Linear accelerator radiosurgery for pituitary macroadenomas: a 7-year follow-up study.
BACKGROUND
A prospective study was conducted to assess the efficacy and side effects of linear accelerator (LINAC)-based radiosurgery (RS) performed with a reduced dose of therapeutic radiation for patients with surgically inaccessible pituitary macroadenomas.


METHODS
From August 1990 through January 2004, 175 patients with pituitary macroadenomas were treated with LINAC-RS according to a prospective protocol. To minimize the risk for radiation-induced damage of the pituitary function, the therapeutic dose to be applied was limited to 20 grays.


RESULTS
Among 175 patients, 142 patients who had a minimum follow-up of 12 months (mean +/- standard deviation, 81.9 +/- 37.2 months) were included in the current study. The local tumor control rate was 96.5%, and the tumor response rate was 32.4%. The mean time (+/- standard deviation) from LINAC-RS to normalization of pathologic hormone secretion was 36.2 +/- 24.0 months. The probability for normalization was 34.3% at 3 years and 51.1% at 5 years. The frequency of endocrine cure (defined as the normalization of hormone secretion without specific medication intake) was 35.2% (mean +/- standard deviation time to cure, 42.1 +/- 25.0 months). Patients with Cushing disease had a statistically significant greater chance of achieving a cure (P = .001). Side effects of LINAC-RS were deterioration of anterior pituitary function (12.3%), radiation-induced tissue damage (2.8%), and radiation-induced neuropathy (1.4%).


CONCLUSIONS
LINAC-RS using a lower therapeutic radiation dose achieved local tumor control and normalization or cure of hormone secretion comparable to the results achieved with gamma-knife RS. Compared with the latter, the time to normalization or endocrine cure was delayed, most probably as a result of dose reduction. However, the lower therapeutic radiation dose did not prevent radiation-induced damage of pituitary function completely.
Voges
Juergen
J
Department of Stereotaxy and Functional Neurosurgery, University of Cologne, Cologne, Germany. j.voges@uni-koeln.de
Kocher
Martin
M
Runge
Matthias
M
Poggenborg
Jorg
J
Lehrke
Ralph
R
Lenartz
Doris
D
Maarouf
Mohammad
M
Gouni-Berthold
Ioanna
I
Krone
Wilhelm
W
Muller
Rolf-Peter
RP
Sturm
Volker
V
D000236:Adenoma / Q000378:metabolism / Q000503:physiopathology / Q000601:surgery*; D000293:Adolescent; D000324:Adrenocorticotropic Hormone / Q000378:metabolism; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D005260:Female; D005500:Follow-Up Studies; D013006:Growth Hormone / Q000378:metabolism; D006801:Humans; D007018:Hypopituitarism / Q000209:etiology; D008297:Male; D008875:Middle Aged; D010902:Pituitary Gland / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D010911:Pituitary Neoplasms / Q000378:metabolism / Q000601:surgery*; D011388:Prolactin / Q000378:metabolism; D011446:Prospective Studies; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods*; D013997:Time Factors; D016896:Treatment Outcome
D000324:Adrenocorticotropic Hormone; D011388:Prolactin; D013006:Growth Hormone