For retroperitoneal sarcomas, do you consider neoadjuvantly boosting the "posterior rind" or area at high risk of positive margin?

I routinely recommend preoperative IMRT to treat retroperitoneal sarcoma, although we have no level 1 evidence to support this approach. Currently the EORTC is conducting a phase III trial to investigate a role preoperative radiation (3DCRT or IMRT) in treatment of retroperitoneal sarcoma (primary endpoint is abdominal/pelvic recurrence-free survival). Also I always consider SIB boost to the high-risk tumor area predicted for recurrence after surigical resection, a regimen of IMRT 45 Gy to entire tumor plus margin/SIB 57.5 Gy to high-risk area in 25 daily fractions was reported to safely treat retroperitoneal sarcoma in a small cohort of patients (Tzeng, Cancer 2006). Also I would recommend that the high-risk tumor area be carefully contour...