Defining the expected 30-day mortality for patients undergoing palliative radiotherapy: A meta-analysis

The expected 30-day mortality rate for patients treated with palliative radiationisnotestablished. The primary objective of this study is todefinetheproportion of patientswith advanced cancerwho diewithin 30-daysofpalliative radiotherapy(PR). Additionally, we explored the short term survival of patient subgroups undergoing PR treatment.

We searched MEDLINE, CINAHL, Embase and Cochrane Database of Systematic Reviews from January 1st 1980 to June 26, 2020. We included PUBMED's related search and reference lists to further identify articles. A meta-analysis of these research studies and reviews was performed. Published and unpublished English language randomized controlled trials, observational or prospective studies, and systematic reviews that reported 30-day mortality for patients with advanced cancer who received PR were eligible. Data extraction was done by two independent authors and included study quality indicators. To improve distribution and variance, all proportions were transformed using logit transformation. A random-effects model was used to pool data, using Der Simonian and Laird method of estimation where possible and appropriate.

The data from 42 studies contributing 88,516 patients with advanced cancer who received PR were evaluated. The summary proportion of mortality in patients with advanced cancer within 30 days of receiving PR was 16% (95% CI = 14% to 18%). We found substantial heterogeneity in our data (I² = 98.76%, p < 0.001), hence we applied subgroup analysis to identify potential moderating factors. We found a higher 30-day mortality rate after PR in the following groups: multiple treatment sites (QM(1) = 9.54, p = 0.002), hepatobiliary primary (QM(1) = 24.20, p < 0.001), inpatient status (QM(1) = 92.27, p < 0.001), Eastern Cooperative Oncology Group performance status (ECOG) 3-4 (QM(1) = 8.70, p = 0.003), United States (U.S.) patients (QM(1) = 28.70, p < 0.001) among others.

We found that 16% of patients with advanced cancer receiving PR die within 30 days of treatment. Our findingcan be used asabenchmarktoestablishaglobal quality metric for radiation oncology practice audits.