Energy expended for hospital and clinic electricity, climate control and ventilation is by far the biggest source of greenhouse gas emissions in radiotherapy, a treatment used in more than half of cancer cases, a new study found.
The Lancet Oncology study, led by UC San Francisco researchers, sought to quantify the environmental footprint associated with radiotherapy across 10 cancer types, including breast, lung and prostate cancer. The assessment considered factors ranging from patient and staff travel to medical equipment and reusable and single-source supplies.
Seventy-four percent of total greenhouse gas emissions came from the energy used to operate buildings and equipment, while patient and staff transit to and from medical facilities contributed 25% of total emissions, on average.
Medical facilities tend to consume more energy than other buildings in the commercial sector by being open 24 hours a day and occupied by thousands of staff, patients, and visitors, and by requiring a great deal of energy for heating, ventilation, and air conditioning (HVAC) to control temperatures and airflow. Also, there are many energy-intensive activities and equipment in these buildings such as sterilization, MRI scanners and radiation treatment machines, also called linear accelerators.
“When we think about reducing environmental impact, we often point our finger at the largest equipment in the room, which is our treatment machines. Yet running those accounts for just 3% of the total energy used for radiotherapy treatments,” said Katie Lichter, MD, MPH, first author of the study and a UCSF resident in radiation oncology. “HVAC is the main culprit.”