Cystic craniopharyngioma treated by 90yttrium silicate colloid

Fourteen children and 3 adults with cystic craniopharyngiomas were treated with intracavitary 90Y, by the procedure described by Backlund. Their ages ranged from 2 to 65 years and postoperative follow-up ranged from 6 to 40 months. Leksell's stereotactic technique was employed to determine coordinates by CAT. Cyst volume was quantified both geometrically and isotopically with 99Tc, values differing by 7%. Dosimetry was determined by applying the formula developed by Loevinger et al., and 20,000 rads were administered throughout to the cystic wall. All 17 patients, except for 4 children, had previously received surgery, shunts or radiotherapy, alone or combined. In 4 cases, 90Y injection was the only treatment, while in 6, the cyst was evacuated at 10 days following radiocolloid injection. Skull and spinal column gamma chamber studies were carried out on all patients at 24, 48, and 72 hours post injection, but no isotope leakage could be detected. The patients returned to normal activities except one with multiple cysts who died. There were no changes in the endocrinologic profile. In one case, a decrease in visual acuity 18 months after treatment, improved following corticoid administration.

Though preliminary, these results are encouraging since it seems that the severe neuro-endocrinologic sequelae of open surgery may be avoided.