ESTRO 2024 - Abstract Book

S2920

Interdiscplinary - Other

ESTRO 2024

The Christie NHS FT, Christie Medical Physics and Engineering, Manchester, United Kingdom. The University of Manchester, Division of Cancer Sciences, Manchester, United Kingdom

Purpose/Objective:

Climate change is increasingly acknowledged to be a health emergency due to its effect on weather systems and food supplies, and without sizeable actions, this will only get worse. However, the healthcare system itself forms 4.7% of the entire carbon footprint of the EU, so the sector is a large contributor to the problem as well. In the UK about 120,000 cancer patients are treated with radiotherapy each year, 50% of all cancer patients [1]. Several studies have now shown that patient travel forms the majority of the measured carbon footprint of external beam radiotherapy (EBRT) [2,3]. Hypofractionation has been highlighted as one potential way to reduce this carbon footprint [3,4] but another possibility could be to build more, small satellite centres that are nearer to patients. This work estimates the carbon footprint of building a new 2 linac centre and determines how many years it would take to mitigate this due to reduced patient travel.

Material/Methods:

Three aspects of the carbon footprint of a satellite centre were considered in this work: The building of the centre, patient travel and staff travel.

Building plans for a satellite centre located 8 miles from the main centre were used to estimate the carbon footprint of the new building. This was performed using two methods due to the uncertainty in the estimate:

Method 1) Scaling up the carbon footprint of a UK house

Method 2) Using the volume of material used in the build and using the conversion factor for average construction material [5].

In both cases the carbon footprint from the concrete [5] of the 2 linac bunkers was added to the calculated value of each method.

Post codes were extracted from Mosiaq for all the patients treated on both linacs on one day at the satellite centre (49 patients in total). An online route planning tool was then used to determine the distance to the satellite centre and, for comparison, main centre. UK conversion factors [5] were used to calculate the carbon footprint of these two journeys.

An email was sent to staff working at the satellite centre asking them to give their post code, mode of transport and the number of days they work at the satellite centre on average a week.

The carbon footprint from each of these aspects was combined to determine, on average, how many years it would take for the reduced patient travel to offset the building of the new centre.

Results:

The mean distance patients travelled to the satellite centre was 19.7 km, compared to 30.9 km if they had been treated at, and therefore travelled to the main centre (see Figure 1). Once the return journey, the number of fractions, and the conversion factor for an average car [5] were taken into account the mean carbon footprint per patient of 116.0 kgCO 2 e for travel to the satellite centre and 176.2 kgCO 2 e for the main centre.