Medication ingested to control blood-sugar levels can skew the results of cancer screenings using FDG-PET, according to a study presented at SNM’s annual meeting on June 7 in Salt Lake City.
According to the study, diabetic patients taking tablet-form medications to help control blood-sugar levels prior to being screened for cancer using PET showed abnormally high intestinal absorption of 18F-FDG, a sign that normally indicates a cancerous tumor.
“The use of certain medications can influence where and how much of the imaging agent is taken up by the body,” said Kyle Hurtgen, certified nuclear medicine technologist, Saint Louis University Hospital in St. Louis, Mo., and lead author of the study. “It is important for technologists to know the patient’s history and use that information to their advantage to help physicians detect cancer and provide the best possible treatment for diabetic patients.”
Of the 39 patients selected for known or highly suspected extra-abdominal malignancy, 26 cancer patients who had diabetes were divided into two subgroups: those diabetic who reported receiving, oral hypoglycemics (OH) within the last 24 hours (13 patients) and those who did not receive OH (13 patients). The remaining 13 cancer patients without diabetes were controls.
All 39 patients underwent FDG PET/CT on the same scanner and according to the standard oncology protocol. Intense FDG bowel uptake was significantly higher in OH patients (61.5 percent) as compared to those who were not on OH medications (15.4 percent) or controls (0 percent).
The researchers concluded that OH significantly increased FDG uptake in the colon and raised questions of stopping OH treatment before FDG PET/CT scans.
Also, knowledge of potential problems is important to avoid false interpretation of PET/CT scans, particularly in patients with intra-abdominal malignancy, they noted.