Accuracy of infrared thermography in the diagnosis of canine mammary cancer.

Abstract

BACKGROUND: Infrared thermography (IRT) is a noninvasive imaging technique increasingly applied in medical fields, including breast cancer detection. HYPOTHESIS/OBJECTIVES: To evaluate the diagnostic accuracy of IRT in assessing the biological behavior and progression of canine mammary tumors (CMTs) and to investigate associations with routine prognostic factors. ANIMALS: Eighty-one female companion dogs were enrolled, including 17 healthy controls and 64 dogs with 80 mammary tumors (MTs), which were categorized as benign (n = 9), low-grade malignant (n = 30), or moderate- to high-grade malignant (n = 41). METHODS: This prospective comparative cohort study qualitatively and quantitatively evaluated thermographic images by analyzing the distribution of white pixels (WPs), red pixels (RPs), and yellow pixels (YPs) based on surface temperature. Thermal symmetry, vascular patterns, and necrotic areas were assessed, as well as their correlation with tumor malignancy and survival. RESULTS: Control dogs showed symmetrical mammary thermal patterns, whereas MT dogs exhibited asymmetries associated with vascularization and necrosis. Benign tumors had a higher WP distribution, whereas high-grade malignancies showed a significantly increased RP distribution. An RP threshold of 16.9% differentiated tumors by aggressiveness. Dogs with >16.9% RPs had shorter survival (P = .004). RP distribution correlated with the malignancy grade (P = .003). CONCLUSIONS AND CLINICAL IMPORTANCE: IRT identified thermal patterns linked to tumor aggressiveness and survival in dogs with CMTs, indicating that it is a valuable, noninvasive tool for initial evaluation, surgical planning, and prognostic assessment in CMT.