Cystic craniopharyngioma: long-term results after intracavitary irradiation with stereotactically applied colloidal beta-emitting radioactive sources.

OBJECTIVE: Long-term follow-up data were analyzed to assess the value of intracavitary irradiation with stereotactically applied beta-emitting radioisotopes for the treatment of craniopharyngioma cysts. METHODS: Sixty-two of 70 consecutive patients with predominantly cystic craniopharyngiomas were selected for retrospective analysis. Beta-Emitting isotopes were injected intracystically using a computed tomography-guided and computer-assisted three-dimensional stereotactic treatment planning and application system (cumulative dose to the inner surface of the cyst wall, 200 Gy). RESULTS: The tumor response rate gained with yttrium-90-labeled silicate (66 of 78 cysts) or phosphorous-32-labeled chromic phosphate (8 of 78 cysts) was 79.5%. Four cysts treated with rhenium-186-labeled sulfate did not respond. Mean survival after intracavitary irradiation was 9.0 +/- 0.9 years (median follow-up, 11.9 yr). In patients with solitary cysts, the mean survival was 12.5 +/- 1.4 years (actuarial 5- and 10-yr survival rates, 80 and 64%, respectively). Six months postoperatively, visual deficits (38 of 62 patients) had improved in 23 patients and were stable in 15 patients. The side effects that occurred 6 to 12 months after treatment with yttrium-90 were complete blindness (three patients), worsening of visual field cuts (one patient), third nerve palsy (one patient), and diabetes insipidus and/or panhypopituitarism (three patients). CONCLUSIONS: Intracavitary irradiation using yttrium-90 or phosphorous-32 is highly effective in the treatment of cystic craniopharyngiomas. If applied as initial treatment in patients with solitary cysts, it is the only required therapy over a long period.

Intracavitary treatment of intrasellar cystic craniopharyngeomas with 90-Yttrium by trans-sphenoidal approach--a technical note.

Intracavitary irradiation of intrasellar cystic craniopharyngeomas by stereotactic cyst puncture and injection of radioactive solutions is not yet possible. Therefore we designed a new method which allows such intracavitary irradiation. Its principle is a transphenoidal approach with only a small bony opening of the sella floor, followed by cyst puncture, exclusion of cyst leakage by Metrizamid injection under x-ray control, injection of Y-90-colloid solution at a dosage which delivers a radiation of 200 Gy to the cyst wall, and finally tight closure of the puncture site using fibrin glue and gelfoam. This method has been used in three patients with good results (follow-up 12-15 months) and without complications. Even though long-term follow-up is not yet available, our preliminary results suggest that this method will be useful for future patients with intrasellar cystic craniopharyngeomas.

Advances in radiation therapy for craniopharyngiomas.

The overall survival for patients with craniopharyngioma is excellent. However, conventional treatments that include aggressive surgery and standard irradiation have been associated with significant morbidity. Focal radiation treatment with stereotactic radiosurgery has a role in selected cases, but may also be damaging to sensitive normal tissues such as the optic chiasm. Stereotactic radiotherapy (SRT) is a technique that allows for conventionally fractionated radiation under stereotactic guidance. Thus, highly focal and precise radiotherapy is now coupled with fractionation, enabling the treatment of selected tumors with a potentially improved therapeutic index. Dose optimization with SRT for focally discrete tumors should result in equivalent local control and survival compared to patients treated with conventional irradiation. We anticipate a significant decrease in late effects, especially neuropsychological and neuroendocrine sequelae.

Stereotactic internal irradiation for cystic craniopharyngiomas: a 6-year experience.

Fourteen adults and 4 children with cystic craniopharyngiomas were treated with stereotactic beta-irradiation during a 6-year period. Of these patients, 10 were primary cases, and 8 were recurrences after previous major surgery. Radioactive phosphorus (32P) or yttrium (90Y) in colloidal forms were used as the radiation agents. Cyst volumes (10-130 ml) were assessed intraoperatively by the 99Tc radiodilution method. According to our treatment program, the radiation dose to the cyst wall was 20,000 rad and the total irradiation time 2 weeks. The follow-up period ranged from 1 to 6 years, with an average of 3.8 years. Postoperative shrinkage of the cysts and clinical improvement were observed in most patients. Pertinent clinical data and results of treatment are described.