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NCT Number: NCT05269550

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

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

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Key information

Conditions

Prostate Cancer Genital Diseases Genital Diseases, Male Genital Neoplasms, Male Male Urogenital Diseases Neoplasms Neoplasms by Site Prostatic Diseases Prostatic Neoplasms Urogenital Diseases Urogenital Neoplasms

Age range

18 year and older

Sex eligibility

Male

Study type

Interventional

Phase

Not applicable

Primary location

London Health Sciences Centre, London, Ontario, Canada

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Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Age > 18 years of age
  • Histologically confirmed carcinoma of the prostate
  • High-intermediate risk or high risk as defined by NCCN criteria:
  • High intermediate: 2 or 4 intermediate risk factors (T2B-T2C, Gleason GG 2 or 3, PSA 10-20) or GG 3 or intermediate risk with equal or >50% biopsy core involvement
  • High-risk: one of T3a, Gleason GG 4 or 5, or PSA >20 ng/ml
  • Very-high risk: one of primary Gleason Pattern 5, >4 cores Grade Group 4 or 5, clinical T3b, or more than 1 high-risk feature
  • Conventional imaging (bone scan and abdominal pelvic computed tomography) negative for extra-pelvic nodal, skeletal or visceral metastases
  • Willing to give informed consent to participate in this clinical trial
  • Able and willing to complete EPIC questionnaires

Exclusion criteria

  • Prior prostate cancer treatment (apart from prior 5-alpha reductase inhibitor treatment); androgen deprivation therapy prior to enrollment or treatment planning not permitted
  • Men with clinical T4 disease are excluded
  • Contraindication to radical prostate radiotherapy e.g. connective tissue disease or inflammatory bowel disease
  • Contraindication to prostate MRI (i.e. non0compatible stent, pacemaker, prosthesis, etc.)
  • Contraindication to use of PSMA PET agent PSMA 1007 due to intolerance or allergy
  • Anticoagulation medication (if unsafe to discontinue for gold seed insertion)
  • Diagnosis of bleeding diathesis
  • Poor baseline urinary function defined as a score of 5 ("big problem") on question 5 of the EPIC 26 (Overall, how big a problem has your urinary function been for you during the last 4 weeks?)
  • Definitive extra-pelvic nodal or distant metastatic disease on conventional staging investigations

Treatment and study plan

High-Intermediate Risk Patients-cohort 1

Radiation

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)

High Risk or Very High-Risk Patients-cohort 1

Radiation

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)

High-Intermediate Risk Patients-cohort 2

Radiation

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.

High Risk or Very High-Risk Patients-cohort 2

Radiation

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.

Primary outcomes

  1. 6-month Toxicity

    Time frame: 6-months

    6-month gastrointestinal (GI) and genitourinary (GU) toxicity using the Common Terminology Criteria for Adverse Events version 5.0 (CTCAE v5.0).

  2. 6-week Toxicity

    Time frame: 6-weeks

    6-week gastrointestinal (GI) and genitourinary (GU) toxicity using the Common Terminology Criteria for Adverse Events version 5.0 (CTCAE v5.0).

  3. Expansion cohort: Median minimum dose to dominant intra-prostatic lesion

    Time frame: 6-months

    Expansion cohort: Median minimum dose to dominant intra-prostatic lesion

Secondary outcomes

  1. Quality of Life measured by the Expanded Prostate Cancer Index Composite (EPIC-26) questionnaires

    Time frame: 5 years

    Quality of life measured by the Expanded Prostate Cancer Index Composite (EPIC-26) questionnaires.

  2. Disease Free Survival

    Time frame: 5 years

    Five-year disease-free survival (DFS) as a composite of biochemical control, patient death or development of clinical metastases or institution of salvage ADT.

Other outcomes

  1. Translational Endpoint 1

    Time frame: 24 months

    Serial PSMA PET/MRI images will be collected at baseline, 6 months and 2 years to characterize the imaging response of prostate cancer to treatment and potentially identify imaging biomarkers (including pharmacokinetic, radiomic and quantitative PET and mpMRI metrics) that predict for five-year DFS

  2. Translational Endpoint 2

    Time frame: 24 Months

    Baseline collection of diagnostic tissue biopsy samples and serial collection of blood and urine over multiple time points (baseline, 6 months, 1 year, 2 years post radiotherapy) for correlative biologic biomarker analyses with imaging changes and disease-free survival and toxicity post treatment

  3. Translational Endpoint 3

    Time frame: 2 years

    A prostate biopsy at baseline and 2 years will allow for correlation of histopathology with PSMA PET/MRI images. Specifically, we will investigate biopsy correlations with pre-treatment PSMA PET/MRI images and whether a negative PSMA PET/MRI is correlated with a negative 2-year post treatment biopsy (shown to correlate with long term disease control

  4. Translational Endpoint 4

    Time frame: 5 years

    Examine novel clinical prognostic biomarkers (i.e. percentage of Gleason Pattern 4 on biopsy, 4- year PSA response rate) and their correlation with imaging findings and 5-year Disease Free Survival

  5. Translational Endpoint- Expansion cohort

    Time frame: 6 months

    Characterize intra-prostatic foci on pre, post 3-month ADT and 6 months post radiotherapy on PSMA PET/MRI + sodium MRI imaging

Sponsors and collaborators

Lead sponsor

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

Other

Registry information

Official study title

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

Acronym: ARGOS/CLIMBER

Important dates

Study start
2022
Primary completion
2028
Study completion
2028
First posted
Mar 8, 2022
Registry last updated
Jul 28, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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