Prone Partial Breast Irradiation (PBI): a Prospective Randomized Trial

Prone Partial Breast Irradiation (PBI): A Prospective Randomized Trial Comparing Five Versus Three Fractions

The purpose of this study is to test whether a radiotherapy regimen of 8 GY x 3 days over 5 days (every other day) is as safe (well-tolerated) and effective as 6 Gy x 5 over five consecutive days

Study Overview

• Status: Active, not recruiting
• Conditions: Breast Cancer
• Intervention / Treatment: Radiation: PBI Radiotherapy 6 Gy; Radiation: PBI Radiotherapy 8 Gy

Detailed Description

Despite the fact that less extensive experience than that of brachytherapy is available, PBI delivery through an external-beam has many advantages. First of all, it is likely to be more acceptable to the patient since it is non-invasive and it does not require a surgical procedure or anesthesia. Moreover, since it is delivered after surgery, the pathological analysis of the segmental mastectomy specimen is available to inform the selection of the best candidates. In addition, EB-PBI is likely to become more widely reproducible, since it does not rely on the experience and skills of the radiation oncologist performing the brachytherapy implant. Besides, once the technique is established, it can be widely applied at any facility provided with a linear accelerator, without the risk presented by some brachytherapy approaches that can not be completed because of the unfavorable interplay of patient's anatomy with the technical limitations of the applicator.

The women in this study will receive either 5 or 3 radiation fractions to the tumor bed. We have chosen to study T1 post menopausal women because in this subset: 1) the tumor is small enough to be treated by partial breast radiation 2) the odds of having multicentric disease are low, making it ethical to avoid whole breast irradiation, 3) the most benefit from reducing the radiation schedule from 5 to 3 could be expected.

All patients will receive either 8 Gy x 3 over 5 days, every other day or 6 Gy x 5 over 5 days, on five consecutive days

• Study Type: Interventional
• Enrollment (Actual): 284
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • New York
    • New York, New York, United States, 10016
      • NYU Langone Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 50 years to 90 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Post-menopausal women defined as either:

  1. at least 2 years without menstrual period
  2. patients older than 50 with serological evidence of post-menopausal status
  3. hysterectomized patients of any age with FSH confirmation of post- menopausal status

• pT1 breast cancer, excised with negative margins. Criteria for low risk-pTis:

  1. Screen-detected
  2. Low to intermediate nuclear grade
  3. < 2.5cm in size
  4. Resected with negative margins at >3mm)
• clinically N0 or pN0 or sentinel node negative breast cancer

Exclusion Criteria:

• previous radiation therapy to the ipsilateral breast
• presence of a proportion of DCIS in the core biopsy specimen which is compatible with extensive intraductal component (EIC)

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: PBI Radiotherapy 6 Gy; Prone partial breast irradiation of 6 Gy x 5 over 5 days, on five consecutive days	Radiation: PBI Radiotherapy 6 Gy; Patients will receive 3D-Conformal or Intensity Modulated Radiation Therapy (IMRT) of 6 Gy x 5, over 5 consecutive days; Other Names: Intensity Modulated Radiation Therapy; 3D-Conformal; Prone partial breast irradiation
Experimental: PBI Radiotherapy 8 Gy; Prone partial breast irradiation of 8 Gy x 3 over 5 days, every other day	Radiation: PBI Radiotherapy 8 Gy; Patients will receive 3D-Conformal or Intensity Modulated Radiation Therapy (IMRT) of 8 Gy x 3, over 5 days, every other day; Other Names: Intensity Modulated Radiation Therapy; 3D-Conformal; Prone partial breast irradiation

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Percentage of Participants With Grade 2 or 3 Fibrosis	60 months

Secondary Outcome Measures

Outcome Measure	Time Frame
Rate of Isolated Local/Regional Recurrences	1 year post randomization
Rate of Concomitant Local/Regional and Distant Recurrences	1 year post randomization
Rate of Isolated Local/Regional Recurrences	2 years post randomization
Rate of Concomitant Local/Regional and Distant Recurrences	2 years post randomization
Rate of Isolated Local/Regional Recurrences	3 years post randomization
Rate of Concomitant Local/Regional and Distant Recurrences	3 years post randomization

Collaborators and Investigators

• Sponsor: NYU Langone Health
• Investigators: Principal Investigator: Naamit Gerber, MD, NYU Langone Medical Center

Study record dates

Study Major Dates

• Study Start (Actual): October 28, 2014
• Primary Completion (Actual): December 7, 2023
• Study Completion (Estimated): December 7, 2026

Study Registration Dates

• First Submitted: October 24, 2014
• First Submitted That Met QC Criteria: October 24, 2014
• First Posted (Estimated): October 28, 2014

Study Record Updates

• Last Update Posted (Estimated): December 30, 2025
• Last Update Submitted That Met QC Criteria: December 8, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: breast cancer; cancer; breast; partial breast irradiation; prone; PBI
• Additional Relevant MeSH Terms: Neoplasms by Site; Skin Diseases; Breast Diseases; Skin and Connective Tissue Diseases; Neoplasms; Breast Neoplasms; Therapeutics; Radiotherapy; Radiotherapy, Computer-Assisted; Radiotherapy, Intensity-Modulated; Radiotherapy, Conformal
• Other Study ID Numbers: 14-01306

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: No