Please select the option that best describes you:
Topics:
Radiation Oncology • Genitourinary Cancers
What bowel constraints do you use when treating definitive bladder?
When treating intact bladder cases to 63-64.8 Gy with shrinking fields, the max bowel dose is close to the rx dose. Old RTOG trials often just used V45 < 300 but aim for V45 <195 cc from QUANTEC. Do you have a max constraint or a V55 constraint? We use V55 < 5-10 cc from GYN cases but has not been typically possible.
Answer from: Radiation Oncologist at Community Practice
I often find a V60<10 cc bowel constraint too restrictive and challenging to meet without significant compromise of tumor coverage due to the aforementioned tendency of the bowel to sit atop the bladder dome, and requisite standard PTV margins.First and foremost, I obtain daily CBCT for these pat...
Sign in or Register to read more
Answer from: Radiation Oncologist at Academic Institution
The SWOG S1806 trial approaches this by contouring small bowel loops (excluding large bowel) and constraining this to Max (0.03cc) <55 Gy, V50 Gy <15 Gy, V45 Gy<100cc, V40 Gy<130cc and <30%, and V30 Gy <150cc.
IMRT can help if you are running into trouble with the lower dose...
Comments
Radiation Oncologist at Comprehensive Cancer Centers of Nevada
I find that it's often difficult to meet small bow...
I find that it's often difficult to meet small bow...