Radiotracer access gaps narrow after copper-64 adoption

Access gaps tied to neuroendocrine tumor radiotracers widened after gallium-68 DOTATATE/DOTATOC adoption, then narrowed after copper-64 DOTATATE became available, according to a study in the Journal of the American College of Radiology.

The study examined geographic access to 3 radiotracers used for neuroendocrine tumor imaging: indium-111 pentetreotide, gallium-68 DOTATATE/DOTATOC, and copper-64 DOTATATE. Researchers from the Harvey L. Neiman Health Policy Institute evaluated how newer PET-based tracers affected travel burden by patient urbanicity.

The shift matters because gallium-68 DOTATATE/DOTATOC offers PET-based imaging for neuroendocrine tumors but has a short half-life of about 68 minutes. That limits distribution and generally requires local production. Copper-64 DOTATATE, introduced later, has a longer 12.7-hour half-life, which makes broader distribution more feasible.

The researchers analyzed Medicare claims for neuroendocrine tumor radiotracer imaging from 2014 to 2023. They used patients’ home locations and imaging facility locations to estimate travel distance and compare access for metropolitan, micropolitan, and small-rural patients.

Use patterns changed quickly. Gallium-68 DOTATATE/DOTATOC accounted for 33.8% of radiotracer use in 2017 and rose to 90.9% by 2020. After copper-64 DOTATATE entered the market in 2021, its share reached 40.6% by 2023, while indium-111 pentetreotide fell to 2%.

When gallium-based PET radiotracers were the main PET option, patients in small-rural areas had to travel substantially farther than those in metropolitan and micropolitan areas. The Neiman Institute said rural patients had to travel long distances because gallium-68 radiotracers must be produced close to the imaging site.

“PET/CT-based imaging with gallium-68 can only be performed when the radiotracer is produced locally due to its extremely short half-life,” said Cindy Yuan, MD, assistant professor of clinical radiology at Indiana University School of Medicine.

Copper-64 DOTATATE changed the access pattern. The Neiman Institute said its introduction in 2021 largely eliminated metropolitan-micropolitan versus small-rural differences in access to PET-based radiotracers.

Patients still traveled farther for PET-based tracers than for indium-111 pentetreotide, likely reflecting the availability of PET scanners. Yuan said the willingness to travel farther may reflect the clinical superiority of PET-based radiotracers.

The findings also have implications for theranostics. Elizabeth Rula, PhD, executive director of the Neiman Institute and a study co-author, said access disparities to diagnostic radioligands likely reflect similar disparities to therapeutic radioligands because diagnostic imaging typically precedes therapy.

Eric Christensen, PhD, research director at the Neiman Institute and senior author, said copper-64 helped restore parity in urbanicity-based access to PET-based radiotracers that did not exist when gallium-68 tracers were the only PET-based option.

The results suggest isotope logistics can shape patient access even when newer imaging agents offer clinical advantages. For rural nuclear medicine programs, longer-lived radiotracers may help reduce travel burden and expand access to neuroendocrine tumor imaging.