LOW-DOSE ELECTIVE BRAIN IRRADIATION IN SMALL CELL-CARCINOMA OF THE LUNG

Elective brain irradiation (EBI) in a dosage of 3000 rad (midplane) in 2 weeks (nominal standard dose (NSD) = 1314 ret) has proven highly effective in preventing initial brain relapse in small cell lung carcinoma. However, the optimal radiation dose for EBI is unknown. 55 patients (31 with regional disease, 24 with extensive disease) without brain metastases were treated with a 4 drug chemotherapy program, (lomustine (CCNU), methotrexate, cyclophosphamide, vincristine) plus radiotherapy (R.T.), 3000 rad in 2 weeks to the primary chest lesion and were randomized to EBI or a control group. The EBI consisted of 2400 rad whole brain, midplane, in 8 fractions, 10 days (NSD = 1130 ret) given at the same time as the R. T. to the primary (3 weeks post-initial chemotherapy). Though all 54 evaluable patients received CCNU 50 Mg/M2 q. 6 weeks, there were 5 initial brain relapses among 31 control patients (16%) vs none in the 23 EBI patients. The time at risk for recurrence was similar in the two groups, i.e. 31 weeks median in the EBI and 32 weeks in the no-EBI patients. Brain relapses occurred in 2/17 with limited disease and 3/14 with extensive disease. It appears that 2400 rad in 8 fractions is as effective for EBI as larger doses. Toxicity was limited to alopecia. Survival was not significantly affected by EBI, though there is a suggestion of improvement in the regional group. © 1979.