Original Research ARTICLE
18F-FDG - PET/CT in canine mammary gland tumors
- 1Biomedical Research Institute, National Autonomous University of Mexico, Mexico
- 2National Institute of Cancerology (INCan), Mexico
- 3Faculty of Veterinary Medicine and Zootechnics, National Autonomous University of Mexico, Mexico
- 4Waldorf Pet Hospital, Mexico
- 5Veterinary Hospital Kiin, Mexico
Medical imaging techniques play a central role in clinical oncology, helping to obtain important information about the extent of disease, and plan treatment. Advanced imaging modalities such as Positron Emission Tomography–Computed Tomography (PET/CT), may help in the whole-body staging in a single procedure, although the lesions should be carefully interpreted. PET/CT is becoming commonly used in canine cancer patients, but there is still limited information available on specific tumors such as mammary cancer. We evaluated the utility of fluorine-18 fluorodeoxyglucose (18F-FDG)-PET/CT to detect malignant lesions in 8 female dogs with naturally occurring mammary tumors. A whole-body scan was performed prior to surgery, and mammary and non-mammary lesions detected either on PET/CT or during pre-surgical physical exam were resected when possible and submitted for histopathological examination. Multiple mammary lesions involving different mammary glands were detected in 5/8 dogs, for a total of 23 lesions; there were 11 non-mammary-located lesions in 6/8 dogs, three of these were lung or lymph node metastasis. A total of 34 lesions were analyzed: 22 malignant (19 mammary tumors and 3 metastatic lesions), and 12 benign (4 mammary lesions and 8 of non-mammary tissues). Glucose uptake by maximum standardized uptake value (SUVmax) was analyzed and correlated with tumor size, and benign versus malignant pathology. We found that the minimum tumor size needed to distinguish malignant lesions according to the SUVmax was 1.5cm; benign and malignant lesions <1.5cm did not differ in glucose uptake (mean SUVmax = 1.1). In addition, a SUVmax value >2 was 100% sensitive for malignancy. Combining these data, lesions >1.5cm with a SUVmax >2 had a positive predictive value of 100%. Finally, we did not find an association between SUVmax and histologic subtype or grade, which may be present in a larger sample. Thus, 18F-FDG PET/CT is useful for distinguishing malignant from benign lesion but further imaging of dogs with diverse tumors, should establish characteristic SUV value cutoffs for detecting primary and metastatic disease, and distinguishing them from benign lesions.
Keywords: Canine mammary gland tumors, PET/CT, FDG-PET/CT, canine cancer, Molecular Imaging
Received: 15 May 2019;
Accepted: 07 Aug 2019.
Copyright: © 2019 Sánchez, Romero, López, Campuzano, Ortega, Morales, Guadarrama, Cesarman-Maus, Lizano and García-Pérez. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
PhD. Marcela Lizano, National Institute of Cancerology (INCan), Mexico, México, Mexico, email@example.com
MD. Osvaldo García-Pérez, National Institute of Cancerology (INCan), Mexico, México, Mexico, firstname.lastname@example.org