Modelling Study with an Interactive Model Assessing the Cost-effectiveness of Ga-68 Prostate-specific Membrane Antigen Positron Emission Tomography/Computed Tomography and Nano Magnetic Resonance Imaging for the Detection of Pelvic Lymph Node Metastases in Patients with Primary Prostate Cancer

Background Outcomes of extended pelvic lymph node dissection (ePLND) show that only 16% of prostate cancer (PCa) patients harbour lymph node (LN) metastases. Ga-68 prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) and nano magnetic resonance imaging (nano-MRI) might be noninvasive alternatives for ePLND; however, it remains uncertain whether they are cost-effective. Objective To develop an interactive model to determine the cost-effectiveness of 68Ga PSMA PET/CT and nano-MRI as compared with ePLND for the detection of pelvic LN metastases in patients with intermediate- to high-risk PCa. Design, setting, and participants Decision tree with state transition model for men with intermediate- to high-risk PCa. Input data was derived from systematic literature searches. Outcome measurements and statistical analysis Quality-adjusted life years (QALYs) and healthcare costs were modelled over lifetime. Sensitivity analyses were used to assess uncertainty. Results and limitations Assuming 100% sensitivity of ePLND, no QALY loss after ePLND, and no treatment improvement due to imaging, the PSMA PET/CT and nano-MRI strategies seem to be less expensive per patient (€3047 and €2738, respectively) and result in loss of QALYs (0.07 and 0.03, respectively) compared with the ePLND strategy. PSMA PET/CT and nano-MRI are both cost saving and more effective when ePLND has a sensitivity of ≤60% and ≤84%, ePLND results in a QALY loss of 0.060 and 0.024 over lifetime, or the imaging techniques reduce recurrences by 26% and 8%, respectively. Conclusions PSMA PET/CT and nano-MRI seem to be cost-effective compared with ePLND since they save cost, but at the possible expense of a small QALY loss. Our interactive model provides insight into the influence of important model parameters on the cost effectiveness of 68Ga PSMA PET/CT and nano-MRI, and the opportunity for updating the cost effectiveness when new evidence becomes available. Patient summary We developed an interactive model that can be used in shared decision making regarding the use of extended pelvic lymph node dissection, 68Ga prostate-specific membrane antigen positron emission tomography/computed tomography, or nano magnetic resonance imaging for lymph node staging in individual patients with intermediate- to high-risk prostate cancer. Owing to remaining uncertainty, we cannot yet give advice about the use of these techniques.