Feasibility of spacers to facilitate postoperative radiotherapy for retroperitoneal sarcomas.

INTRODUCTION: The role and timing of postoperative radiotherapy (PORT) in the management of retroperitoneal sarcoma (RPS) remains controversial.

METHOD: This is a retrospective cohort review of patients undergoing curative resection for RPS at a single institution between January 2011 and July 2016. Patient selection was through the South Australian Soft Tissue Tumour Multidisciplinary Group (MDT) based at Royal Adelaide Hospital. An individualised approach, including assessment of resectability, histopathological grade and subtype, and radiotherapy considerations, was taken for each patient. Patients offered preoperative radiotherapy or palliation were excluded. A saline-filled spacer was inserted following operative resection. Radiotherapy commenced postoperatively. Patients underwent laparotomy to remove the device approximately 6 weeks post completion of PORT. Primary endpoints were technical feasibility, perioperative morbidity and radiation toxicity. Secondary endpoints were local recurrence (LR), distant recurrence (DR) and death.

RESULTS: During the study period, 40 patients with RPS were managed through the MDT. Twelve patients (ages 33-78) underwent PORT utilising spacers. Radiotherapy toxicity was reported in four patients and extensive adhesions observed in another four patients during spacer removal. Median follow-up was 35 months (range 4-60). Seven patients remain alive and disease free. Four patients developed LR, three developed DR. Three patients died; two with DR and one with LR. Two patients with recurrent/progressive disease are alive; one with DR and one with LR.

CONCLUSION: Use of intraoperative spacers to facilitate PORT is feasible, with acceptable toxicity following resection of RPS. Patient selection for this approach remains to be determined.