Assessing current and future demand for PET-CT imaging in England: a comparative analysis of 2013 and 2022 Royal College of Radiologists Guidelines.

Objectives: This study aimed to provide a comprehensive analysis of the increasing demand for PET-CT imaging in England, driven by advancements in technology and updated clinical guidelines. By comparing the 2013 and 2022 guidelines issued by the Royal College of Radiologists, the analysis sought to quantify the gap between actual PET-CT provision and modeled requirements, benchmarked against international comparators, to inform strategic planning for equitable access to advanced imaging. Methods: A detailed modeling approach was developed, mapping guideline-based PET-CT scan requirements to disease incidence and stage for major oncological indications (prostate, lymphoma, neuroendocrine tumors, lung, breast, gynecological cancers) and key non-oncological conditions (dementia, cardiovascular disease). Actual scan volumes were extracted from the NHS Diagnostic Imaging Dataset and cross-referenced with provider data. Unmodeled indications were estimated using proportional scaling. Model outputs were validated against PET-CT utilization rates in Finland, adjusted for UK disease incidence. Future demand projections incorporated population growth, demographic shifts, and evolving disease prevalence. Results: For 2021, modeled estimates indicated a substantial shortfall in PET-CT provision for several high-impact indications, notably prostate cancer, dementia, neuroendocrine tumors, and breast cancer, where actual scan volumes were 2-7 times lower than modeled need. Modeled demand for England (361 900 scans/year) exceeded actual provision (239 367 scans/year) by over 50%. Comparative analysis with Finland confirmed that England's PET-CT rates lagged for most indications except lung cancer. Projections suggest continued growth in demand, particularly for dementia and neuroendocrine tumors, with overall PET-CT needs expected to rise sharply by 2040. Conclusions: England's current PET-CT capacity falls significantly short of evidence-based requirements, especially for emerging indications in neurology and oncology. Without strategic investment and expansion, this gap will widen, risking delayed diagnosis and suboptimal care. Enhanced data collection and ongoing validation are critical for responsive service planning. Advances in knowledge: This is the first study to comprehensively model PET-CT demand in England across multiple disease categories using updated clinical guidelines and international benchmarking. It provides a robust, data-driven framework for forecasting imaging needs, supporting national policy and equitable resource allocation.