PSMA-PET and MRI for Detection of Recurrent Prostate Cancer After Radical Treatment

PSMA-PET and MRI for Detection of Recurrent Prostate Cancer After Radical Treatment - a Multicenter Study

Approximately one third of prostate cancer patients experience biochemical relapse following initial radical prostatectomy or curative radiotherapy. To determine further treatment, it is of utmost importance to accurately differentiate local and regional recurrence from distant metastatic disease. Unfortunately, the currently used medical imaging methods (MRI and bone scan) lack sensitivity for detection of nodal and skeletal metastases, which can lead to over-treatment of patients with occult metastatic disease. PET imaging with prostate specific membrane antigen (PSMA)-ligands has shown a promising potential for improving the detection accuracy in recurrent prostate cancer, especially when combined with the excellent soft-tissue contrast of MRI. However, evidence is mostly based on retrospective single center studies so far, including patients with a wide variety of PSA levels.

Improving the sensitivity for detection of metastatic disease is a crucial step in reducing over-treatment of prostate cancer patients with biochemical relapse following radical treatment. The purpose of this prospective multi-center study is to standardize PSMA PET/CT and PET/MRI imaging across three university hospitals in Norway, and investigate its merit for detection of recurrent prostate cancer. The long-term overall goal is offering prostate cancer patients a more personalized treatment plan aiming to improve the chances of survival and quality of life.

Inclusion Criteria (surgery cohort):

• Prostate cancer patients with biochemical relapse in accordance with the European Association of Urology (EAU) guidelines on prostate cancer; two consecutive measurements with PSA ≥ 0.2 ng/ml following radical prostatectomy or PSA > 2.0 ng/ml above the nadir following definitive radiotherapy
• Potential candidates for loco-regional pelvic salvage treatment based on age and co-morbidity

Exclusion Criteria:

• Previous salvage therapy for recurrent prostate cancer
• General contra-indications for an MRI exam (pacemaker, aneurysm clips, any form of metal in the body, or severe claustrophobia)
• Serious concomitant systemic disorders or reduced cognitive functioning that in the opinion of the investigator would compromise the patient's ability to complete the study or interfere with the evaluation of the efficacy and safety of the study objectives
• Impaired renal function defined as estimated glomerular filtration rate (eGFR) < 30 ml/min/1.73 m2
• Hormonal treatment during the last three months