Professor Jean-Michel Hannoun-Levi

ESTRO-Elekta Brachytherapy Award

ESTRO 2026 Congress Report

Accelerated partial-breast irradiation (APBI) is the latest major transformation in breast radiotherapy, which has moved over decades from whole-breast irradiation that used to take several weeks towards personalised, patient-centred approaches. It is an  effective strategy for the treatment of selected patients with low-risk early breast cancer, based on the concept that most local recurrences occur close to the original tumour bed. By reducing the treated volume while maintaining optimal target coverage, APBI allows excellent tumour control while decreasing unnecessary irradiation of healthy tissues.

The development of very APBI (vAPBI) represents a further step in this evolution. Using multi-catheter interstitial brachytherapy exploits the unique physical advantages of this treatment – a very high dose supplied within the target volume combined with a rapid dose fall-off – to deliver a highly conformal dose distribution directly to the surgical cavity, thereby maximising normal tissue preservation. This approach has enabled the dramatic reduction of treatment duration from several weeks to only one or two days, with schedules based on four, three, or even a single fraction.

The international GEC-ESTRO vAPBI cohort represents one of the largest evaluations of this innovative approach. This retrospective multicentre study included 579 patients, who were treated in eight European centres in four countries. Most patients presented with favourable prognostic factors, such as small tumours, negative margins, hormone-receptor-positive disease, and no nodal involvement. Treatment was delivered using multi-catheter interstitial brachytherapy, either peri- or post-operatively. Of this population, 215 patients (37.1%) received single-fraction treatment, 220 (38.0%) three fractions, and 144 (24.9%) four fractions. Overall, 37.1% of patients completed their treatment in one day.

 

After a median follow-up of 64 months, clinical outcomes were highly encouraging. The five-year cumulative incidence of local recurrence was only 2%, while metastatic recurrence was very low (1%). Breast-cancer-specific survival reached 100%, and overall survival was 93%. Importantly, no significant differences in oncological outcomes were observed when comparing four-, three-, and single-fraction schedules or treatment delivered in one versus two days.

 

Late toxicity was also favourable, with very low rates of severe adverse events. The grade 3 toxicity rate was exceptionally low (0.3%), confirming that use of brachytherapy-based vAPBI can maintain excellent normal tissue tolerance despite extreme hypofractionation. No significant toxicity differences were observed according to the number of fractions or overall treatment durations.

Although more data are required from longer follow-up and additional quality of life and cosmetic data, these results support vAPBI as one of the most promising developments in modern breast radiation oncology. By combining precision, efficacy, treatment convenience, and preservation of quality of life, vAPBI perfectly illustrates the transition toward individualised cancer care: delivery of the right dose, to the right volume, for the right patient, in the shortest appropriate time.

This approach may redefine the patient experience of breast radiotherapy as it transforms a treatment that historically lasted several weeks into a highly focused intervention that is completed within one or two days without compromising oncological safety.

 

Professor Jean-Michel Hannoun-Levi receiving the ESTRO-Elekta Brachytherapy Award from Dr Elena Dizendorf, Director of Medical Science, Brachytherapy at Elekta.