Randomized Study Comparing Partial Breast Irradiation and Whole Breast Irradiation After Breast-Conserving Surgery in Women With Early Breast Cancer

What this Trial Is About

Researchers are studying women with a newly diagnosed invasive breast cancer that is node negative and 3 cm or smaller in size to compare two types of radiation therapy after breast-conserving surgery BCS. The study aims to see if partial breast irradiation PBI given once daily over one week is not worse than whole breast irradiation WBI in preventing cancer return and whether it results in better cosmetic outcomes. This is a randomized, single-blind trial focusing on local recurrence and patient-assessed cosmesis three years after treatment. Participants will be randomly assigned to receive either PBI or WBI. Both treatments deliver a total of 26 Gy radiation in 5 fractions, given once daily over 5 to 7 days with up to 8 days allowed for scheduling reasons. PBI targets the tumor bed plus a margin of normal tissue, while WBI targets the whole breast. Patients will not know which treatment they receive to avoid bias in cosmetic assessments. Stratification factors include tumor size, estrogen receptor status, and clinical center. During the study, participants will be monitored for local recurrence annually for five years and will assess their cosmetic outcome at three and five years post-treatment. Researchers will also evaluate survival, disease-free survival, radiation side effects, and quality of life at various intervals. Clinical assessments and nurse evaluations of cosmesis will occur at three and five years. Overall, participant involvement spans several years with multiple follow-up visits to measure outcomes and safety.

A Randomized Trial of Five Fraction Partial Breast Irradiation (RAPID2)