Favorite Hypofrac Schemes

[ramsesthenice]

low lying bowel that has to be cropped out of the prostate PTV

Right on cue. Just simed a guy yesterday. Has very low lying bowel with an intact prostate (favorable IR disease). Tried prone and supine scans and even prone with a full bladder he still had small bowel draping down to the SVs. Thank god he has low volume disease and all of his disease on MRI and biopsy is in the right apex. I don't usually do this but I opted not to take the entire median lobe to full dose (contoured the most caudal/anterior median lobe separate from the rest of the gland) and will be using conventional fractionation. I would have been willing to still go 2.5 per day using an SIB but this guy specifically said if in doubt he would rather come a couple extra weeks. Its never all or none.

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[KHE88]

Right on cue. Just simed a guy yesterday. Has very low lying bowel with an intact prostate (favorable IR disease). Tried prone and supine scans and even prone with a full bladder he still had small bowel draping down to the SVs. Thank god he has low volume disease and all of his disease on MRI and biopsy is in the right apex. I don't usually do this but I opted not to take the entire median lobe to full dose (contoured the most caudal/anterior median lobe separate from the rest of the gland) and will be using conventional fractionation. I would have been willing to still go 2.5 per day using an SIB but this guy specifically said if in doubt he would rather come a couple extra weeks. Its never all or none.

One of my most hated clinical scenarios. Do we give an older guy potentially fatal toxicity to treat a low risk prostate cancer? Had a guy with a loop dropping around the bladder to within a cm of the proximal SV. In my case, I still treated the whole gland but used basically no PTV margin near the bowel, made a PRV around the bowel, and put very hard high dose constraints on it, and did daily cone beams.

Your plan sounds solid. If 46-50 Gy can sterilize microscopic disease in nodes, one would think it could sterilize microscopic disease in uninvolved prostate on biopsy and imaging. I'd still push as high as I could and keep bowel max under 54 with only a few cc above 50.

Have another one of these coming up for planning. Lovely.