Prospective Study of Ultrahypofractionated Proton Beam Therapy for Localized Prostate Cancer

NCT07699705 | Recruiting DMC

• 1 other identifier: NCC2024-0253
• Study Type: interventional
• Target: 50
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this prospective observational cohort study is to evaluate the long-term efficacy and safety of ultrahypofractionated proton beam therapy in patients with localized prostate cancer and to identify clinical and treatment-related factors associated with oncologic outcomes and treatment-related toxicity. The main questions it aims to answer are: What are the long-term biochemical recurrence-free survival, clinical progression-free survival, overall survival, and acute and late treatment-related toxicity outcomes following ultrahypofractionated proton beam therapy? Which clinical characteristics, treatment planning parameters, and patient-reported outcomes are predictive of long-term oncologic outcomes and treatment-related toxicity? Participants will: Receive protocol-based ultrahypofractionated proton beam therapy (35-40 Gy\[RBE\] in 5 fractions). Undergo routine clinical evaluation, laboratory testing including prostate-specific antigen (PSA), and imaging studies according to the institutional follow-up schedule. Complete patient-reported outcome questionnaires (EPIC-CP and Visual Analog Scale \[VAS\]) before treatment and during follow-up. Be followed prospectively to assess biochemical recurrence, clinical progression, survival outcomes, and acute and late treatment-related toxicities.

Conditions

Prostate Neoplasm

Keywords

prostate neoplasm; proton therapy

Outcome Measures

Primary Outcomes (1)

• Biochemical recurrence-free survival

  Biochemical recurrence is defined according to the Phoenix definition (PSA nadir + 2 ng/mL). Biochemical recurrence-free survival is measured from completion of proton beam therapy to biochemical recurrence or last follow-up.

  Up to 5 years after completion of proton beam therapy

Secondary Outcomes (5)

• Patient-reported quality of life

  baseline, postRT 1 month, 4 months, 7 months and 1 year

• Clinical recurrence-free survival

  Up to 5 years after completion of proton beam therapy

• Overall survival

  From completion of proton beam therapy to 5 years after treatment

• Treatment-related genitourinary toxicity

  Up to 5 years after completion of proton beam therapy

• Treatment-related gastrointestinal toxicity

  Up to 5 years after completion of proton beam therapy

Study Arms (1)

ultrahypofractionated proton beam therapy

EXPERIMENTAL

Participants receive definitive ultrahypofractionated proton beam therapy (35-40 Gy\[RBE\] in 5 fractions) for localized prostate adenocarcinoma using image-guided proton therapy. Participants are prospectively followed for oncologic outcomes, treatment-related toxicity, and patient-reported quality of life.

Radiation: Ultrahypofractionated Proton Beam Therapy

Interventions

Ultrahypofractionated Proton Beam Therapy RADIATION

Ultrahypofractionated proton beam therapy is delivered using pencil beam scanning (PBS) with image-guided proton therapy. Before treatment planning, all participants undergo placement of an absorbable rectal hydrogel spacer and two intraprostatic gold fiducial markers. Treatment planning is performed using CT simulation with MRI fusion after hydrogel stabilization. Daily cone-beam CT (CBCT) with fiducial marker matching is used for image guidance and patient positioning. A total dose of 36.25-40.0 Gy(RBE) is delivered in 5 fractions over approximately 1-2 weeks. Unlike conventional proton beam therapy using opposed right and left lateral beam arrangements, this protocol employs four oblique beam angles (right anterior oblique, right posterior oblique, left posterior oblique, and left anterior oblique) to optimize dose conformity while minimizing radiation exposure to adjacent normal tissues.

ultrahypofractionated proton beam therapy

Eligibility Criteria

• Age: 19 Years+
• Gender Eligibility Details: Only individuals who are biologically male are eligible because prostate cancer occurs in the prostate gland, a male-specific organ.
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Histologically confirmed localized adenocarcinoma of the prostate.
• No evidence of distant metastasis (M0).
• Eastern Cooperative Oncology Group (ECOG) performance status of 0-2.
• Eligible to receive definitive image-guided ultrahypofractionated pencil beam scanning proton beam therapy according to the study protocol.
• Ability to complete study questionnaires and comply with scheduled follow-up assessments.
• Provision of written informed consent before study enrollment.

You may not qualify if:

• Residual or recurrent prostate cancer following prior radical prostatectomy.
• Previous pelvic radiotherapy.
• Evidence of distant metastatic disease.
• Active malignancy within the previous 1 year, except adequately treated basal cell carcinoma or squamous cell carcinoma of the skin, carcinoma in situ of the cervix, or completely resected T1N0M0 malignancies.
• Uncontrolled psychiatric illness, severe traumatic brain injury, chronic alcohol or substance dependence, or other medical conditions that, in the investigator's judgment, would preclude safe participation or adequate follow-up.
• Inability or unwillingness to provide written informed consent or comply with study procedures.

Sponsors & Collaborators

• National Cancer Center, Korea: lead

Study Sites (1)

National Cancer Center, Korea

Goyang-si, Gyeonggi-do, 10408, South Korea

RECRUITING

MeSH Terms

Conditions

Prostatic Neoplasms

Condition Hierarchy (Ancestors)

Genital Neoplasms, Male; Urogenital Neoplasms; Neoplasms by Site; Neoplasms; Genital Diseases, Male; Genital Diseases; Urogenital Diseases; Prostatic Diseases; Male Urogenital Diseases

Central Study Contacts

Hyuna Park Clinical Research Coordinator, BS

CONTACT

82-31-920-0491; 77313@ncc.re.kr

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER GOV
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Clinical staff

Study Record Dates

• First Submitted: July 2, 2026
• First Posted: July 13, 2026
• Study Start: November 4, 2024
• Primary Completion (Estimated): December 31, 2034
• Study Completion (Estimated): December 31, 2034
• Last Updated: July 13, 2026

Record last verified: 2026-07

Data Sharing

• IPD Sharing: Will not share

Locations

KR (1)