MRI and PET/CT for triaging stage IB clinically operable cervical cancer to appropriate therapy: decision analysis to assess patient outcomes.

Objective: We evaluated the ability of pretreatment MRI and PET/CT to improve outcomes for patients with clinically staged International Federation of Gynecology and Obstetrics (FIGO) IB cervical cancer.

Materials And Methods: We developed a decision-analytic model to predict outcomes for a hypothetical patient cohort with FIGO IB cervical cancer who underwent pretreatment MRI, PET/CT, MRI and PET/CT, or no further imaging (direct pursuance of surgery). The model incorporated imaging performance, underlying parametrial extension and lymph node involvement, surgery and chemoradiation treatment options, and survival penalties from incorrect assessment of disease extent. Three outcomes were compared: 5-year overall survival, percentage of patients receiving correct primary therapy, and percentage of patients spared "trimodality therapy" (surgery followed by chemoradiation). Sensitivity analysis was performed to assess the effects of model uncertainty on outcomes.

Results: The preferred imaging strategy depended on the outcome studied. Five-year overall survival was comparable across strategies but was highest with the no-imaging strategy (92.37%) and with PET/CT (92.36%) and lowest with MRI (92.30%). Triage to correct primary therapy was highest with PET/CT (89.27%) and lowest with MRI (68.21%). Avoidance of trimodality therapy was highest with combined MRI and PET/CT (95.01%) and lowest with the no-imaging strategy (82.32%). Results were somewhat sensitive to imaging test performance characteristics but stable across most parameter ranges tested.

Conclusion: Pretreatment imaging of FIGO IB cervical cancer patients can optimize triage to appropriate therapy. Although imaging does not appear to improve survival, PET/CT maximizes patient triage to correct therapy, and combined MRI and PET/CT spares the most patients unnecessary trimodality therapy.