Jorun Holm

RE-PRISMA Recurrent and Metastatic Prostate Cancer: Impact of 18F-PSMA-1007 PET/CT on clinical decision making and response monitoring

The number of men diagnosed with prostate cancer has increased rapidly over the last 20 years. Today, approximately 40.000 Danish men are diagnosed with the disease. Annually, more than 1.100 men die due to prostate cancer. Half of the male population aged 60 or older has cancer cells in their prostate gland, even though many have yet to be diagnosed.

Among the diagnosed men the development of the cancer varies to a large degree. Some get aggressive cancer types demanding immediate and intensive treatment. Others have benign cancer types that develop slowly or not at all. To assure that proper treatment is provided, it is crucial to establish which type and what stage of prostate cancer we are dealing with. Excessive treatment may cause unnecessary side effects and lower the quality of life. Insufficient treatment may shorten the lives of the patients.

In the RE-PRISMA project the two focus groups are men suspected of recurrent prostate cancer and men where cancer has spread to other organs in the body. Our aim is to develop more accurate methods of imaging. More accurate and personalized imaging, as well as genetic analysis, will improve the chances of tailor-made treatment options for each patient. The project will be carried out in collaboration with clinicians, geneticists and patient representatives.

The imaging we are going to use in this project is an 18F-PSMA-1007-PET/CT scan recently introduced at Odense University Hospital (OUH) in April 2019. This scan is the newest generation of prostate targeted imaging in Denmark and worldwide, and it is due time to document the benefits for the patient in a clinical setting. Prostate-Specific Membrane Antigen (PSMA) is a protein expressed on the surface of prostate cancer cells. It can be detected by a radiolabeled PSMA-tracer. The imaging technique starts with injecting a small amount of PSMA-tracer into the blood followed by a body scan with either PET/CT or PET/MR.

The primary goals are to evaluate 1) what impact 18F-PSMA-1007-PET/CT imaging has on treatment decisions for the group of men with suspected recurrent prostate cancer and 2) response prediction and monitoring in the group of men with prostate cancer that has spread to other organs. We test the hypothesis that this new imaging results in superior treatment decisions compared with traditional imaging. Another goal is to evaluate if a PET/MR scan can further improve the treatment decisions compared to the PET/CT scan. A further goal is to explore whether computerized artificial intelligence contribute to more accurate and objective scan evaluations possibly making treatment monitoring easier to interpret and understand for clinicians and patients. Therapies based on PSMA-targeting radiolabeled agents are currently being developed with promising results, but are beyond the scope of this project.

The RE-PRISMA project is intended as part of a Prostate Research Centre (PASSPORT) that is planned as a multidisciplinary center at OUH with collaborators in the Region of Southern Denmark. In the PhD-project, the necessary cooperation with Departments of Radiology, Urology and Oncology at OUH is already established. As a trained specialist in Nuclear Medicine, I will personally evaluate all scans. We intend an international collaboration with the Professor Weber group at Technical University of Munich. They have high expertise in PSMA imaging, and we have successfully worked together on previous projects.

RE-PRISMA and a collaborative study set in the Department of Clinical Genetics got a joint conditional approval by The Regional Committees on Health Research Ethics in June 2019. The genetic study applies to the same patient group as RE-PRISMA, exploring if genetic markers in blood and tissue can improve treatment monitoring. We aim to recruit 300 patients from the Region of Southern Denmark over three years beginning in the fall of 2019.

Two patient representatives with former primary prostate cancer are participating as collaborators in RE-PRISMA. They have already provided valuable input to the project: ethical considerations, designing patient information letters and comments on the layman’s protocol. Through PROPA, the Danish Patient Union for Prostate Cancer, the representatives will share the key findings of this project.