Single vs Hypofractionated Irradiation For Timely Access to Partial Breast Radiotherapy

Not Applicable

Not yet recruiting

• Conditions: Breast Cancer Early Stage Breast Cancer (Stage 1-3)

• Registration Number: NCT06885671
• Lead Sponsor: British Columbia Cancer Agency

Brief Summary

Partial Breast Irradiation (PBI) is a targeted radiation approach commonly administered post-lumpectomy, specifically targeting the tumour bed. This targeted therapy reduces the exposure to other nearby tissues such as lungs, heart, and chest wall. However, traditional PBI treatment involves lengthy multiple fraction courses which presents a burden to patients from rural and remote communities, who must travel long distances to receive high quality cancer care. The purpose of this study is to compare single fraction (SF) PBI vs. multiple fraction (MF) PBI.

Detailed Description

Radiation can be delivered in multiple fractions, or doses, and can take up to several weeks or months of treatment depending on the type of cancer. Radiation can also be offered in a single fraction. Both techniques have evidence for use in clinical care. Multiple fraction is offered to reduce the amount of radiation given at a single time that could reduce late toxicities. However, single fraction radiotherapy is more cost-effective and saves patient time. With this trial, we will compare single fraction vs. multiple fraction PBI in regards to their impact on quality of life, rates of provider and participant reported toxicities, and local control.

Study Timeline

• Status Verified: 2024-10
• Study First Submitted: 2025-03-14
• Study First Submitted QC: 2025-03-14
• Study First Posted: 2025-03-20
• Last Update Submitted: 2025-09-17
• Last Update Posted: 2025-09-19
• Study Start: 2025-11-01
• Primary Completion: 2027-06
• Study Completion: 2027-06-01

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: Female
• Target Recruitment: 60

Inclusion Criteria

• Female participants age 40 or older

• Able to provide informed consent

• pTis-2 pN0 cM0 breast cancer less than 3 cm in maximum size

• Able to complete electronic or paper entry of participant reported outcomes independently or with assistance from caregiver/family/friend/research staff

• Eastern Cooperative Oncology Group (ECOG) performance status 0 - 2

• A history and physical examination, including ECOG performance status, performed within 8 weeks prior to enrollment.

• Participant is judged able to:

  • Maintain a stable position during therapy
  • Tolerate immobilization device(s) that may be required to deliver PBI safely

• Negative pregnancy test for People of Child-Bearing Potential (POCBP) within 4 weeks of RT start date

Exclusion Criteria

• History of non-breast malignancies except adequately treated non-melanoma skin cancers, in situ cancers treated by local excision or other cancers curatively treated with no evidence of disease for ≥ 5 years.
• Seroma not visible
• Ipsilateral implanted cardiac device
• Prior radiotherapy requiring summation for planning.
• Requirement for a radiation boost (as determined by the treating investigator)
• Positive lymph nodes > 3 cm
• Positive surgical margins
• Surgical cavities lacking clear delineation
• Known germline BRCA1/2 mutation.
• Serious medical comorbidities precluding radiotherapy (e.g., connective tissue disorders such as lupus or scleroderma)
• Pregnant or breastfeeding

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
Number of participants accrued	2 years	Number of participants accrued in each of the BC cancer centres over a 2-year period for randomization to 1 vs 5 fractions of radiotherapy for PBI.

Secondary Outcome Measures

Name	Time	Method
Time from CT simulation to partial breast radiotherapy	Baseline	Measured as the time from the day of CT simulation to the first fraction of PBI for Arm 1 or day of single-fraction PBI for Arm 2
Local Control Rates	2 weeks, 2 months, 6 months, 12, months, 18 months, and 24 months post-treatment	Local control measured as the absence of ipsilateral in-breast recurrence, defined as histologic evidence of invasive or in situ breast cancer in the ipsilateral breast
Quality of life assessed using the POSI-Breast questionnaire	Baseline, 2 weeks, 2 months, 6 months, 12 months, 18 months, and 24 months post treatment	Prospective Outcomes and Support Initiative (POSI) for Breast Data will be used to measure and compare the quality of life of participants in both arms.
Rates of provider-rated toxicities: Occurrences of adverse events as measured by CTCAE	Baseline, 2 weeks, 2 months, 6 months, 12 months, 18 months, and 24 months post treatment	Participant-Reported Outcomes version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) Data will be used to measure and compare participant-reported toxicities in both arms.
Rates of participant-reported toxicities	Baseline, 2 weeks, 2 months, 6 months, 12, months, 18 months, and 24 months post-treatment	Occurrences of adverse events as measured by PRO-CTCAE
Overall Survival (OS)	Approximately at the end of year 2 (study completion)	Time from randomization to death from any cause, or last follow-up, whichever occurs first.
Progression-Free Survival (PFS)	6 weeks, 6 months, 12 months, 18 months, and approximately at the end of 24 months	Time from randomization to disease progression at any site, death, or last follow-up, whichever occurs first.