Prostate Bed & Urinary Incontinence

[jbernar1]

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There was a publication showing that prostate bed radiation does not affect continence so no need to wait months on end for maximal continence. I can't seem to find the reference now that I need it. Would someone please post it? Thanks.

 

[medgator]

I'd still wait 3-4 months post rrp unless continence has returned 100%. I believe the trials waited that long (swog waited up to 16 weeks, German study started 6-12 weeks after depending on function)

No harm in waiting imo and you don't want xrt blamed in case the patient's continence doesn't fully return

 

[jbernar1]

Patient is 4.5 months out.

 

[seper]

I'm curious too if you guys know of good quality data on the subject

 

[Chartreuse Wombat]

There was a publication showing that prostate bed radiation does not affect continence so no need to wait months on end for maximal continence. I can't seem to find the reference now that I need it. Would someone please post it? Thanks.

Small, older study that may not be germane given the dose and technique but it is randomized

http://www.ncbi.nlm.nih.gov/pubmed/9400462

 

[seper]

that's does not address the question of XRT @ 4 wks vs. 12 wks

 

[Chartreuse Wombat]

that's does not address the question of XRT @ 4 wks vs. 12 wks

Didn't know that was the question...first post said "months on end". All of the phase III studies (SWOG, EORTC and German) required XRT within 16 weeks of RP. My sense is that many urologists/radiation oncologists delay radiotherapy until "complete healing". I think that this is another example of oncolore; studies from the 1980's suggested that postop head and neck XRT did not need to be delayed until complete wound healing (in fact there was a detriment to delaying XRT). Not a perfect analogy for sure but the point is that there is little evidence to support the notion that radiotherapy "freezes" the continence picture (although many still do this in practice).

 

[jbernar1]

I think I found it.

PMID: 25752388

http://www.ncbi.nlm.nih.gov/pubmed/?term=25752388

 

[seper]

Thanks, a nice paper. It however does not address the question of adjuvant XRT @ 4 wks vs. 12 wks at all. Majority of these patients were salvage RT (Figure E1).

 

[Haybrant]

Ive had a couple guys recently for salvage whose bladder sizes are not growing much. We'll have them drink a lot of water but theyre bladders just don't get that big. What do you guys do in this situation. What constraints are appropriate for salvage? ive got a guy (psa up to 1.5 who they finally sent) whose bladder is V40 just below 50% but V60 is about 35% and V70 about 25%. What dose range is reasonable for post op, have always tried to get to 7020. Thank you

 

[Gfunk6]

I think you are using the right approach - using OAR dose constraints as your guide. I usually go to 68.4 Gy but some of my partners are going to 70.2 Gy. In rare cases where you are performing salvage for macroscopic disease, may consider as high as 72 Gy plus.

 

[Mandelin Rain]

I use the RTOG SPPORT trial for constraints. Rarely get met, though they have large allowances for bladder DVH.

I do 64.8 Gy for the rare adjuvant case I see. 70.2 Gy if non-zero PSA, but I will scale it back to 68.4 and then 64.8 Gy based on bladder DVH if looks lousy. No science to that approach, but it makes me feel better.

 

[Chartreuse Wombat]

Ive had a couple guys recently for salvage whose bladder sizes are not growing much. We'll have them drink a lot of water but theyre bladders just don't get that big. What do you guys do in this situation. What constraints are appropriate for salvage? ive got a guy (psa up to 1.5 who they finally sent) whose bladder is V40 just below 50% but V60 is about 35% and V70 about 25%. What dose range is reasonable for post op, have always tried to get to 7020. Thank you

I have copied the constraints from RTOG 0534 which recently completed accrual. To my knowledge these have not been validated and are best guesses. The odd thing is that you are asked to exclude the bladder within the CTV from the DVH which strikes me as a bad idea since the bladder is certainly being irradiated to that dose whether it is in or our of the PTV. The other issue is that there is no level I evidence to support doses above 70 Gy in the postop setting. I am aware of the retrospective comparisons but they are fraught with bias. Randomized trials are ongoing.

 

[Haybrant]

I have copied the constraints from RTOG 0534 which recently completed accrual. To my knowledge these have not been validated and are best guesses. The odd thing is that you are asked to exclude the bladder within the CTV from the DVH which strikes me as a bad idea since the bladder is certainly being irradiated to that dose whether it is in or our of the PTV. The other issue is that there is no level I evidence to support doses above 70 Gy in the postop setting. I am aware of the retrospective comparisons but they are fraught with bias. Randomized trials are ongoing.

View attachment 213919

Thanks for attaching that. Ya I also had not heard of excluding the CTV from bladder but the more Ive seen it the most it made some sense as long as you're not getting a big hotspot in there. I mean you have to cover the bladder neck gradually pulling back till the top of the symphysis. And actually what you posted also has a constraint for Bladder - CTVp (although admittedly to me it seems very high!). I try to achieve conventional bladder doses as best as possible but for some guys its just not going to be. I think as mandolin says, I might consider going back to 68.4.