title: Long-term results of hypofractionated stereotactic radiotherapy with CyberKnife for growth hormone-secreting pituitary adenoma: evaluation by the Cortina consensus.
abstract: The aim of the present study was to evaluate the safety and feasibility of hypofractionated stereotactic radiotherapy (SRT) with CyberKnife for growth hormone-secreting pituitary adenoma (GH-PA). Fifty-two patients with GH-PA were treated with hypofractionated SRT between September 2001 and October 2012. Eight patients had clinically silent GH-PA and 44 were symptomatic. Only 1 patient was inoperable. The other patients had recurrent or postoperative residual tumors on MRI. All patients had received pharmacotherapy prior to SRT with a somatostatin analog, dopamine agonist, and/or GH receptor antagonist. The marginal doses were 17.4-26.8 Gy for the 3-fraction schedule and 20.0-32.0 Gy for the 5-fraction schedule. Endocrinological remission was assessed by the Cortina consensus criteria 2010 (random GH <1 ng/ml or nadir GH after an oral glucose tolerance test <0.4 ng/ml and normalization of age- and sex-adjusted insulin-like growth factor-1). The median follow-up period was 60 months (range 27-137). The 5-year overall survival, local control, and disease-free survival rates were 100, 100, and 96 %, respectively. Nine patients (5 clinically silent and 4 symptomatic patients) satisfied the Cortina criteria without receiving further pharmacotherapy, whereas the remaining 43 patients did not. No post-SRT grade 2 or higher visual disorder occurred. Symptomatic post-SRT hypopituitarism was observed in 1 patient. CyberKnife hypofractionated SRT is safe and effective when judged by imaging findings for GH-PA. However, it may be difficult to satisfy the Cortina consensus criteria in most symptomatic patients with SRT alone. Further investigations of optimal treatments are warranted.
authors.affiliation: Department of Radiation Oncology, Nagoya Proton Therapy Center, Nagoya City West Medical Center, 1-1-1, Hirate-cho, Kita-ku, Nagoya, 462-8508, Japan. h-iwa-ncu@nifty.com.|Department of Neurosurgery, Yokohama CyberKnife Center, Yokohama, Japan. h-iwa-ncu@nifty.com.
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Iwata
authors.affiliation: Department of Neurosurgery, CyberKnife Center, Japanese Red Cross Medical Center, Tokyo, Japan.
authors.forename: Kengo
authors.initials: K
authors.lastname: Sato
authors.affiliation: Department of Neurosurgery, CyberKnife Center, Japanese Red Cross Medical Center, Tokyo, Japan.
authors.forename: Ryutaro
authors.initials: R
authors.lastname: Nomura
authors.affiliation: Department of Neurosurgery, CyberKnife Center, Japanese Red Cross Medical Center, Tokyo, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Tabei
authors.affiliation: Department of Neurosurgery, CyberKnife Center, Japanese Red Cross Medical Center, Tokyo, Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Suzuki
authors.affiliation: Department of Neurosurgery, Yokohama CyberKnife Center, Yokohama, Japan.|Radiation Oncology Center, Suzukake Central Hospital, Hamamatsu, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Yokota
authors.affiliation: Division of Quality Management with Radiotherapy, Yokohama CyberKnife Center, Yokohama, Japan.
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Inoue
authors.affiliation: Department of Neurosurgery, Yokohama CyberKnife Center, Yokohama, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Ohta
authors.affiliation: Department of Hypothalamic and Pituitary Surgery, Toranomon Hospital, Tokyo, Japan.
authors.forename: Shozo
authors.initials: S
authors.lastname: Yamada
authors.affiliation: Department of Radiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
authors.forename: Yuta
authors.initials: Y
authors.lastname: Shibamoto
mesh_terms: D000236:Adenoma / Q000378:metabolism / Q000532:radiotherapy*; D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D049912:Growth Hormone-Secreting Pituitary Adenoma / Q000378:metabolism / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D016634:Radiosurgery / Q000379:methods; D011879:Radiotherapy Dosage; D016019:Survival Analysis; D016896:Treatment Outcome; D055815:Young Adult
keywords: Cortina consensus; CyberKnife; Growth hormone-secreting pituitary adenoma; Hypofractionated stereotactic radiotherapy; Optic pathway