor.

27:01

T two, again, helpful for anatomic localization comparing

27:04

to pretreatment imaging,

27:05

but not really of much other utility for, uh,

27:09

radical prostatectomy imaging.

27:11

So a score of one is they have this somewhat hypo intense

27:15

fesco urethral anastomosis

27:17

and semin vessels, bed remnants

27:19

Two is if there's diffuse thickening, you can see

27:21

how much thicker this is compared to this score of one.

27:25

Uh, but that, that's really the only abnormality

27:27

that you see if there's focal symmetric

27:29

or mass like signal intensity.

27:31

In this case, there's symmetric thickening

27:33

of the seminal vesical beds.

27:34

You get a score of three and you're looking for

27:36

that asymmetric focal

27:38

or mass like, um, hyper ISO to hyperintensity

27:42

on T two weighted imaging, which you can kind of see here.

27:45

Again, if that's, if you don't know the primary, uh,

27:48

where which side the primary tumor is on,

27:50

and in this case, if you do know that,

27:53

that it's on the same side

27:54

and you see something on T two,

27:55

then you can give it a scorify.

27:56

But T two has no bearing on the ultimate PI RR score

28:01

that he would be issuing.

28:04

So let's look at a few examples after radical prostatectomy.

28:08

Um, this is a 71-year-old man had three plus four prostate

28:11

cancer involving all four quadrants of the prostate.

28:13

So now you can pick, you know,

28:14

whichever side you like in terms of the side of recurrence.

28:18

Had extra prostatic extension at the left base,

28:20

underwent a radical prostatectomy seven years prior,

28:22

has a PSA elevation to 0.4.

28:25

So biochemical recurrence. So what do we see on DCE?

28:28

We see focal mass, like early enhancement adjacent

28:31

to the left bladder base.

28:32

So this is why it's important to be sure to include

28:36

that entire bladder wall in your imaging.

28:38

Uh, we can see that there is somewhat

28:40

of an asymmetric focal mass like abnormality on T two.

28:43

Compare that to the right side.

28:45

Um, but not really getting much from diffusion.

28:48

Here you can see just no corresponding abnormality,

28:50

DCE again, highlighting the importance of this.

28:54

So common sites of local recurrence, just to reiterate, the,

28:57

the VUA remnants, semi vess rectal vesical pouch adjacent

29:01

to the bladder, those are all places that you want

29:03

to be sure that you are looking on your small field of view

29:07

sequences for recurrence.

29:10

Another patient, this patient had three

29:12

plus three prostate cancer.

29:13

Uh, radical prostatectomy 17 years prior had a

29:16

focal positive apical margin.

29:18

And now the PSA has reached the threshold

29:20

of calling biochemical recurrence.

29:22

So this patient has a much more obvious tumor.

29:25

We can see that there's focal mass, like early enhancement.

29:28

Um, the tumor is, uh, was on the same side as this,

29:32

so we were able to give a score of five.

29:34

We see a T two abnormality as well

29:37

as a corresponding a DC abnormality.

29:39

This is the minority of cases for ra

29:42

for radical prostatectomy,

29:43

seeing an abnormality on all three

29:45

sequences most frequently.

29:46

You're only gonna see this on DCE if, uh, if you get lucky,

29:50

maybe on diffusion as well, I think rarely on T two.

29:53

Um, when it's at the vesco uretal anastomosis.

29:55

I'll show you a few examples elsewhere where it's,

29:58

it's quite obvious whatever sequence you use.

30:01

But, um, this is sort of an uncommon experience of, uh,

30:06

being able to see this abnormality on all three

30:08

sequences at the VUA.

30:11

So this patient, uh, was treated

30:12

with Salva salvage radiation for this

30:14

and subsequently had an undetectable PSA next case.

30:19

Uh, this patient had a radical prostatectomy 27 years prior.

30:22

It can come back much later, unfortunately, um,

30:26

had extra prostatic extension underwent radiation therapy,

30:28

intermittent androgen deprivation.

30:30

PSA is now markedly elevated.

30:32

So in this case, we see this, uh,

30:35

fairly substantial lesion adjacent to the bladder neck, kind

30:39

of extending through to, uh, abut the anterior rectal wall.

30:44

Um, abutting the meso rectal fascia showing early mass like

30:47

enhancements corresponding T two focal hypo intense mass

30:51

marked diffusion restriction.

30:53

This one's, uh, you know, fairly easy case to be able

30:56

to identify that by just reiterating that you, you want

30:59

to look along that posterior bladder, uh,

31:02

the vesco rectal space, this is a place

31:03

where recurrence occurs.

31:06

Here's an example of a patient

31:08

with a 64-year-old man Gleason for plus four,

31:10

involving both lobes of the prostate,

31:12

had EPE on the left side underwent a prostatectomy

31:16

and then started having some symptoms.

31:18

Uh, the PSA was still in the, uh, reassuring range,

31:23

but they decided to image this, uh, patient anyway.

31:26

And what do we see? We see focal mass,

31:29

like early enhancement.

31:31

Um, T two, you can kind of see a little bit of that as well.

31:34

And what really seals the deal, I think on a case like this

31:37

where it's such a small abnormality,

31:39

you're like, is that diffuse?

31:40

Is that focal? The diffusion here I think is helpful,

31:43

even though diffusion does not

31:45

play a role necessarily in the prior R classification,

31:49

you can still kind of work backwards from diffusion to DCE

31:52

and okay, there is a corresponding abnormality.

31:55

Um, so the high B value,

31:56

it can be useful in detecting subtle cytes

31:59

of disease recurrence.

32:01

Um, so based on these findings,

32:03

the patient underwent a transurethral resection

32:05

with pathologic confirmation of recurrence.

32:07

So seeing the abnormality on both

32:11

of these parameters is used can be useful

32:13

after radical prostatectomy in challenging cases like this,

32:17

even though DCE is ultimately going to be the score

32:20

that influences the PI RR classification.

32:25

Uh, our next case is a 65-year-old man,

32:27

Gleason four plus five

32:29

prostate cancer status post prostatectomy has markedly

32:32

elevated PSA, uh, a diagnosis

32:34

and now is rising from eight to 13.

32:37

So we can see focal mass like early enhancement.

32:40

This, uh, is just illustrating the value

32:42

of subtraction imaging.

32:44

Again, many of our cases you don't need it,

32:46

but it is quite helpful to have it to really highlight

32:48

that early enhancement.

32:50

I will say that, um, you know, we, we personally use, um,

32:54

dyad for prostate MRI interpretation,

32:56

and you may have this capability in whatever packs

32:58

that you use, but being able to

33:01

use a multiplanar reformat to view this and say the coronal

33:05

or sagittal plane and still be able to, you know, move

33:08

through different time points in a different plane

33:10

and not having that process be clunky, I think is,

33:12

is quite useful in these cases to detect, uh,

33:16

more subtle cases of recurrent prostate cancer.

33:19

There's focal mass like, um, intermediate signal intensity.

33:23

I think it's harder to see this on the

33:25

axial compared to the sagittal here.

33:26

The sagittal is really useful.

33:28

Sorry, that is, that should be labeled sagittal.

33:30

But, um, here you can see

33:31

that there is this intermediate T two signal intensity kind

33:35

of along the anterior bladder neck.

33:37

So your other obliquities, uh, are, are definitely a value.

33:40

I've shown you mostly axial T two,

33:42

but certainly you wanna look at each of those

33:44

and we see nice corresponding diff uh,

33:46

nice corresponding diffusion abnormality.

33:48

So we get a DC score of five T, two

33:50

of five and diffusion of five.

33:52

This patient underwent A-P-S-M-A PET CT one month later

33:55

and had not only that sighted disease growing,

33:58

but also had nodal disease

34:00

that we did not see at the time of the MRI.

34:04

Okay, so a few pitfalls to be aware of

34:07

and to some other considerations for using PI rrr.

34:11

Um, having prior knowledge of the site of the index lesion

34:15

and using laterality, that's something

34:17

that's different from pyres.

34:19

So when we have these cases, that's usually a key data point

34:22

that we like to try and find if possible.

34:25

Sometimes it's just not possible.

34:27

Uh, and then you, you need to have both that diffusion score

34:30

and DC score for, um,

34:32

if you're looking at a post-radiation patient to be able

34:35

to reach a score of five, um,

34:37

or if it's a radical prostatectomy patient,

34:40

they don't specifically, um, discuss midline lesions.

34:44

So you kind of have a choice in terms of

34:46

how you want to address those.

34:49

And then residual prostate tissue

34:51

after prostatectomy does occur.

34:53

Uh, the prevalence is reported to be about one to 3%, um,

34:56

detectable prostate tissue on MRI after prostatectomy.

34:59

Here's an example, patient

35:01

with a Gleason four plus five prostate cancer radical

35:03

prostatectomy, and it looks like there's some residual

35:06

prostate tissue here as well

35:08

as residual seminal vesicle tissue.

35:10

And when we look at this patient on DCE,

35:13

we are really just seeing diffuse enhancement.

35:16

There's really nothing that's focal,

35:17

we don't see anything on diffusion.

35:19

So this would get an overall py rads

35:21

or PI RR score, excuse me, of two.

35:23

So benign tissue, um, may enhance,

35:26

but it typically is not going to have

35:28

that early enhancement abnormal diffusion restriction.

35:31

You can use that to help you, uh, attempt

35:34

to distinguish it from prostate cancer.

35:36

Seminal vesical tissue remnants are,

35:38

are far more common than actual prostatic tissue itself, up

35:41

to 20% of patients who've undergone a prostatectomy.

35:44

So you'd like to recognize that that is what that is, uh,

35:47

in its very characteristic location, kind

35:49

of posterior the bladder, um, to avoid misinterpreting it

35:52

as local recurrence just on the basis of having,

35:55

having that still there.

35:56

Of course, if the, the dynamic enhancement is abnormal,

35:59

if it's focal early enhancement,

36:01

then you do want to raise suspicion.

36:04

Um, PI RRR really does not account specifically

36:06

for remnant benign prostatic tissue in the prostate bed.

36:09

So your T two sequences can be helpful.

36:11

Here's another example. A 72-year-old man

36:14

who had at Gleason four plus three prostate cancer underwent

36:17

a prostatectomy as a PSA 1.2.

36:20

There is some mass like enhancement along the right side,

36:24

but this was late enhancement, not early,

36:26

don't really see anything abnormal on diffusion weighted

36:29

imaging or a DC and on T two, um, it's hard to tell.

36:34

This ended up being, uh, biopsy

36:36

and was benign prostatic tissue.

36:38

So there was just some residual prostate tissue there.

36:41

But you know, this would get an, a higher R score of three

36:44

because there is focal mass, like late enhancement.

36:47

So this is something that I,

36:48

I don't think you could confidently say by imaging

36:51

that this is not recurrent tumor,

36:53

but the degree of suspicion should be appropriately lower

36:56

because the enhancement is late as opposed to early.

36:59

So this was given that pi RR score of three.

37:04

And then just from a a technique standpoint, um,

37:07

you are going to encounter susceptibility artifacts

37:10

that may hinder your ability

37:11

to detect recurrent prostate cancer.

37:14

So surgical clips, brachytherapy seeds, you will,

37:16

will have some of that T two star related signal loss

37:19

and you may, um, have your evaluation be obscured.

37:23

Uh, you, the diffusion weighted imaging typically is single

37:26

shot echo planar imaging sequence is very sensitive

37:29

to magnetic susceptibility.

37:30

So diffusion may be limited in cases like that.

37:34

Um, so that's just important to be aware of this patient.

37:36

Essentially, we're relying just on, uh, DCE

37:41

because the T two

37:42

and the diffusion are limited, but that's okay.

37:44

DC is our primary sequence.

37:45

So if there's one sequence that we want

37:48

to ideally have not degraded, it would be the DCE.

37:51

Um, the

37:53

after brachytherapy, the prostate seeds,

37:56

the brachytherapy seeds will often kind of migrate, uh,

37:59

inferiorly or coddly.

38:00

And so, um, you may expect that they're no longer going

38:04

to be, uh, uniformly distributed throughout the gland.

38:07

Uh, PI RR does not have any, uh,

38:10

integrated quality assessment ratings such as pi qual.

38:14

Um, so that might be an area for future development to try

38:18

and give some indication of the, the quality

38:19

and reliability of the, the study that is being interpreted.

38:23

Uh, and pet, pet pet MRI, um,

38:26

could certainly be helpful in overcoming limitations

38:28

of susceptibility by integrating that metabolic data.

38:31

So here's an example where we have this fairly large

38:34

susceptibility artifact on the left side

38:36

of the gland really can't do much on T two or diffusion

38:40

or DCE in this ma in this case.

38:42

You can see there's, it's just really obscuring

38:44

where we're looking, whereas the PSMA PET CT

38:47

that this patient had, um, it's helpful.

38:49

So you want to integrate, uh, all

38:52

of those data points if possible, even though it's,

38:54

there's no sort of formal rubric for doing so with pi rr.

38:59

Uh, how about androgen deprivation therapy?

39:02

So it's not specifically referenced in PI rr,

39:05

but there have has been a study looking at the performance

39:08

of PI R in patients

39:09

who got androgen deprivation therapy alone, uh, prior

39:13

to radical prostatectomy.

39:15

So a little bit different population,

39:18

but they used a similar cutoff

39:19

and found relatively similar, uh, performance of sensitivity

39:22

and specificity in the, in the eighties.

39:25

So not formally addressed by PI RR,

39:27

but it seems as if you may still be able

39:29

to use a similar scoring system with some efficacy.

39:35

So future development, um, where

39:38

may PI RR go from from here, uh, incorporating PSMA PET TT

39:42

to refine the probability of local recurrence, um,

39:45

I think would be, would be quite useful.

39:47

Um, here's an example of,

39:49

I think this is a very challenging case.

39:51

So the top, uh, row here is showing data from ct,

39:56

the, the PET information and then fused PET ct.

39:58

This was a 68-year-old man Gleason four plus three prostate

40:01

cancer on the right side undergone radiation therapy

40:04

and androgen deprivation with a slowly rising PSA.

40:08

So he had this MRI first,

40:10

and we didn't see any of this, uh,

40:13

or did not recognize any of this on the MRI.

40:15

Then he had the PSMA PET ct,

40:18

and I think it would be very easy to kind

40:20

of blow off this small focus

40:22

of activity posterior to the bladder.

40:25

Uh, but when cor, going back

40:27

and correlating this finding with the MRI,

40:30

we were actually able to identify this small focus of DCE

40:34

as well as abnormal diffusion signal intensity.

40:37

I think it's impossible to call anything on T two here,

40:40

but, uh, we were able to kind

40:41

of work backwards from the PSMA PET CT to

40:44

identify this on the MRI.

40:46

So again, it's really helpful if you've,

40:48

if you've got one or the other.

40:50

Um, it's extremely useful, I think, to,

40:52

to look at the other exam and,

40:54

and see if, uh, you're able to sort

40:56

of combine the data from both of those

40:58

to, to be more effective.

41:01

Okay. So in summary, high RR provides a framework

41:05

for systematic evaluation of the treated prostate

41:07

after radical prostatectomy

41:09

or radiation therapy, having access

41:12

to either the pre-treatment imaging

41:14

or knowledge of the site of the primary tumor.

41:16

Maybe a path note

41:17

or a clinical note does inform your

41:19

interpretation in scoring.

41:21

So that's something you would like to look for if available.

41:25

And it provides complimentary information

41:27

for local recurrence, uh, to the local, regional

41:30

or distant staging data from PSMA, Pepsi T

41:33

and potentially future iterations might address integration

41:36

of metabolic modalities.

41:38

And if you are, uh, looking for more on this topic, um,

41:43

we published this fairly recently in radiographics.

41:45

This will look familiar since it's much

41:47

of the same information from that, uh, article

41:50

as in this presentation.

41:51

And then I think there's a, a nice, uh,

41:53

commentary from the same issue kind of talking about, um,

41:56

putting PI rrr into, uh, perspective in the,

42:00

the treatment of these patients.

42:03

And that is all. So I will stop sharing here,

42:08

and if there are questions in the q

42:13

and a, let me just look and see.

42:17

Okay, uh, great. So we have a couple questions.

42:19

Uh, first question is any specific standard high B value?

42:23

So, um, pi rrr like py rads, um,

42:27

suggest using a B value of 1400.

42:30

We typically will acquire a B 50 a B 800

42:34

and then calculate or synthesize the B 1400.

42:38

The, the synthesized

42:39

or calculated B value I think is useful twofold.

42:42

One is that it's faster. Uh, you're not spending the time

42:45

to actually acquire that,

42:46

so it doesn't take additional imaging time.

42:49

Uh, and two, because you're not spending

42:51

so much longer acquiring many averages to try

42:54

and attain adequate signal to noise,

42:56

you would potentially have less motion, um,

42:59

on a calculated B 1400 compared to a a, an acquired B 1400.

43:04

You do have the drawback that because it is synthesized

43:07

and not calculated, the noise profile is a little bit

43:09

different, but I, I think the,

43:11

the benefits outweigh the, the drawbacks.

43:14

Um, so that, that is useful.

43:17

Um, we do occasionally on some

43:19

of the protocols have a b calculated B 2000,

43:21

and that can potentially be, uh, useful as well

43:23

to just make those, those small abnormalities, uh, helpful,

43:27

but at least a B 1400.

43:30

Uh, second question is, is the a CR going

43:32

to come out with a scoring system?

43:33

I mean that, my question is, is, uh, is there ever going

43:37

to be a successor to PI Rads 2.1?

43:38

It's, it's been, uh, seven, seven years I think.

43:41

Um, so I have not, uh, per personally seen any,

43:46

any movement on that front.

43:47

I would really hope that the next version of rads, kind

43:51

of similar to rads, may try to subsume all of the

43:55

prostate related standardized reporting under its,

43:57

its umbrella so that it's, it's all integrated into

44:01

one scoring system for pre-treatment prostate,

44:04

for whole gland therapy, for focal ablation, for quality.

44:07

Uh, rather than having, you know, four

44:09

or five different scoring systems, uh, to try

44:12

and keep track of, which I think most people just

44:14

legitimately is asking too much.

44:16

Um, it would be nice to have it all under one umbrella.

44:19

Um, the next question is the benefit

44:22

of using MRI if I already have a PET scan

44:24

that demonstrates recurrence.

44:26

Um, and so that is a great question

44:28

'cause I've certainly found myself asking like,

44:30

you've got a a P SM A, there's very clearly a recurrence.

44:32

Why are we doing this? Um,

44:34

our radiation oncologist at least tell us as justification

44:37

that, um, knowing the extent of

44:40

of disease in the prostate gland can be helpful

44:43

for them in planning their radiation.

44:46

So I think a more precise anatomic localization can

44:49

be, um, useful.

44:51

But I, I think it's a, it's a great point, you know,

44:53

if you know there's systemic disease, like why,

44:55

what is the, the added value?

44:57

And, um, so I think it's, it can be helpful

45:00

to have a discussion with your referrers if you're seeing

45:03

things that don't make sense to, to make sure

45:05

that there's kind of a rationale for them, particularly

45:07

for doing MRI

45:09

after, uh, a pet that that pretty clearly shows recurrence.

45:14

Um, the next question here is, what should be the role

45:17

of prostate MRI at the community hospital level?

45:19

So I think there's a, the major role still, I think, um,

45:23

community academic whatever is, is really detection

45:27

of suspected prostate cancer.

45:29

You know, based on physical exam findings or PSA, uh, more

45:32

and more patients are undergoing active surveillance rather

45:36

than, uh, treatment for, you know, Gleason grade group one

45:40

or two, so a three plus three

45:41

or three plus four prostate cancer.

45:43

Um, when they have small volume disease

45:45

and don't have high risk factors,

45:47

then it's potentially reasonable

45:50

to not treat those patients since much of the time.

45:52

That's overtreatment

45:53

and to just, uh, do surveillance with PSA

45:57

and with yearly MR mri.

45:58

So I think that's definitely a, um, a benefit of,

46:03

of, uh, of doing prostate MRI.

46:05

And then more and more we're doing quite a bit of this

46:07

as well, um, looking for recurrence

46:10

after either whole gland therapy or after,

46:13

after focal ablation.

46:14

So I think there's, there's many roles,

46:16

and I'm sure you've seen as we have that are

46:18

prostate volume just continues to, to grow by,

46:20

by leaps and bounds every year.

46:23

Okay. Uh, next question.

46:25

What standard B value is ideal B 1000 or B 2000?

46:29

So you certainly acquiring the, the kind of higher B value

46:33

that you acquire can be a B 800 or a B 1000,

46:37

but you want to have some type of even higher B value,

46:40

whether that is calculated

46:42

or acquired of at least a a B 1400.

46:45

So we, we acquire a B 50 and a B 800

46:49

and then, uh, calculate or synthesize a a B 1400 and

46:53

or a B 2000.

46:55

Uh, so we do A-P-S-M-A PET CT in all cases.

46:58

I think it really depends on each individual patient

47:02

and the degree of, uh, of PSA elevation

47:06

or, you know, what has led to the concern

47:08

for biochemical recurrence.

47:10

Um, I think there's certainly a role for, for doing both.

47:14

Uh, but in, in select cases,

47:16

maybe there's not really a suspicion for systemic disease

47:19

and an MRI alone may be sufficient.

47:23

Uh, this next question is, can a 3D isotropic T two, um, and

47:28

or a T one fat sat be more helpful than

47:30

corresponding 2D sequences?

47:32

So we do a three DT two sequence in addition

47:35

to our two DT two sequence, primarily for gland eg gland

47:39

and lesion segmentation with the idea

47:41

that those thinner slices will potentially result in

47:45

more accurate fusion biopsy.

47:47

I don't think there's really data supporting that,

47:49

but um, it's something that we, we've done for some time.

47:52

The, the waiting on that sequence is different than, uh,

47:57

the, the signal waiting on a 2D, uh, T two sequence.

48:00

And so we have not personally found in our experience

48:04

that it is a replacement

48:06

for doing two DT two weighted imaging.

48:08

It, it certainly would be nice.

48:10

It takes, it takes a long time to do, even

48:12

with a shorter TR than what we would normally use.

48:15

So if you wanted to have similar parameters, um, in terms

48:18

of the tr and te as you do for a 2D sequence,

48:22

it is a really long sequence.

48:23

So I'm hoping with newer, um, acceleration techniques,

48:27

deep learning that that's coming, that you might be able to,

48:30

to do that in a time that is not too dissimilar

48:34

to 2D imaging

48:35

and be able to have something

48:36

that looks similar from a signal waiting perspective without

48:38

taking far longer, um,

48:42

lesions abutting the capsule should be included in the score

48:46

or labeled as an ancillary finding.

48:48

So for pi rr, there's no real specific, um,

48:53

call out to whether it's abutting the capsule or not.

48:56

It's really, it's sort of, sort of a binary.

48:59

Is there a lesion or not?

49:01

I think the, the more description you can include about the

49:04

location, whether it's peripheral or transitional

49:06

or extending outside of the prostate, um, is,

49:09

is certainly helpful for, you know, the radiation oncologist

49:13

or surgeon who, whomever is, is referring the patient.

49:16

Um, comparing, uh,

49:18

like a true Likert score versus versus py RAD

49:21

score, which one do we prefer?

49:22

We, we were adopted pi rads pretty early now, it's been,

49:25

I guess it was 10 years ago.

49:27

Um, and I think it's really helpful

49:30

for standardizing reporting so that whether it's you

49:34

or you know, one of one

49:35

of your colleagues who's reporting the urologist

49:38

or whoever's referring the patient,

49:39

they get a sort of a consistent product.

49:42

So we, we really, I mean, PI RADS is what we use.

49:45

We use it for every case. Um, the value of PI RRR is

49:49

that it's, it's really a specific reporting system

49:51

that is meant for, for post whole gland treatments.

49:54

And so, uh, I would certainly strongly encourage you to,

49:58

to use it when you're reporting these patients.

50:01

Is there a role for prone prostate MRI? Interesting idea.

50:06

Um, I have, uh, I don't know actually, uh,

50:09

I think you could certainly see some value in reducing

50:12

anterior abdominal wall motion.

50:15

Um, I have uh, found that, uh, with some of the newer,

50:20

uh, acceleration techniques,

50:21

you can potentially do phase ENC coating right

50:24

to left rather than anterior to posterior

50:26

for your axial imaging, uh,

50:28

which normally wouldn't make sense,

50:29

but with some of these deep learning techniques,

50:31

it is a possibility that could potentially reduce some of

50:34

that transmitted abdominal wall motion.

50:37

Um, if that's sort of what you were getting at in terms

50:39

of a reason for doing prone, uh, MRI,

50:41

we don't do it ourselves personally,

50:42

but certainly something interesting, uh, to try out.

50:47

Next question is 1.5 T sufficient or three T ideal?

50:51

That is a great question. Um, we, uh, I,

50:54

I definitely having just, you know,

50:56

working on protocol updates myself across 1.5

50:59

and three T scanners, um, i, I make compromises at 1.5 T

51:04

because of the signal to noise in terms of kind

51:07

of maybe stretching the field of view

51:09

to be a little bit larger, but still within the,

51:11

the PI rads, um, criteria

51:13

or their technical standards to improve the signal to noise.

51:17

Um, and you just, you can't, I think it's very hard

51:19

to achieve the same quality of imaging

51:22

with 1.5 T versus three T for the same amount of time

51:26

that you spend imaging.

51:28

So in general, we, um, in our academic practice

51:31

where we have, you know, a lot of scanners, more options,

51:34

we are typically doing everyone at three T except if they

51:36

have an implant that is not MRI conditional at three T.

51:41

So that includes patients who have hip arthroplasties.

51:43

We do those at three T using metal artifact reduction

51:47

techniques, um, such as warp for for T two and,

51:50

and that readout segment of DWI

51:53

and have, have found that to be, uh, reasonably effective.

51:56

Now in some of our other sites, community practices

51:59

or places where they only have a 1.5 T scanner, um,

52:03

I think it's still acceptable to do it particularly for,

52:06

for smaller patients.

52:07

You know, we, I would, we generally try

52:09

to limit the patients to A BMI of of less than 35, uh,

52:12

because you know, the further away the coil is from the

52:15

prostate, the, uh, the lower the

52:17

signal to noise is going to be.

52:18

And so those are the patients where I think it's a,

52:20

it's a struggle for larger patients to, to get, uh,

52:24

imaging at 1.5 t that is going to be,

52:27

uh, you know, adequate.

52:32

Uh, okay. Let's see.

52:33

Did we catch everything, um,

52:37

for our contrast imaging?

52:39

Do you need to do it with fat suppression?

52:41

I think this was in the, uh, the chat.

52:44

So, um, the, the issue with using fat suppression

52:48

for your dynamic contrast imaging, um,

52:50

there's really not much of an issue.

52:51

Certainly can, um, you may pay a small price

52:54

on temporal resolution.

52:56

So we, we typically, um, don't use fat sat

53:00

and then use the subtraction imaging to be able to have

53:03

that greater lesional conspicuity.

53:05

I think there definitely is a role, uh,

53:07

for using, uh, fat sat.

53:09

So, uh, if you have it

53:10

and it can keep your temporal resolution

53:12

to still be adequate than absolutely,

53:19

I think believe we've covered everything.

53:21

If there's any more questions, I am, uh, happy

53:25

to answer those.

53:30

There's one more in the q and a.

53:32

Um, and I'm not sure if it was

53:35

referencing the question before.

53:37

Um, yeah, so when, when, so the, maybe that I could,

53:40

I'll interpret that question a couple different ways.

53:42

So timing wise, if they are asking for an MRI

53:47

for suspected recurrence

53:48

after prostatectomy radiation,

53:50

ideally you wanna wait three months, um,

53:52

that allows enough time for postoperative inflammation

53:57

or post-radiation inflammation to subside.

53:59

So, um, kind of like for post-radiation, uh, imaging

54:04

of the liver for rads, if, if they've undergone a Y 90,

54:07

you wanna wait uh, three months to do that.

54:10

Now if we could also interpret the question as, uh, when

54:13

to do this in general, and again, pi RR is really

54:16

for post prostatectomy and post uh, radiation imaging.

54:20

Super. I think you got 'em all.

54:23

Alright, well thank you everyone for attending

54:25

and hopefully you found this useful

54:26

and, uh, we'll be empowered to use this in your practice.

54:30

Yeah, thank you and thank you so much Dr.

54:33

Chetty, for this awesome review. Really appreciate it.

54:35

Appreciate you being here

54:37

and for everyone else for participating

54:39

and asking such ques great questions.

54:41

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54:45

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54:47

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54:51

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54:54

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54:55

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54:59

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55:02

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