BACKGROUND AND PURPOSE: To optimize and reduce the toxicity of pituitary adenoma irradiation, we evaluated the feasibility and effectiveness of fractionated stereotactic radiotherapy (FSR) in 51 patients with functional adenoma; 12 of them had Cushing's disease. PATIENTS AND METHODS: Eleven females and one male, median age: 49 years, 8 of them relapsed and 4 had persistent hormonal secretion after surgery. The delivered dose was 50 grays (Gy) (5 x 1.8 Gy/week) using 5 convergent micro-beams scanning in arc therapy mode. The median planned target volume (PTV) receiving 90 to 100% of the total dose was 2,1 cm(3). We used relocatable non-invasive stereotactic device Brain Lab, and adapted Linac for stereotactic radiotherapy. RESULTS: Nine out of twelve patients (75%) presented with complete remission after a median time of 29 months, 3/12 patients with partial remission. Actuarial probability to have hormonal persistent secretion was 88% at on year, 44% from 3 to 5 years, 22% at 7 years, and 11% to 0% after 7 years. The 12-corticotroph adenomas were significantly (p=0.007) more radiosensitive than 39 non-corticotroph adenomas. Toxicity was significantly lower for corticotrope adenoma, with no radio-induced pituitary deficiency and no neurological or optic injury. CONCLUSIONS: Combined surgery and FSR appears to be safe and effective for treatment of pituitary adenomas. However, long-term follow-up is required to determine the impact in terms of tumor response and hormone deficiency. The focused treated volume obtained by FSR seems more suitable for these benign tumours than standard radiotherapy. In addition to this conformal approach, the use of standard fractionation reduced the risk of severe damage to the optic chiasma, which is sometimes observed after radiosurgery and is inherent in single fraction radiotherapy.
BACKGROUND AND PURPOSE: To optimize and reduce the toxicity of pituitary adenoma irradiation, we evaluated the feasibility and effectiveness of fractionated stereotactic radiotherapy (FSR) in 51 patients with functional adenoma; 12 of them had Cushing's disease. PATIENTS AND METHODS: Eleven females and one male, median age: 49 years, 8 of them relapsed and 4 had persistent hormonal secretion after surgery. The delivered dose was 50 grays (Gy) (5 x 1.8 Gy/week) using 5 convergent micro-beams scanning in arc therapy mode. The median planned target volume (PTV) receiving 90 to 100% of the total dose was 2,1 cm(3). We used relocatable non-invasive stereotactic device Brain Lab, and adapted Linac for stereotactic radiotherapy. RESULTS: Nine out of twelve patients (75%) presented with complete remission after a median time of 29 months, 3/12 patients with partial remission. Actuarial probability to have hormonal persistent secretion was 88% at on year, 44% from 3 to 5 years, 22% at 7 years, and 11% to 0% after 7 years. The 12-corticotrophadenomas were significantly (p=0.007) more radiosensitive than 39 non-corticotroph adenomas. Toxicity was significantly lower for corticotrope adenoma, with no radio-induced pituitary deficiency and no neurological or optic injury. CONCLUSIONS: Combined surgery and FSR appears to be safe and effective for treatment of pituitary adenomas. However, long-term follow-up is required to determine the impact in terms of tumor response and hormone deficiency. The focused treated volume obtained by FSR seems more suitable for these benign tumours than standard radiotherapy. In addition to this conformal approach, the use of standard fractionation reduced the risk of severe damage to the optic chiasma, which is sometimes observed after radiosurgery and is inherent in single fraction radiotherapy.