Interstitial irradiation for craniopharyngioma

The results of interstitial irradiation treatment for craniopharyngioma in two patients with six year follow-ups are presented. Stereotactic interstit ial irradiation with Iodine-125 sources as sole therapy was employed in two adult patients who refused surgical resection. The diagnoses were confirme d by stereotactic biopsy. The first tumour which underwent interstitial irr adiation was solid and 4 cm in diameter, and the second, 2.7 cm in diameter , had both cystic and solid components. The implanted Iodine-125 seeds deli vered 67 Gy and 60 Gy to tumour periphery at the rate of 12 and 14 cGy/ h, respectively, were removed at the end of designated radiation periods. Tumo ur shrinkage and central hypodensity, first observed 3 months after irradia tion, continued until one tumour shrank to less than 1 cm at 12 months, and the other disappeared completely at 24 months. In both cases functional in tegrity was restored, and neither radiation induced toxicity nor recurrence has occurred six years after treatment. The results in these two cases sug gest that solid craniopharyngiomas are sensitive to interstitial irradiatio n.