Diagnostic value of FDG PET/CT in surveillance after curative resection of breast cancer

Introduction: With increasing incidence of breast cancer and improvement in treatment, the concern on surveillance management also has increased. However, there is a debate regarding routine surveillance follow-up examination. To evaluate the diagnostic value of routine surveillance fluorine-18 fluorodeoxyglucose (FDG) PET/CT for detecting clinically unexpected recurrence in patients with breast cancer after curative resection.

Methods: This retrospective study reviewed 2,742 consecutive patients with breast cancer who underwent FDG PET/CT between 2006 and 2016. The diagnostic performance of surveillance PET/CT was analyzed with sensitivity, specificity, positive predictive value, negative predictive value, and accuracy. Findings from pathologic examination, other imaging modalities, or clinical follow-up were used as the reference standard. The frequency of positive scans and diagnostic performance were compared according to clinical variables, including time between imaging and curative resection, initial clinical prognostic stage, protocol of primary treatment and response to neoadjuvant chemotherapy. The Chi-squared test or Fisher’s exact test were used for comparison among subgroups and P values < .001 were considered as significantly different.

Results: A total of 2,121 scans in 1,681 women with breast cancer (48 years ± 9 at diagnosis) in surveillance were included in the study. The frequency of positive surveillance PET/CT findings was 5.0% (105 of 2,121 scans) and the sensitivity, specificity, positive predictive value, negative predictive value and accuracy for detecting clinically unsuspected recurrent breast cancer or second primary malignancy were 100% (74 of 74 scans), 98.5% (2,016 of 2,047 scans), 70.5% (74 of 105 scans), 100% (2,016 of 2,016 scans) and 98.5% (2,090 of 2,121 scans), respectively.

Conclusions: In conclusion, surveillance fluorodeoxyglucose PET/CT showed good diagnostic performance and comparable rate of positive findings with conventional imaging modality in the detection of clinically unexpected recurrent breast cancer after curative surgery.