Positive surgical margins in soft tissue sarcoma treated with preoperative radiation: is a postoperative boost necessary: in regard to Al Yami et al. (Int J Radiat Oncol Biol Phys 2010;77:1191-1197).

摘要

We credit Al Yami et al. for addressing the value of postoperative boost radiation in soft tissue sarcoma patients with positive margins after 50 Gy of preoperative radiotherapy. It is worth commenting that postoperative boost radiotherapy was formerly used in patients with negative margins, until data from Sadoski et al. (1) demonstrated that it could be eliminated.The authors compared 41 patients receiving 50 Gy of preoperative radiotherapy and a postoperative external beam radiotherapy boost with 52 patients who did not receive a boost. They reported no local control advantage, with a 5-year local control rate of 90.4% in the no-boost group vs. 73.8% in the boost group (p = .13). Series of patients with positive surgical margins who received adjuvant radiotherapy documented a local control rate of ~70%, suggesting the no-boost group here was carefully selected (2, 3). There is likely value in identifying patients for whom a boost is not necessary. Indeed, the Princess Margaret group has identified patients with (1) a positive margin in a low-grade, well-differentiated liposarcoma or (2) "planned positive" margin on an anatomically fixed critical structure as at low risk of local recurrence (4.2% and 3.6%, respectively) (4). In contrast, there are patients with a poor histologic response, margins broadly or multifocally positive, margins positive after re-excision, and "unplanned positive margins" (4), for whom additional treatment, if effective, is likely warranted.