Novel PET radiotracer reduces number of false-positive cancer findings after COVID-19 vaccination - Medical Xpress

A caller imaging agent, ⁶⁸Ga-FAPI, tin trim the fig of false-positive PET/CT findings among crab patients precocious vaccinated for COVID-19. New probe published up of people successful the Journal of Nuclear Medicine shows that ⁶⁸Ga-FAPI imaging offers superior lesion detection without vaccine-related tracer uptake successful locoregional lymph nodes that is communal with ¹⁸F-FDG imaging. This tin assistance to forestall costly follow-up and mendacious absorption decisions for crab patients.

One broadside effect of the COVID-19 vaccine is that ¹⁸F-FDG (the astir commonly utilized PET imaging agent) is taken up by immune cells responding to the mRNA inflammatory stimulus caused by the vaccine. This is known arsenic a reactive uptake and does not ever bespeak that a tumor is present.

"This reflection is concerning arsenic vulnerable groups, specified arsenic oncologic patients, acquisition some regular COVID-19 booster shots and medical imaging," said Tristan T. Demmert, researcher successful the Department of Nuclear Medicine astatine Essen University Hospital successful Essen, Germany. "False affirmative findings connected ¹⁸F-FDG PET owed to reactive uptake whitethorn trigger mendacious absorption decisions."

To find a mode to debar these mendacious positives, researchers compared 2 radiotracers, ⁶⁸Ga-FAPI and ¹⁸F-FDG. Using a ample prospective imaging registry, researchers investigated 11 oncologic patients who had received a COVID-19 vaccination wrong six weeks, had ⁶⁸Ga-FAPI and ¹⁸F-FDG imaging connected the aforesaid day, and had documentation of tracer uptake successful locoregional lymph nodes. Visual readings of the images were performed by 2 atomic medicine physicians.

Significant lymph node uptake adjacent to the injection tract was noted successful 11/11 patients with ¹⁸F-FDG PET/CT versus 0/11 with ⁶⁸Ga-FAPI PET/CT. In addition, ¹⁸F-FDG detected 73 percent of tumor lesions, portion ⁶⁸Ga-FAPI detected 94 percent of each tumor lesions.

"In patients with suspected tumors successful the axillary region, a costly follow-up was often recommended to debar incorrect diligent treatment. According to our results, this could person been prevented by utilizing ⁶⁸Ga-FAPI, which would person allowed higher tumor detection astatine the aforesaid time," noted Demmert. "Considering that further booster vaccinations are expected, ⁶⁸Ga-FAPI could amusement its imaginable successful avoiding vaccine-related misinterpretations connected PET/CT portion providing equivalent tumor detection."

Provided by Society of Nuclear Medicine and Molecular Imaging