2024 article
Outcomes of Stereotactic Radiation Therapy Versus Fractionated Radiation Therapy in 44 Dogs With Pituitary Masses: A Multi-Institutional Retrospective Study (2016-2022)
Gieger, T. L., Magestro, L., Walz, J., Yoshikawa, H., & Nolan, M. W. (2024, June 18). VETERINARY AND COMPARATIVE ONCOLOGY.
ABSTRACT Although canine pituitary masses (PM) are increasingly treated with stereotactic radiotherapy (SRT), historical literature supports superior outcomes with conventional full‐course fractionated radiation therapy (FRT). A multi‐institutional retrospective study was performed, including dogs with PM treated from 2016 to 2022 with SRT (total dose 30 or 35 Gy in 5 daily fractions) or FRT (total dose 50–54 Gy in 19–20 daily fractions). The influence of potential prognostic/predictive factors was assessed, including pituitary: brain height, pituitary: brain volume, sex, age and endocrine status (functional [F] vs. nonfunctional [NF] PM). Forty‐four dogs with PM were included (26 F, 14 NF, 4 unknown). All patients completed protocols as scheduled (SRT = 27, FRT = 17) and two dogs had suspected Grade 1 acute neurotoxicity. During the first 6 months after RT, 5/27 (19%) dogs treated with SRT (4 F, 1 NF) and 3/17 (18%) dogs treated with FRT (all F) died or were euthanised because of progressive neurologic signs. The overall median survival time was 608 days (95% CI, 375–840 days). Young age at the time of treatment was significant for survival ( p = 0.0288); the overall median survival time was 753 days for dogs <9 years of age (95% CI, 614–892 days) and 445 days for dogs ≥9 years of age (95% CI, 183–707 days). Survival time was not associated with treatment type or any other factor assessed herein. A prospective study using standardised protocols would further validate the results of the present study and potentially elucidate the predictors of early death.