Observed Versus Expected Use of Diagnostic Imaging and Radiotherapy in Prostate Cancer in the Lazio Region (Italy): An Integrated Population-Based and Literature-Informed Framework for Healthcare Planning.

Background/Objectives: Accurate estimation of healthcare service requirements is essential for planning oncological care pathways, particularly in resource-constrained settings. We developed a combined methodological framework integrating pragmatic rapid literature reviews and population-based cohort analyses to estimate expected and observed utilization of diagnostic imaging and radiotherapy services along the prostate cancer care pathway in the Lazio Region (central Italy). Methods: Observed utilization was assessed using incident prostate cases recorded in the Lazio Region Cancer Registry in 2019 (n = 3047) and provisional cases in 2022 (n = 3254), through linkage with regional health information systems. For each cohort, 16 indicators (magnetic resonance imaging, biopsy, metastatic staging imaging, radiotherapy) were calculated, estimating usage proportions, median delivery times, and stratifying by age class. The expected requirement was estimated through four rapid literature reviews of the Italian literature and applied to incident prostate cancer cases. Results: Sixteen indicators covering diagnostic, staging, and therapeutic services were analyzed. Observed utilization varied across the prostate cancer care pathway, including diagnostic imaging, biopsy, surgery, and radiotherapy. For example, radiotherapy was expected in approximately 33-42% of patients, whereas the observed utilization was 23.00% of cases (95% CI 21.48-24.61) in 2019 and 22.52% of cases (95% CI 21.07-24.03) in 2022. The provision of imaging for metastatic staging-40.85% (95% CI 39.06-42.67) in 2019 and 34.84% (95% CI 33.19-36.53) in 2022-was lower than the expected value of 50%. Differences in utilization patterns by age group and timing of service delivery were observed. Literature-informed expected estimates exceeded observed utilization for several services, including both diagnostic and therapeutic components of the pathway. Conclusions: Overall, variations were identified between observed utilization and literature-informed expected estimates, suggesting the utility of evaluating potential areas for healthcare pathway optimization. This reproducible and adaptable methodology can be applied to other care pathways and healthcare settings, thereby supporting strategic resource allocation and continuous monitoring.