Value of fourth and subsequent post-therapy follow-up 18F-FDG PET/CT scans in patients with breast cancer

Abstract

Objective To evaluate the accuracy and value of the fourth and subsequent post-therapy follow-up fluorine-18 fluorodeoxyglucose (18F-FDG) PET/computed tomography (CT) scans in the clinical assessment of breast cancer patients. Materials and methods Ninety-two female patients, with a total of 426 fourth and subsequent follow-up PET/CT scans, were retrospectively included. Patients were followed for a median of 23.7 months (range, 0.7–124.4) from the fourth follow-up PET/CT. The diagnostic accuracy of PET/CT, its impact on clinical assessment, patients’ management, and survival outcome were established. Result Of the 426 follow-up PET/CT scans, 264 (62%) were interpreted as positive and 162 (38%) were interpreted as negative. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the fourth and subsequent follow-up PET/CT scans were 97.7, 98.1, 98.8, 96.3, and 97.9%, respectively. Fourth and subsequent follow-up PET/CT were useful in excluding a tumor in 13.4% (39/292) of patients with a clinical suspicion of recurrence and identifying suspected recurrence in 10.5% (14/134) of patients without previous clinical suspicion. A change in management was noted in 6.7% (9/134) of scan times when the scans were performed without previous clinical suspicion of recurrence or therapy response and was 27.7% (81/292) when the scans were performed with clinical suspicion. Overall survival differed significantly between patients with all negative follow-up scans (n = 23) and those who had at least one positive follow-up scan (n = 69) (hazard ratio of 4.65, P < 0.001). Conclusion The fourth and subsequent PET/CT scans performed after the completion of primary treatment led to a change in management in 27.7% of patients when the scans were performed with clinical suspicion and only in 6.7% of patients when performed without clinical suspicion or context.

Diagnostic Value of FDG PET/CT in Surveillance after Curative Resection of Breast Cancer

“…The diagnostic sensitivity, specificity, PPV, NPV and accuracy of the 134 scans were 93.3%, 99.2%, 93.3%, 99.2% and 98.5%, respectively, which showed comparable diagnostic performance to our study except in PPV (93.3% vs. 69% in our study). They categorized indeterminate findings (FDG-avid lesions, but not clearly identified as recurrence) as 'negative', which may lead to higher PPV values than those in our study [4]. In our study, the sensitivity and NPV were 100%, which means that negative findings of surveillance PET/CT might be also clinically valuable by reassuring that a patient did not have recurrence or another malignancy.…”

“…It is well-known that fluorine-18 fluorodeoxyglucose (FDG) PET/CT is the most valuable imaging modality in detecting recurrence or metastasis in patients with breast cancer with documented or suspected recurrence detected at physical, laboratory, or other conventional imaging examinations [3][4][5]. With excellent diagnostic sensitivity and accuracy, FDG PET/CT can provide clarification on whether the recurrence is isolated, which potentially alters treatment options.…”

“…On the other hand, current guidelines recommend against routine FDG PET/CT imaging for breast cancer surveillance of asymptomatic patients because of the high cost and lack of evidence. To our knowledge, with the exception of a study with a small number of subjects [4], no previous studies investigated the diagnostic value of routine surveillance FDG PET/CT primarily for detecting recurrent breast cancer. In the Republic of Korea, between 2006 and 2016, surveillance FDG PET/CT in cancer patients was covered by National Healthcare Insurance after curative therapy even without clinical suspicion of recurrence [6].…”

Clinical Indications and Impact on Management: Fourth and Subsequent Posttherapy Follow-up 18F-FDG PET/CT Scans in Oncology Patients

“…The indications were categorized in 4 groups: PET/CT for diagnosis of tumor recurrence (303/1,659, 18.3%), PET/CT before starting therapy for tumor recurrence (64/1,659, 3.9%), PET/CT to assess therapy response for tumor recurrence (507/1,659, 30.6%), and follow-up PET/CT after completion of treatment for tumor recurrence (785/1,659, 47.3%). Overall, fourth and subsequent follow-up 18 F-FDG PET/ CT scans resulted in change in management in 31.6% of the scans (356 of 1,128) when the scans were obtained for medical necessities (indications [1][2][3][4][5][6][7][8][9][10][11], and in 5.6% of the scans (30/531) when the scans were obtained without any medical necessity (indication 12). Conclusion: The fourth and subsequent PET/CT scans obtained after completion of primary treatment led to a change in management in 31.6% of the scans when acquired for appropriate clinical reasons.…”

“…Any additional follow-up 18 F-FDG PET/CT scans (beyond 3) will be covered only at the discretion of local Medicare administrative contractors, justified by a medical necessity (6). Previously, we evaluated the role of fourth and subsequent follow-up 18 F-FDG PET/CT scans obtained after primary treatment completion, in different cancers, and the results showed that 18 F-FDG PET/CT significantly affects the management of these patients especially when there is clinical suspicion of recurrence before performing the scans (7)(8)(9)(10). This study aimed to investigate the common indications of medical necessity to perform a fourth and more follow-up 18 F-FDG PE/CT scans, which may have high impact on the management of patients with different cancers.…”