High-dose fraction radiation therapy for intracranial metastases of malignant melanoma: A comparison with low-dose fraction therapy

Publisher Website
Google Scholar
Abstract
Malignant melanoma is considered unresponsive to conventional radiation therapy when it is delivered at a daily dose rate of 130–300 rad/fraction. Previous studies have suggested that this is in part due to a large shoulder on the radiation survival curve and that higher dose fractions might be beneficial. High‐dose fraction therapy is effective for local control of cutaneous, lymph node, and soft‐tissue metastases. Results in 46 patients treated with high‐ or low‐dose fractions for intracranial metastases over the last decade in the Melanoma Unit and Department of Radiotherapy at Yale have been examined. Twenty‐six patients received high‐dose fraction therapy, generally 600 rad/fraction/week to 2400–3600 rad; 20 patients received low‐dose fraction radiotherapy with 125–400 rad/fraction daily. All patients were given steroids, and most received chemotherapy. Results in both groups were similar. Comparison of high‐ and low‐dose fraction patients revealed: improvement in 38 and 35%, respectively, stability in 23 and 25%, and deterioration in 38 and 40%. Median survival was three months in the high‐dose fraction group and 21/2 months in the low‐dose fraction group. Presence of hepatic metastases had no significant influence upon median survival in patients who received high‐dose fraction radiotherapy. In patients receiving low‐dose fraction, survival was 21/4 months with and three months without hepatic metastases. Death in most patients resulted from progression of central nervous system disease. Side effects, especially headache, were more prominent in the high‐dose fraction group. However, in no instance did side effects require discontinuation of therapy. The greater ease of delivery for weekly high‐dose fraction radiotherapy outweighed any other difference between the regimens.