Role of FDG-PET/CT in the diagnosis of recurrent breast cancer

Abstract

In patients with recurrent breast cancer, FDG PET/CT has demonstrated superior efficacy compared to conventional imaging (CI) in identifying loco-regional or distant recurrence. This holds true regardless of whether recurrence is suspected based on clinical examination, CI, or an increase in tumor markers (TM) such as CA 15.3 or CEA, and even if tumor markers are within normal ranges. PET/CT is also a powerful imaging modality for conducting a whole-body workup of a known recurrence aiding in the determination of whether the recurrence is isolated. To investigate our experience with the concordance of FDG-PET/CT and CI, we studied cases of breast carcinoma retrospectively collected between 2022 and 2023 from our institution's archive. PET images were analyzed by at least two nuclear medicine specialists. We then compared them with the findings of CI and analyzed their accuracy based on patients' follow-up. A total of 25 patients was selected. PET-CT was effective in clarifying uncertain findings from CT scans. It ruled out bone metastasis in two out of nine equivocal cases and confirmed seven out of nine. It excluded three out of seven pulmonary lesions while confirming three. It also confirmed other uncertain lesions in CT, such as muscular and parietal ones. Moreover, PET/CT detected additional lesions not seen in CT [bone (n=4) and liver (n=1)]. In conclusion, this study supported the findings of prior studies, highlighting the valuable contribution of PET/CT in the detection of recurrent breast cancer and its superiority to CI.