PSMA MRI Guided Prostate SBRT (ARGOS)/Comprehensive, Longitudinal Evaluation of Imaging Biomarkers Post Radiotherapy (CLIMBER)

Summary

This study is a prospective Phase I/II protocol enrolling men with either high intermediate-risk or high-risk or very high-risk prostate cancer. All men will have PSMA Targeted PET (using the PSMA targeting ligand PSMA 1007) and multiparametric magnetic resonance imaging (mpMRI) for delineation of intra-prostatic foci of cancer and any involved regional lymph nodes based on high SUV uptake on PET or mpMRI (T2W, DWI/ADC, DCE) appearance suspicious for cancer. Tumour delineation will be performed by fusing the PSMA PET and mpMRI with planning CT simulation images. Fiducial marker implantation for treatment guidance will be mandatory but use of other organs at risk protection strategies (i.e. GU Loc, Space-OAR) will be allowed but not mandatory. Patients will be treated with image-guided SBRT using the fiducial markers for intra-fraction motion management. Dose escalation to imaging defined targets (intra-prostatic and involved nodes on PSMA PET + MRI) will be accomplished through a simultaneous boost technique. Maintaining dose to organs at risk will take precedence over boost dose targets (targeted maximum dose of 50Gy/5 fractions to imaging defined prostatic lesion; 35Gy/5 fractions to imaging defined involved nodes).

Cohort extension: We hypothesize that integration of neoadjuvant androgen deprivation therapy will provide for pretreatment cancer downstaging and will allow us to achieve higher target doses to the imaging defined DILs than currently achieve. Additionally, we plan to include a novel sodium MRI protocol into the baseline imaging to compare DIL volumes delineated by this modality to those by mpMRI and PSMA PET and to characterize changes in sodium MRI in response to ADT alone and subsequent radiotherapy

Conditions

• Prostate Cancer

Interventions

RADIATION

High-Intermediate Risk Patients-cohort 1

Patients will receive 35Gy/5 fractions to the whole prostate (25 Gy to proximal Seminal Vesicles) with a simultaneous boost to PET/MRI defined intra-prostatic foci to a target maximum dose of 50Gy/5 fractions. Six months of androgen deprivation therapy will commence with the end of radiotherapy (concurrent plus adjuvant)

RADIATION

High Risk or Very High-Risk Patients-cohort 1

Patients will receive 35Gy/5 fractions to the whole prostate (25Gy to whole Seminal Vesicles) with a simultaneous boost to PET/MRI defined intra-prostatic foci to a target maximum dose of 50Gy/5 fractions. Pelvic lymph nodes will receive 25Gy/5 fractions synchronous with prostate treatment with a simultaneous boost to imaging involved nodes to a maximum of 35Gy/5 fractions. Eighteen months of androgen deprivation therapy will commence with the end of radiotherapy (concurrent plus adjuvant)

RADIATION

High-Intermediate Risk Patients-cohort 2

Patients will receive 35Gy/5 fractions to the whole prostate (25 Gy to proximal Seminal Vesicles) with a simultaneous boost to PET/MRI defined intra-prostatic foci to a target maximum dose of 50Gy/5 fractions. Androgen deprivation therapy will commence 3 months before radiotherapy (concurrent plus adjuvant) and will continue for a total of 6 months.

RADIATION

High Risk or Very High-Risk Patients-cohort 2

Patients will receive 35Gy/5 fractions to the whole prostate (25 Gy to proximal Seminal Vesicles) with a simultaneous boost to PET/MRI defined intra-prostatic foci to a target maximum dose of 50Gy/5 fractions. Androgen deprivation therapy will commence 3 months before radiotherapy (concurrent plus adjuvant) and will continue for a total of 18 months.

Sponsors & Collaborators

• London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's

  lead OTHER

Study Design

Allocation

NA

Purpose

TREATMENT

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

18 Years

Sex

MALE

Healthy Volunteers

No

Timeline & Regulatory

Start

2022-05-03

Primary Completion

2028-12-15

Completion

2028-12-15

Countries

• Canada

Study Locations