Survival, neurologic response, and prognostic factors in dogs with pituitary masses treated with radiation therapy and untreated dogs.
BACKGROUND
Pituitary masses in dogs are not uncommon tumors that can cause endocrine and neurologic signs and, if left untreated, can decrease life expectancy.


OBJECTIVE
Dogs with pituitary masses that received radiation therapy (RT) have more favorable neurologic outcomes and longer survival times compared with untreated dogs.


METHODS
Nineteen dogs with a pituitary mass identified on CT or MR imaging were irradiated with 48 Gy given in 3 Gy daily-dose fractions. Twenty-seven untreated control dogs had pituitary masses.


METHODS
Medical records of dogs with pituitary masses were retrospectively reviewed for clinical signs, mass size, and outcome.


RESULTS
Median survival time was not reached in the treated group. Mean survival time in the treated group was 1,405 days (95% confidence interval [CI], 1,053-1,757 days) with 1-, 2-, and 3-year estimated survival of 93, 87, and 55%, respectively. Median survival in the nonirradiated group was 359 days (95% CI, 48-916 days), with a mean of 551 days (95% CI, 271-829 days). The 1-, 2-, and 3-year estimated survival was 45, 32, and 25%, respectively. Dogs that received RT for their pituitary tumors had significantly longer survival times than untreated dogs (P = .0039). Treated dogs with smaller tumors (based on maximal pituitary-to-brain height ratio or area of tumor to area of brain) lived longer than those with larger tumors (P < .001).


CONCLUSIONS
When compared with untreated dogs, RT increased survival and controlled neurologic signs in dogs with pituitary masses.
Kent
Michael S
MS
Department of Surgical and Radiological Sciences, University of California, Davis, CA 95616, USA. mskent@ucdavis.edu
Bommarito
David
D
Feldman
Edward
E
Theon
Alain P
AP
D000324:Adrenocorticotropic Hormone / Q000097:blood; D000818:Animals; D004283:Dog Diseases / Q000097:blood / Q000473:pathology* / Q000532:radiotherapy*; D004285:Dogs; D005260:Female; D053208:Kaplan-Meier Estimate; D008297:Male; D010911:Pituitary Neoplasms / Q000097:blood / Q000473:pathology / Q000532:radiotherapy / Q000662:veterinary*; D011882:Radiotherapy, High-Energy / Q000662:veterinary; D012189:Retrospective Studies
D000324:Adrenocorticotropic Hormone