CHICAGO— Preliminary clinical results of whole-body PET/MR imaging in oncology indicate the hybrid modality may be comparable to PET/CT and useful in certain types of cancer, according to research presented today by Osman M. Ratib, MD, PhD, chair of radiology and head of nuclear medicine at University Hospital of Geneva in Switzerland, at the 96th annual Radiological Society of North America (RSNA) conference.
Ratib and his colleagues evaluated the performance and clinical applicability of combined imaging protocols on a hybrid PET/MR scanner for oncology, focusing on the optimization of imaging protocols and acquisition of diagnostic quality whole-body images in clinically acceptable timeframe. The prototype configuration provides sequential PET and MR images.
The research team employed standard PET and MRI protocols to optimize acquisition and developed optimized imaging protocols combining whole-body MR attenuation correction data with standard MR diagnostic protocols of both modalities while reducing the total time of the study.
Ratib and colleagues evaluated nearly 100 oncologic studies. In the alpha phase, they imaged 52 patients with PET/CT followed by PET/MR, and most patients also had complementary diagnostic MR scans, shared Ratib. Researchers graded image quality and reported standard uptake value (SUV).
During the beta phase, researchers scanned 45 patients and focused on optimizing protocols.
Initial studies included lymphomas, head and neck tumors, prostate and breast tumors as well as lung and colon cancers. The researchers reported that the diagnostic quality of fused PET/MR images were comparable to corresponding PET/CT images and measured local SUV were comparable.
“There were no differences in image quality or identification of abnormal lesions [between PET/MR and PET/CT],” stated Ratib, who offered several indications where PET/MRI could be useful, which included:
- Locating distant metastases in head and neck cancers;
- Detecting prostate cancer recurrence; and
- Screening for breast cancer metastases.
Sequental hybrid PET/MR scanning is clinically applicable and may be a more effective way of acquiring PET and MRI data in cases where both datasets are needed, concluded Ratib.