Single vs Hypofractionated Irradiation For Timely Access to Partial Breast Radiotherapy

Phase II Single vs Hypofractionated Irradiation For Timely Access to Partial Breast Radiotherapy: SHIFT-PB

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.

Study Overview

• Status: Not yet recruiting
• Conditions: Breast Cancer Early Stage Breast Cancer (Stage 1-3)
• Intervention / Treatment: Radiation: Multiple Fraction PBI; Radiation: Single Fraction 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 Type: Interventional
• Enrollment (Estimated): 60
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Robert Olson, MD, MSC, FRCPC; Phone Number: 250-645-7300; Email: rolson2@bccancer.bc.ca
• Study Contact Backup: Name: Lindsay Mathews; Phone Number: 250-645-7300; Email: lindsay.mathews@bccancer.bc.ca

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Female participants age 40 or older
• Able to provide informed consent
• pTis-2 pN0 cM0 breast cancer, with tumor size <3 cm as per provincial guidelines
• 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.
• Uncontrolled concurrent malignant cancer
• Seroma not visible
• Ipsilateral implanted cardiac device
• Prior radiotherapy requiring summation for planning.
• Inability to meet mandatory planning constraints.
• Requirement for a radiation boost (as determined by the treating investigator)
• Positive surgical margins
• Surgical cavities lacking clear delineation (surgical clips are not required but may assist in target 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 Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Multiple Fraction PBI (Arm 1); For participants randomized to Arm 1, PBI will be delivered with a dose of 26 Gy in 5 daily fractions.	Radiation: Multiple Fraction PBI; Participants randomized to Arm 1 will receive PBI with a dose of 26 Gy in 5 daily fractions.
Experimental: Single Fraction PBI (Arm 2); For participants randomized to Arm 2, PBI will be delivered in a single fraction with a dose of 13 Gy.	Radiation: Single Fraction PBI; Participants randomized to Arm 2 will receive PBI in a single fraction with a dose of 13 Gy.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of participants accrued	Number of participants who sign consent to be randomized to 1 vs 5 fractions of radiotherapy for PBI over a 2 year period	2 years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Overall Survival (OS)	Time from randomization to death from any cause, or last follow-up, whichever occurs first.	Approximately at the end of year 2 (study completion)
Progression-Free Survival (PFS)	Time from randomization to disease progression at any site, death, or last follow-up, whichever occurs first.	6 weeks, 6 months, 12 months, 18 months, and approximately at the end of 24 months
Time from CT simulation to plan approval	Measured as the time from the day of CT simulation to the date of plan approval.	Baseline
2-Year Local Control Rates	Absence of ipsilateral in-breast recurrence, defined as histologic evidence of invasive or in situ breast cancer in the ipsilateral breast 2 years post-treatment	6 weeks, 6 months, 12, months, 18 months, and 24 months post-treatment
Quality of life assessed using the POSI-Breast questionnaire	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.	Baseline, 6 weeks, 6 months, 12 months, 18 months, and 24 months post treatment
Rates of provider-rated toxicities: Occurrences of adverse events as measured by CTCAE	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.	Baseline, 6 weeks, 6 months, 12 months, 18 months, and 24 months post treatment
Participant-reported toxicities	Occurrences of adverse events as measured by PRO-CTCAE	Baseline, 6 weeks, 6 months, 12, months, 18 months, and 24 months post-treatment

Collaborators and Investigators

• Sponsor: British Columbia Cancer Agency
• Investigators: Principal Investigator: Robert Olson, MD, MSc, FRCPC, BC Cancer - Prince George

Publications and helpful links

General Publications

• Olson R, Cua M, Matthews Q, Laing J, Narinesingh D, Nichol A, Berrang T, Koulis T, Karan T, Chng N. Phase II single vs hypofractionated irradiation for timely access to partial breast radiotherapy (SHIFT-PB). BMC Cancer. 2025 Aug 8;25(1):1285. doi: 10.1186/s12885-025-14720-w.

Study record dates

Study Major Dates

• Study Start (Estimated): January 1, 2026
• Primary Completion (Estimated): December 31, 2029
• Study Completion (Estimated): December 31, 2029

Study Registration Dates

• First Submitted: March 14, 2025
• First Submitted That Met QC Criteria: March 14, 2025
• First Posted (Actual): March 20, 2025

Study Record Updates

• Last Update Posted (Actual): November 17, 2025
• Last Update Submitted That Met QC Criteria: November 14, 2025
• Last Verified: November 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Neoplasms by Site; Neoplasms; Skin Diseases; Breast Diseases; Breast Neoplasms
• Other Study ID Numbers: SHIFT-PB

Drug and device information, study documents

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