A Retrospective Study Of 27 Dogs With Intranasal Neoplasms Treated With Cobalt Radiation

McEntee MC, Page RL, Heidner GL, et al.

Veterinary Radiology & Ultrasound 1991;32:135-139.

Twenty-seven dogs with sinonasal neoplasms were treated with cobalt radiation. Cytoreductive surgery was performed in six of the patients prior to initiation of irradiation. Dogs received from 4,180 to 5,400 cGy on a Monday/Wednesday/Friday schedule given in 10 to 12 fractions over a four week period. All dogs had a computed tomography (CT) based, computer generated radiation treatment plan. Survival time ranged from 2.5 to 46.0 months with a mean and median of 20.7 ± 3.3 and 12.8 months, respectively. The one- and two-year survival rates were 59% and 22%. Survival time compares favorably to those reported previously for dogs treated with cytoreductive surgery and orthovoltage x-rays. Survival time is longer than that reported previously using megavoltage radiation alone or in conjunction with surgery. It is likely that the improved survival reported herein is, at least in part, related to the use of computed tomography for tumor localization and computer generation of the treatment plan. No prognostic variables were identified in the present study. Survival time was not significantly different between dogs with carcinoma versus sarcoma. There was no significant difference between patients that had undergone cytoreductive surgery prior to radiotherapy, and those patients treated with radiotherapy alone.