yttrium-silicate and Brain-Neoplasms

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.

Topics: Adolescent; Aged; Brain Neoplasms; Child; Child, Preschool; Colloids; Craniopharyngioma; Female; Humans; Infant; Male; Middle Aged; Silicates; Silicic Acid; Silicon Dioxide; Stereotaxic Techniques; Yttrium; Yttrium Radioisotopes

20 patients suffering from cystic craniopharyngioma were treated with intracavitary irradiation on 25 occasions. The beta emitting radionuclide 90Y silicate colloid was instilled into the cyst or cystic part of the tumour. 17 patients on 22 occasions underwent follow-up CT and ophthalmological examinations 1 to 144 (average: 34) months after the intracavitary radioisotope therapy. An 23 occasions there was an average of 82 to 90% volume decrease of the craniopharyngioma cysts. On two occasions the volume has remained unchanged and the result of the 90Y therapy cannot be evaluated yet. The neuroophthalmological prognosis was good only when a relatively intact optic disc was seen; when the disc was atrophic the visual deterioration proved to be irreversible. Pathologically, it is the fibrotic tissue that is responsible for the shrinkage of the cyst.

Topics: Brain Neoplasms; Colloids; Craniopharyngioma; Female; Humans; Male; Silicates; Silicic Acid; Silicon Dioxide; Vision Disorders; Yttrium; Yttrium Radioisotopes