Stereotactic radiosurgery for recurrent surgically treated acromegaly: comparison with fractionated radiotherapy.
OBJECTIVE
The authors tested the assumption that gamma knife radiosurgery is more effective than fractionated radiotherapy for the treatment of patients with acromegaly who have undergone unsuccessful resective surgery. Untreated and uncured acromegaly causes illness and death. Acromegalic patients in whom growth hormone and, particularly, insulin-like growth factor I are not normalized must undergo further treatment.


METHODS
After unsuccessful operations, 16 patients suffering from recurrent and uncured acromegaly underwent stereotactic radiosurgery (25 Gy to the tumor margin, 50 Gy maximum), the outcome of which was compared with the result obtained in 50 patients who received fractionated radiotherapy (40 Gy). The cumulative distribution functions of the two groups (Kaplan-Meier estimate) differed significantly (p < 0.0001 in the log-rank test of Mantel). The mean time to simultaneous normalization of both parameters was 1.4 years in the group treated with the gamma knife and 7.1 years in the group treated with fractionated radiotherapy.


CONCLUSIONS
The authors suggest the use of stereotactic radiosurgery as the preferred treatment for recurrent acromegaly resulting from unsuccessfully resected tumors.
Landolt
A M
AM
Neurosurgery Department, Institute of Neuroradiology, Klinik Im Park, Zürich, Switzerland. 1000123.1666@compuserve.com
Haller
D
D
Lomax
N
N
Scheib
S
S
Schubiger
O
O
Siegfried
J
J
Wellis
G
G
D000172:Acromegaly / Q000188:drug therapy / Q000532:radiotherapy / Q000601:surgery*; D000236:Adenoma / Q000532:radiotherapy / Q000601:surgery; D000328:Adult; D000368:Aged; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use; D001971:Bromocriptine / Q000627:therapeutic use; D019583:Dose Fractionation, Radiation; D005260:Female; D005500:Follow-Up Studies; D006727:Hormone Antagonists / Q000627:therapeutic use; D019382:Human Growth Hormone / Q000037:antagonists & inhibitors / Q000097:blood; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000032:analysis / Q000037:antagonists & inhibitors; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015282:Octreotide / Q000627:therapeutic use; D010911:Pituitary Neoplasms / Q000532:radiotherapy / Q000601:surgery; D011832:Radiation Injuries / Q000209:etiology; D016634:Radiosurgery / Q000379:methods; D011879:Radiotherapy Dosage; D012008:Recurrence; D012086:Reoperation; D019233:Retreatment; D016896:Treatment Outcome
D018931:Antineoplastic Agents, Hormonal; D006727:Hormone Antagonists; D019382:Human Growth Hormone; D001971:Bromocriptine; D007334:Insulin-Like Growth Factor I; D015282:Octreotide