Patient is very anxious won’t accept waiting but it’s a good point did think about it and can rediscuss it given the issues. Bladder is full he doesn’t have problem with incontinence. Bowel dmax is 49 now. Remember he was high risk due to both SVs invaded at surgery
This is excessively conservative for a patient who you are treating this aggressively (PSA < 0.1 even, considering ADT, etc.). First off is to differentiate, is this small intestine or large intestine. Whether you need 7020, especially at the overlap with bowel, is another question. 64 is fine per SAKK although most probably doing at least 66 or so.
A
small bowel point dose of 60Gy would be very reasonable. The images you have posted seem to appear that this may be rectosigmoid colon which can take D2cc up to 65Gy as per cervical brachy data (with some of that sigmoid getting concurrent chemo as well) - traditional prostate constraints for the sigmoid are WAY too tight for the clinical case as described.
I would never give ADT here. I would also never treat pelvic LNs for a GG2 w/ + margin, slow PSADT, basically no factors for LN recurrence.
I’m an adder almost always in postop at least for 6mos. (There are some Stage I hnscc at MDACC that get concurrent chemoRT…) The hormones are not nec a walk in the park but the data points toward better outcomes as we all know.
Does it (bolded) at all PSAs? For something besides biochemical PFS benefit? Early salvage was done without ADT on RADICALS/RAVES. Would love your thought process here.
We have faced the same issue in the past and usually resorted to giving a bowel constraint of 60 Gy and planning.
We do however do this as well:
We scan these patients several times during the treatment course (mostly one weekly) to be certain that the initial planning CT represents daily anatomy and is not misleading. We generally do this immediately before / after a daily treatment without letting the patient void in between. We fuse these repeat CTs with the initial planning CT, draw the "new" bowel into the initial planning CT and thus end up with multiple DVHs for every "bowel-scenario". From time to time, you may find that the bowel loop magically disappears or moves to a more (or less!) favorable location in the pelvis. After 5 weeks of treatment (at around 50 Gy) we have half a dozen bowel DVHs and can estimate what the cumulative dose was and how much we want to push our constraint. We then make the final and either go on with the set constraint or, if it's violated, cone down after 50 Gy to a smaller volume. In your case this would generally mean to crop PTV in the initial seminal vesicle region, which you would rather not do, since this was a pT3b tumor.
You may call this workflow "poor (wo)man's adaptive RT". I imagine that these patients would benefit from online adaptive RT (either CT- or MR-based).
If you can't acquire a sufficient dose into your PTV, I would certainly add ADT.
Just the day before yesterday, I faced a similar problem in a patient receiving intracavitary brachytherapy for cervical cancer.
One small bowel loop ended up between sigma and uterus, ruining an otherwise perfect treatment plan.
It was the MRI that actually picked it up, I later realized that I may have not identified it correctly on the CT only.
Holy **** - this is a LOT of effort for salvaging prostate cancer. Can I ask why?
Do you guys wait 2 months in salivate setting after ADT to start RT?
??
Neoadjuvant ADT is really only a thing in
definitive RT, and even that has been challenged by evaluating the data, where concurrent + adjuvant is at worst equal to neoadjuvant, and potentially slightly better than neoadjuvant. I don't see a utility of routine use of neoadjuvant anymore in the
definitive setting.
For
salvage RT, only reason to not start RT at initiation of ADT is because the patient's continence hasn't improved sufficiently and you know they need RT at some early time point (within say 3-12 months) after their surgery where urinary continence is still and issue and has ability to recover.
Depends on the patient/margin. If he had a focally positive gg1 Margin or even benign tissue at Margin this may be a recurrence that never becomes clinically significant. Say the doubling time is 18 months or 2 years.
Arguing against that is he’s young and anxious and t3b disease. Certainly reasonable to salvage. Could also get another PSA or two first to assess the trend. Plenty of room to do that and still salvage at <0.2
This would be my answer for this patient as well. 0.06 is a very, VERY low PSA from a tumor that is overwhelmingly likely in the prostatic fossa. I consider early salvage at PSAs above 0.1. I do not think I have treated anyone with a detectable PSA < 0.1.
Can add based on SPORT/getug/rtog trial, can omit based on Spratt analysis showing less benefit in and more cardiac issues in patients <0.6.
Are you going to treat pelvic nodes?
1) Why treat with ADT in this patient who is EARLIER than what would even be considered 'early salvage'?
2) PSA < 0.34 (yes, arbitrary number is arbitrary), with GG2 and a positive margin. Why treat the LNs?
If we use psadt as a metric for post-op salvage in a 56 yo, why not use it pre-op for surgery? Protect showed no os benefit to anything in this guy right?
?? Because is there data that it matters? PSADT has been shown to have an effect. You're talking about ProtecT which was the FIRST definitive therapy, but this patient isn't receiving definitive therapy. He has to be treated as having more aggressive disease than the folks treated on ProtecT, no?
It’s also about time following patients and experience. I’ve had patients go from undetectable to detectable PSA and then back again several times. PSA fluctuates more then we care to admit for reasons we don’t really understand beyond hand waving about residual benign tissue and prostatitis Voodoo. It’s also about balancing post op recovery time with the benefits of salvage xrt.
So while salvage xrt is absolutely underused or often used too late, it’s also not a matter of “whoop, PSA is .04, let’s fire up the cobalt”
Can't believe I'm agreeing with the Urologist on indications for salvage RT, but here we are. There's being early and aggressive, and there's something earlier than that.
/soapbox
How did point dose become a thing in plan evaluation. Point dose is meaningless for clinical outcomes. At best, it’s a marker for… what 10% or 20% or whatever of the organ is getting. I can give an 85 Gy point dose in one fraction to the skull base and a patient have zero side effects. Much more important is how much of an organ is getting how much of a dose or more. When I hear “60 Gy point dose to the sigmoid” I think: you would take 99.9% of the sigmoid getting 59 Gy?
/soapbox
Sometimes a significant difference between 'point dose' (what TPS reports as 'max dose', which could be to one voxel) and 'clinically significant point dose' - Timmerman defines this as 0.035cc, others may use 0.01cc, some others may use 0.1cc. No validation that one is inherently better than another.
I would limit clinically significant point dose of small bowel to 60Gy, not the max dose to a voxel. Point dose is not in a vaccum, simply another parameter to evaluate.
