Phase II Study of Pencil Beam Scanning Proton Stereotactic Body Radiation Therapy for Prostate Cancer
Public ClinicalTrials.gov record NCT04842890. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.
Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.
Brief summary
Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.
This is a single arm phase II study of image-guided pencil beam scanning proton SBRT (40Gy RBE in 5 fractions delivered every other day) for patients with low- and intermediate-risk prostate cancer. The primary aim is to assess GU/GI toxicity of proton SBRT and compare this to historic outcomes associated with photon-based prostate SBRT. The primary endpoint is 2-year grade 3+ GU/GI toxicity free rate by CTCAE v5.0, which is expected to be ≥95%. Toxicity will be evaluated by the treating radiation oncologist at least once during SBRT, then following SBRT at 1, 3, 6, 12, 18, and 24 months. The treatment will be considered safe if grade 3 or higher GU/GI toxicity free rate at 2 years is \>85% (95% rate expected with a 10% non-inferiority margin). The accrual goal is 61 patients over 3 years. To ensure that unexpected significant toxicity is identified, all grade 3 or higher toxicities will be reported to the study PI and the trial will stop accruing if at any point 4 or more patients experience a grade 3 or higher toxicity after completing SBRT. This is felt to be conservative given the vast experience with photon SBRT at this dose with an expected G3+ toxicity of \~5%. Secondary objectives are to examine patient-reported urinary, gastrointestinal, sexual, and financial outcomes using IPSS, EPIC-26, and COST questionnaires at the same follow-up timepoints as above. Baseline measures of these domains will be obtained prior to treatment as well. Clinical outcomes will also be evaluated with PSA measured at each follow-up, as well as prostate MRI and biopsies at 2 years. Patients will be followed for at least 2 years to determine rates of PSA relapse, salvage treatment, development of metastases, death from prostate cancer, and overall survival. A dosimetric comparison will be performed where each patient will be planned for proton and photon SBRT to determine possible advantages of proton SBRT.
Study identification
- NCT ID
- NCT04842890
- Recruitment status
- Active, not recruiting
- Study type
- Interventional
- Phase
- Phase 2
- Enrollment
- 61 participants
Conditions and interventions
Conditions
Eligibility (public fields only)
- Age range
- 18 Years and older
- Sex
- Male
- Healthy volunteers
- Healthy volunteers not accepted
This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.
Study timeline
- Start date
- Jan 7, 2021
- Primary completion
- May 31, 2026
- Completion
- Dec 31, 2030
- Last update posted
- Apr 12, 2026
2021 – 2031
United States locations
- U.S. sites
- 1
- U.S. states
- 1
- U.S. cities
- 1
| Facility | City | State | ZIP | Site status |
|---|---|---|---|---|
| The New York Proton Center | New York | New York | 10035 | — |
Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.
About this trial record page
- What this page shows
- Public field values for ClinicalTrials.gov record NCT04842890, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
- What this page does not do
- No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
- Where the data comes from
- Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
- Last refresh
- Last update posted Apr 12, 2026 · Synced Sep 16, 2026
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Open the official record
The complete protocol, eligibility criteria, and contact information for NCT04842890 live on ClinicalTrials.gov.