Twice-daily prophylactic cranial irradiation for patients with limited disease small-cell lung cancer with complete response to chemotherapy and consolidative radiotherapy - Report of a single institutional phase II trial

Prophylactic cranial irradiation (PCI) has been demonstrated to significant ly reduce the incidence of brain relapse from limited disease small-cell lu ng cancer (LD SCLC), but concerns about neurologic toxicity remain. The pur pose of this report was to update a phase II institutional trial that explo red the impact of twice-daily PCI on neurologic toxicity as well as outcome for this group of patients. All eligible subjects had documented complete response to induction chemotherapy and consolidative chest irradiation. The whole brain was treated with twice-daily fractions of 1.5 Gy with megavolt age Irradiation to an approximate total dose of 30.0-36.0 Gy. Although not devised as a randomized study, approximately half of the eligible patients declined the protocol enrollment of their own volition and were retrospecti vely evaluated as a "historical" control group regarding the incidence of b rain metastases. Fifteen patients accepted twice-daily PCI, with 12 deferri ng treatment. Median follow-up was 20 months. Disease-free survival at 2 ye ars was 54% with twice-daily PCI versus 0% without any PCI (p = 0.013). Ove rall survival at 2 years was 62% with twice-daily PCI versus 23% without PC I (p = 0.032). No statistically significant neurologic deterioration was de tected in the PCI group posttreatment. Thus, twice-dairy PCI should be cons idered for patients with LD SCLC who achieve a complete response to chemoir radiation. A multi-institutional randomized trial would be necessary before making definitive recommendations.