What is the optimal radiotherapy utilization rate for lung cancer?-a systematic review

Lung cancer is a major cause of morbidity and mortality globally. Although radiotherapy (RT) may be beneficial in the radical and/or palliative management of many lung cancer patients, it is underutilized worldwide. Population-level development of RT resources requires estimates of optimal radiotherapy utilization rates (ORUR) and actual radiotherapy utilization rate (ARUR). A systematic review of PubMed database for English-language articles from January 2009 to January 2019 was performed. Keywords included utilization, underutilization, demand, epidemiologic, benchmark, RT and cancer. Data abstracted included: study population, diagnosis, stage, year of diagnosis, timing of RT, intent of RT, ARUR, and ORUR. Eligible studies provided ARUR or ORUR for lung cancer, small cell lung cancer (SCLC), or non-small cell lung cancer (NSCLC). Included ARUR were based on at least 1,000 patients who were diagnosed or treated in 2009 or later. Included ORUR were based on evidence review or ARUR in 2009 or later. The initial search strategy yielded 1,627 unique abstracts. After review, 105 articles were determined appropriate for full-text review. From these, a final set of 21 articles met all inclusion criteria. In eight papers, ORUR was estimated. Estimated lifetime ORUR ranged from 61% to 82%. Methods for estimation included the evidence-based guideline model, Malthus model, and criterion-based benchmarking (CBB) model. The majority of estimates (6/8) used the evidence-based guideline model. Fifteen papers provided ARUR on lung cancer, inclusive of SCLC and NSCLC. ARUR within 9 months to 1 year of diagnosis ranged from 39% to 46%. Lifetime ARUR was an estimated 52% in Ontario, Canada. Palliative intent ARUR ranged from 12% in Central Poland to 46% in Ontario, Canada. RT is underutilized for lung cancer globally, and there is wide geographical variation in the level of underutilization.