Main Session
Sep
27
PQA 02 - Pediatric Cancer, Sarcoma and Cutaneous Tumors, Medical Education & Professional Development, and Health Services Research
Presenter(s)
Katie Lichter, MD, MPH - Dartmouth Cancer Center, St. Johnsbury, VT
R. Chuter1, V. Newton-Sullivan2, M. Hardy3, L. Stolarzcyk4, K. Lichter5, and K. Tanderup6; 1The Christie NHS Foundation, Manchester, United Kingdom, 2University College London Hospital NHS Foundation Trust, London, United Kingdom, 3The Clatterbridge Cancer Centre NHS Foundation Trust, Liverpool, United Kingdom, 4Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark, 5Department of Radiation Oncology & Applied Sciences, The Dartmouth Institute for Health Policy & Clinical Practice, Geisel School of Medicine at Dartmouth, Dartmouth Cancer Center, Lebanon, NH, 6Department of Oncology, Aarhus University Hospital, Aarhus, Denmark
Purpose/Objective(s):
While the carbon footprint of photon-based external beam radiotherapy has been reported, multicenter environmental impact data for proton beam therapy (PBT) remain limited. As PBT utilization expands, quantifying treatment-related greenhouse gas emissions is critical to inform sustainable delivery.Materials/Methods:
A multicenter carbon footprint assessment was conducted across four PBT centers: three high-energy facilities (two in the United Kingdom and one in Denmark) and one low-energy facility in the United Kingdom. A bottom-up methodology quantified carbon dioxide equivalent emissions (kgCO2e) associated with defined treatment-related processes. System boundaries included treatment-related electricity consumption, energy use of major equipment components, construction amortized over a 100-year facility lifespan, patient and staff transportation, anesthetic gases, and consumables. Background building energy consumption unrelated to treatment delivery was excluded to isolate treatment-specific emissions and enable cross-center comparison. Emissions were calculated using nationally appropriate greenhouse gas conversion factors. At one center, component-level electricity consumption was directly measured to characterize the relative contribution of individual system elements.Results:
The per-patient carbon footprint ranged from 1,628–4,067 kgCO2e in high-energy centers and was 1,138 kgCO2e in the low-energy center. Treatment-related electricity consumption represented the dominant emission source, accounting for 61–68% of total emissions in the United Kingdom centers and 38% in Denmark. Construction contributed 17–30% of total emissions in high-energy facilities compared with 3% in the low-energy facility. Component-level analysis demonstrated that the radiofrequency amplifier accounted for 55% of treatment energy use, followed by magnets (21%), servers (18%), and gantries (7%). Transportation-related emissions varied across centers and were influenced by geographic accessibility and transportation infrastructure. Inter-center variability was primarily driven by differences in renewable electricity penetration, overnight radiofrequency power management practices, and annual patient throughput.Conclusion:
This multicenter carbon footprint assessement demonstrates variability in the per-patient carbon footprint of PBT, with treatment electricity representing the primary contributor. High-energy systems were associated with greater emissions compared with low-energy systems. Per-patient emissions from PBT appear higher than previously reported estimates for linac-based radiotherapy, underscoring the importance of targeted mitigation strategies within proton therapy delivery. Operational factors, including renewable energy sourcing, equipment power management, and throughput optimization, may represent modifiable opportunities to reduce the environmental impact of proton therapy.