Optimizing energy consumption in radiotherapy: standard vs. hypo-/ultra-hypofractionation and becoming SMART (specific, measurable, achievable in radiotherapy).

Abstract

Purpose: The healthcare sector is a large greenhouse gas producer. Especially in radiotherapy (RT), a lot of electricity is consumed by the medical linear accelerator (linac) and associated patient travel. Our aim was to ascertain by how much electrical energy consumption and patient travel can be reduced by replacing normofractionated (NF) with emerging moderately hypofractionated (UF) or ultra-hypofractionated (UHF) concepts.

Methods: We connected an energy meter to our linac (VersaHD, Elekta©, Stockholm, Sweden) and evaluated different fractionation concepts (NF, HF, UHF) for 30 patients with target volumes of the prostate, breast, and spine. In addition to the energy measurements, we also conducted an analysis of the carbon dioxide (CO₂) emissions associated with the variations in patient travel.

Results: This study measured the energy consumption of a linac (in kWh) and its impact on CO₂ emissions for various radiotherapy fractionation concepts. Ultra-hypofractionated regimens consistently showed the lowest energy consumption and variability across prostate, breast, and bone metastasis treatment courses, while NF regimens had significantly higher energy consumption and variability. Transitioning from NF to UHF regimens reduced CO₂ emissions by up to 75%, driven by fewer patient visits and lower electricity consumption. These findings highlight the environmental and logistical benefits of HF and UHF treatment protocols.

Conclusion: The adoption of HF and UHF treatment concepts can significantly reduce energy consumption and CO₂ emissions, achieving an up to 75% reduction per treatment course. This is primarily due to decreased patient travel and electricity consumption at the linac. Extrapolated globally, these changes offer further potential to mitigate climate change.