Reducing bowel side effects by changing proton beam spot placement for prostate cancer
Reduction of Gastrointestinal Toxicity in Prostate Cancer by Proton Spot Placement
This will test whether deleting proton beam spots near the rectum and small bowel during pencil-beam proton therapy lowers bowel and bladder side effects in men with low- or intermediate-risk prostate cancer.
Quick facts
| Phase | Not applicable |
|---|---|
| Study type | Interventional |
| Enrollment | 500 (estimated) |
| Ages | 18 Years and up |
| Sex | Male |
| Sponsor | Covenant Health Cancer Center Academic / other |
| Drugs / interventions | chemotherapy |
| Locations | 1 site (Knoxville, Tennessee) |
| Trial ID | NCT06200259 on ClinicalTrials.gov |
What this trial studies
Men with low- or intermediate-risk prostate cancer are randomized to two planning approaches for pencil-beam scanning proton therapy: an experimental "Spot Delete" plan that prohibits proton spots from stopping in the rectum, sigmoid, and small bowel, or a control plan using the treatment planning system's default spot placement. Treatment plans are created from CT simulation, dose constraints are kept the same between arms, and a computational model of proton linear energy transfer (LET) is used to study its relationship to rectal and bladder toxicity. Clinical teams will record gastrointestinal and genitourinary toxicities in the electronic medical record and collect patient-reported outcomes (IPSS, EPIC). The goal is to see if spot-placement adjustments can reduce acute or late bowel and bladder side effects without compromising tumor coverage.
Who should consider this trial
Good fit: Ideal candidates are adults with pathologically confirmed low- or intermediate-risk prostate adenocarcinoma (clinical stage T1–T2c, PSA <20 ng/mL, Gleason ≤7), ECOG 0–1, who have not had prior pelvic radiation or prior systemic prostate cancer therapy and can complete IPSS and EPIC questionnaires.
Not a fit: Patients with prior pelvic radiotherapy, regional lymph nodes requiring treatment, active inflammatory bowel disease (diverticulitis, ulcerative colitis, Crohn's), or those with higher-risk disease needing different radiation fields are unlikely to benefit.
Why it matters
Potential benefit: If successful, the technique could reduce rectal and bladder side effects such as diarrhea, bleeding, and urinary symptoms for men receiving proton therapy.
How similar studies have performed: Previous work has linked higher proton LET to rectal toxicity, but randomized testing of a "Spot Delete" planning technique is novel and unproven.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: * Pathological proven diagnosis of prostatic adenocarcinoma * History and physical exam to establish clinical staging * Clinical stage T1-T2c (AJCC 7th edition) * Prostate specific antigen (PSA) \< 20 ng/mL * Gleason Score ≤ 7 * Eastern Cooperative Oncology Group (ECOG) Performance status 0-1 * Patients must be 18 years of age or older * Willingness and ability to complete the International Prostate Symptom Score (IPSS) survey and Expanded Prostate Cancer Index Composite (EPIC) questionnaire Exclusion Criteria: * Prior radiotherapy to the pelvic area * Prior prostate cancer therapy: cryotherapy or hyperthermia * Prior systemic therapy (chemotherapy) for prostate cancer * Regional lymph nodes (common iliac, external iliac, internal iliac, presacral) are a target of treatment * Active diverticulitis, ulcerative colitis, or Crohn's disease
Where this trial is running
Knoxville, Tennessee
- Thompson Proton Center — Knoxville, Tennessee, United States (Recruiting)
Study contacts
- Principal investigator: Samantha Hedrick, PhD, DABR — Thompson Proton Center
- Study coordinator: Samantha Hedrick, PhD, DABR
- Email: shedrick@covhlth.com
- Phone: 865-862-1600
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.