Outcomes of postoperative stereotactic radiosurgery to the resection cavity versus stereotactic radiosurgery alone for melanoma brain metastases

To investigate local control and radiation-induced brain necrosis in patients with melanoma brain metastases who received complete resection plus fractionated stereotactic radiosurgery (fSRS, 3 × 9 Gy) or fSRS alone. Factors associated with the clinical outcomes and the development of brain necrosis have been assessed. One hundred and twenty consecutive patients with 137 melanoma brain metastases who received surgery plus fSRS (S + fSRS) or fSRS alone were analyzed. All lesions evaluated in the study were treated with a dose of 27 Gy given in 3 fractions over three consecutive days. Cumulative incidence analysis was used to compare local failure (LF), distant brain failure (DBF), and radiation-induced brain necrosis (RN) between groups from the time of SRS. At a median follow-up of 13 months, median OS times and 1-year survival rates were comparable: S + fSRS, 14 months and 85%; fSRS, 12 months and 85% (p = 0.2). Median DBF did not differ significantly by group, being 14 months for both groups. Nine patients who received S + fSRS and 20 patients treated with fSRS recurred locally (p = 0.03). Six-month and 1-year LF rates were 5 and 12% in S + fSRS group and 17 and 28% in fSRS group (p = 0.02). RN occurred in 21 patients (S + fSRS, n = 14; fSRS, n = 7; p = 0.1). The cumulative 1-year incidence of RN was 13% after S + fSRS and 8% after fSRS (p = 0.15). In conclusion, postoperative SRS (3 × 9 Gy) to the resection cavity is an effective treatment modality for melanoma brain metastases associated with better local control as compared with fSRS alone.