Reduction of Gastrointestinal Toxicity in Prostate Cancer by Proton Spot Placement

NCT ID: NCT06200259

Last Updated: 2025-12-18

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: NA
• Total Enrollment: 500 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-12-15
• Study Completion Date: 2040-01-02

Brief Summary

This purpose of this study is to examine the placement of proton spots during pencil beam scanning proton therapy for low and intermediate risk prostate cancer. The researchers will test a unique technique called "Spot Delete" to control the placement of spots during treatment planning. They will also use a special computer model to study how the energy of the proton beam (linear energy transfer) is related to rectal and bladder side effects. The study involves creating a treatment plan based on a CT scan, which helps guide the proton beam in the body. The clinical team uses this CT scan to find the best placement for the protons. The "Spot Delete" method prevents protons from stopping in the rectum, sigmoid, and small bowel, which is thought to be related to acute or late toxicities, such as tenesmus, diarrhea, fecal incontinence, proctitis, and rectal hemorrhage.

Detailed Description

Patients will be randomized into two groups of spot placement. In the experimental arm, "Spot Delete" will be used to prohibit proton spots from being placed in the rectum, sigmoid, and small bowel. In the control arm, proton spots are placed by the treatment planning system are not modified. Medical staff will document gastrointestinal toxicities (diarrhea, fecal incontinence, proctitis, and rectal hemorrhage) and genitourinary toxicities (hematuria, urinary incontinence, urinary retention, urinary obstruction, urinary pain, urinary frequency, and urinary urgency) in the electronic medical record.

This study carries the same risks as regular proton therapy. Proton therapy, like other cancer treatments, may cause the aforementioned side effects. It is important to note that the "Spot Delete" technique aims to specifically address the bladder and bowel reactions, so there might be a potential reduction in this particular risk. Dose constraints will be the same for each treatment arm. Though not expected, it is theoretically possible that this method may counterintuitively increase side effects involving the bladder or bowel. Likewise, increased side effects in other organs are not expected, but are theoretically possible. For this reason we believe there is clinical equipoise between the two trial arms.

Conditions

Prostate Cancer; Prostate Adenocarcinoma; Prostate Carcinoma

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

"Spot Delete"

A unique technique called "Spot Delete" will be utilized to control the placement of spots during treatment planning, to prohibit proton spots from being placed in the rectum, sigmoid, and small bowel. A specialized computer model will be used to study how the energy of the proton beam (linear energy transfer) is related to rectal and bladder side effects.

Group Type: EXPERIMENTAL

Spot Delete planning for proton therapy

Intervention Type: RADIATION

The method of adjusting the placement of proton spots or targets that are placed by the treatment planning system during pencil beam scanning for proton therapy

Control Arm

The proton spots that are placed by the treatment planning system are not modified

Group Type: ACTIVE_COMPARATOR

Traditional proton treatment planning system

Intervention Type: RADIATION

In the control arm, the proton spots placed by the treatment planning system are not modified.

Interventions

Spot Delete planning for proton therapy

The method of adjusting the placement of proton spots or targets that are placed by the treatment planning system during pencil beam scanning for proton therapy

Intervention Type: RADIATION

Traditional proton treatment planning system

In the control arm, the proton spots placed by the treatment planning system are not modified.

Intervention Type: RADIATION

Other Intervention Names

Pencil beam scanning proton therapy

Eligibility 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

• Minimum Eligible Age: 18 Years
• Eligible Sex: MALE
• Accepts Healthy Volunteers: No

Sponsors

Thompson Cancer Survival Center

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Samantha Hedrick, PhD, DABR

Role: PRINCIPAL_INVESTIGATOR

Thompson Proton Center

Locations

Thompson Proton Center

Knoxville, Tennessee, United States

Site Status: RECRUITING

Countries

United States

Central Contacts

Samantha Hedrick, PhD, DABR

Role: CONTACT

Phone: 865-862-1600

Email: shedrick@covhlth.com

Catherine Duke-Taylor, BS

Role: CONTACT

Phone: 865-862-1600

Email: cduke@CovHlth.com

Facility Contacts

Catherine Duke-Taylor, BS

Role: primary

Jessica M Severt, RN, BSN

Role: backup

Other Identifiers

2023-485 INV

Identifier Type: -

Identifier Source: org_study_id