Accelerated Partial Breast Irradiation With 3D-CRT and IMRT (APERT)

Accelerated Partial Breast Irradiation After Breast Conserving Surgery for Low-risk Invasive Breast Cancer: 3D Conformal Radiotherapy (3D-CRT) and Intensity Modulated Radiotherapy (IMRT) - Prospective Phase II Study

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

breast cancer, breast conserving therapy, accelerated partial breast irradiation, 3D conformal radiotherapy, intensity modulated radiotherapy

Accelerated partial breast irradiation delivered by 3 dimensional conformal radiotherapy or intensity modulated radiotherapy

9 x 4.1 Gy accelerated partial breast irradiation delivered by 3D-CRT or IMRT over 5 consecutive days, using twice-a-day fractionation.

Late radiation side-effects at 5 years scored by the RTOG (Radiation Therapy Oncology Group) EORTC (European Organization for Research and Treatment of Cancer) late radiation morbidity scoring scheme

quality of life measured by the EORTC (European Organization for Research and Treatment of Cancer) QLQ-30 and BR-23 questionnaires

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)

Mozsa E, Meszaros N, Major T, Frohlich G, Stelczer G, Sulyok Z, Fodor J, Polgar C. Accelerated partial breast irradiation with external beam three-dimensional conformal radiotherapy. Five-year results of a prospective phase II clinical study. Strahlenther Onkol. 2014 May;190(5):444-50. doi: 10.1007/s00066-014-0633-1. Epub 2014 Mar 12.