Results of a randomized comparison of radiotherapy and bromodeoxyuridine with radiotherapy alone for brain metastases: report of RTOG trial 89-05.

To determine if the addition of bromodeoxyuridine (BrdUrd) to radiotherapy prolongs survival when compared to radiotherapy alone in patients with brain metastases. Seventy-two patients with brain metastases were randomized to 37.5 Gy in 15 fractions of 2.5 Gy or to the same dose with BrdUrd 0.8 g/m2 per day for 4 days of each of 3 weeks. Drug treatment was begun on Thursday or Friday before the first week of radiotherapy. Patients had a Karnofsky performance score of at least 70, a neurological function classification of 1 or 2, and any primary tumor except central nervous system (CNS), leukemia, or lymphoma. The primary was absent, controlled, or under active radiotherapy. Patients were free of other metastases. They were stratified by primary site (breast, lung or other), number of metastases (single or multiple) and age (< 60 vs. > 60). There was no significant difference between the two treatment arms (p = 0.904). The study was open from October 1989 to March 1993 and accrued 72 patients. Only one patient in the RT only arm remains alive. The two treatment arms were balanced with respect to all stratification variables. Toxicity due to radiotherapy was similar in both arms. BrdUrd caused significant Grade 4 and 5 hematologic and skin toxicity in five patients. Two patients died due to hematologic toxicity and one from a Stevens-Johnson type skin reaction. Phenytoin played a role in the skin reactions and ranitidine was associated with the hematologic deaths. Ranitidine was eliminated, BrdUrd was discontinued after any hematologic toxicity, and no further Grade 4 or 5 toxicities were seen. The median survival was 6.12 months in the radiotherapy group and 4.3 in the BrdUrd group (p = 0.904). Patients with solitary brain metastases had significantly better survival (p = 0.031). BrdUrd did not enhance the efficacy of the radiotherapy regimen tested, in spite of the fact that brain metastases have shown high labeling indices. The toxicity of this schedule of BrdUrd administration was apparently increased by ranitidine and phenytoin.