Diagnostic accuracy of spectral Doppler indices and shear wave elastography in dogs with mammary tumors and their relationship to tumor proliferation
İslamoğlu Esen, Günay Uçmak, Ateş, Erdogan Bamac, Kaşıkçı,The combination of several sonographic techniques can provide important information on pathological feature of the mammary tumors. This study aims to evaluate the diagnostic accuracy of spectral Doppler indices and shear wave elastography (SWE) in dogs with mammary tumors and their relationship to tumor proliferation. The study consisted of malignant epithelial tumors (Group MET; n=49) and healthy mammary tissues (Group C; n=15). Ultrasonographic findings (echotexture, echogenicity, mass width, etc.), tissue Ki-67 levels, Doppler US ultrasonography and sonoelastographic measurements were performed. Ultrasonography was performed by a single experienced veterinary sonographer prior to mastectomy using Resona i9 US device equipped with a linear transducer (L20-5s). Histopathological results were used as the gold standard. Tissue Ki-67 levels were measured by using canine Ki-67 Protein (Ki67P) ELISA kit. The distribution of echotexture and echogenicity in Group MET were mostly heterogeneous and hyperechoic. Also, the most frequent vascular pattern was mixed pattern in Group MET, and vascularization amount did not differ in terms of histological grades in canine mammary carcinomas. Vvascular resistivity (RI) and pulsatility indexes (PI) were not significantly different in benign and malignant canine mammary gland tumors. Doppler spectral vascular indexes, peak systolic velocity (PSV) and end diastolic velocity (EDV) were increased in malignant tumors and showed adequate sensitivity and specificity values, as being malignancy predictors on canine mammary masses in this study. Shear wave speed and stiffness of malignant tumors were higher than healthy mammary tissue. The highest Shear wave speed and tissue elasticity were observed in Grade 3 carcinomas and in tumors larger than 5 cm. Tissue Ki-67 concentration was significantly associated with Doppler velocimetry parameters and SWE measurements. Also, Ki-67 had an accuracy in predicting malignancy in canine mammary masses with moderate sensitivity and high specificity. Tissue Ki-67, RI, PSV, Shear wave speed, and elasticity amounts have 100% specificity to distinguish the malignant mammary tumors compared to healthy mammary tissues in dogs. It was concluded that a combination of imaging techniques should be applied for a more accurate diagnosis of mammary tumors.