Ninety-day mortality following curative intent radiotherapy for stage I-III lung cancer in the Netherlands

Background and purpose: The 90-day mortality following lung cancer treatment is a common performance indicator. The aim of this study was to investigate 90-day mortality following (chemo)radiotherapy for stage I–III lung cancer to evaluate the applicability of this outcome indicator in this patient population. Materials and methods: The Netherlands National Cancer Registry was queried for this retrospective population-based study. Early mortality rates from the start and end of radiotherapy are reported with 95% confidence intervals (CI). The association between clinical characteristics and 90-day mortality was evaluated with multivariable logistic regression analysis. Results: 18,355 Patients treated between 2015 and 2020 were included. The 90-day mortality was 2.56% in stages I-II and 4.60% in stage III, was significantly higher in males, elderly patients and patients with a poor performance status and independent of facility volume. In stage I-II, 90-day mortality was lower after stereotactic versus conventional radiotherapy (2.0% versus 5.25%, OR 0.5 (95%CI 0.4–0.7)). In stage III, mortality decreased from 5.26% in 2015–2016 to 3.73% in 2019–2020 (OR 0.7 (95% CI 0.5–0.9)) and was lower after concurrent versus sequential chemoradiotherapy (3.4% versus 5.9%, OR 1.5 (95%CI 1.2–1.9)). Early mortality increased to 3.20% in stages I-II and 6.70% in stage III when calculated from the end of radiotherapy. Conclusion: Short-term mortality rates following curative intent radiotherapy for lung cancer in the Netherlands are low and independent of facility volume. It was demonstrated that 90-day mortality is an arguable indicator to monitor radiotherapy quality and that standardization of definitions and relevant case-mix factors is warranted.