The purpose of GKRS, in the case of secretory pituitary adenomas, is to control
tumor growth and normalize endocrinological hypersecretion. Secretory adenomas seem to require a higher radiation dose than nonfunctioning pituitary adenomas. Ganz suggested that the effective dose for secretory adenomas should be higher than 25 Gy according to the details. Laws and Vance estimated that a higher percentage of control of hyper-functioning syndromes could be accomplished with the higher margin dose. The lowest effective radiation dose in our study was 12 Gy delivered to the tumor margin; the mean marginal dose was 22.2 Gy. According to our experience, the suitable margin dose should depend on the endocrinological type of the secretory pituitary adenoma. However, Selumetinib supplier the Selleck PD0325901 recent report of Pollock buy 8-Bromo-cAMP for functioning adenomas revealed the radiation dose was not related to endocrinological outcome. In nearly all published series, stereotactic radiosurgery afforded excellent control of tumor growth. Hayashi reported that the tumor control rate for pituitary adenoma after GKRS was between 93% and 94%, and that the tumor shrinkage rate ranged from 46% to 56.7%. Many studies reported a greater
than 95% control of tumor size with follow-up varying from months to years[18, 19]. Some series have even demonstrated improvement in visual function following radiosurgery upon shrinkage of the tumor. Most
pituitary adenomas tend to be slow growing lesions. As such, it may be misleading to evaluate series of patients with relatively short follow-up. In our previous study, the effects of MASEP GKRS may get stable within three years after the treatment, and this study shows concordant results within the follow-up more than 5 years. At the time when GKRS started, the results of microsurgery were disappointing regarding ACTH-producing pituitary adenomas and the role of GKRS as primary therapy was evaluated. We have not seen any recurrences after MASEP GKRS in patients who through obtained remission in contrast to pituitary microsurgery with progressive increase of recurrences of Cushing’s syndrome with time. Cushing’s disease is a serious catabolic illness that requires rapid normalization of cortisol hypersecretion. Thus pituitary microsurgery is the primary treatment for Cushing’s disease; gamma knife surgery can be applied when open surgery is contraindicated or refused or as a secondary treatment when open surgery has failed or the tumor extends into the cavernous sinuses. Many series utilized the 24 h urine cortisol collection as part of the criteria for endocrinological evaluation, and the endocrinological’cure’rates ranged from 17 to 83%[20, 21].