Proton-Beam Therapy Increasingly Popular in the US

By Linda Carroll

May 06, 2022

NEW YORK (Reuters Health) - Physicians in the U.S. are increasingly using proton-beam therapy (PBT) to treat newly diagnosed cancer patients, a new study finds.

An analysis of data from nearly six million patients diagnosed with cancer between 2004 and 2018 revealed that use of PBT rose by more than 8% per year, researchers report in JAMA Network Open.

PBT "provides the opportunity for better precision in dose delivery than other types of external beam radiotherapy," the researchers explain.

The technology's use in the U.S. "has been increasing for the treatment of both cancers for which PBT is the recommended modality and for cancers for which PBT's superiority over photo-based radiation therapy is still being investigated," said first author Dr. Leticia Nogueira of the Emory Rollins School of Public Health, in Atlanta.

"Most patients treated with PBT for cancers still under investigation have Medicare coverage," Dr. Nogueira told Reuters Health by email. "Health-insurance coverage is one of the main determinants of clinical trial enrollment, which is crucial for evidence development and comparative effectiveness analyses for the appropriate use of PBT."

To explore how often PBT is being used to treat patients newly diagnosed with cancer, Dr. Nogueira and her colleagues turned to data from the National Cancer Database (NCDB), a hospital-based cancer registry jointly sponsored by the American College of Surgeons and the American Cancer Society. The database captures about 72% of all cancer cases in the U.S. from more than 1,500 facilities accredited by the American College of Surgeons' Commission on Cancer.

The researchers used the American Society of Radiation Oncology (ASTRO) Model published in 2017 to retrospectively classify patients into two groups: Group 1 included patients treated for ocular tumors, head and neck tumors, central-nervous-system tumors, hepatocellular carcinoma, skull and spine tumors and rhabdomyosarcoma; Group 2 included patients treated for prostate, lung, breast, esophagus, pelvic and abdominal tumors, as well as thoracic lymphomas. The patients' self-identified race and ethnicity were extracted from medical records.

Overall, close to 6 million patients eligible to receive PBT were included in the study (mean age at diagnosis, 63; 54% female). The use of PBT increased from 0.4% in 2004 to 1.2% in 2018 (annual percent change, 8.12%) due to increases in Group 1 from 0.4% in 2010 to 2.2% in 2018 (APC, 21.97) and increases in Group 2 from 0.03% in 2014 to 0.1% in 2018 (APC, 30.57).

Among patients in Group 1, PBT targeted to the breast increased from 0.0% to 0.9% (APC, 51.95%), and PBT targeted to the lung increased from 0.1% to 0.7% (APC, 28.06%) between 2010 and 2018.

Among patients in Group 2, the use of PBT targeted to the prostate decreased from 1.4% in 2011 to 0.8% in 2014 (APC, -16.48%) and then increased to 1.3% in 2018 (APC, 12.45).

Most patients in Group 1 treated with PBT had private insurance coverage in 2018 (55%) while Medicare was the most common insurance type among those in Group 2 (53%).

SOURCE: JAMA Network Open, online April 29, 2022.