Accurate knowledge of the biodistribution of 18F-choline is essential for the correct interpretation of PET/CT imaging in restaging of patients with prostate cancer, according to a study published in this month’s Nuclear Medicine Communications.
The study included 80 patients who underwent whole-body 18F-choline PET/CT imaging for primary staging or biochemical recurrence of prostate cancer.
Giovanni Simonetti, MD, professor of radiology at the University Hospital Tor Vergata in Rome, and colleagues observed physiological 18F-choline uptake in liver, pancreas, spleen, salivary and lachrymal glands and also in the urinary tract due to renal excretion. There was less intense tracer uptake in the bone marrow and intestines.
The researchers found abnormal and unexpected PET findings in 18.7 percent of patients, not owing to prostate cancer localizations.
“The majority of these findings were owing to inflammation (12 of 15); a case of low grade lymphoma was detected; two patients showed focal brain uptake of 18F-choline and were subsequently submitted to MRI: in one a meningioma and in the other a low-grade brain tumor were diagnosed,” said Simonetti.
The researchers noted that CT-enabled differentiation of physiological bowel activity and 18F-choline excretion in the ureters while correlative imaging with MRI was important for the brain.
“Accurate knowledge of the biodistribution of 18F-choline is essential for the correct interpretation of PET/CT imaging,” said Simonetti.