Magnetic Resonance (MR) Imaging With Hyperpolarized Bicarbonate (13C) to Measure Tissue pH in Prostate Cancer

April 28, 2026 updated by: Robert Flavell, MD, PhD

A Pilot Study of Magnetic Resonance (MR) Imaging With Hyperpolarized Bicarbonate (13C) to Measure Tissue pH in Localized Prostate Cancer

This is a single site, prospective pilot study to determine the feasibility and safety of the administration of HP 13C bicarbonate in 10 patients with prostate cancer to determine potential hydrogen (pH) values in surrounding tissue. The proposed study will evaluate pre-surgical participants with histologically confirmed localized prostate cancer who receive infusion of hyperpolarized 13C injection prior to MR imaging with endorectal coil.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

PRIMARY OBJECTIVE:

I. To determine the feasibility of tumor pH measurement in men with prostate cancer using hyperpolarized 13C bicarbonate imaging.

SECONDARY OBJECTIVE:

I. To determine the safety of administration of hyperpolarized 13C-bicarbonate.

EXPLORATORY OBJECTIVES:

I. To correlate the measurement of tissue pH with pathologic grade.

II. To correlate tissue pH maps with immunohistochemistry staining (IHC), gene expression (RNA-Seq), and spatial transcriptomics. *Bristol Myers Squibb (BMS) collaboration

OUTLINE:

Men with biopsy-proven adenocarcinoma of the prostate scheduled to undergo radical prostatectomy at University of California, San Francisco (UCSF) within 12 weeks of enrollment will receive infusion with hyperpolarized 13C bicarbonate and undergo metabolic MR imaging with endorectal coil. Participants will be followed for 5-9 days after the hyperpolarized 13C-bicarbonate injection, or removal from study, or until death, whichever occurs first. Participants removed from study for unacceptable study related adverse event(s) will be followed until resolution or stabilization (as determined by the investigator) or until initiation of new anti-cancer therapy, whichever occurs first.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
1

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Early Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • United States
    • California
      • San Francisco, California, United States, 94143
        • University of California, San Francisco

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Patients age >=18 years.
  2. Patients must have biopsy-proven adenocarcinoma of the prostate; biopsy may be performed outside of University of California, San Francisco (UCSF) if detailed results of sextant biopsy are available.
  3. Tumor size of at least 1.0 cm in long axis on Magnetic resonance imaging (MRI) or ultrasound; if no prior imaging is available, at least 3 cores positive on biopsy.
  4. Patients must have planned radical prostatectomy at UCSF within 12 weeks following protocol MRI/ magnetic resonance spectroscopy imaging) (MRSI).
  5. Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1.

  6. Demonstrates adequate organ function as defined below:

    1. Adequate bone marrow function:

      • Absolute neutrophil count >=1,500 cells/µL.
      • Platelets >=75,000 cells/µL.
      • Hemoglobin >=9.0 gm/dL.

    2. Adequate hepatic function:

      • Total bilirubin <1.5x upper limits of normal (ULN) (within normal institutional limits, unless elevated due to Gilbert's syndrome and direct bilirubin is within normal limits).
      • Aspartate aminotransferase (AST)/serum glutamic-oxaloacetic transaminase (SGOT) <=1.5 X institutional upper limit of normal.
      • Alanine aminotransferase (ALT)/serum glutamic-pyruvic transaminase (SGPT) <=1.5 X institutional upper limit of normal.

    3. Adequate renal function:

      • Creatinine clearance >= 50 calculated using the Cockcroft-Gault equation, unless data exists supporting safe use at lower kidney function values, no lower than 30 mL/min/1.73 m^2.
  7. Ability to understand and the willingness to sign a written informed consent document.

Exclusion Criteria:

  1. Patients who because of general medical or psychiatric condition, or physiologic status, cannot give valid informed consent.
  2. Patients unwilling or unable to undergo MR imaging, including patients with contraindications to Magnetic resonance imaging (MRI) as per UCSF radiology departmental guidelines.
  3. Patients who cannot tolerate or have contra-indications to endorectal coil insertion, for example, patients with a prior abdominoperineal resection of the rectum or latex allergy.
  4. Patients with contra-indications to injection of gadolinium contrast as per UCSF radiology departmental guidelines.
  5. Patients who take carbonic anhydrase inhibitors (e.g. acetazolamide, dichlorphenamide, methazolamide).
  6. Metallic hip implant or any other metallic implant or device that distorts local magnetic field and compromises the quality of MR imaging.
  7. Cryosurgery, surgery for prostate cancer, prostatic or pelvic radiotherapy prior to study enrollment. No limit on number of prior prostate biopsies. Prior Transurethral Resection of the Prostate (TURP) is not allowed.
  8. Poorly controlled hypertension, with blood pressure at study entry >160/100. The addition of anti-hypertensives to control blood pressure is allowed for eligibility determination.
  9. Congestive heart failure or New York Heart Association (NYHA) status >= 2. A history of clinically significant electrocardiogram (EKG) abnormalities, including QT prolongation, a family history of prolonged QT interval syndrome, or myocardial infarction (MI) within 6 months of study entry. Patients with rate-controlled atrial fibrillation/flutter will be allowed on study.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Diagnostic
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Pre-surgical participants with prostate cancer
The hyperpolarized 13C bicarbonate injection includes the administration of 35 mL injected intravenously (IV) at a rate of 5 mL/second followed by a 20 mL saline flush at 5 mL/second, followed by magnetic resonance (MR) imaging. The intervention will include routine and safety assessments 5 to 9 days after the injection.
Drug: Hyperpolarized Bicarbonate (13C)
Given IV
Other Names:
  • Hyperpolarized (HP) bicarbonate 13 (13C)
  • HP C13
Procedure: Magnetic Resonance imaging
Magnetic resonance imaging is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body
Other Names:
  • MR scan
  • Magnetic Resonance scan

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Proportion of participants with a signal to noise ratio > 2
Time Frame: Day of MR imaging (1 day)
The feasibility of a study will be determined by the ability to generate adequate signal to noise ratio to measure acidity (pH) in tumor or adjacent healthy tissue. This study will be considered successful if the 13C bicarbonate (CO2) and 13C-CO2 resonances in tumor or normal prostate are qualitatively detectable and signal to noise ratios are greater than 2. The point estimation and 95% confidence intervals (CI) of the participants having sufficient signal to noise ratio will be obtained using the Wilson Score confidence interval method.
Day of MR imaging (1 day)

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Percentage of participants with reported treatment-emergent adverse events
Time Frame: Up to 9 days
To assess the safety of the administration of hyperpolarized 13C bicarbonate; adverse events will be collected and recorded by type, severity (grade) and attribution according to the NCI Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. The percentage of participants with grade 2 and higher, treatment-emergent adverse events will be reported.
Up to 9 days

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Robert Flavell, MD, PhD

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Bristol-Myers Squibb
U.S. Army Medical Research Acquisition Activity

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Robert Flavell, MD, PhD, University of California, San Francisco

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
July 6, 2023

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 31, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 31, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
May 1, 2023

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 1, 2023

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
May 9, 2023

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 4, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 28, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 23922
  • NCI-2023-03218 (Registry Identifier: NCI Clinical Trials Reporting Program (CTRP))

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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