Histological grade is an important prognostic factor in dogs with soft tissue sarcoma (STS) and is a key consideration in surgical planning. Complete surgical excision is the mainstay of treatment, and high-grade tumors generally require wider surgical margins and consideration of adjuvant therapy because of their higher risk of recurrence and metastasis. Accurate preoperative assessment of tumor grade is therefore important for treatment planning, but preoperative biopsy grading does not always match the final histological grade after surgery. Therefore, additional methods that can complement preoperative grade assessment are needed. This exploratory study investigated whether computed tomography (CT)-based radiomic features differed between low- and high-grade canine STS. Twenty-seven dogs with STS (20 low-grade [13 grade 1, 7 grade 2] and 7 high-grade [grade 3]) were included in this study. From preoperative contrast-enhanced CT images, 107 radiomic features were extracted according to the Image Biomarker Standardisation Initiative (IBSI) guidelines. Nine features were then selected through a three-stage process consisting of statistical filtering, exclusion of volume-dependent features, and hierarchical clustering. These features showed discriminatory performance for differentiating low-grade from high-grade tumors, with apparent AUC values of 0.843–0.957. GLDM-SmallDependenceLowGrayLevelEmphasis had the highest apparent AUC of 0.957 (95% CI: 0.864–1.000). Low-grade tumors tended to show higher values for low-gray-level texture features, whereas high-grade tumors showed higher values for features related to heterogeneous high-gray-level texture patterns. These findings suggest that CT-based radiomics may serve as a complementary tool for preoperative grade assessment in canine STS. Although these findings are encouraging, the reported AUC values reflect exploratory performance within this study cohort, and future prospective studies with larger cohorts and external validation are needed to confirm these findings.

To Cite This Article: Lee S, Kim J, Kim S, Lee K and Yoon H, 2026. CT radiomics for histological grade assessment of canine soft tissue sarcoma: a pilot study. Pak Vet J, 46(9): 2303-2310. http://dx.doi.org/10.29261/pakvetj/2026.219