What are your preferred target doses for bulky T4 rectal adenocarcinomas with extensive GU and anal sphincter involvement as well as common illiac and inguinal adenopathy, as part of total neoadjuvant therapy when future APR is planned?  

In particular, many guidelines suggest a max point dose of 50Gy for small bowel but in cases of extensive disease how do you reconcile loops of bowel immediately adjacent to gross disease, most commonly encountered when primary tumor approaches the rectosigmoid junction or with frank common illiac adenopathy that persists even after prone positioning and optimized bladder filling especially in very thin patients?