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

Official Title

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


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).

Trial Description

Primary Outcome:

  • 6-month Toxicity
  • 6-week Toxicity
Secondary Outcome:
  • Quality of Life
  • Disease Free Survival

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Canadian Cancer Society

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