Prostate CancerNCT03159676
Proton-Based Stereotactic Ablative Body Radiotherapy for Prostate Cancer
An observational study of Prostate Cancer, run by Mayo Clinic at 1 site in United States.
Trial summary
Stereotactic ablative body radiotherapy (SABR), or stereotactic body radiotherapy (SBRT), is a specialized form of radiotherapy used to treat prostate cancer with five treatments over two weeks, compared with a conventional eight-week or longer treatment course. Read more about this study
- Who is it for?
- Ages 18 years and older, men only
- Conditions the study is for
- Prostate Cancer
- What is being tested?
- Proton beam
- Type of treatment
- Surgery or procedure
- How many people
- 150 participants
- Where
- 1 siteUnited States
- Study dates
- 12 May 2017to 31 Dec 2024
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- Men only
- Adult, Older adult
Study population: Adult male patients with prostate cancer.
Who may be able to join
- Male, age ≥ 18 years.
- Histological confirmation of adenocarcinoma of prostatic origin.
- AJCC 7th edition clinical T1b-fdiabetes mellitus T2b.
- AJCC clinical staging rules do not include findings from biopsy or imaging.
- Gleason score ≤7 (International Society of Urological Pathologists grades 1-3).
- Serum prostate-specific antigen ≤20 ng/mL.
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- Prostate-specific antigen <10 ng/mL, if dutasteride within last 90 days or finasteride within last 30 days.
- Zubrod performance score 0-1.
- Prostate volume <75-cc, determined by ultrasound, computed tomography or magnetic resonance imaging (modality with lesser volume is acceptable).
- If neoadjuvant-concurrent androgen suppression is used, the prostate volume after the start of androgen suppression may be used.
- American Urological Association voiding symptom index ≤15.
- Ability to complete questionnaire(s) by themselves or with assistance.
- Participation in a patient-reported outcomes survey program, inclusive of the Expanded Prostate Index Composite and CTCAE instruments.
- Ability to provide informed written consent.
Who cannot join
- Radiological- or pathologically-confirmed seminal vesicle invasion, lymph node involvement, or distant metastatic disease.
- Radiological- or biopsy-confirmed extraprostatic tumor extension without AJCC 7th edition clinical T3a classification remain eligible.
- Prior or anticipated external radiotherapy or brachytherapy, transurethral resection of the prostate, prostatic cryoablation/focused ultrasound/laser therapy, prostatectomy, or prostatic enucleation.
- Prior bilateral orchiectomy, planned long-term (>6 months duration) androgen suppression or peripheral androgen blockade, or chemotherapy or immunotherapy for prostate cancer.
- Prior hemi- or total hip arthroplasty.
- Diabetes mellitus associated with vascular ulcers or wound healing problems, ulcerative colitis, connective tissue disorder, or chronic (≥120 days) warfarin or clotting factor inhibitor (e.g., rivaroxaban) use planned.
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- Co-morbid severe concurrent disease which, in the judgment of the investigator, would result in life expectancy <5 years.
- Patients with a left cardiac ventricular assist device are ineligible.
- Patients with an implanted medical electronic device (e.g., cardiac pacemaker) remain eligible if device monitoring complies with standard of practice (e.g., Cardiology and Medical Physics evaluation, function checks and during-treatment monitoring).
- Immunocompromised due to HIV positive state.
- Medical or psychiatric conditions that preclude informed decision-making or adherence.
- Prior registration to an Institutional Review Board-approved therapeutic research study that includes proton beam therapy or photon-based radiotherapy (e.g., randomization to proton beam therapy vs. photon-based radiotherapy).
- Registration to a non-therapeutic (e.g., biomarker, medical physics) only research study is not an exclusion.
- Inability to start radiation per protocol.
Trial locations and contacts
1 site in 1 country.
United States1 site
Mayo Clinic in Rochester
Rochester, Minnesota, 55905
About this study
Official title: Proton-Based Stereotactic Ablative Body Radiotherapy (SABR) for Select Patients With Clinically Localized Prostate Cancer.
Stereotactic ablative body radiotherapy (SABR), or stereotactic body radiotherapy (SBRT), is a specialized form of radiotherapy used to treat prostate cancer with five treatments over two weeks, compared with a conventional eight-week or longer treatment course. The purpose of this trial is to investigate the effect that proton-based SABR has on quality-of-life in patients with localized prostate cancer. The evaluation and treatment will otherwise follow standard of care, and is not considered investigational.
Read the detailed description
Patients with low-risk or intermediate-risk, clinically localized prostate cancer will be evaluated according to standard of care medical practices. The evaluation includes history and examination, prostate-specific antigen (PSA) blood testing, and review of the prior prostate biopsy pathology report; radiology scans (for example, computed tomography [CT], magnetic resonance imaging [MRI], radionuclide bone scan) may be done also; recently completed testing may not need to be repeated. Small markers will be placed in the prostate to guide the proton beam stereotactic ablative body radiotherapy (SABR) treatments, and a hydrogel spacer may also be placed between the prostate and the rectum to push the rectum away from the prostate; the hydrogel spacer will dissolve a few months later. Participants will receive five (5) proton SABR treatments over a two (2) week time period. The study will have participants complete a quality-of life questionnaire and be evaluated for side-effects before starting SABR, at the end of SABR, at three (3), six (6) and 12 months after SABR, and then yearly for five (5) years. Evaluation of the cancer status will follow standard of care practices for at least ten (10) years.
- Conditions
- Prostate Cancer
- Being tested
- Proton beam
- Keywords
- Prostate cancer, Radiation therapy, Radiotherapy, Proton, Proton beam, Stereotactic ablative body radiotherapy, Stereotactic body radiotherapy, SABR, SBRT, Localized, Low risk, Intermediate risk
- Medical subject headings
- Prostatic Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Proton beamRadiation
Also called Radiation therapy, Radiotherapy, Stereotactic ablative body radiotherapy, Stereotactic body radiotherapy
Proton beam
What is being measured
The primary outcome is the main question the study is designed to answer.
Adverse Events
Will be assessed by the number of late grade ≥3 Gastrointestinal and Renal and Urinary/Genitourinary adverse event incidents recorded at 24 months after SABR
Measured: 24 months
Secondary outcomes (3)
Biochemical (PSA) failure
Assessed as time from registration until the date prostate-specific antigen value is ≥ prostate-specific antigen nadir + 2.0 ng/mL estimated by the Gray cumulative incidence method.
Measured: 120 months
Quality of life - EPIC
ssessed as time from registration until the date prostate-specific antigen value is ≥ prostate-specific antigen nadir + 2.0 ng/mL estimated by the Gray cumulative incidence method.. The EPIC consists of 13 questions answered on varying 5-point scales (e.g., Very Poor/Non to Very Good or No Problem to Big Problem). Subdomains for urinary, bowel, and sexual function will be summarized descriptively. Changes across time will be evaluated to assess patient function and quality of life after study treatment.
Measured: Baseline; 120 months
Overall survival
Overall survival is defined as the length of time participants are alive after the start of treatment.
Measured: 120 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 May 2017
- Study start12 May 2017
- Primary completion31 Dec 2024
- Study completion31 Dec 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Prostate CancerStudies of the same condition, open and under way.
- More trials run by Mayo ClinicThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case only
- Time perspective
- Prospective
- Enrolment
- 150 participants (actual)
Sponsor and investigators
- Lead sponsor
- Mayo Clinic
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Bradley (Brad) Stish, Mayo Clinic
- Investigators
- Brad J. Stish, MD, Principal investigator, Mayo Clinic
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03159676
- Sponsor's protocol ID
- 17-000680
- Other IDs
- ROR1752, NCI-2024-01752
- Status last verified
- Feb 2026
- First submitted
- 17 May 2017
- Last updated
- 25 Feb 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 25 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Proton-Based Stereotactic Ablative Body Radiotherapy (SABR) for Select Patients With Clinically Localized Prostate Cancer.
- ClinicalTrials.gov ID
- NCT03159676
- Acronym / sponsor ID
- 17-000680
- Conditions
- Prostate Cancer
- Keywords
- Prostate cancer, Radiation therapy, Radiotherapy, Proton, Proton beam, Stereotactic ablative body radiotherapy, Stereotactic body radiotherapy, SABR
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 150 participants (actual)
- Lead sponsor
- Mayo ClinicUniversity, hospital or other
- Study start
- 12 May 2017 (actual)
- Primary completion
- 31 Dec 2024 (actual)
- Study completion
- 31 Dec 2024 (actual)
- First posted
- 19 May 2017 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Stereotactic ablative body radiotherapy (SABR), or stereotactic body radiotherapy (SBRT), is a specialized form of radiotherapy used to treat prostate cancer with five treatments over two weeks, compared with a conventional eight-week or longer treatment course. The purpose of this trial is to investigate the effect that proton-based SABR has on quality-of-life in patients with localized prostate cancer. The evaluation and treatment will otherwise follow standard of care, and is not considered investigational.
Detailed description
Patients with low-risk or intermediate-risk, clinically localized prostate cancer will be evaluated according to standard of care medical practices. The evaluation includes history and examination, prostate-specific antigen (PSA) blood testing, and review of the prior prostate biopsy pathology report; radiology scans (for example, computed tomography [CT], magnetic resonance imaging [MRI], radionuclide bone scan) may be done also; recently completed testing may not need to be repeated. Small markers will be placed in the prostate to guide the proton beam stereotactic ablative body radiotherapy (SABR) treatments, and a hydrogel spacer may also be placed between the prostate and the rectum to push the rectum away from the prostate; the hydrogel spacer will dissolve a few months later. Participants will receive five (5) proton SABR treatments over a two (2) week time period. The study will have participants complete a quality-of life questionnaire and be evaluated for side-effects before starting SABR, at the end of SABR, at three (3), six (6) and 12 months after SABR, and then yearly for five (5) years. Evaluation of the cancer status will follow standard of care practices for at least ten (10) years.
Study design
- Observational model
- Case only
- Time perspective
- Prospective
Who may qualify
- Ages
- 18 years and older
- Sex
- Male only
- Age groups
- Adult, Older adult
- Study population
- Adult male patients with prostate cancer.
Key inclusion criteria (14 listed)
- Male, age ≥ 18 years.
- Histological confirmation of adenocarcinoma of prostatic origin.
- AJCC 7th edition clinical T1b-fdiabetes mellitus T2b.
- AJCC clinical staging rules do not include findings from biopsy or imaging.
- Gleason score ≤7 (International Society of Urological Pathologists grades 1-3).
Key exclusion criteria (14 listed)
- Radiological- or pathologically-confirmed seminal vesicle invasion, lymph node involvement, or distant metastatic disease.
- Prior or anticipated external radiotherapy or brachytherapy, transurethral resection of the prostate, prostatic cryoablation/focused ultrasound/laser therapy, prostatectomy, or prostatic enucleation.
- Prior bilateral orchiectomy, planned long-term (>6 months duration) androgen suppression or peripheral androgen blockade, or chemotherapy or immunotherapy for prostate cancer.
- Prior hemi- or total hip arthroplasty.
- Diabetes mellitus associated with vascular ulcers or wound healing problems, ulcerative colitis, connective tissue disorder, or chronic (≥120 days) warfarin or clotting factor inhibitor (e.g., rivaroxaban) use planned.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Proton beamAlso: Radiation therapy, Radiotherapy, Stereotactic ablative body radiotherapy, Stereotactic body radiotherapyProton beam | Radiation | – |
Primary outcome
Adverse Events
Time frame: 24 months
Will be assessed by the number of late grade ≥3 Gastrointestinal and Renal and Urinary/Genitourinary adverse event incidents recorded at 24 months after SABR
3 secondary outcomes
Biochemical (PSA) failure
Time frame: 120 months
Quality of life - EPIC
Time frame: Baseline; 120 months
Overall survival
Time frame: 120 months
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 25 Feb 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Brad J. Stish, MD principal investigator
Mayo Clinic
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Prostate Cancer, run by Mayo Clinic at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 14 inclusion and 14 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 25 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Adverse Events (time frame: 24 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 25 Feb 2026; AzTrials last refreshed its copy on 31 Oct 2026.