accelerated partial breast irradiation with 3d-crt and imrt

Conditions: Breast Cancer; Radiation Toxicity; Side Effects

Summary: the purpose of this study is to determine in a phase ii clinical trial whether accelerated partial breast irradiation after breast conserving surgery using 3 dimensional external beam radiotherapy (3d-crt) and intensity modulated radiotherapy (imrt) for low-risk invasive breast cancer patients is safe without causing serious late radiation side-effects.

it is a sequential phase ii trial. eligible patients after breast conserving surgery (bcs) are treated with accelerated partial breast irradiation (apbi) using three-dimensional conformal radiotherapy (3d-crt) for the first 45 patients or intensity modulated radiotherapy (imrt) for the second 45 patients. primary end-point of the study: late radiation side-effects at 5 years. early stopping criteria: not used as primary end-point is late side-effects. interim analysis: not planned secondary end-points: cosmetic results, quality of life, local recurrence-free survival, regional recurrence free survival, distant metastasis free survival, relapse free survival, overall survival, cancer specific survival. null-hypothesis for primary end-point: the incidence of severe (\>g2) late radiation side-effects after apbi using 3d-crt or imrt will not exceed 10%. stratification: * by treatment delivery: 3d-crt - first 45 patients; imrt - second 45 patients * by bra capsize: capsize a-b; c; and d-d+ treatment intervention: 9 x 4.1 gy apbi using 3d-crt (first 45 patients) or imrt (second 45 patients) delivered within 5 days, using twice-a-day fractionation. clinical target volume (ctv) and planning target volume (ptv) definition: ctv = excision cavity + 20 mm minus the actual pathological surgical margin in mm ptv = ctv + 5 mm in each direction follow-up: * ecog ps, physical examination (inspection and palpation), registration of side-effects (rtog (radiation therapy oncology group) eortc (european organization for research and treatment of cancer)) early and late radiation morbidity scoring scheme) and cosmetic results (using the harvard scale) : 7-14 days after rt, than in every 3 months for 2 years, and every 6 months for 5 years. * mammography: at 6, 12, 18, 24 months, and annually thereafter * quality of life questionnaire (qlq) (e.g. eortc (european organization for research and treatment of cancer) qlq-30 and breast (br)-23) before rt, at 7-14 days after rt, at 3, 6, and 12 months, and annually thereafter * digital photography: before treatment, at 7-14 days after treatment, and yearly thereafter

Eligibility criteria:
inclusion criteria: * previous breast conserving surgery within 12 weeks (in case of adjuvant chemotherapy within 28 days after completion of chemotherapy) * patient age \> 40 years * ecog performance status: 0-1 * life expectancy \>5 years * invasive ductal, papillary, mucinous, medullary or tubular carcinoma * unifocal tumor * pathological tumor size \< or = 30 mm * pathological negative axillary nodal status with axillary dissection or sentinel lymph node biopsy * surgical clips in the tumor bed * pathological surgical free margins of at least 2 mm * written informed consent of patients exclusion criteria: * stage iii-iv * multifocal tumor * extensive intraductal component (eic) * ductal or lobular carcinoma in situ (dcis or lcis) * invasive lobular cancer (ilc) * lymph-vascular invasion (lvi) * contralateral breast cancer * history of treatment for previous breast cancer * lactation or breast feeding women * paget-disease of the nipple * psychiatric disorder * increased radiosensitivity (e.g. collagen vascular disease)

Keywords: breast cancer breast conserving therapy accelerated partial breast irradiation 3d conformal radiotherapy intensity modulated radiotherapy