Positive surgical margins in soft tissue sarcoma treated with preoperative radiation: is a postoperative boost necessary?
OBJECTIVE
For patients with an extremity soft tissue sarcoma (STS) treated with preoperative radiotherapy and surgically excised with positive margins, we retrospectively reviewed whether a postoperative radiation boost reduced the risk of local recurrence (LR).


METHODS
A total of 216 patients with positive margins after resection of an extremity STS treated between 1986 and 2003 were identified from our institution's prospectively collected database. Patient demographics, radiation therapy parameters including timing and dose, classification of positive margin status, reasons for not administering a postoperative boost, and oncologic outcome were collected and evaluated.


RESULTS
Of the 216 patients with a positive surgical margin, 52 patients were treated with preoperative radiation therapy alone (50 Gy), whereas 41 received preoperative radiation therapy plus a postoperative boost (80% received 16 Gy postoperatively for a total of 66 Gy). There was no difference in baseline tumor characteristics between the two groups. Six of 52 patients in the group receiving preoperative radiation alone developed a LR compared with 9 of 41 in the boost group. Five-year estimated LR-free survivals were 90.4% and 73.8%, respectively (p = 0.13).


CONCLUSIONS
We found that including the postoperative radiation boost after preoperative radiation and a margin-positive excision did not provide an advantage in preventing LR for patients treated with external beam radiotherapy. Given that higher radiation doses placed patients at greater risk for late complications such as fracture, fibrosis, edema, and joint stiffness, judicious avoidance of the postoperative boost while maintaining an equivalent rate of local control can reduce the risk of these difficult-to-treat morbidities.
Al Yami
Ali
A
Orthopaedic Surgery, University Musculoskeletal Oncology Unit, Mount Sinai Hospital, Toronto, ON, Canada.
Griffin
Anthony M
AM
Ferguson
Peter C
PC
Catton
Charles N
CN
Chung
Peter W M
PW
Bell
Robert S
RS
Wunder
Jay S
JS
O'Sullivan
Brian
B
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000671:Amputation, Surgical; D005260:Female; D018219:Histiocytoma, Benign Fibrous / Q000473:pathology / Q000517:prevention & control / Q000532:radiotherapy / Q000601:surgery; D006801:Humans; D007890:Leiomyosarcoma / Q000473:pathology / Q000517:prevention & control / Q000532:radiotherapy / Q000601:surgery; D023821:Limb Salvage; D008080:Liposarcoma / Q000473:pathology / Q000517:prevention & control / Q000532:radiotherapy / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000517:prevention & control; D018365:Neoplasm, Residual; D011182:Postoperative Care; D011879:Radiotherapy Dosage; D019233:Retreatment; D012509:Sarcoma / Q000473:pathology / Q000517:prevention & control / Q000532:radiotherapy* / Q000601:surgery; D055815:Young Adult