Total body bone mineral density (TBBMD) was measured by X-ray absorptiometry in 46 brain tumor patients aged from 3.8 to 28.7 years (mean 14.9 y) at a mean of 6.4 y (range 1.4-14.8 y) after end of treatment for brain tumor. Tumors were astrocytic, grade 1, in 25 patients. Tumors were resected in 45 and biopsied in 1. Eleven received chemotherapy. Radiotherapy was cranial in 10 and craniospinal in 5. One third of the patients had low TBBMD (z scores < -2.0). Only combined craniospinal irradiation was significantly associated with low z scores, while cranial irradiation showed a borderline statistical association. 
COMMENT. The cause of the osteoporosis among children treated for brain tumor is multifactorial, and includes craniospinal irradiation. Other possible factors are glucocorticoid treatment, motor handicaps, and impaired nutrition. Early identification could lead to effective therapy.