0:00

So on this case I throw this one in there, not

0:03

because the abnormality is subtle,

0:04

but sometimes these are really tough to approach.

0:08

You know, when there the abnormality is

0:09

so extensive, how do we do this?

0:11

Because we don't wanna get into a point

0:12

where we're measuring SUVs for every single lesion.

0:16

And when I report, I try

0:18

and kind of loosely adhere to resist criteria.

0:21

So I'll describe the pattern of where the abnormality

0:24

with the disease is

0:25

and then I will pick some target lesions.

0:28

So maybe depending on the lymph nodes, I'll probably pick,

0:30

you know, between two and five lymph nodes depending on the

0:33

extent to help and give an SUV or a specific uptake.

0:36

Um, value measurement.

0:37

Um, and then you know, a few target lesions.

0:40

'cause I think sometimes the SUVs does help as we see

0:43

that it can allow us

0:45

to determine the certainty in which something

0:47

is involved or not.

0:49

But this case, this isn't subtle,

0:50

this is clearly diffuse abnormality through the skeleton.

0:54

And this is confluent metastatic disease.

0:56

This patient, it is just everywhere.

0:59

So this is what catches our eye the most is the M staging.

1:03

But we need to try and look through that.

1:04

What is the prostate or the prostate bed doing if the

1:06

patient's had a prostatectomy?

1:07

Are there lymph nodes you can kind of see through here.

1:10

There's lots of dots through there, especially

1:12

through the retroperitoneum.

1:13

And so we need to look closely

1:15

to see if there's involved lymph nodes.

1:17

We'll come back to the skeleton in a moment,

1:19

but let's be systematic.

1:21

So we'll zoom up our fused image

1:23

and we'll go all the way down to the prostate.

1:26

So this patient has got a few things going on

1:29

and so let's bring in our

1:32

ct the correlation.

1:35

Okay, patients had some intravenous iodine contrast,

1:37

which is really useful um,

1:39

because we've got a lot kind of sitting in the middle.

1:41

The patient's probably had a terp

1:43

transurethral resection of the prostate.

1:45

But we get the sense that yes, while the central area

1:48

of uptake would be accounted for by radio urine in

1:51

that terp defect,

1:52

there is more extensive uptake throughout the left hemi

1:56

gland and involvement of that right seminal vesl

1:59

as it comes down to the back.

2:00

So that seminal vesl is coming in.

2:02

That's all PSMA avid probably

2:04

involvement of the left as well.

2:06

So multifocal disease in the prostate.

2:08

There's also involvement of the

2:09

right peripheral gland as well.

2:10

Bilateral peripheral glands actually.

2:13

So we'll go through and describe that carefully.

2:15

And then pausing here, what is this?

2:18

So coming up, this is a really enlarged lymph node

2:22

and I actually, and I have, we'll confess in practice

2:25

'cause I'm usually working with patients

2:27

who are at the very start of their prostate cancer journey.

2:29

They're about to undergo their first line of treatment

2:31

or they're coming in for um, a small biochemical recurrence.

2:35

I don't often see bulky lymphadenopathy like this.

2:37

This is very advanced disease.

2:39

So here this is um, a large PSMA expressing um, ator

2:43

or pelvic side wall lymph node.

2:45

And you can see that there's multiple abnormal lymph nodes

2:48

tracking along the iliac stations

2:49

and even encasing that aorta.

2:51

Let's go up here. All this abnormal soft tissue which is

2:54

encasing the aorta greater than 180 degrees actually here,

2:58

just completely surrounding it through the retroperitoneum.

3:01

Um, and then tracking up retro accrual

3:04

through the mediastinum here.

3:07

So I would be looking very closely at the mediastinum,

3:10

which doesn't seem to have too much going on,

3:12

but you may have picked it.

3:13

There is supraclavicular lymphadenopathy here

3:16

and just checking our low dose ct.

3:18

There it is that enlarged lymph nodes just in

3:21

that supraclavicular space

3:24

and we're still ignoring the skeleton.

3:25

Let's check our lungs. And sometimes I'll do this to myself.

3:30

I don't like satisfaction

3:32

of search is real in nuclear medicine as it is in radiology.

3:35

So I try and stay systematic with cases like these and

3:39

'cause they're so complex and there's so much to see,

3:41

this is really where your search patterns

3:44

will come back to help.

3:46

Um, a bit of congestion here through the, the bases.

3:49

Is there a little nodule in there? There?

3:52

Looks like there might be something down in here.

3:54

So let's kind of see if we can see it on the fusion can't.

3:57

This is where I tend

3:59

to become more reliant on the pure gray scale.

4:02

I find that fusions don't perform as well in the lungs.

4:06

Um, I apologize that kind of,

4:07

I can't do too many adjustments here

4:09

with the gray scale imaging.

4:10

So they just kind of here for comparison,

4:13

but I don't see too much going on here.

4:14

So that might be a bystander nodule.

4:17

Um, but you'd really want to be interrogating that closely.

4:20

The lungs should be white as we said.

4:22

So any kind

4:24

of focal uptake in the lungs raises concern for a nodule.

4:28

Alright, let's get to the skeleton.

4:30

So there's our mip, um,

4:32

and we can see if we put on the bone windows here

4:35

that there is diffuse sclerosis.

4:39

But interestingly, it doesn't look as impressive.

4:42

And this is one of the really interesting things about PSMA

4:45

PET is it can show disease that, you know, maybe a bit

4:49

of a tough call or you may not really see the extent of on,

4:53

um, diagnostic imaging.

4:55

Yes, there's tive pattern, it is kind of heterogeneously,

4:58

um, lytic and sclerotic.

4:59

So yes, we, we would kind of call this,

5:01

but you know, you can really see

5:03

the extent of the abnormality.

5:04

And on the FUS you can see

5:06

that pretty much every single bone,

5:07

all the mar cavities are involved

5:09

with intensely PSMA expressing disease.

5:13

And this is pretty much as close as you'll get

5:15

to A-P-S-M-A super scan

5:16

as you would on like something like a bone scan.

5:19

And we, one of the common questions we get asked is

5:22

how do you tell the difference between a metabolic

5:23

and um, metastatic super scan on bone scan?

5:27

Um, and this actually I think shows my answer really well

5:30

with metabolic bone disease.

5:31

Yes, there's increased osteoblastic activity,

5:33

increased bone turnover, but it's everywhere.

5:35

It's involving the axial

5:36

and throughout the appendicular skeleton.

5:38

Whereas metastatic disease predominantly involves the axial

5:41

and proximal appendicular skeleton

5:44

and it appears heterogeneous.

5:45

And a good tip is if something looks so confluent like this,

5:48

you just go to the edge of the lesion

5:50

and you can see that there we're saying

5:52

to see discreet bone lesions coming out there and that CPS

5:56

Heterogeneous as well.

5:58

So something else that I like to do

6:00

with these cases is yes, it's everywhere.

6:03

So I would be using words such

6:05

as extensive throughout the skeleton.

6:07

You know, really trying to paint a picture of the extent

6:09

of the disease, um, is I like to really make sure

6:13

that I look for things that could cause the patient,

6:15

you know, an issue and we could treat in the meantime.

6:18

And when it's everywhere like this,

6:19

you really gotta be on your toes.

6:21

So I'll describe that there's a disease involved, the base

6:23

of skull, um, because it may be in fact in cranial nerves.

6:26

And then I'll do something like that.

6:27

I call running the spine, going down

6:29

through the spinal canal, looking

6:31

to see if there are any lesions

6:34

that have breached the cortex

6:35

and have soft tissue extending into the epidural space

6:38

because if there is a particular lesion which is causing a

6:41

cord compression or particular neurological symptoms,

6:44

then the patient can have that targeted with radiotherapy.

6:48

So in conclusion with these ones, I like to keep it simple,

6:52

you know, you know,

6:53

bilateral large tumor within the prostate gland

6:56

with involvement of bilateral seminal vesicles,

6:59

extensive lymphadenopathy above and below the diaphragm,

7:01

and including bulky retroperitoneal lymphadenopathy,

7:04

which in case is the aorta extensive skeletal metastatic

7:07

disease with P-S-M-A-V-D throughout the skeleton.

7:11

And then keep it at that,

7:12

truly trying to paint that picture.

7:14

Okay. And so let's move on to the next section.