Management of Cystic Craniopharyngiomas with Intracavitary Irradiation with 32P

Background: Cystic craniopharyngiomas are the most frequent intracranial neoplasm of nonglial origin in children. Follow-up data were analyzed to assess the value of intracavitary irradiation with stereotactically applied 32P radioisotopes for the treatment of patients with craniopharyngioma cysts admitted to Shohada Tajrish Hospital, Tehran, Iran, between 1998 and 2005. Methods: Patients with predominantly cystic craniopharyngiomas, who underwent stereotactic intracavitary irradiation, were followed for tumor response and complications. Beta-emitting 32P isotopes were injected into cysts using a computed tomography-guided and computer-assisted three-dimensional stereotactic treatment planning and application system. The cumulative dose to the inner surface of the cyst wall was 250 Gy. Results: Twenty-two (12 females and 10 males) patients with a mean±SD age of 14.0±6.6 (range: six to 35) years were studied. The tumor response rate gained with 32P-labeled chromic phosphate was 73% (16 of 22 cysts). The mean±SD survival after intracavitary irradiation was 25.4±6.8 (95% CI: 12.0 – 38.7) months. Conclusion: Intracavitary irradiation using 32P is highly effective in the treatment of cystic craniopharyngiomas. In patients with solitary cyst treated exclusively with this method, it has been the only necessary therapy over a long period. It seems reasonable to recommend intracavitary irradiation as the initial treatment for selected patients and as palliative therapy in those with recurrence.