The value of 18-FDG PET/CT in early-stage breast cancer compared to traditional diagnostic modalities with an emphasis on changes in disease stage designation and treatment plan

BackgroundProper preoperative staging is vital in the treatment of breast cancer patients. The aim of our study was to assess the value of the diagnostic information provided by PET/CT in surgical practice in breast cancer cases considered early-stage by conventional diagnostic modalities.MethodsWhole-body 18-FDG PET/CT was performed on 115 breast cancer patients in whom traditional diagnostic modalities showed no signs of distant metastases or extensive axillary and/or extra-axillary lymphatic spreading, and the size of the primary tumor was <4 cm.ResultsThe sensitivity of PET/CT in the detection of the primary tumor was 93%. The sensitivity of the traditional diagnostic modalities in the detection of multifocality was 43.8% while that of PET/CT was 100% (p < 0.001). In the assessment of axillary lymph nodes, ultrasound had a sensitivity of 30% and a specificity of 95%. The corresponding estimates for PET/CT were 72% and 96%, respectively. PET/CT detected distant metastases in 8 patients. TNM classification was modified after PET/CT scanning in 54 patients (47%). PET/CT data changed the treatment plan established upon the results of traditional imaging modalities in 18 patients (15.6%).ConclusionsPET/CT is able to assess primary tumor size and axillary lymphatic status more accurately than traditional diagnostic methods. It can detect distant metastases in 7–8% of those patients who were declared free of metastasis by clinical investigations. PET/CT scan modifies the disease stage determined by traditional diagnostic modalities in almost half of the patients and leads to a change in the treatment plan in every 6th patient.