0:00

So this section is all about the pitfalls of PSMA imaging.

0:04

And so I really kind of want to showcase a few examples

0:08

of things that are A-P-S-M-A

0:10

AVID that aren't prostate cancer.

0:11

And we're going to finish up by having a look at some cases

0:14

of PSMA negative disease

0:15

and when different scans can help us to troubleshoot issues

0:19

for the patient and guide patient management effectively.

0:22

So for this one, you'll have noticed

0:23

that I have given two PET scans.

0:25

One is A-P-S-M-A PET and one is an FDG.

0:28

And you're like, well why are we doing FDG?

0:29

Because we're in A-P-S-M-A talk,

0:31

but we'll see why in just a moment.

0:33

So as always, we will start with our rotating MIB

0:36

and we won't go through necessarily the full um, gamut

0:39

of reporting these scans.

0:41

We'll just kind of stick to the salient abnormalities,

0:43

but you can see that there is focal abnormal increased

0:46

uptake in the prostate, inferior

0:47

to the bladder on a background of some heterogeneous uptake.

0:50

Not too much going on in terms of nodal disease elsewhere

0:53

through the pelvis, which looks pretty good.

0:55

But you'll notice as we spin this gentleman there is

0:58

something going on in the lungs and we always look

1:01

and we always try and work out what's going on there.

1:04

So let's start with the prostate here.

1:06

There is abnormal uptake corresponding to

1:09

what we saw on the rotating MIT that's increased

1:11

above background, kind of heterogeneous,

1:13

but it's extending to the peripheral zone

1:15

and it is asymmetrical.

1:16

So I'd be calling this consistent with disease

1:18

and probably looking at the MRI to confirm that's the side

1:21

of lesion and as per like our primary score,

1:23

we'd probably be sitting that as a primary four.

1:25

So coming up and when we check our lymph nodes

1:27

and that all has looked good.

1:29

So scrolling all the way up to the thorax

1:31

to see what's going on here.

1:33

And yes, there's a lesion.

1:35

So here's one I prepared earlier

1:37

with our lung window on this case.

1:39

And so there is a nodule

1:42

and it is mildly PSMA expressing not as hot

1:44

as the primary though, and it would be really unusual

1:47

for a primary prostate cancer without nodal disease

1:51

to go straight to the lung.

1:52

That is just a really uncommon pattern.

1:54

So already alarm bells are ringing

1:56

that something else is going on here.

1:58

So we'll check the lungs really carefully,

2:00

make sure there are no further nodules,

2:01

really interrogate the mediastinal lymph

2:04

nodes to see what's happening.

2:05

And also coming up in this one.

2:08

Is there anything going on in the head and neck?

2:10

No, all looks good.

2:12

So the patient had a diagnostic CT

2:15

and then they came back to us for an FDG pet.

2:18

And let's bring the two rotating MIPS up

2:20

and I'll put them just

2:22

so we can scroll backward and forward.

2:23

Sorry, this one's a little bit darker,

2:25

so I'll just adjust the level,

2:26

make the background a bit wider here.

2:29

There we go. That's much nicer.

2:31

So you can see we will make true right, true left,

2:34

there's uptake in the prostate

2:35

and a little bit of uptake in that lesion there compared

2:38

to here where we've only really got one

2:40

small focus of uptake.

2:41

So it's much, much less extensive

2:42

and a more pronounced area of uptake in that lung.

2:47

Interestingly though, we've also got uptake in the base

2:51

of the neck and there's also something sitting here in the

2:53

retroperitoneum as well as two

2:59

More dominant lesions in the abdomen.

3:03

So we're seeing much, much more, let's go back again,

3:05

were those bowel lesions?

3:07

Oh maybe there, but it would be a tough call, tough call.

3:11

Maybe something in here as well.

3:14

I, but certainly we're seeing much, much more.

3:17

So as we can see the prostate cancer

3:19

and let's go all the way down the bottom

3:22

is not predominantly FTG Abbott.

3:25

Maybe one small component is got a little bit of uptake,

3:29

but that could be within physiological limits.

3:30

So this really does showcase that FT G is not the right

3:34

FTG PET is not the right test

3:35

for well differentiated prostate cancer.

3:38

But coming up we've got a large lesion here as well

3:42

as some focal uptake here.

3:45

And the patient at this point had already undergone

3:47

colonoscopy and had been diagnosed with two synchronous

3:51

bowel tumors, bowel carcinomas,

3:55

and then coming up to the lung there's our focal lesion.

4:00

And so being um, a lung cancer person, we'll just kind

4:03

of briefly stop here

4:05

and see that we've got a nodule in the lung which has an

4:08

irregular speculated border.

4:10

The patient has got background emphysema,

4:12

so they've got a higher risk for lung cancer.

4:14

It's tethering in that fissure.

4:16

And actually this was a case

4:19

of a primary lung cancer biopsy proven,

4:22

but then we remember we had one more spot of uptake.

4:25

So let's go back to our fusion, come up to the pace of neck.

4:29

And then there was a FDG AVID nodule in the left side

4:33

of the thyroid, which was completely negative on PSMA.

4:37

So this was actually also biopsied

4:39

and this was a thyroid cancer.

4:41

So this patient had prostate cancer,

4:43

two synchronous bowel primary tumors, lung cancer,

4:45

and a thyroid cancer as well.

4:48

So I chose this case to show

4:51

because we've got a whole gamut of malignancies, some

4:54

that demonstrate uptake on PSMA PET and some which don't.

4:58

And you can see that really the prostate cancer was well

5:00

shown on the PSMA.

5:01

The lung cancer had a little bit of uptake,

5:03

but the thyroid cancer and the bowel cancers didn't have

5:05

much at all or it was difficult

5:07

to discern from background physiological activity.

5:10

So that can be a pitfall.

5:11

You can see other malignancies on PSMA pet

5:14

and you need to keep your guard up.