Comparative efficacy and workflow efficiency of integrated PET/MRI versus sequential PET/CT and MRI in gynecologic...

To compare the diagnostic performance of PET/MRI versus PET/CT for lymph node and metastatic disease detection in patients with gynecologic cancers, and to assess whether PET/MRI offers improved staging accuracy and operational efficiency.

49 patients with known gynecologic malignancies underwent both PET/CT and PET/MRI as part of a prospective study. Imaging protocols followed standard guidelines for each modality, with PET/CT and PET/MRI performed consecutively. Images were independently evaluated by experienced radiologists who assessed primary tumor, nodal, and metastatic disease. Subgroup analysis was performed for cervical cancer patients. Each patient's time in the imaging department for each scan was recorded, and statistical analysis included calculation of sensitivity, specificity, McNemar testing, and Cohen's Kappa for inter-rater agreement.

This study prospectively confirms prior findings of PET/MRI's superior nodal detection in gynecologic cancers while providing novel evidence regarding operational efficiency and workflow optimization. PET/MRI demonstrated superior detection of nodal metastases compared to PET/CT, identifying additional adenopathy in 5 patients (p = 0.031) and leading to staging changes in 18 patients within the cohort. In the cervical cancer subset, PET/MRI resulted in more upstaging and downstaging events, though subgroup statistical significance was not reached. PET/MRI also identified more primary tumors missed by PET/CT. The average total imaging time was significantly reduced with PET/MRI (180.3 min) compared to the combined PET/CT and MRI workflow (291.2 min), reflecting a 38.1% reduction in time burden. Qualitative assessment rated PET/MRI superior to PET/CT in 67.3% of cases.

While diagnostic superiority confirms current literature, this study provides the first prospective quantitative assessment of workflow efficiency in gynecologic oncology imaging. PET/MRI outperforms PET/CT in the detection of nodal disease and in overall diagnostic evaluation for patients with gynecologic cancers. In addition to superior staging accuracy, PET/MRI reduces patient time burden, supporting its use as a preferred, patient-centric imaging modality. Wider clinical adoption and further research are warranted to validate these findings in larger, multi-institutional cohorts.