PET/MRI Clinical Research
UCSF participated in the initial FDA clinical trial used to obtain FDA approval for the first time-of-flight PET/MRI in 2014. Since the installation of the machine, researchers at UCSF have been working on numerous applications leveraging the capabilities of the new technology. The UCSF Radiopharmaceutical Facility can produce over 30 radiotracers that can be applied in PET/MRI research. A few example research applications are listed below:
Imaging of Neuroendocrine Tumors
We have been evaluating the utility of Ga-68 DOTA-TOC PET/MRI for the staging of patients with neuroendocrine tumor (of note Ga-68 DOTA-TOC is not FDA approved). We have imaged over 100 patients using DOTA-TOC PET/CT at UCSF under and Investigational New Drug approval from the FDA. We have imaged over 15 patients with neuroendocrine tumor using PET/MRI, and using this technology we have been able to provide gold standard imaging of the liver while providing whole body staging for metastatic disease. The removal of a contrast enhanced CT from the PET/CT study decreases patient radiation dose by over 50%, which is an important issue in this patient population. Please follow this link to view a video about DOTA-TOC PET/MRI.
Prostate Cancer Staging
Imaging plays an important role in staging of patients with prostate cancer. At UCSF, we have helped to develop multiparametric MRI as a robust imaging modality for imaging primary tumors in order to determine biopsy and surgical management (Kurhanewicz lab). One limitation in initial staging of prostate cancer is the limited detection of nodal metastasis, which is particularly important in patients with high-risk disease. Using agents such as C11 and F18 choline as well as Ga-68 labeled PSMA, we can use combined PET and MRI to provide staging of the primary tumor while imaging for metastatic disease in the same study.
Novel Pulse Sequences and Post-Processing for Attenuation Correction
One of the main limitations of PET/MRI is related to attenuation correction. In the setting of PET/CT attenuation correction is easily implemented as the CT images can be converted to attenuation maps. MRI on the other hand does not image density and so an attenuation map cannot be simply created. This issue can lead to errors in quantitative uptake measurements on PET/MRI. Therefore we are working on both MRI pulse sequence development and post-processing approaches to create accurate attenuation correction maps in the setting of PET/MRI.
Information for researchers wanting to use the PET/MRI.