A Multi-centre Randomized Trial to Determine if Accelerated Partial Breast Irradiation, Utilizing 3D CRT, is as Effective as Whole Breast Irradiation Following Breast Conserving Surgery in Women With Ductal Carcinoma in Situ or Invasive Breast Cancer With Negative Axillary Lymph Nodes
Following breast conserving surgery or on completion of chemotherapy, patients will be
stratified according to age, tumour histology, tumour size, adjuvant hormonal therapy and
clinical centre. Patients will be allocated to receive either whole breast irradiation or
3D CRT accelerated partial breast irradiation.
Radiation therapy will be administered as soon as possible following the healing of the
surgical incision (3-4 weeks) and within 12 weeks if the patient is not treated with
chemotherapy. If the patient is treated with chemotherapy, radiation therapy will begin
after 2 weeks and not beyond 8 weeks after the last dose of chemotherapy.
Patients treated with whole breast irradiation will receive a total dose of 42.5 Gy in 16
fractions, given on a daily basis, over a time period of 22 days. Patients with large
breast size are permitted to receive a total dose of 50 Gy in 25 fractions, given on a daily
basis, over a time period of 35 days. Boost irradiation is permitted in patients treated
with whole breast irradiation. Boost irradiation of 10 Gy/4-5 fractions daily over a time
period of 4-7 days is permitted for patients deemed at moderate to high risk of local
recurrence as per local cancer centre guidelines.
Patients treated with 3D CRT accelerated partial breast irradiation will receive a total
dose of 38.5 Gy in 10 fractions, delivered twice a day, over a time period of 5-8 days.
Each daily dose must be separated by 6-8 hours.
Patients will be followed indefinitely and assessed formally at 6 and 12 months after the
date of randomization and then on a yearly basis. Patients will be assessed for acute and
late radiation toxicity, cardiac toxicity, recurrent disease, new primary cancer, cosmetic
outcome, quality of life and overall survival.
Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Treatment
ipsilateral breast tumour recurrence defined as recurrent invasive or in situ cancer in the ipsilateral breast including the axillary tail.
ongoing throughout study
Tim Whelan, MD
Ontario Clinical Oncology Group / Juravinski Cancer Centre
Canada: Health Canada