Treatment of pituitary adenomas by fractionated stereotactic radiotherapy: a prospective study of 110 patients.
OBJECTIVE
To optimize and reduce the toxicity of pituitary adenoma irradiation by assessing the feasibility and effectiveness of fractionated stereotactic radiotherapy (FSR).


METHODS
Between 1990 and 1999, 110 consecutive patients, 47 with a functioning adenoma, were treated according to a strategy of either early surgery and FSR (n = 89) or FSR only (n = 21). Of the 110 patients, 75 had persistent macroscopic tumor and 47 persistent hormonal secretions; 15 were treated in the prophylactic setting. The linear accelerator-delivered dose was 50.4 Gy (5 x 1.8 Gy weekly), with a 2-mm safety margin.


RESULTS
After a minimal follow-up of 48 months, only 1 patient had developed progression. Of the 110 patients, 27 (36%) had a complete tumor response, 67 (89.3%) had an objective tumor response, 20 (42%) had a hormonal complete response, and 47 (100%) had a hormonal objective tumor response. The proportion of patients without a complete tumor response, objective tumor response, complete hormonal response, and objective hormonal response was 85.1%, 62%, 83%, and 59.3% at 4 years and 49.3%, 9%, 59.3%, and 10.6% at 8 years, respectively. The sole unfavorable predictive factor was preoperative SSE >20 mm for tumor response (p = 0.01) and growth hormone adenoma for the hormonal response (p <0.001). No late complications, except for pituitary deficiency, were reported, with a probability of requiring hormonal replacement of 28.5% and 35% at 4 and 8 years, respectively. Nonfunctioning status was the sole unfavorable factor (p = 0.0016).


CONCLUSIONS
Surgery plus FSR is safe and effective. FSR focused to the target volume seems more suitable than standard radiotherapy, and standard fractionation reduces the risk of optic neuropathy sometimes observed after single-dose radiosurgery. Therefore, FSR allows us to consider combined transrhinoseptal surgery and early radiotherapy, with a curative goal without patient selection.
Colin
Philippe
P
Department of Radiation, Polyclinique Courlancy, Reims, France; Department of Neurosurgery, Centre Hospitalier Universitaire Reims, Reims, France. courlancy.colin@wanadoo.fr
Jovenin
Nicolas
N
Delemer
Brigitte
B
Caron
Jean
J
Grulet
Herve
H
Hecart
Annie-Claude
AC
Lukas
Celine
C
Bazin
Arnaud
A
Bernard
Mary-Helene
MH
Scherpereel
Bernard
B
Peruzzi
Philippe
P
Nakib
Iab
I
Redon
Charles
C
Rousseaux
Pascal
P
D000236:Adenoma / Q000378:metabolism / Q000601:surgery*; D000293:Adolescent; D000324:Adrenocorticotropic Hormone / Q000378:metabolism; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D002648:Child; D019583:Dose Fractionation, Radiation; D005240:Feasibility Studies; D005260:Female; D013006:Growth Hormone / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D010911:Pituitary Neoplasms / Q000378:metabolism / Q000601:surgery*; D011388:Prolactin / Q000378:metabolism; D011446:Prospective Studies; D016634:Radiosurgery / Q000379:methods*; D014786:Vision Disorders / Q000601:surgery; D014792:Visual Acuity
D000324:Adrenocorticotropic Hormone; D011388:Prolactin; D013006:Growth Hormone