Access to Radiation Therapy Expands, Especially in Densely Populated Areas

Researchers found there has been a 17% growth in radiation therapy facilities over the last 15 years, with expansion specifically improving for those who already live near such facilities.

There has been a 17% growth in radiation therapy (RT) facilities over the last 15 years, with expansion specifically improving for those who already live near RT facilities, according to a study presented at the American Society for Radiation Oncology (ASTRO) Annual Meeting.1

Based on a 50-mile threshold, researchers found that 4.5% of the US population still has limited geographic access to RT, suggesting a need for interventions to mitigate this disparity.

“Radiation therapy is one of the primary treatments for cancer, but one in 20 Americans lives quite far from a radiation therapy clinic,” lead author Sean Maroongroge, MD, MBA, a radiation oncology resident at The University of Texas MD Anderson Cancer Center in Houston, said in a press release.2 "If we do not incentivize or find ways to help people who live farther from treatment sites get access to radiation therapy, then this gap may continue to widen over time."

"With the growth of telemedicine, especially during the COVID-19 pandemic, there are a lot of ways we can think about transforming care, but radiation therapy delivery requires patients to come to a treatment facility," Maroongroge added.

Of note, the last time a comprehensive inventory of US RT facilities was completed was in 2005, based on data from state regulatory agencies and international dosimetric quality assurance bodies. Researchers therefore sought to update this database to include changes observed over the last 15 years.

For this study, the investigators compiled data from state regulatory agencies regarding the location of facilities that deliver RT for human medical treatment from 2018 to 2020. Additionally, data was also compiled from the databases of 2 independent peer review organizations that provide nationwide dosimetry auditing for radiation therapy units, including Radiation Dosimetry Services (RDS) and the Imaging and Radiation Oncology Core (IROC).

In 2020, a total of 2332 US RT facilities were reported compared to 1987 in 2005, which represents a 17% growth in facilities over nearly 15 years. More specifically, 33% (662/1987) of sites in the prior dataset did not exist in the updated dataset based on geolocation with latitude and longitude coordinates alone.

However, 25.6% of county centroids were found to be currently located within 12.5 miles of a RT facility, while 16.9% are located more than 50 miles away. In addition, a third of sites demonstrated geographic turnover over time, representing facility closures, movement, or methodological differences in data capture.

Ultimately, based on population attribution to county centroids, nearly 70% of the US population lives within 12.5 miles of an RT facility; a 65% increase from that observed in 2005.

"The disproportionate growth suggests that new sites are being built closer to people who are already close, rather than closer to people who are farther away,” said Maroongroge. “It could be that those are the people who need access the most, and we need to think carefully about how to help these patients get access to care.”

"The most unfortunate cases I see are when nonclinical factors undermine the type of care patients receive," Maroongroge continued. "I have patients who just say that it's just not feasible for them to get radiation if they have to travel a long distance. The financial stress and the weight of logistical burdens can't be understated in terms of how much they dominate patients' lives."

Moving forward, the researchers intend to validate their results with additional datasets to better understand the populations who are at risk and identify potential levers to create change. Further, access for people who live close to facilities is also an area of interest.

"There are a lot of questions in terms of policy and perhaps even technology that may help us deliver better care to underserved patients," Maroongroge concluded.


1. Maroongroge S, Wallington DG, Taylor PA, et al. Geographic Access to Radiation Therapy in the United States. Presented at the American Society for Radiation Oncology (ASTRO) Annual Meeting. Abstract #: 203.

2. Access to radiation therapy has grown, especially in densely populated areas [news release]. Arlington, Virginia. Published October 27, 2020. Accessed November 2, 2020.,-especially