Stereotactic Radiosurgery With Or Without Whole Brain Radiotherapy Of Patients With 1 To 4 Melanoma Brain Metastases

Melanoma brain metastasis poses a difficult therapeutic challenge. Melanoma is perceived as radioresistant histology and is thought to be less responsive to whole brain radiotherapy (WBRT). Stereotactic radiosurgery (SRS) is regarded as one of the treatment options that may improve local control in patients with a small number of lesions. The aim of this study was to examine the outcomes of patients with 1 to 4 melanoma brain metastases treated with SRS with or without WBRT. Exempt review was granted by our cancer hospital institutional review board for the collection of data of patients with melanoma brain metastases treated with Gamma Knife (GK)-based SRS in our department. All patients were then deidentified before data analysis. In the period of 2000 to 2007, a total of 32 patients (17 male and 15 female) with 1-4 brain metastases from melanoma primary (59 lesions) were treated with SRS. The median age was 55 years (range: 27 - 81). The median KPS was 90 (range: 70 - 100). Distribution of number of lesions was as follows: one lesion in 18 patients; 2 lesions in 5 patients; 3 lesions in 5 patients; 4 lesions in 4 patients. Distribution of RTOG recursive partitioning analysis (RPA) classes was as follows: RPA I - 1 patient, RPA II - 31 patients. Twenty-eight patients received systemic therapy and 4 had control of their extracranial disease. Nine patients received WBRT. Median follow up for patients was 6.1 months (range: 1.3 to 30.9 months). The median marginal dose to the lesions was 20 Gy (range: 15-22 Gy) delivered to the 50 % isodose line. The cumulative treatment volume ranged from 0.587 to 27.41 cm3 (median: 4.3 cm3). Eighteen patients (56.3%) developed distant brain failure. The 3-, 6-, 9-, 12-, and 18-month local control (LC) rates were 77%, 70.4%, 53.6%, 53.6% and 53.6% respectively. The corresponding freedom-from-local progression (FFLP) rates were 77.7%, 69.5%, 56.9%, 56.9% and 56.9%. The corresponding free-from-distant-brain failure (FFDBF) rates were 71.7%, 47.5%, 36.9%, 36.9% and 27.7%. The corresponding progression free survival (PFS) rates were 53.1%, 31.3%, 24.3%, 17.4% and 13%. The corresponding overall survival (OS) rates were 81.3%, 55.4%, 44.5%, 26% and 21.6%. The addition of WBRT did not impact on LC, FFLP, FFDBF, PFS or OS. The number of lesions (1 vs. 2-4) did not impact on FFDBF, PFS, or OS. SRS did yield fair LC and FFLP in patients with 1 to 4 brain metastases from melanoma. However, there was a high incidence of distant brain failure (56.3%) and OS remained poor (26% at 12 months). The addition of WBRT did not significantly impact any of the endpoints examined. Intracranial disease burden in terms of number of metastases (1 versus 2-4) did not appear to affect FFDBF, PFS, or OS.