Vienna, Austria

ESTRO 2023

Session Item

May 15
11:40 - 12:40
Plenary Hall
Highlights of Proffered Papers - Latest clinical trials
Anna Kirby, United Kingdom;
Matthias Guckenberger, Switzerland
Proffered Papers
12:00 - 12:10
Accelerated partial breast irradiation: 10-year results of a randomized GEC-ESTRO phase III trial
Vratislav Strnad, Germany


Accelerated partial breast irradiation: 10-year results of a randomized GEC-ESTRO phase III trial

Vratislav Strnad1, Csaba Polgár2, Oliver Ott3, Guido Hildebrandt4, Daniela Kauer-Dorner5, Hellen Knauerhase4, Tibor Major6, Jaroslaw Lyczek7, Jose Luis Guinot8, Cristina Gutierrez Miguelez9, Pavel Slampa10, Peter Niehoff11, Michael Allgäuer12, Kristina Lössl13, Bülent Polat14, Rainer Fietkau15, Annika Schlamann16, Alexandra Resch5, Anna Kulik17, Leo Arribas18, Ferran Guidea9, Christine Gall19, Wolfgang Uter19

1University Hospital Erlangen, Dept. of Radiation Oncology, Erlangen, Germany; 2National Institute of Oncology Budapest, Dept.of Radiation Oncology, Budapest, Hungary; 3University Hospital Erlangen, Dept. of Radiation Oncology, Erlangen, Germany; 4University Hospital Rostock, Dept. of Radiation Oncology, Rostock, Germany; 5University Hospital AKH, Dept. of Radiation Oncology, Vienna, Austria; 6National Institute of Oncoogy Budapest, Dept. of Radiation Oncology, Budapest, Hungary; 7Podkarpacki Hospital Cancer Center , Dept. of Radiation Oncology, Brzozów, Poland; 8Valencian Institute of Oncology , Dept. of Radiation Oncology, Valencia, Spain; 9Catalan Institute of Oncology , Dept. of Radiation Oncology, Barcelona, Spain; 10Masaryk Memorial Cancer Institute , Dept. of Radiation Oncology, Brno, Czech Republic; 11Sana Hospital Offenbach, Dept. of Radiation Oncology, Offenbach, Germany; 12Hospital Barmherzige Brüder Regensburg, Dept. of Radiation Oncology, Regensburg, Germany; 13University Hospital Bern, Inselspital, Dept. of Radiation Oncology, Bern, Switzerland; 14University Hospital Würzburg, Dept.of Radiation Oncology, Würzburg, Germany; 15University Hospital Erlangen, Dept.of Radiation Oncology, Erlangen, Germany; 16University Hosital Leipzig, Dept.of Radiation Oncology, Leipzig, Germany; 17Instytut im Marii Skłodowskej , Dept. of Radiation Oncology, Warsaw, Poland; 18Valencian Institute of Oncology, Depr. of Radiation Oncology, Valencia, Spain; 19University Erlangen-Nuremberg, Department of Medical Informatics, Biometry and Epidemiology, Erlangen, Germany

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Purpose or Objective

Different techniques exist for the delivery of accelerated partial breast irradiation (APBI) for appropriately selected patients with early breast cancer after breast-conserving surgery (BCS). The long-term 10y.-results of a Phase 3 trial evaluating the non-inferiority of APBI using multicatheter brachytherapy compared to whole-breast irradiation (WBI) are presented.

Material and Methods

We randomized patients aged ≥40 years with low risk invasive breast cancer and ductal carcinoma in-situ after BCS to receive either 50 Gy WBI with tumor bed boost of 10 Gy or APBI using multicatheter brachytherapy. The primary endpoint was local recurrence rate in the “as-treated” population. Secondary endpoints were overall survival, disease-free survival, cumulative incidence of regional recurrence and distant metastasis, incidence and severity of acute and late side effects, cosmesis. The trial is registered with, NCT00402519.


Between 2004 and 2009, 1184 participants with early stage breast cancer were randomly assigned to   receive either WBI with boost or APBI using interstitial multicatheter brachytherapy. Median follow-up of patients was 10.4 years. The cumulative incidence of local recurrence at 10 years was 1.58% (95% CI: 0.37; 2.8%) in the WBI and 3.51% (95% CI: 1.99; 5.03%) in the APBI arm  (difference 1.93%  (95% CI: -0.018; 3.87, p=0.074). 10-year disease-free survival was 87.95% (95%CI: 85.1 – 90.91%) with WBI and 84.89% (95%CI: 81.97 – 87.91%) with APBI (difference -3.06%, 95% CI: -7.22;1.09%; p=0.18).  10-year overall survival was 89.5% (95% CI: 86.9–92.2%) in WBI-treated and 90.5% (95% CI: 88.1–92.9%) in APBI-treated patients (difference 1·95% CI: -2·66–4·56; p=0·5). Finally, the patients in APBI arm showed significantly lower incidence of treatment-related late-side events > grade 2 (p=0.021).


The efficacy of adjuvant APBI using multicatheter brachytherapy after breast conserving surgery for early breast cancer is similar to adjuvant WBI with tumor bed boost and is associated with lower incidence of late side effects.