Implementing Simulation-Free Radiotherapy (SFRT) Rapid Access Palliation in Routine Care: A Propensity Score Weight-Adjusted Analysis of the SFRT-1000 Cohort

Purpose/Objective(s)

The feasibility of simulation-free radiotherapy (SFRT) has been demonstrated but information regarding its impact on routine care is lacking. The hypothesis was that SFRT is scaleable and beneficial in routine care. Key endpoints of this single institution study were SFRT utilization, impact on consultation-to-RT time and on-couch treatment duration.

Materials/Methods

All patients receiving palliative RT in the study period were eligible for consideration of SFRT unless mask immobilization, a stereotactic technique, or a definitive dose was required. Timing metrics were compared to a contemporary local cohort that received simulation-based palliative RT using unadjusted medians (Wilcoxon rank-sum test) and a propensity score-weighted regression. Electronic patient-reported outcomes (ePROs) captured 2-week toxicity and pain response.

Results

Between April 2018 and February 2024, there were 2845 palliative radiation courses were delivered, of which 1904 were eligible for this study. One thousand of the 1904 courses (52.5% SFRT utilization) were treated using the SFRT protocol, including 668 with IMRT/VMAT. Median patient age was 71 years with 60% being male and 32% being ECOG 2-4. SFRT reduced median consultation-to-RT time from 7.0 to 5.1 days (P < 0.0001) corresponding to an adjusted average treatment effect (aATE) of -2.3 days (95% CI = -2.9 to -1.7). SFRT increased median on-couch treatment duration from 16 min to 18 min (P < 0.0001; aATE 2.0 min, 95% CI = 0.2 to 3.9). SFRT utilization in eligible courses increased from 41% to 54% between the years 2018 and 2019 and 2022 and 2024. PRO-CTCAE grade 3 acute toxicity was 9% and at 4 weeks post RT patients with moderate/severe pain at baseline (≥ 5/10) had had a mean pain reduction of 3.5 points (7.1 to 3.6).

Conclusion

Using widely available technologies the SFRT-1000 cohort demonstrates routine care scalability with patient-centered and workflow benefits. SFRT is an attractive new palliative RT paradigm implementable in most settings.