Observed Versus Expected Use of Diagnostic Imaging and Radiotherapy in Prostate Cancer: A Population-Based 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 and applied a population-based methodological framework to estimate observed and expected utilization of diagnostic imaging and radiotherapy along the prostate cancer care pathway in the Lazio Region (central Italy). Methods: The cohort study included all incident cases recorded in the Regional Cancer Registry in 2019 (n = 3047) and estimate in 2022 (n = 3254), through the integration of cancer registry data and 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. Results: Expected utilization was consistently higher than observed utilization. Radiotherapy was expected in approximately 40% 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. Conclusions: Overall, a gap was identified between expected and delivered care, suggesting the need to review the provision of diagnostic and therapeutic services. This reproducible and adaptable methodology can be applied to other care pathways and healthcare settings, thereby supporting strategic resource allocation and continuous monitoring.