Abstract
Nineteen dogs with mast cell tumors treated with chemotherapy were evaluated by computed tomography (CT). Were evaluated aspects related to contours, attenuation, post-contrast enhancement and presence of cleavage with adjacent structures. The RECIST criteria and volumetric measurement of lesions were performed to assess the response to treatment. The mast cell tumors presented a homogeneous or heterogeneous attenuation, presented more frequently a well delineated and regular contours and moderate enhancement after intravenous administration of the iodinated contrast media. The methods RECIST and volumetric measurements showed an excellent agreement to the classification of therapeutic response, providing a good parameter of the response to treatment. The CT examination proved to be useful in the delimitation of the tumor and an important tool for planning of surgical margins.