title: Hypofractionated stereotactic radiotherapy with CyberKnife for nonfunctioning pituitary adenoma: high local control with low toxicity.
abstract: The aim was to evaluate the clinical outcome of hypofractionated stereotactic radiotherapy (SRT) with CyberKnife for nonfunctioning pituitary adenoma. From October 2000 to March 2009, 100 patients with nonfunctioning pituitary adenoma were treated with hypofractionated SRT. Forty-three patients were male, and 57 were female. The patient's ages ranged from 16 to 82 years (median, 59 years). Five patients were medically inoperable, and 1 refused surgery; the remaining 94 were recurrent cases or those receiving postoperative adjuvant SRT. No patients had a history of previous cranial radiotherapy. Tumor volume ranged from 0.7 to 64.3 mL (median, 5.1 mL). The marginal doses were 17.0 to 21.0 Gy for the 3-fraction schedule and 22.0 to 25.0 Gy for the 5-fraction schedule. Toxicities were evaluated with the Common Terminology Criteria for Adverse Events version 4.0. The median follow-up period for living patients was 33 months (range, 18-118.5 months). The 3-year overall survival and local control rates were 98% and 98%, respectively. In-field and out-field tumor regrowth were observed in 3 and 2 patients, respectively. Transient cyst enlargement occurred in 3 cases. A post-SRT grade 2 visual disorder occurred in 1 patient. Symptomatic post-SRT hypopituitarism was observed in 3 of 74 patients who had not received hormone replacement therapy after surgery. CyberKnife SRT involving 21 Gy in 3 fractions or 25 Gy in 5 fractions is safe and effective for surgical treatment of nonfunctioning pituitary adenoma. Hypofractionated SRT appears useful for protecting the visual nerve and neuroendocrine function, especially for tumors located near the optic pathways and large tumors.
authors.affiliation: Department of Radiology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan. h-iwa-ncu@nifty.com
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Iwata
authors.forename: Kengo
authors.initials: K
authors.lastname: Sato
authors.forename: Koshi
authors.initials: K
authors.lastname: Tatewaki
authors.forename: Naoki
authors.initials: N
authors.lastname: Yokota
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Inoue
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Baba
authors.forename: Yuta
authors.initials: Y
authors.lastname: Shibamoto
mesh_terms: D000236:Adenoma / Q000473:pathology / Q000601:surgery*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D019583:Dose Fractionation, Radiation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000473:pathology / Q000601:surgery*; D010911:Pituitary Neoplasms / Q000473:pathology / Q000601:surgery*; D011446:Prospective Studies; D016634:Radiosurgery; D015996:Survival Rate; D016896:Treatment Outcome; D055815:Young Adult