Publication
Outcome and prognosis for canine appendicular osteosarcoma treated with stereotactic body radiation therapy in 123 dogs
Publisher:
Wiley
Date:
13-01-2021
DOI:
10.1111/VCO.12674
Abstract: Canine appendicular osteosarcoma is commonly treated with limb utation however, limb‐sparing options are frequently desired or necessary for a subset of patients. We evaluated 123 patients and 130 sites treated with stereotactic body radiation therapy (SBRT). Eighty‐two out of 98 dogs (84%) had maximum lameness improvement at a median of 3 weeks for a median of 6 months duration. Histopathologic evaluation of available s les from utation or necropsy revealed % tumor necrosis in 50% of limbs consistent with local disease control. Of evaluable patients, 41% fractured and 21% pursued an utation after treatment. Fine needle aspirate (n = 52) and needle core biopsy (n = 28) did not result in increased fracture risk compared to those without tumor s ling (n = 50). Median survival time (MST) was 233 days and time to first event was 143 days. Gross tumor volume and planned target volume were significantly inversely associated with survival and tumor location was significantly associated with survival. Dogs with salvage utation had a significantly longer MST compared to those without (346 vs 202 days P = .04). The presence of metastatic disease at the time of treatment in 15 dogs did not significantly impact survival time (200 vs 237 days without metastasis P = .58). Skin side effects correlated significantly with dose with 33% of patients with acute grade 3 effects developing consequential late grade 3 effects. While SBRT improves lameness in most patients, further investigation is needed to identify candidates with minimal early fracture risk prior to initiating therapy.