Intracystic irradiation for craniopharyngiomas.

Data collected over a 36-year period were used to assess the value of stereotactically applied intracystic colloidal yttrium-90 (YTx) for the treatment of recurrent cystic craniopharyngiomas (CRF's). The article compares data from 95 YTx procedures carried out on 78 patients during the years 1975 and 2011, using a cumulative beta dose of 270 Gy aimed at the inner surface of the cyst wall. After YTx, the initial cyst volumes decreased an average of 74.7 %. In 54 patients, the volume reduction exceeded 80 %. In 32 patients, the cyst disappeared completely within one year. The mean survival rate following YTx was 7.5 years (range 0.7-31 years). The survival rates at 5, 10, 15, 20, 25, and 30 years were 56, 29, 15, 8, 3, and 1 %, respectively. Late complications of YTx were related to the anatomical location of the cyst, either presellar or retrosellar. A presellar, that is, prechiasmatic/suprasellar localization resulted in neuro-ophthalmological complications in 5.1 % of the cases, while internal carotid artery injury accounted for 1.4 % of the complications. The treatment of retrosellar (retrochiasmatic, suprasellar) tumors may cause hypothalamic, fornix, or pontomesencephalothalamic damage, from untoward radiation to the so-called perforating arteries. This complication occurred in 5.2 % of the cases. In the multimodality management of craniopharyngioma cysts, intracavity YTx irradiation is a valuable treatment alternative despite sporadic complications arising in some surgical cases. The formula for the calculation of the dynamics of reduction of CRF's following yttrium-90 colloid brachytherapy was supported by correlating the collected data. The focus was on our minimally invasive YTx following multiple surgeries of cystic CRFs.