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

Norwegian University of Science and Technology300 enrolled

Overview

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.

Study Type

OBSERVATIONAL

Enrollment

300

Conditions

Prostatic Neoplasms

Interventions

Eligibility

Sex: MALEMin age: 18 Years

Medical Language ↔ Plain English

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

Locations (3)

Haukeland University Hospital

Bergen, Norway

University Hospital of North Norway

Tromsø, Norway

St Olavs Hospital

Trondheim, Norway

Outcomes

Primary Outcomes

Detection rates of prostate cancer recurrence after radical treatment using a standardized imaging protocol consisting of PSMA PET/CT and PET/MR

Consensus scoring and decision by nuclear medicine physician and radiologist on presence of local recurrent or metastatic lesions

Time frame: baseline

Secondary Outcomes

Differences in detection rates between 68Ga- and 18F-PSMA tracers

Comparison of detection rates between the two radioisotopes based on consensus scoring

Time frame: baseline

Differences in detection rates after radical treatment between whole-body PET/CT with and without PET/MR

Comparison of number of present local recurrent or metastatic lesions

Time frame: baseline

Number of equivocal findings with and without addition of PET/MR to the whole-body PET/CT

Comparison of the number of local recurrent and metastatic lesions scored as equivocal

Time frame: baseline

Detection rates of the combined PET/MR and PET/CT protocol compared with MRI-only.

Comparison of detection rates using MRI only compared to the detection rates based on consensus decision using the combined PET/MR and PET/CT protocol

Time frame: baseline

Detection rate dependency on prostate specific antigen (PSA) level and kinetics at time of imaging in addition to Gleason score and stage of primary cancer

Detection rates stratified according to PSA levels, kinetics and Gleason score

Time frame: baseline

Inter-reader variability for interpretation of the PSMA PET/CT and PET/MR

Retrospective re-evaluation of images at minimum three sites

Time frame: baseline

Detection of differences in image quality between participating centra

Image quality will be scored on a 5-point Likert Scale by a nuclear medicine physician and radiologist and compared between the centra

Time frame: baseline

Sensitivity and specificity of the standardized whole-body PET/CT and targeted PET/MR protocol for detection of recurrence based on long-term clinical follow-up

A reference standard based on evidence from histopathology, clinical follow-up and follow-up imaging will be established using criteria defining presence and absence of local recurrent and metastatic disease

Time frame: baseline images and long term follow-up

Head to head comparison of uptake patterns of 68Ga- and 18F-PSMA

A selected subset of patients will be invited for a second imaging session.

Time frame: baseline

Evaluation of locoregional PET-uptake according to primary radical treatment

Comparison of locoregional PET-uptake in patients treated with primary radiotherapy versus primary prostatectomy

Time frame: baseline