PET/MRI of Prostate Cancer
Joseph Ippolito1

1Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, United States

Synopsis

This educational talk provides an overview of PET/MRI in the evaluation of prostate cancer with a focus on the strengths and weaknesses of PET/MRI versus PET/CT as well as the individual strengths and weaknesses of MRI versus PET. This talk also discusses methods for evaluating initial staging as well as biochemical recurrence in prostate cancer patients and discusses current progress made in the radiopharmaceutical field and its ability to synergize with emerging methods in MRI.

Target Audience

This syllabus is aimed at radiologists in training and in clinical practice who perform genitourinary MRI studies and interested in learning more about the application of PET/MRI to prostate cancer evaluation.

Objectives

1. To discuss the different types of PET/MRI imaging systems.

2. To discuss the strengths and weaknesses of PET and MRI as individual modalities in the evaluation of prostate cancer.

3. To compare the strengths and weaknesses of simultaneous PET/MRI with PET/CT in the evaluation of prostate cancer with emphasis on MR-based attenuation correction of soft tissue and osseous lesions.

4. To discuss methods for imaging prostate cancer at initial staging and at biochemical recurrence with PET/MRI.

5. To illustrate the strengths of PET/MRI in prostate cancer with case examples using different radiopharmaceuticals.

6. To discuss the progress made in developing clinical radiopharmaceuticals for prostate cancer.

Purpose

To provide an overview of the strengths and weaknesses of PET/MRI in the evaluation of prostate cancer.

Methods

A literature review was conducted to identify key concepts of PET/MRI that are relevant to the clinical radiology field, focusing on relevant physics and instrumentation, key MRI sequences, and application of prostate cancer radiopharmaceuticals. Clinical case examples were used to reinforce these concepts.

Results

1. PET and MRI are both complementary and synergistic. Although anatomic detail and spatial resolution are suboptimal with PET and sensitivity is suboptimal with MRI, these limitations are overcome when the two modalities are combined.

2. PET/MRI offers several advantages over PET/CT, including reduced radiation exposure, better lesion detection, applicability to numerous molecular and functional imaging techniques, and improved reader confidence.

3. PET/CT still holds some advantages over PET/MRI including better osseous lesion quantification, faster scanning time, instrument availability, and insurance reimbursement in some cases.

4. PET/MRI protocols can be optimized differently to evaluate for initial staging versus disease recurrence.

Conclusion

PET/MRI is rapidly emerging as an essential modality for genitourinary cancer imaging, specifically prostate cancer. Although some limitations still exist for PET/MRI compared to PET/CT, advancements continue to be made that are narrowing the gap between the two modalities.

Acknowledgements

The presenter would like to acknowledge Kathryn Fowler, M.D.; Tyler Fraum, M.D.; Pamela Woodard, M.D.; Farrokh Dehdashti, M.D.; Kooresh Shoghi, Ph.D.; and Jeff Michalski, M.D. for their assistance with this presentation.

References

1. Rosenkrantz AB, et al. AJR American Journal of Roentgenology. 2016;206(1):162-172.

2. Lindenberg L, et al. Semin Nucl Med. 2016; Nov;46(6):536-543

3. Stecco A, et al. Radiol Med. 2016;Jun;121(6):502-509

4. Kitajima K, et al. Clin Imaging. 2014; Jul-Aug;38(4):464-469.

5. Grueneisen J, et al. Eur J Nucl Med Mol Imaging. 2015; Nov;42(12):1814-1824.

6. Queiroz MA, et al. Eur Radiol. 2015; Aug;25(8):2222-30.

Proc. Intl. Soc. Mag. Reson. Med. 26 (2018)