Dual-time 18 F-FDG PET/CT for the detection of liver metastases in breast cancer

OBJECTIVE: The aim was to investigate the diagnostic potential of dual-time-point F-fluorodeoxyglucose positron emission tomography/computed tomography (F-FDG PET/CT) in patients with breast cancer with known or suspected liver metastases and to assess its clinical value on clinical management. PATIENTS AND METHODS: A total of 151 consecutive patients with breast cancer who underwent F-FDG PET/CT scan for staging or restaging, in whom an additional delayed scan of the liver was performed, were retrospectively evaluated. RESULTS: Overall, F-FDG PET/CT showed the presence of 146 liver metastases in 57 patients. Overall, 54 of these lesions were clearly identified at standard whole-body acquisition, 49 were suspected and 43 were missed in early acquisition. Only 59.6% of patients with liver involvement were clearly identified at the first scan. A high percentage of patients (48.3%) showed at least one liver lesion suspected on standard acquisition which was not more confirmed in late scan. Maximum tumour standardized uptake value of liver metastases was significantly higher in delayed as compared with standard acquisition (6.5±2.4 vs. 5.3±1.6; P<0.0001). The higher detection rate in late acquisition altered patient management in a relative low number of cases in the whole series (15.8%) and in a higher proportion (28.6%) in the group of patients with exclusive liver involvement. CONCLUSION: The results of the study revealed the potential usefulness of late liver acquisition in patients with breast cancer with suspected or known liver metastases. Its use should be advocated in case of inconclusive results on standard acquisition to improve the study interpretation confidence or to increase the accuracy in specific clinical settings.