Small Animal Surgery Resident Texas A&M College of Veterinary Medicine and Biomedical Sciences College Station, Texas
Safety and Feasibility of Short-Course Preoperative Radiation Therapy Followed by Surgical Excision for Canine Solid Tumors. Stocks C1, Smith-Oskrochi L1, Deveau M1, Wustefeld-Janssens B2, Hollenbeck D1. 1Texas A&M University, College of Veterinary Medicine, College Station, TX; 2Colorado State University, Flint Animal Cancer Center, Fort Collins, CO.
There are clearly defined benefits of delivering radiation therapy (RT) in a neoadjuvant setting. The objective was to report early RT toxicity and surgical site complication data for dogs that received short-course preoperative radiation therapy (SCPO-RT). Data for dogs that had a SCPO-RT protocol followed by surgical excision was analyzed retrospectively. Twenty-five Gray (Gy) in five fractions delivered on consecutive days was prescribed. Surgery was performed either on the last day of RT or two-to-three weeks after completion. The VRTOG radiation morbidity scoring system was applied. Postoperative complications were graded retrospectively using the Clavien-Dindo classification for surgical complications. Thirty-five dogs with 36 surgical sites met the inclusion criteria. The most common tumor type was soft tissue sarcoma (n = 24; 67%) followed by mast cell tumor (n = 11; 31%) and adenocarcinoma (n = 1; 3%). Among the 36 courses of SCPO-RT, 36% (n = 13) had acute radiation toxicity. Six were classified as grade 1, six grade 2, and one was classified as grade 3. Postoperative complications were reported in six of the 36 cases (17%). The Clavien-Dindo classifications were grade 1 in two, grade 2 in two, grade 3b in one, and grade 5 in one dog, respectively. No dog had long-term surgical complications and the four that were followed, were resolved by 21 days. Overall SSI rate was 11%. The results of this study show that the SCPO-RT protocol was relatively well tolerated and the surgical site complications risk associated with a curative intent resection was moderate.