An estimation of the carbon footprint of Positron Emission Tomography (PET) imaging

To provide an initial estimate of the carbon footprint of PET/CT imaging at a UK imaging centre, indicating the major contributing factors to the emission of greenhouse gases.

Data were collected for patient and staff travel, energy use, consumables and waste from the PET/CT department at the Paul Strickland Scanner Centre (PSSC). Additional travel data from two other UK departments were used as a guide to ensure reasonable representation of UK travel distances. Data were converted to carbon dioxide equivalent emissions (kg CO₂e) and expressed in terms of emissions per patient scanned.

The carbon footprint of PET/CT imaging at PSSC was measured as 19 kg CO₂e or 21 kg CO₂e per patient, depending on the scanner used. The most significant contributors to this were patient travel, and the energy taken by the scanner (this includes the energy taken when the scanner is not operating).

Whilst 20 kg CO₂e is not large by healthcare standards, it is not negligible, representing around 4% to 10% of the emissions of a typical course of radiotherapy. The findings demonstrate the areas of focus to reduce the footprint, and act as a base for future work. This is an initial estimate and does not include the footprint of production and distribution of the radiotracer, nor the "embedded footprint" of the imaging facility and equipment.