Short summary

Men diagnosed with prostate cancer and intermediate or high risk of metastases are being examined to show if metastases are present. Today the examinations done are CT and PET-bone scintigrafi. A new examination is now available, PSMA-PET/CT, and we want to show that this examination can replace the two examinations. In a smaller group of patients we will also do a PSMA-PET/MR to detect the extension of the primary tumor before treatment.

Rationale

PCa is the most frequent cancer form in men in developed countries with approximately 4,500 new cases reported annually in Denmark, The relative 5-year survival is 87%. 

Choice of treatment regimen at primary diagnosis is based on risk stratification, staging of the disease, and general health condition of the patient. In intermediate and high risk PCa, further staging procedures besides T-staging is warranted. CE-CT or magnetic resonance (MR) is used for N-staging in cases when pelvic lymph node dissection is avoided during radical prostatectomy or when surgery is refrained from. M-staging is traditionally obtained from bone scintigraphy, which reflects bone metabolism and has a reported sensitivity as well as specificity of 80%. BS has been substituted with NaF-PET in clinical routine at our department, and will as well in this study.  

The transmembrane protein, PSMA, is expressed in abundance on the surface of prostate cancer cells. Radiolabelled ligands targeting PSMA has been developed for use in PET/CT-scanners.  

The 18F labeled PSMA-PET/CT has so far shown detection rates of up to 94% in patients with biochemical recurrence of PCa after radical prostatectomy with curative intend. The literature regarding 18F-PSMA-PET/CT for staging of primary PCa comprises only two retrospective studies with 10 and 8 patients, respectively, both of them also focusing on the added value of combining 18F-PSMA-PET with mpMRI for a combined T- and N-staging.

Indeed, randomized controlled studies in well powered designs addressing patient relevant outcomes of staging primary in PCa with 18F-PSMA-PET/CT compared to conventional imaging are considered highly relevant. 

Description of the cohort

448 men diagnosed with prostate cancer of intermediate and high risk of metastases, or low risk and suspicion of metastases. They will be enrolled at time of diagnosis and before treatment.

Data and biological material

Blood test results, scan results, clinical information from patient records, pathology.

Collaborating researchers and departments

Nuclear Medicine Department Odense University Hospital

• Malene Grubbe Hildebrandt, head of research, PhD
• Mie Holm Vilstrup, consultant

Department of Urology, Odense University Hospital

• Mads Hvid Poulsen, associate professor, PhD

Department of Oncology, Odense University Hospital

• Steinbjørn Hansen, associate professor, PhD

Publications associated with the project

1. Clinical impact on stage migration and treatment strategy when using 18F-PSMA PET/CT compared to conventional imaging in primary staging of PCa (Group A vs B).

2. A prospective comparative accuracy study of 18F-PSMA PET/CT for N- and M-staging compared to conventional imaging in primary PCa (Group B).

3. The added value of PSMA-PET/mpMRI compared to PSMA-PET/CT on T, N, and R-staging (R = resection level) (Subgroup of B).

4. The impact on progression free survival and biochemical relapse when using 18F-PSMA PET/CT compared to conventional imaging in primary staging of PCa (Group A vs. B - planned as a joint publication with PhD student from the Department of Urology).