PSMA Scan post Ra223 treatments

[Tinuriel]

No huge win from his recent treatment is discernable. The doctor (RO) says there's no way of knowing if it won him any extra time. However, we can only assume things might have been worse without it. As we walked out the door, he came back to us specifically to tell us how good he looked (unstated..." for someone as sick as you are?"). We continue to be grateful that he has had no pain from any of these tumors.

We will talk to our medical oncologist on Sept. 13th to chart out what comes next. My guess is we are looking at starting Docetaxel before Christmas. We are also going to talk to a specialist on available clinical trials that he could be eligible for.

Here's the actual report, the first PSMA scan he's had. I'm new to SUV values - these seem high, especially since his last scan SUVs were all below 10. I'm curious what those of you who know how to read these will make of these results (I removed things stated as "normal" for brevity's sake).

"1. There is new prominent PSMA avid subcarinal mediastinal adenopathy as well as a PSMA avid nodule within the left lung base laterally consistent with metastatic disease.

(the doc said these need to be biopsied to confirm that it's metastatic prostate cancer, and explore possible immunotherapies)

2. There are multiple PSMA avid osseous metastasis as described below.

Created by: Randal J Wilson, MD Signed by: Randal J Wilson, MD Signed on: 8/25/2023 10:33 EDT Location: OHRR20

Narrative

EXAM: PET/CT TUMOR SKULL TO THIGH WITH PSMA INDICATION: Restaging metastatic prostate cancer.. COMPARISON: Prior PET scans with the most recent Axumin PET scan dated 12/6/2022.. TECHNIQUE: Sagittal, coronal and axial tomographic images were obtained from proximal thighs to skull vertex 64 minutes after the intravenous injection of 5.1 mCi of GA68 gozetotide PSMA-11. Concordant, low-dose, uninfused CT images were also obtained for attenuation correction and for localization of nuclear findings.

PET SCAN FINDINGS:

THORAX:

There is a new 1.6 x 3.4 cm subcarinal mediastinal lymph node (the space between the lungs just below the esophagus) with a maximum SUV of 125.

There is a new 1.8 x 2.2 cm nodule within the left lung base laterally with a maximum SUV of 32.2.

OSSEOUS STRUCTURES:

There are multiple PSMA avid osseous lesions. The dominant lesions have maximum SUV as follows:

Left skull base 6.4,

C2 vertebral body 12.2,

T1 right transverse spinous process 17,

bilateral ribs most prominent involving the 11th of 11 rib posteriorly 12.2,

T4 vertebral body 38.5,

T10, T11 and T12 vertebral bodies and posterior elements 82.2, (previous 7.9, 3)

and L3 vertebral body 93.4. (previous L4 6.8) "

You guys are gold. It's a privilege to have you along with us on this journey.

[Peace-to-you]

Even if you think your RO is great…It’s always a good idea to get a second opinion. Doctors are people too, they can and do miss things

[SeosamhM]

Hi, T. First - yes, the whole "you look good" thing is old. Way old. Too old. It's exactly the same thing as looking over a piece of chicken in the fridge to determine its viability for dinner. I suppose as long as they keep it to "you look good" and not "you don't smell too bad"....

Second, I deem you are keeping on top of - and ahead of - things. It's a good space to be in and I thank you for being a great companion!

Third is your question as to the meaning of your husband's scans. "SUV" means "specific uptake value," which is a technical term to help refine what is a very qualitative process of reading some types of scans. Unless you are an expert, it is not advisable to directly compare one scan to another when SUV is an important component of the reading. While PSMA is very specific very good at telling us when PCa is (almost) certainly present (and "it could be a PCa tumor" becomes "yep, it's probably a PCa tumor"), this specificity isn't absolute in a quantitative sense, i.e., it cannot really tell us "how much" PCa is there. Only sort of.

Think of paint. We can tell that one paint is "bluer" than another paint, but unless we see the entire color palette for "blue," we can't really say what is the "bluest." And the PSMA-avid palette can change subtly for each PSMA scan. Radiologists simply use "SUV" as a way to describe what they see and compare regions.

So, writing as an experienced aPCa patient (not a doctor), if this scan was mine:

1. It reiterates that my cancer is still all around my body and that it is largely confined to bone. This is not news. But it is disappointing that, after Ra233, PSMA-avidity seems to have actually risen in my spine (using the paint analogy, those suckers are definitely "bluer"..! 🙁). But other than the lymph node, it isn't affecting soft tissue, so good news. As you say, I would "assume things would have been worse without (Ra233)." It was a good call on treatment, in my opinion.

2. The lymph node involvement is interesting and represents a great isolated, "easy" (?) biopsy opportunity to see the actual cells of my active cancer and get some specific genomic information that may help guide treatment. It is possible that PSMA-avidity was incidental and there is no mPCa, but I would actually hope that it was a met. I want information.

3. "Docetaxel before Christmas"...wasn't that on the Hallmark Channel? 🤔 Another basic call on treatment that I would accept in the absence of specific genomic information.

While your husband has no pain from his mets (awesome), get on top of spine health now if you have not already (e.g., orthopedic spine specialist, DEXA bone scan, MRI of thoracic spine). This is not an MO/RO specialty and our cancer treatments degrade our bones.

Good luck to you and your husband! - Joe M.

[Blue-Mockingbird in reply to SeosamhM]

I reiterate what SeosamhM said and get on top of your husband’s spine health. My husband wasn’t referred to a neurosurgeon until he was having trouble walking. Turns out he has a compression fracture of his T7 and says there’s nothing he can do because of the compromised bones surrounding it. Best to you both 🤞🏽

[Tinuriel in reply to Blue-Mockingbird]

Great suggestion, will do! I'm sorry about your experiences and wish you had better intel in your own situation. Best to you, too!

[Tinuriel in reply to SeosamhM]

Wow, thanks, SeosamhM! This was a comprehensive and informative reply, and I will definitely follow up on your suggestions. I felt greatly encouraged after reading it. I hadn't thought about the difference between soft tissue and lymph nodes, nor needing to ask about bone health. We'll pursue that. Thanks for taking the time to respond.