Phase II single vs hypofractionated irradiation for timely access to partial breast radiotherapy (SHIFT-PB)

Area of Science:

• Oncology
• Radiation Oncology
• Clinical Trials

Background:

• Breast cancer is a leading global cancer incidence.
• Whole breast irradiation (WBI) is standard for early-stage disease post-breast-conserving surgery.
• Partial breast irradiation (PBI) shows comparable efficacy and toxicity to WBI, with various fractionation schedules recommended.

Purpose of the Study:

• To test the feasibility of randomizing patients to single-fraction (13 Gy) versus 5-fraction (26 Gy) partial breast irradiation (PBI) for early-stage, node-negative breast cancer.
• To assess accrual rates across multiple cancer centers within a defined timeframe.
• To evaluate secondary endpoints including treatment time, local control, quality of life, and toxicity.

Main Methods:

• Phase II randomized controlled trial.
• Primary objective: Feasibility of randomizing patients to 1 vs. 5 fractions of PBI.
• Accrual target: 60 participants across 4 of 6 BC Cancer centers over 2 years.

Main Results:

• The primary outcome is the successful accrual and randomization of 60 participants.
• Secondary outcomes include time from CT simulation to radiotherapy, local control rates, quality of life (POSI-Breast), and toxicity rates (CTCAE, PRO-CTCAE).
• Overall survival and progression-free survival are also secondary endpoints.

Conclusions:

• Successful feasibility testing of single-fraction PBI randomization could lead to a Phase III non-inferiority trial.
• If non-inferior, single-fraction PBI offers potential benefits in reducing wait times and improving access to radiation.
• This approach may particularly benefit patients in rural and remote areas requiring travel for treatment.