PBI for Low-risk Breast Cancer

September 4, 2026 updated by: Jinli Ma, Fudan University

A Randomized Phase III Trial Comparing 1-Week vs. 3-Week Partial Breast Irradiation Via IMRT After Breast-Conserving Surgery for Clinical Low-Risk Breast Cancer

This non-inferiority, phase 3 clinical trial evaluates the cosmetic non-inferiority of a one-week regimen (26 Gy/5 Fx) versus a three-week regimen (40 Gy/15 Fx) using intensity-modulated radiation therapy (IMRT) for partial breast irradiation (PBI) in low-risk breast cancer patients post-breast-conserving surgery. It also compares secondary outcomes including efficacy, safety, and quality of life between the two groups.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

818

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • China
      • Shanghai, China, 200032
        • Recruiting
        • Fudan University Shanghai Cancer Center
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Female patients with an estimated life expectancy greater than 5 years.
  • Meets criteria for either primary invasive breast cancer or pure ductal carcinoma in situ (DCIS).
  • For invasive breast cancer: Age 40-75 years; Underwent breast-conserving surgery with sentinel lymph node biopsy or axillary lymph node dissection; pT ≤ 3 cm (unicentric/unifocal or total multifocal size ≤ 3 cm); favorable histology (invasive ductal, mucinous, tubular, or solid papillary carcinoma, DCIS component permitted); ER+ and/or PR+; pN0(i- or i+); M0; surgical margins ≥ 2 mm.
  • For pure DCIS: Age 18-75 years; Underwent breast-conserving surgery with or without sentinel lymph node biopsy; low-to-intermediate nuclear grade; tumor size ≤ 2.5 cm; surgical margins ≥ 3 mm.
  • Presence of surgical clips or distinct postoperative seroma/tissue changes in the tumor bed allowing precise target delineation.
  • ECOG performance status 0 or 1.
  • Eligible for systemic therapy, without prior neoadjuvant systemic therapy.
  • Able to tolerate radiotherapy procedures and position immobilization.
  • No contraindications to radiotherapy.
  • Written informed consent provided.

Exclusion Criteria:

  • Unfavorable histological subtypes (e.g., invasive lobular carcinoma, invasive micropapillary carcinoma).
  • Positive axillary, internal mammary, or supraclavicular lymph nodes.
  • Presence of distant metastasis.
  • Paget's disease of the nipple.
  • History of prior ipsilateral or contralateral invasive breast cancer or DCIS.
  • Bilateral breast cancer.
  • Known germline BRCA1 or BRCA2 mutation.
  • Prior radiotherapy to the ipsilateral breast, chest wall, or regional lymph nodes.
  • Active or prior second malignancy (except adequately treated non-melanoma skin cancer).
  • Severe non-malignant comorbidities (e.g., cardiovascular disease, pulmonary disease, systemic lupus erythematosus, or scleroderma) precluding definitive radiotherapy.
  • Pregnant or lactating patients.
  • Inability or unwillingness to comply with scheduled follow-up visits.

Inability or unwillingness to provide written informed consent.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: 3-week partial breast irradiation (PBI）
Control group
Radiation: 3-week PBI
40.05Gy/15Fx/3w, 2.67Gy/Fx, once daily
Experimental: 1-week PBI
Experimental group
Radiation: 1-week PBI
26Gy/5Fx/1w, 5.2Gy/Fx, once daily

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
3-year adverse cosmesis
Time Frame: 3 years
Adverse cosmetic outcome (defined as 'Fair' or 'Poor') was evaluated by an independent panel using standard photographic assessment based on the EORTC Cosmetic Rating System.
3 years

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Acute adverse events
Time Frame: 6 months
The incidence and severity of acute adverse event include radiation dermatitis, pruritus, skin pain, radiation esophagitis, and radiation pneumonitis.
6 months
Late adverse events
Time Frame: 3 years
The incidence and severity of late adverse event include breast induration, skin hyperpigmentation, telangiectasia, breast oedema, and pulmonary fibrosis.
3 years
Locoregional recurrence
Time Frame: 5 years
Locoregional recurrence is defined as the first documented recurrence in the ipsilateral breast or regional nodes.
5 years
Distant metastasis
Time Frame: 5 years
Distant metastasis is the first confirmed recurrence in any distant organ/site beyond the ipsilateral breast and regional nodes.
5 years
Overall survival
Time Frame: 5 years
Overall survival is the time from randomization to death from any cause.
5 years
Quality of life (QoL)
Time Frame: 5 years
Quality of life will be evaluated via standardized QoL scales.
5 years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Fudan University

Investigators

  • Principal Investigator: Jinli Ma, Fudan University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

September 16, 2021

Primary Completion (Estimated)

September 16, 2029

Study Completion (Estimated)

September 16, 2031

Study Registration Dates

First Submitted

September 4, 2026

First Submitted That Met QC Criteria

September 4, 2026

First Posted (Actual)

September 11, 2026

Study Record Updates

Last Update Posted (Actual)

September 11, 2026

Last Update Submitted That Met QC Criteria

September 4, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • FDRT-BC013

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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