How CT scans help predict soft tissue sarcoma grades in dogs

Abstract

Soft tissue sarcomas (STSs) constitute a heterogeneous group of tumors that originate from mesenchymal cells. Imaging plays an important role in the assessment of the oncological stage of STSs. Computed tomography findings facilitate the identification of the tumor location and margins in relation to the surrounding anatomic boundaries and thereby enable preoperative planning of tumor management. The histological grade is among the most important parameters that affect tumor recurrence and metastasis rates. However, the prediction of STS histological grades using CT characteristics has not yet been elucidated. This study retrospectively investigated CT findings of patients with different STS grades for differentiation. Thirty dogs with STSs (12 Grade 1, 10 Grade 2, and 8 Grade 3) were included from three animal hospitals. The investigated CT features included tumor delineation, dysmorphic intratumoral or peritumoral vessels, contrast enhancement patterns, peripheral rim enhancement, intratumoral calcification, degree of intratumoral cystic lesions, peritumoral fat stranding, metastatic regional lymphadenopathy, and lung metastasis. Quantitative findings included tumor size and pre- and postcontrast attenuation. Tumor size, dysmorphic intratumoral or peritumoral vessels, peritumoral fat stranding, and metastatic regional lymphadenopathy significantly differed among tumor grades. On post hoc analysis, Grade 3 tumors were significantly larger, had a higher prevalence of dysmorphic vessels than Grade 1 tumors, and had a significantly higher rate of adjacent metastatic lymphadenopathy than Grade 2 tumors. Predicting STS grades before the histopathological examination could potentially aid in the planning of the STS resection margins.