Treatment of cystic craniopharyngioma with phosphorus-32 intracavitary irradiation

Abstract

Purpose: The aim of the study was to evaluate the effect of phosphorus-32 colloid ([(32)P]) intracavitary irradiation on the treatment of patients with cystic craniopharyngiomas.

Methods: Twenty patients with predominantly cystic craniopharyngiomas were admitted from 1981 to 2006. Eleven patients had [(32)P] intracavitary irradiation by stereotactic injection or Ommaya cyst instillation as the primary treatment, and the remaining nine had the same internal irradiation as an adjuvant treatment after tumor resection. A calculated irradiation dose of 400 approximately 500 Gy per once was delivered to the cyst wall.

Conclusion: The patients were followed up ranging from 36 to 336 months; no operative morbidity or mortality was found from [(32)P] intracavitary irradiation. Fourteen patients (70%) had tumor progression and required further two to four times intracavitary irradiation. All 20 cases achieved tumor shrinkage or stabilization with effective outcome 3-6 months after the last [(32)P] therapy. For patients with cystic craniopharyngioma, [(32)P] administration by stereotactic injection or Ommaya cyst instillation is a safe and helpful option, which could improve the life quality, prolong the life span, and enhance the survival rate of cystic craniopharyngioma patients.

Fig. 1

Pattern of Ommaya reservoir system

Fig. 2

Case 2: MRI of cystic craniopharyngioma in a 5-year-old boy before (a cyst diameter≈3.8 cm) and after (b cyst diameter≈1.2 cm) [³²P] treatment

Fig. 3

Case 3: MRI of cystic craniopharyngioma in a 1.7-year-old boy before (a cyst diameter≈4.4 cm) and after (b cyst diameter≈1.5 cm) [³²P] treatment

Fig. 4

Case 2: The bremsstrahlung scanning of cystic craniopharyngioma in a 5-year-old boy treated with intracavitary [³²P] in intervals up to the third day of postinstillation: It is never presented the bremsstrahlung image outside the target cyst