Role of PET/CT in Breast Cancer

Introduction: Breast cancer is the most common cancer type in women and the leading cause of cancer-related deaths in women worldwide. F-fluorodeoxyglucose (FDG) positron emission tomography with computed tomography (PET/CT) is widely used in the initial staging, evaluation of the therapeutic response, and detection of recurrent disease. However, with the increasing use of FDG PET/CT, sites of increased activity have been occasionally discovered in unexpected locations which may not correlate with the patient’s clinical history or the expected spread of the primary malignancy. The aim of this study is to detect the diagnostic value of PET/CT in breast cancer patients; comparing PET/CT performance with that of contrast enhanced CT in diagnosis of breast cancer and distant metastasis. Material and Methods: A prospective study carried out at National liver institute –Menoufia University from January 2016 to December 2017. It included 30 female patients. All patients had pathologically confirmed breast cancer. All patients underwent 18F-FDG PET/CT examination. Patients fasting for about 6 hours before study, then 370–550 MBq of 18F-FDG was injected. Approximately after 60 min from injection, PET/CT scans were performed. Following PET imaging, volumetric contrast enhanced CT scanning was performed from skull base to mid-thigh on the same PET/CT machine. Images were reconstructed and viewed on workstation. Results: The study included 30 female patients with breast cancer, mean age: 53.56 years ±10.64 (SD), age range: 33-73years. Detection of contralateral breast affection in 2 patients (6.7%) and distant metastasis were seen on PET/CT. Sites of distant metastasis included: bone (n=12), axillary lymph nodes (n=11), cervical lymph nodes (n=6), mediastinal lymph nodes (n=12), abdominal lymph nodes (n=8), liver (n=5), lung (n=11) and other visceral sites metastasis (n=9).PET/CT detected breast lesions with a sensitivity of 100% and specificity of 95.4%. In contrast, the sensitivity and specificity of CT alone were 81.2% and 90.4% respectively. Conclusion: PET/CT has superiority over CT alone in detecting breast lesions and distant metastases.