The role of hyperfractionated re-irradiation in metastatic brain disease: a single institutional trial.

Progression of brain metastases after brain irradiation has prompted several studies on retreatment of the brain. Increased durations of survival and improved quality of life have been reported. Fifteen patients with previously treated brain metastases were entered into this pilot study between May 1990 and January 1994. All patients had neurologic and/or radiologic evidence of progression of brain metastases. The lung was the primary site in 60% of cases. The remaining 40% had breast, ovarian, and skin primaries. The median interval between the first treatment and retreatment was 10 months. All patients received whole-brain irradiation with or without a boost for their initial treatment course. Doses ranged from 3,000 to 5,500 cGy for initial treatments (median, 3,000). Retreatment consisted of limited fields with a median side equivalent square of 8.8 cm. Patients were retreated with a median dose of 3,000 cGy (range, 600-3,000 cGy). A median cumulative dose of 6,000 cGy was achieved. Retreatment consisted of twice-daily fractions (150 cGy/fraction). Retreatment was tolerated without serious complications. Of the 15 patients treated, nine (60%) experienced improvement, and five (27%) had stabilization of neurologic function and/or radiographic parameters. Median survival was 3.2 months; two of the re-irradiated patients survived greater than or equal to 9 months. In conclusion, reirradiation is a viable option in patients with recurrent metastatic lesions of the brain, and the use of a limited retreatment volume makes this a well-tolerated, low-morbidity treatment that leads to clinical benefits and, in some instances, enhanced survival. The influence of hyperfractionation on the outcome needs to be investigated further in large series.