0:00

So rounding out this session, we're going to do a bit

0:03

of a roundup of some other lesions which you may encounter

0:06

on PSMA PET scanning, which can demonstrate abnormal uptake.

0:09

And so as we saw

0:10

before, it's always important to remember that not all

0:13

that is PSMA AVID is prostate cancer.

0:15

And you need to be able to kind of pull together the scan

0:19

and really think about it.

0:20

You know, what am I seeing? Is it definitely metastatic

0:23

or NA disease or could it be something else?

0:25

So we're gonna go

0:26

through some cases which I've collected with different lesions.

0:30

So in this case we can see

0:31

that there is focal uptake in the prostate.

0:33

And this was the patient's primary prostate cancer.

0:35

There were expected to have local disease,

0:37

there were Gleason seven low risk,

0:40

but there, if you look on this mib,

0:41

there is something going on in the thorax.

0:44

So here is our prostate lesion.

0:48

All looks pretty straightforward, focal intense uptake.

0:51

SUV greater than 12, it would've correlated

0:53

with other imaging and biopsy findings.

0:55

And then we have this rib lesion. So what's going on?

1:00

We saw, we met some rib lesions that were mildly avid,

1:03

had focal mild uptake in a previous section,

1:06

which would be consistent with small areas

1:08

of fibrous dysplasia.

1:09

But this is quite hot. We saw that on the rotating mip.

1:12

So what does it look like on low dose ct?

1:14

And it looks a little different, doesn't it?

1:16

We've got this bubbly lucency, we've got interruption

1:19

of the cortex, it's a bit expansile

1:21

and if we blow it up here,

1:23

we get a little bit more of a look at it.

1:25

So it's expanding that rib and a bubbly lucency

1:28

and really PSMA expressing really avid.

1:31

Um, so what is this? And we looked at it,

1:34

we thought it was an chondro.

1:35

So chondro lesions can demonstrate in um, intense

1:39

or variable PSMA expression

1:41

and based on the findings, we thought

1:42

that was the most likely diagnosis in this

1:44

case for this case.

1:46

And we've seen a few cases like this in our

1:49

scrollable images before.

1:51

The patients who come in for PSMA pets, usually older

1:54

or elderly gentlemen who can certainly come in

1:58

with additional comorbidities.

2:00

And in this case they came in with some back pain

2:02

and they were known to have prostate cancer.

2:05

Um, and there was a wedge compression fracture here in the

2:08

upper lumbar spine.

2:10

There was some mild heterogeneous uptake.

2:12

But our thought on this was that it was most likely going

2:15

to be related to a wedge compression fracture here

2:19

and on the lead ct, yes there was some sclerosis

2:22

but some irregularity of the end plate there, um,

2:26

which would be consistent with healing.

2:27

So we call this as a compression fracture.

2:30

In reality you would be comparing with prior imaging

2:32

to see if it was there before.

2:34

Um, and if there was high clinical suspicion

2:37

for metastatic disease and we couldn't find it on the pet

2:39

or if there was ongoing clinical concern,

2:42

repeat imaging would be useful

2:43

as you would expect the avidity to stay the same

2:45

or improve as the fracture healed.

2:50

So in summary, there's a whole lot

2:51

of benign bone lesions which can have PSMA ligand uptake

2:54

and I've included a paper in the related readings if you're

2:57

interested in learning more about this.

2:59

This can include Paget's disease, fibrous dysplasia,

3:01

arthritis, both degenerative and inflammatory.

3:04

So facet joint arthritis

3:05

and plate arthritis in the spine, even into spinous bursitis

3:08

between the spinous processes as they run together.

3:11

It's not uncommon to see some uptake

3:12

around the large ball and socket joints as well.

3:15

SCH smalls nodes can have some PSMA avidity as well

3:18

and healing fractures as we saw in that last case.

3:22

So now moving on to this case here,

3:24

this patient did have prostate cancer.

3:25

They also had some link from local nodes.

3:27

You can see, um, uptake in the prostate

3:29

and then um, a node adjacent to that ureter.

3:32

But what is this kind of less avid kinda poorly defined area

3:36

of uptake in the thorax?

3:38

So when we correlated with the low dose ct,

3:40

there was poorly defined moderately increased PSMA

3:43

expression deep to the wing of the scapula.

3:47

And so this is actually a common FDG PET lesion.

3:50

They can be quite avid.

3:52

Um, and it's a very typical location, um,

3:54

because they arise a secondary to the movement

3:56

of the scapula overlying the thorax.

3:58

And so we thought that this was an ELAs fibroma Dorsey.

4:02

Um, so an incidental soft tissue lesion.

4:05

We've had a look and we've saw a peripheral nerve shaped

4:07

tumor case in the prior section as well.

4:09

But other lesions which can have PSMA uptake

4:12

or PSMA expression include he angios both in the liver

4:16

or in the spine or elsewhere in the body, um,

4:19

gynecomastia as well.

4:20

So increased soft tissue, um, in the retro areola space,

4:23

particularly in men who are on a DT

4:26

or androgen deprivation therapy.

4:28

Fibromas inflammatory lesions such as diverticulitis

4:31

or adenomas, particularly in the adrenal glands can have

4:34

some variable PSMA expression.

4:36

Also moving on to the thorax, um,

4:40

here's a case of an area

4:42

of poorly defined ground glass attenuation at the lung apex.

4:45

And you can see, and this is a really nice example of

4:47

where we can use the gray scale imaging

4:49

to highlight abnormalities in the lungs.

4:51

It's quite more apparent here on this far image.

4:54

This patient had a history of cough.

4:56

They were known to have some respiratory symptoms

4:58

and this was thought to be, um, an area of infection

5:01

or inflammation in the lungs with that mild PSMA uptake.

5:05

Similarly, this is a patient who had fibro apical scarring

5:09

and you can see that there's a lot

5:10

of purple there here on this image.

5:12

And it correlated to that kind

5:14

of fibro calcific scarring at the lung apices.

5:16

And this is not uncommon to see.

5:19

And but what I'd like you to do is compare this image

5:22

with this image.

5:24

So this is intense, it's very abnormal, it's widespread.

5:28

You can see that there's quite intense uptake

5:30

here in the lower mediastinum,

5:33

which was PSMA expressing lymphadenopathy.

5:36

This patient based on their patterns of disease,

5:38

had very widespread lymphadenopathy

5:40

and metastatic disease, multiple nodules.

5:42

Um, and you can see that, um, even on low dose ct,

5:45

there's some kind of a regular nodule

5:47

or thickening along the interstitium of the lungs here.

5:49

Some no more discreet nodules as well.

5:51

This was a metastatic disease.

5:53

This wasn't infection or inflammation.

5:55

And this was seen in, um,

5:57

this patient had quite widespread disease both above

6:00

and below the diaphragm.

6:01

And this was correlating to this region

6:03

of abnormal increased uptake here.

6:06

Could there be a component of, um, lymphatic congestion?

6:08

Yes, maybe because of bulky highly lymphadenopathy,

6:11

but we were concerned that this was lymphangitis

6:13

carcinomatosis particularly

6:15

where you see this intense area corresponding

6:18

to interstitial thickening in the lungs.

6:21

In summary, benign lung pathology,

6:22

which can have PSMA ligand uptake includes fibrosis

6:26

and scarring including bronchiectasis as well, acute

6:29

or resolving infection

6:30

or inflammation, whether that be granulomatous

6:32

or interstitial lung disease or pneumoconiosis

6:34

or other, um, community or hospital acquired, um, infection

6:38

and also vasculitis as well.

6:40

So there's been cases of, um, granulomatosis

6:43

with polyangiitis, for example.

6:45

Um, because it's an inflammatory process,

6:47

it may be PSMA expressing.

6:50

So rounding us out with one more case

6:53

and there's a few things going on in this patient.

6:55

On the mip. We can see

6:57

that there is some uptake in the prostate

6:58

and that corresponds to this region up here.

7:01

Um, there's also a large lesion in the lung

7:03

and this is another example

7:05

of a synchronous primary lung cancer,

7:06

which was detected on PSMA pet.

7:09

Not all malignancies that you see that are avid

7:12

and necessarily prostate cancer.

7:13

And this was biopsy proven lung cancer,

7:16

but there was something else going on

7:17

in this patient as well.

7:18

And a little bit of increased uptake in this liver.

7:21

And if you see just through here, this is actually a case

7:25

of a liver abscess in this patient.

7:28

So this region of geographic increased uptake was infectious

7:32

inflammatory, um,

7:33

and another benign lesion,

7:35

which was mimicking disease on A-P-S-M-A pet.