Longer pelvic PET acquisition times during PET/MRI increase lymph node detection rates
Researchers from the University of California, San Francisco (UCSF) have found that longer pelvic PET acquisition times during PET/MRI can improve the quality of care for patients with rectal cancer. The team published its findings in the American Journal of Roentgenology.
For the study, rectal cancer patients underwent whole-body PET/MRI in additional to a dedicated pelvic PET/MRI with both three- and 15-minute pelvic PET acquisitions. Radiologists then interpreted the exams with PET only, MRI only and then combined PET and MRI. A radiologist also read the three-minute pelvic PET acquisition and 15-minute pelvic PET acquisition separately.
Overall, 94 abnormal lymph nodes were detected. More than 39 percent were seen only on the 15-minute pelvic PET acquisition. And of the 57 lymph nodes measured 5 mm or smaller, more than 30 percent were see only on the 15-minute pelvic PET acquisition.
During the study, 17 patients were imaged for initial staging. Of those patients, more than 64 percent were upstaged as a result of the extended pelvic PET acquisition time.
“These findings indicate that PET/MRI of the pelvis in rectal cancer staging should include a dedicated 15-minute PET acquisition of the pelvis, particularly given that this extended PET acquisition time does not increase overall scan time,” wrote lead author Jason Bailey, MD, department of radiology and biomedical imaging at UCSF, and colleagues.
The authors also noted that their study had limitations. The sample size was small, for instance, and comparison with the patients’ pathology results “was not feasible.”
Michael has more than 18 years of experience as a professional writer and editor. He has written at length about cardiology, radiology, artificial intelligence and other key healthcare topics.