Therapy of meningeal melanocytomas

Meningeal melanocytomas are rare, benign central nervous system lesions with a high probability of recurrence. To the authors' knowledge, approximately 100 cases have been reported since 1972, when the entity first was described. In the current study, four therapies were compared with regard to local control and survival to identify which is best.

All reported cases were reviewed with regard to extent of resection, radiotherapy, local control, and survival. If published data were incomplete, the authors were contacted for additional data. Patients were categorized by therapy: complete resection (CTR), complete resection followed by radiotherapy (CTR-RT), incomplete resection (ITR), and incomplete resection followed by radiotherapy (ITR-RT). Local control and survival were calculated using the Kaplan-Meier method. A multivariate analysis was performed including age, gender, tumor location, confirmation of extent of resection, and treatment schedule.

A total of 89 patients were included: 46 with CTR, 3 with CTR-RT, 23 with ITR, and 17 with ITR-RT. The 5-year local control rate was 80% after CTR, 100% after CTR-RT, and 72% after ITR-RT versus 18% after ITR (P < 0.001). The 5-year survival rate was 100% after CTR, CTR-RT, and ITR-RT, respectively, versus 46% after ITR (P < 0.001). Multivariate analysis demonstrated that therapy was the only variable that affected local control and survival significantly. In 14 patients treated with ITR-RT, RT was restricted to the tumor region. The radiation dose was 30-40 grays (Gy) in 6 patients, 45-55 Gy in 7 patients, and unknown in 1 patient. The 5-year local control rate was 86% after a dose of 45-55 Gy versus 27% after a dose of 30-40 Gy (P = 0.1).

CTR was found to be significantly superior to ITR with regard to both local control and survival. Outcome was significantly improved by RT after ITR. Doses of 45-55 Gy appeared to be more beneficial than doses of < or = 40 Gy.