ESTRO 2024 - Abstract Book

S154

Brachytherapy - Breast

ESTRO 2024

fractions within 4 days was delivered to the tumor bed plus a 1-2 cm margin. The median follow-up time was 301 months (range: 287-314) for surviving patients. Local control, disease-free (DFS), cancer-specific (CSS), and overall survival (OS), as well as late side effects, and cosmetic results were assessed.

Results:

Five (11.1%) ipsilateral breast tumor recurrences were observed, for a 10-year, and 25-year actuarial rate of 9.4%, and 12.6%, respectively. The 25-year DFS, CSS, and OS was 72.6%, 81.3%, and 62.2%, respectively. Fat necrosis requiring surgical intervention occurred in 1 woman (2.2%). Grade 3 fibrosis was observed in 1 patient (2.2%). No patient developed grade 3 late skin toxicity. Cosmetic results were rated excellent or good in 34 patients (75.5%).

Conclusion:

Twenty-five-year results with APBI using HDR multicatheter interstitial implants continue to demonstrate excellent long-term local tumor control, survival, and cosmetic results with a low-rate of late side effects.

Acknowledgement: This work was supported by the National Research, Development and Innovation Fund of the Ministry of Culture and Innovation under the National Laboratories Program (National Tumor Biology Laboratory (2022-2.1.1-NL-2022-00010)) and the Hungarian Thematic Excellence Program (under project TKP2021-EGA-44) Grant Agreements with the National Research, Development and Innovation Office.

Keywords: breast, APBI, high-dose-rate brachytherapy

1418

Digital Poster

Feasibility of second conservative treatment with interstitial brachytherapy for breast recurrence

Sandra Canós 1 , Miguel Ángel Santos 1 , Mar Vercher 1 , Maria Isabel Tortajada 1 , Daniela Cediel 1 , Mario Vicó 2 , Mireia Pallarés 2 , Victor González-Pérez 2 , Jose Luis Guinot 1 , Leoncio Arribas 1

1 IVO, Radiation Oncology, VALENCIA, Spain. 2 IVO, Medical Physics, VALENCIA, Spain

Purpose/Objective:

According to the literature, the 20-year cumulative incidence of breast recurrence after initial conservative treatment is 15%. Initially, mastectomy has been postulated as the treatment of choice, however, it is not a treatment that prevents second relapses, distant metastases or death from breast cancer. There is currently a growing trend towards the use of a second conservative treatment (SCT) as an alternative for small tumours, reducing the risk of local recurrence by 18%. In terms of cosmetic results, brachytherapy (BT) is the best choice for previously radiated breasts and provides a locoregional recurrence-free survival between 77-100%, according to retrospective studies. Other techniques such as intraoperative radiotherapy (IORT) or EBRT could also be considered.