[Radiation therapy for brain metastases from lung carcinoma: the second prospective randomized trial]

Since September 1980 we have been conducting a prospective randomized trial to determine the best treatment schedule for radiation therapy (XRT) of brain metastasis from lung carcinoma. The first trial (September 1980 to December 1984) used random allocation of two different time-dose radiotherapy schemes: 30 Gy/10 fractions/2 weeks versus 50 Gy/20 fr./4 wks. Treatment results showed no significant difference in neurological improvement or survival between the two arms or in lactate dehydrogenase (LDH) as the most important prognostic factor. The current study (January 1985 to April 1992) examined two sequential trials stratified according to the level of LDH and included 162 patients with brain metastasis from lung carcinoma. Whole brain doses were 30 Gy/10 fr./2 wks (group A, n = 46) or 50 Gy/20 fr./4 wks. (group B, n = 46) in the normal LDH group and 30 Gy/10 fr./2 wks (group C, n = 35) or 20 Gy/5 fr./1 wk. (group D, n = 35) in the high LDH group, while the treatment field was lessened to 30 Gy in group B if possible. The final results showed that 1) the most important prognostic factor as determined by Cox's multivariate analysis was also LDH in the second trial; 2) the incidence of acute side effects tended to depend upon a single dose, i.e., group A (3 Gy) 35% versus group B (2.5 Gy) 21% (p = 0.165), and group C (3 Gy) 23% versus group D (4 Gy) 46% (p = 0.044); 3) median survival time and 1-year survival rates were 5.4 months and 21% in group A, 4.8 months and 17% in group B; 3.4 months and 6% in group C; and 2.4 months and 4% in group D, respectively, and survival curves showed no statistically significant difference between the two treatment groups in each LDH group; 4) improvement in neurological function appeared to increase with total dosage escalation, i.e., 41% in group A versus 45% in group B, and 35% in group C versus 21% in group D (not significant). In conclusion, a short intensive course (30 Gy/10 fr./2 wks) is advantageous for XRT because of the short treatment time and minor acute toxicity in spite of stratification by the level of LDH.