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 P-32 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 P-32 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 32 P-labeled chromic phosphate was 73%(16 of 22 cysts). The mean SD survival after intracavitary irradiation was 25.4 +/- 6.8 (95% Cl: 12.0-38.7) months. Conclusion: Intracavitary irradiation using P-32 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.