Main Session
Sep
27
PQA 02 - Pediatric Cancer, Sarcoma and Cutaneous Tumors, Medical Education & Professional Development, and Health Services Research
2306 - Extreme Hypofractionation as a LINAC-Equivalent Capacity Strategy: A National Public Radiotherapy Network Analysis from Chile
Presenter(s)
Piero Bettoli, MD, MS - Clínica Dávila, Santiago, Region Met
P. Bettoli1,2, F. Carvajal3,4, E. San Martin5, G. Barker6, G. Lazcano Alvarez7, R. Piña8, G. Pavez9, C. Casadiego10, and F. Bakal11,12; 1Clínica Dávila, Santiago, Chile, 2Universidad Mayor, Santiago, Chile, 3Hospital Base Valdivia, Valdivia, Chile, 4Universidad de Chile, Santiago, Chile, 5Hospital Clínico de Magallanes, Punta Arenas, Chile, 6Instituto Nacional del Cáncer, Santiago, Chile, 7Hospital Carlos Van Buren, Valparaiso, Chile, 8Hospital Regional de Concepción, Concepción, Chile, 9Hospital Regional de Antofagasta, Antofagasta, Chile, 10Hospital Regional de Talca, Talca, Chile, 11Ministerio de Salud de Chile, Santiago, Chile, 12Bradford Hill Clinical Research Center, Santiago, Chile
Purpose/Objective(s):
Chile faces a major structural gap in access to radiotherapy (RT), with substantially fewer operational linear accelerators (LINACs) than estimated national needs. Policy responses have largely emphasized new equipment acquisition rather than optimization of existing capacity. Prostate and breast cancer are among the most prevalent RT indications, account for a large share of delivered fractions, and have strong evidence supporting safe and effective extreme hypofractionation. This study aimed to quantify national resource utilization and fractionation patterns across the public RT network and to model system-level capacity gains achievable through increased adoption of extreme hypofractionation.Materials/Methods:
A nationwide assessment was conducted across all operational public RT centers in Chile. Centers reported aggregated annual data on LINAC availability, total treatments, delivered fractions, and fractionation schemes for definitive (non-postoperative) prostate and adjuvant breast cancer. Fraction savings were estimated based on observed fractionation distributions. A policy-relevant scenario targeting 75% adoption of extreme hypofractionation was modeled. Capacity gains were expressed as fraction reduction, LINAC-equivalent units (assuming 6,000–8,000 fractions per LINAC-year), and additional RT courses estimated using the observed network-level mean fractions per treatment.Results:
Across the 16-LINAC national public RT network, prostate and breast cancer accounted for approximately 40% of delivered fractions. Baseline adoption of extreme hypofractionation averaged 45%, with marked inter-center variability from 0% to >90%. Under a 75% adoption scenario, extreme hypofractionation was associated with an annual reduction of ~20,000 fractions, corresponding to 2.5–3.4 LINAC-equivalent units and a 13–15% increase in treatment capacity (~1,500 additional RT courses annually) without expanding installed equipment. Given that adoption already exceeds 90% in at least one center, sensitivity modeling at 90% projected gains equivalent to 4–5 LINAC units, representing nearly 20% expansion within existing infrastructure.Conclusion:
This national modeling analysis suggests that RT access gaps are driven not only by equipment shortages but also by how existing resources are utilized. The marked heterogeneity in hypofractionation adoption highlights a clear implementation gap despite strong clinical evidence and national experience supporting its safety and feasibility. By reframing extreme hypofractionation as a capacity-expansion strategy, these findings provide actionable, system-level evidence to support coordinated national implementation. Importantly, these data are already informing discussions with health authorities and professional societies, facilitating transition from modeling to structured network-level implementation aimed at reducing access disparities in the near term.