Vienna, Austria

ESTRO 2023

Session Item

Breast
6006
Poster (Digital)
Clinical
Partial breast re-irradiation with IMRT for local recurrence after whole breast radiotherapy
Mattia Zaffaroni, Italy
PO-1251

Abstract

Partial breast re-irradiation with IMRT for local recurrence after whole breast radiotherapy
Authors:

Simona Arculeo1, Samantha Dicuonzo2, Anna Morra3, Marianna Alessandra Gerardi4, Lorenzo Colombi5, Colombi Lorenzo6, Federica Cattani7, Stefania Comi8, Paolo Veronesi9, Viviana Galimberti10, Mattia Zaffaroni3, Maria Alessia Zerella3, Roberto Orecchia11, Maria Cristina Leonardi7, Barbara Alicja Jereczek-Fossa3,12

1IEO European Institute of Oncology IRCCS, Division of Radiation Oncology , Milan , Italy; 2IEO European Institute of Oncology IRCCS , Division of Radiation Oncology , Milan, Italy; 3IEO European Institute of Oncology IRCCS, Division of Radiation Oncology, Milan , Italy; 4IEO European Institute of Oncology IRCCS, Milan, Division of Radiation Oncology, Milan , Italy; 5IEO European Institute of Oncology IRCCS, Division of Radiation Oncology, Milan, Italy; 6 University of Milan, Department of Oncology and Hemato-Oncology , Milan, Italy; 7IEO European Institute of Oncology IRCCS, Division of Radiation Oncology, Milan, Italy; 8IEO European Institute of Oncology IRCCS, Division of Radiation Oncology, Milano, Italy; 9IEO European Institute of Oncology IRCCS, Division of Senology, Milan, Italy; 10IEO European Institute of Oncology IRCCS, ivision of Senology, Milan , Italy; 11IEO European Institute of Oncology IRCCS, Scientific Direction, Milan, Italy; 12University of Milan, , Department of Oncology and Hemato-Oncology, Milan, Italy

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Purpose or Objective

Although the standard treatment of in-breast recurrence (IBR) after breast conservative surgery (BCS) and whole breast radiotherapy (WBRT) is still represented by mastectomy, over the last decade there has been an increasing attitude towards performing a second BCS followed by further radiotherapy (RT) with different techniques (intraoperative RT, brachytherapy, external beam RT). The aim of the study is to evaluate chronic toxicity and local control of partial breast re-irradiation (re-PBI) with intensity modulated RT (IMRT), using a hypofractionated scheme

Material and Methods

Eligibility criteria included patients previously treated with WBRT who experienced IBR and were operated on with second BCS. Re-irradiation was limited to the tumor bed and was performed using either TomoTherapy® IMRT with helical modality or BrainLab-VERO® IMRT step-and-shoot. Planning target volume (PTV) was generated by clinical target volume (CTV) with a margin of 5 mm. Daily image guided RT was applied by megavoltage fan beam computerized tomography (CT) for TomoTherapy® and kilovoltage cone beam CT for VERO®. For target volume, the PTV planning objectives were V100%≥95%, V95%≥98%, V90%≥100%, Dmax≤110%. Toxicity was evaluated using LENT-SOMA scale

Results

Between 6/2012 and 3/2018, 59 patients were treated with re-PBI. Prescription dose was 37.05 Gy in 13 fractions. Fifteen (25%) patients were treated with TomoTherapy® and 44 (75%) with VERO®. Overall, median follow-up was 68 months. Data of chronic toxicity > 1 year are available for 44 (74%) patients; 5%,10%, 5% of patients report fibrosis G3, atrophy G2 and teleangectsia G2, respectively. Thirtenn (22%) patients showed a subsequent oncologic event after the retreatment: 1 patient had a second IBR distant from the re-PBI field (1.6% cumulative incidence of IBR), 1 patient had regional recurrence, 7 patients developed distant metastasis (lymph nodes, lung, bones and brain) and 3 had other primitive tumors.

Conclusion

Re-PBI after second BCS represents a feasible alternative to mastectomy with regard to local control, showing good toxicity profile. Longer follow-up is needed to evaluate late toxicity and to establish the role of this treatment modality in local control. Longer follow-up is needed to evaluate late toxicity and to establish the role of this treatment modality in local control.