Comparing Methods to Determine Complete Response to Chemoradiation in Patients with Locally Advanced Cervical Cancer

Simple Summary In patients with locally advanced cervical cancer, there is still a high reported locoregional recurrence rate after chemoradiation therapy. Therefore, timely detection of locoregional residual disease is important for patients to be treated with salvage surgery. Furthermore, it is important to select only the patients who would benefit from salvage surgery and not to expose patients unnecessarily to the risks of surgery. Therefore, the aim of this study is to assess two different imaging techniques, MRI and 18F[FDG]-PET/CT, for their ability to determine the presence of locoregional residual disease after chemoradiotherapy in patients with locally advanced cervical cancer. MRI and 18F[FDG]-PET/CT were compared with pathology-proven locoregional residual disease or locoregional recurrence identified from biopsy and/or salvage surgery. The findings from this research provide insights into the ability of MRI and 18F[FDG]-PET/CT to detect locoregional residual disease.Abstract Objectives: There is no consensus on the most reliable procedure to determine remission of cervical cancer after chemoradiotherapy (CRT). Therefore, this study aims to assess the diagnostic performance of two different imaging techniques, MRI and 18F[FDG]-PET/CT, in determining the presence of locoregional residual disease after CRT in patients with locally advanced cervical cancer. Methods: Patients diagnosed with locally advanced cervical cancer (FIGO 2009) treated with CRT were retrospectively identified from a regional cohort. The accuracy of MRI and 18F[FDG]-PET/CT in detecting locoregional residual disease was assessed with histology as the reference standard. Results: The negative predictive value (NPV) and positive predictive value (PPV) for locoregional residual disease detection of MRI and 18F[FDG]-PET/CT combined were 84.2% (95% CI 73.2-92.1), and 70.4% (95% CI 51.8-85.2), respectively. The NPV and PPV of MRI alone were 80.2% (95% CI 71.2-87.5) and 47.7% (95% CI 35.8-59.7), respectively, and values of 81.1% (95% CI 72.2-88.3) and 55.8 (95% CI 42.2-68.7), respectively, were obtained for 18F[FDG]-PET/CT alone. Conclusion: In this study, the reliability of MRI and 18F[FDG]-PET/CT in detecting locoregional residual disease was limited. Combining MRI and 18F[FDG]-PET/CT did not improve predictive values. Routine use of both MRI and 18F[FDG]-PET/CT in the follow-up after CRT should be avoided. MRI during follow-up is the advised imaging technique. Pathology confirmation of the presence of locoregional residual disease before performing salvage surgery is warranted.