PET imaging method could improve Type 1 diabetes treatment

Yale University researchers have discovered a new PET imaging method that could improve the care of type 1 diabetes patients. The test measures beta-cells masses and could improve monitoring, according to research published online in the August issue of the Journal of Nuclear Medicine.  

For type 1 diabetes patients, tracking beta-cell mass is important, lead author Jason Bini, PhD, a postdoctoral fellow at Yale’s PET Center. But many methods to measure beta-cell function are influenced by a patient’s glucose and insulin levels—and, therefore, unable to measure dormant beta-cells that may be unresponsive to treatment.  

“This work is important for patients because uptake of a radiotracer measured on a PET scan could guide treatment options,” Bini said in a prepared statement. “For example, if a patient has low beta-cell function with high signal in the PET scan, this could represent a patient with dormant beta cells that could respond to a treatment targeting existing cells. If a patient has low beta-cell function and low signal in the PET scan (very few viable or dormant beta cells present), that individual may be a candidate for beta-cell transplantation.” 

For their study, the researchers screened brain radioligands to assess their ability to identify beta cells. They then had 12 healthy controls and two participants with Type 1 diabetes undergo PET/CT scans with six tracers.  

Overall, the dopamine type 2/type 3 (D2/D3)-receptor agonist radioligand carbon-11 (11C)-(+)-4-propyl-9-hydroxynaphthoxazine (PHNO) was the only radioligand to demonstrate sustained uptake in the pancreas with high contrast versus abdominal organs, according to the researchers.  

The researchers believe that 11C-(+)-PHNO is an effective way to differentiate beta-cell mass between healthy individuals and those with Type 1 diabetes to track and guide therapies for diabetes patients. 

“These findings could facilitate development and wider dissemination of novel imaging methods in molecular imaging and nuclear medicine to assess receptor/enzyme pharmacology in diabetes and other endocrine disorders,” Bini said.