accelerated partial breast irradiation for early breast cancer

Conditions: Breast Cancer

Summary: hypothesis: in selected women with node-negative invasive breast cancer treated with breast conserving surgery, postoperative accelerated partial breast irradiation (apbi) limited to the region of the tumour bed delivered by 3-dimensional conformal radiation therapy (3d crt) is technically feasible and reproducible with acceptable treatment toxicity, cosmetic outcome, and local control rate in a multicentre trial.

this is a trog multicentre feasibility study of apbi using 3d crt in selected women with node-negative breast cancer treated by breast conserving surgery with negative margins. this is a one-arm feasibility study in which the primary endpoint is the feasibility rate for apbi using 3d crt. this is defined as the proportion of eligible patients treated without a major protocol deviation. secondary endpoints include radiation toxicity, cosmetic outcome, quality of life, time to ipsilateral breast recurrence, disease-free survival, and overall survival. primary objectives: to evaluate the technical feasibility and reproducibility of apbi limited to the region of the tumour bed using 3d crt following breast conserving surgery. secondary objectives: * to assess the acute and long term toxicity of apbi using 3d crt. * to examine the cosmetic outcome of women with breast cancer treated by breast conserving surgery and apbi using 3d crt. * to determine the time to ipsilateral breast recurrence, disease free survival and overall survival of women with node-negative breast cancer completely resected by breast conserving surgery followed by apbi using 3d crt. * to assess the quality of life of women with node-negative breast cancer treated by breast conserving surgery and apbi using 3d crt.

Eligibility criteria:
inclusion criteria: patients must fulfill all of the following criteria for admission to study: * women aged \>= 50 years. * histologically confirmed diagnosis of invasive breast carcinoma of non-lobular histology. * bilateral mammograms performed within 6 months prior to registration. * treated with breast conserving surgery (primary excision or re-excision) with negative radial resection margins of \>= 2 mm\* for both the invasive and if present, associated intraductal tumour. \*patients with superficial or deep resection margin of \< 2 mm are eligible if surgery has removed all of the intervening breast tissue from the subcutaneous tissue to the pectoralis fascia. * unifocal tumour measuring ≤ 20 mm in maximum microscopic dimension. * negative nodal status determined by sentinel node biopsy, axillary dissection, or for women \> 70 years of age, clinical examination. * no evidence of distant metastasis. * assessed by surgeon and radiation oncologist to be suitable for breast conserving therapy. * ability to tolerate protocol therapy. * protocol therapy must commence no later than 12 weeks from the last surgical procedure or 8 weeks from the last dose of chemotherapy. * availability for long-term follow-up. * women of child-bearing potential must use adequate contraception during rt. * written informed consent. exclusion criteria: patients who fulfill any of the following criteria are not eligible for admission to study: * multifocal or multicentric tumours. * clinical or pathologic evidence of any of the following tumour features: extension to chest wall (excluding pectoralis muscle); oedema (including peau d'orange) or ulceration of skin; satellite skin nodules confined to the same breast; and inflammatory carcinoma. * presence of extensive intraductal component (ductal carcinoma in situ occupying \> 25% of the primary invasive tumour and present adjacent to the primary tumour). * node-positive breast cancer determined by sentinel node biopsy, axillary dissection, or in women \> 70 years of age, clinical examination. * inability to localise surgical cavity on ct scans with no evidence of a surgical cavity, seroma or surgical clips delineating the tumour bed. * treatment target volume estimated to occupy \> 25% of the ipsilateral whole breast volume. * synchronous or metachronous bilateral invasive or intraductal breast cancer. * locally recurrent breast cancer. * ipsilateral breast implant. * serious non-malignant disease that precludes definitive surgical or radiation treatment (e.g. scleroderma, systemic lupus erythematosus, cardiovascular/pulmonary/renal disease). * previous or concomitant malignancies except non-melanoma skin cancer, carcinoma in situ of the cervix, and invasive carcinoma of the colon, thyroid, cervix, or endometrium treated five years prior to study entry. * women who are pregnant or lactating. * psychiatric or addictive disorders that preclude obtaining informed consent or adherence to protocol

Keywords: accelerated partial breast irradiation conformal radiation therapy feasibility early breast cancer