68 Ga PSMA Scan Results are in

Bob,

It is great to know about the positive result of the PET scan. The bandit was identified  and you can pursue a treatment confident of success. You need to discuss the options with a radiologist. Which protocol and field of attack is best to deal with its locations?
One should have in mind about the probability (rather small) of having micrometastases not identified by the scan. The field of attack can be wider than just a spot. The scale regarding the PSMA uptake goes upto 7, and yours is indicated as 5.2. This may be the biggest collony while the prostate bed (faint) may represent micrometastases. Get the best but avoid any possible collateral damage from an RT choice.

 Best of lucks.

VGama

Your full story about the Ga-68 PSMA PET is here; https://csn.cancer.org/node/303009

Isn't the major advantage of the PSMA methodology that it is more sensitive than 'classical' imaging (such as MRI)?

Bob,

This forum search engine is worthless. This is a great site but the admin never tried to improve its search feature. I looked for your “story” to reply as much accurate as possible and it took me long time to find your thread. (https://csn.cancer.org/node/300252)

Regarding your inquire; I think that the one month Casodex has not influenced cancer’s size. I agree with Old Salt’s opinion about the negative result from the MRI contrasting with the positive result of the PSMA PET. The later is more sensitive and should be trusted.
I would think that the lymph nodes in the left pelvis area are probably all affected (an area of 8x7mm) with some nodes (spots) “infested” with tumors (aggregated colony of cancerous cells). The MRI would only recognize these if they were bigger than 1.0 cm (7 mm in diameter for PET), at its best tumor to background ratio T/B and type of imaging isotope. In certain depth this size can increase to 1.5 cm. The small external iliac nodes standing next to the distal (lower portion) ureters are also identified. These should also receive RT if the radiologist finds the best angle to deliver the rays without collateral damages. You need to discuss with the RO about such a possibility and about what could go wrong (scars).
The prostate bed is a common site for SRT. That will include the bladder’s sphincter area (reattached to the urethra) which may cause stricture (commented by Max). Typically doctors wait 6 month since RP to allow proper healing of this area. That period corresponds well with your surgery of April, but you can inquire if that spot can be avoided or even if it is possible of using lower doses (Gy) and still get the full benefit.
The MRI finding of “Bladder: Concentric wall thickening with trabeculations suggestive of chronic bladder outlet obstruction”, this could be a tissue thickening caused by the reattachment of the urethra at surgery or a damage caused by the catheter. Surely radiating these tissues will cause inflammation that can cause problems in voiding. Do as Max suggest above.

Another point for discussion regards the MRI findings at the left sacrum (1.7 cm focus) and at the left ischium (2.1 cm hyperintense focus). MRI’s T2-weighted images are common but are difficult of being diagnosed properly. The focal lesions could relate to many things other than cancer. These are also called UBOs (Unidentified Bright Objects) by the radiologists. For instance, it could be due to neurometabolic diseases, or multiple sclerosis, or arthritis, etc. Your RO will find a meaning for the MRI result even if the PSMA PET is negative at those places. The images can explain something. Do you have a copy?

The RO will use the MRI machine two or three times along the IMRT period to map each field of radiation (organs move constantly). He must always compare it with the PET exam.

I hope you are successful and that you can turn the page of this critical chapter of your life for good.

Best,

VG