The Biggest Energy Users in Cancer Treatment Aren’t What You Think

Climate control, electricity and ventilation in buildings, plus patient and staff commuting, contribute the bulk of emissions for radiotherapy.

By Jess Berthold

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.”

Emissions from patient travel come from the need for patients to commute back and forth for daily radiotherapy sessions, often lasting several weeks and involving significant distances. This highlights the need for more accessible care, greener transit options and supportive services for local housing during treatment, she said.

Less (time) is more efficient

The researchers ran simulations on treatment courses that used more intense radiation over fewer days – called hypofractionation – and found it can reduce emissions by up to 77% for some prostate cancers and 42% for some breast cancers due to less patient travel, energy and resources used per treatment. Past research has shown hypofractionation is just as effective and safe as regular treatment for cases deemed appropriate by physicians.

Telehealth, satellite centers, referrals and local housing accommodations can cut down on the emissions that result from patients commuting to medical centers for radiotherapy. Cancer facilities can also switch their patient transportation services to a service like Uber Green, which requires all drivers to have low-emission hybrid or electric cars, Lichter said.

While radiation oncology departments don’t have much control over hospital-wide energy consumption, health care professionals can promote energy efficiency at their workplaces by advocating for HVAC upgrades and building improvements and supporting sustainability pledges such as the White House/HHS health sector climate pledge, the authors wrote. Such advocacy has led UCSF Health to cut greenhouse gas emissions by 26% since 2015, aim for carbon neutrality by 2025 and phase out the use of natural gas.

It's important for clinical service lines to determine their individual environmental footprints so they can decide on the best and most feasible opportunities for change, Lichter said.

“We’ve known for a while that health care contributes 9% of total greenhouse gas emissions in the U.S., but we, as clinicians, need to drill down by specialty to understand our emissions at baseline,” Lichter said. Unless you measure something, you don't know if it is getting better or worse. And we can’t manage what we do not measure.”

Authors: Additional UCSF co-authors are Ali Sabbagh, MD, Alan Wiztum, PhD, Sue S. Yom, PhD, Chirjiv Anand, PhD, and Ali Sabbagh, MD.

Funding: The work was supported by the Mount Zion Health Fund.