Radiation Therapy in Conjunction With Surgical Stabilization of Impending or Pathologic Fractures Secondary to Metastasis: Is There a Difference Between Single and Multifraction Regimens?

Abstract

Purpose: Patients who undergo surgical stabilization for impending or pathologic fractures secondary to metastasis are often treated with radiation therapy to the involved site. We sought to retrospectively analyze outcomes from single versus multifraction regimens of radiation therapy in this setting. Methods and Materials: From our institutional radiation database, we identified 87 patients between 2004 and 2016 who had an impending or pathologic fracture from metastatic disease and who underwent surgical fixation in conjunction with either neoadjuvant (within 5 weeks before surgery) or adjuvant (within 10 weeks after surgery) radiation therapy, representing 99 total treatment sites. Patients were included on the basis of intention to treat with bimodality therapy. Baseline patient characteristics were compared using 2-sided t tests and Fisher's exact tests. Cumulative incidence of local failure, reirradiation, and reoperation were calculated using the Fine-Gray method for competing risks. Freedom from complication was calculated using the Kaplan-Meier method. Results: Baseline characteristics between the single (n = 52) and multifraction (n = 47) cohorts were similar with the exception of higher rates of synchronous bony metastasis (83% vs 60%, P = .01) and female patients (71% vs 43%, P = .004) in the single fraction cohort. There was no significant difference in overall survival between treatment groups. After a median follow-up of 13 months, there was no significant difference in the single and multifraction cohorts, respectively, in the 1-year cumulative incidence rates of local failure (4% vs 7%, P = .58), reirradiation (5% vs 4%, P = .95), reoperation (4% vs 0%, P = .30), or 1-year freedom from complication (90% vs 95%, P = .40). Conclusions: This is the first study comparing outcomes between single and multifraction radiation therapy in conjunction with surgical stabilization of an impending or pathologic fracture. We found no difference in outcomes between single and multifraction regimens in this setting. Given these findings, single fraction perioperative radiation therapy may be a viable treatment option in appropriately selected patients pending prospective validation of these findings.