Tumor in Transition Zone

I had a biopsy in June, which showed 8/12 positive cores, 2/6 (both G3+3) on the left, 6/6 on the right (3 @ 3+3, 3 @ 3+4).

Yesterday, I got the results of an mpMRI, which contained both good news, and uncertain news:

1) a 2.7 cm x 1.7 x 1.3 Pirads5 tumor (total volume 3.1 cc) in the right transition zone, anterior midline and right lateral, within the midgland. Impression stated, "No evidence of extracapsular spread."

2) "Post biopsy changes in the peripehral zone without definite Pirads lesion." The Findings stated, "High T1 signal noted in the peripheral gland, likely representing blood products."

The good news is the dominant tumor is well-contained in the prostate. The uncertain news is that the MRI couldn't get a fix on the cancerous sections sampled by the biopsy, presumably in the peripheral zone, plus the placement of the dominant tumor in the transition zone, which is deep inside the prostate, surrounding the urethra.

I was 95% decided to do RT before the MRI, but found an older thread on HW in which Tall Allen stated that because of the proximity of the TZ to the uretha, the urinary SE's of RT to a TZ tumor could be severe, so just cutting out that section of urethra via RP would probably result in fewer LT urinary SE's.

Has anyone here had experience with RT for a tumor in the TZ, and if so, what was your experience, especially re: urinary SE's?

In case you are wondering what mix of RT I am considering, my preference is IMRT plus a brachy boost, to mop up any stray bits of the (hopefully) micro-tumors on the peripheral zone and beyond, in addition to zapping the dominant tumor in the TZ. The RO at the MRI consult said that was a reasonable choice, and referred me to the brachy RO for further consultations. He told me that HT as part of a triple play was probably overkill for my profile, that a double play of 25 sessions of IMRT + a brachy boost was more than sufficient, while minimizing SE's, but he would let the brachy doc make the final call on HT, and also whether LDR brachy or HDR brachy was a better choice.

Thanks as always for all of your informed opnions.


Age: 62
PSA, 3/18: 6.1
DRE, 4/18: Stage T2a, right side
Biopsy, 6/18: Left = 2/6 positive, G3+3; Right = 6/6 positive, 3 @ G3+3, 3 @ G3+4; PNI identified in 2 cores
mpMRI, 8/18: PIRADS 5 tumor in the right transition zone. No capsular involvement, seminal vesicles and nuerovascular bundles appear normal. No detail on biopsied cancer found in the peripheral zone.

Is the increased urinary SEs from more radiation to the transition zone or is just because of some artifact of the tumor itself being there? The reason I ask is that in the case of my HDR brachy, they blanketed the prostate with radiation...they didn't increase it any particular area based on where my tumors were located.

It would certainly be a good question for your RO and I'm sure that Allen will also weigh in.

I may have missed this somewhere, but were you trying to avoid surgery?

Before I describe my DH's experience, please rest assured I am in no way trying to spruik surgery here. Everyone has an opinion about the best tx for them, and we never even knew there were various tx available when we started out! Boy have we learned a lot since then.

GG had a large tumor in the transition zone and underwent surgery.

Continent from day 1 - not a single drip. He was totally active and working at full strength directly after his catheter came out at the 10 day mark. Never missed a beat.

All I'm saying is don't rule out surgery entirely. I know some guys do it tough with unwanted side effects, but there is also a cohort who do extremely well. I've been led to believe outcomes are highly dependent on the skill of the person wielding the knife, so if you do decide to go down that road for any reason, just choose carefully. SME's like Tall Allen would definitely be able to point you in the right direction if required.

Either way, it sounds as though you're in a good position to kick this, and we wish you the very best with your tx and decision going forward.

Thanks for the clarification. I thought you said that in another thread. As much as I like RT in its many forms, you've got a tough one there.

It's possible that post RT the inflammation and tumor size will go down enough to not give you a problem, but that could take awhile.

On the other side surgery would clear it without the stricture issue. Given that you're in general good health and active, it's possible you might heal fast and not have any post surgery issues.

It's a lot of guessing. Well, hopefully the Brachy doc can help clarify it for you and give you better info to make a decision with.

Keep us updated,
Andrew

John T-

Help me out (with references if you still have them)- because what you're saying is the opposite of what I read. Why would it matter for surgery if the tumor has pressed into the urethra? - it gets cut out anyway. As long as the tumor doesn't grow above the bladder neck (unlikely, considering the mild urinary symptoms that the OP said), I don't understand how incontinence is more of an issue. I think bladder neck sparing is the critical thing in whether incontinence will be a problem - and the urologist may be able to determine that from the MRI.

Brachytherapy, on the other hand, unavoidably delivers a very large dose to the urethra, and transition zone volume is the #1 predictor of acute urinary retention. P.726: " the transition zone volume or the
transition zone index was the best predictor for obstructive symptoms."

/www.eusupplements.europeanurology.com/article/S1569-9056(08)00100-0/pdf

Allan,
Can't explain it in technical terms. Just repeating what some pretty good medicos told me. When I have three well known specialists in Prostate Cancer telling me something I listen, especially when two well respected surgeons gave me no reason why surgery would be superior in my situation. Dr Bahn gave his advice after looking at Doppler images and Barantsz after 3T MRI. I don' think there were any 3T machines in the US being used on the prostate in the US at that time. In 2009 they were the top clinical diagnosticians around. The surgeons were not interested in even looking at any of the images and that bothered me, Also in 2009 there were only a handful of doctors using robotic surgery. The best surgeons, Scardino, Walsh and Skinner were all open surgery guys. Both Walsh and Scardino mentioned in their books that TZ tumors were more problematic surgically speaking than PZ tumors they did not give any reasons why. Those books were probably written before 2007, so surgical techniques may have advanced especially in Robotics that were in their infancy.

I believe Dr King uses a RapidArc with a Novalis Tx linear accelerator. If you google "sbrt prostate cancer ucla" you'll get a lot of relevant information choices.

Thanks John T and JimBear for the feedback that it is possible to have RT of a TZ tumor without long term urinary SE's.