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

Background: Proper 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. Methods: Whole-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. Results: The 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%). Conclusions: PET/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. (C) 2011 Elsevier Ltd. All rights reserved.