Intra-Operative Electron Radiation Therapy (IOERT) Anticipated Boost in Breast Cancer Treatment: An Italian Multicenter Experience.

Antonella Ciabattoni,Paola Zuccoli,Karen Llange,Loredana Lapadula,Francesca Salerno,Marco Lioce,Daniela Di Cristino,Cristiana Vidali,Agostino Cristaudo,Marina Alessandro,Giovanni B Ivaldi,Fabiana Gregucci,Alba Fiorentino,Marco Krengli,Antonio Stefanelli,Vincenzo Fusco,Francesca Corazzi

doi:10.3390/cancers14020292

Abstract

Simple SummaryIn breast cancer, IOERT represents an attractive therapeutic option to deliver a boost directly on the tumor bed during surgery with all the relative radiobiological advantages. According to the literature, the present multicenter research demonstrates the safety and efficacy of this treatment using a large group of patients treated in daily clinical practice. Between January 2011 and March 2018, 797 patients were evaluated. Median follow-up was 57 months (range 12–109 months). Acute toxicity ≥ G2 occurred in 179 patients (22.46%). No patients reported late toxicity > G2. Obj-cosmetic result was excellent in 45%, good in 35%, fair in 20% and poor in 0% of cases. Subj-cosmetic result was excellent in 10%, good in 20%, fair in 69% and poor in 0.3% of cases. At 5 years, in-field LC was 99.2% (95% CI: 98–99.7); out-field LC 98.9% (95% CI: 97.4–99.6); DFS 96.2% (95% CI: 94.2–97.6); OS 98.6% (95% CI: 97.2–99.3).In breast cancer, the use of a boost to the tumor bed can improve local control. The aim of this research is to evaluate the safety and efficacy of the boost with intra-operative electron radiotherapy (IOERT) in patients with early-stage breast cancer undergoing conservative surgery and postoperative whole breast irradiation (WBI). The present retrospective multicenter large data were collected between January 2011 and March 2018 in 8 Italian Radiation Oncology Departments. Acute and late toxicity, objective (obj) and subjective (subj) cosmetic outcomes, in-field local control (LC), out-field LC, disease-free survival (DFS) and overall survival (OS) were evaluated. Overall, 797 patients were enrolled. IOERT-boost was performed in all patients during surgery, followed by WBI. Acute toxicity (≥G2) occurred in 179 patients (22.46%); one patient developed surgical wound infection (G3). No patients reported late toxicity ≥ G2. Obj-cosmetic result was excellent in 45%, good in 35%, fair in 20% and poor in 0% of cases. Subj-cosmetic result was excellent in 10%, good in 20%, fair in 69% and poor in 0.3% of cases. Median follow-up was 57 months (range 12–109 months). At 5 years, in-field LC was 99.2% (95% CI: 98–99.7); out-field LC 98.9% (95% CI: 97.4–99.6); DFS 96.2% (95% CI: 94.2–97.6); OS 98.6% (95% CI: 97.2–99.3). In conclusion, IOERT-boost appears to be safe, providing excellent local control for early-stage breast cancer. The safety and long-term efficacy should encourage use of this treatment, with the potential to reduce local recurrence.

Highlights

Breast cancer is the most common malignant disease among women, and it still represents the leading cause of death from cancer among them (28% in patients under 50 years, 21% in those between 50 and 69 years, and 14% in those older than 70), even though there has been a downward trend in the mortality (0.8%/year) in recent years, due to the spread of screening programs, early diagnosis and therapeutic progress [1,2]
From January 2011 to March 2018, 797 patients with a median age of 58 years underwent anticipated intra-operative electron radiotherapy (IOERT)-boost during breast-conserving surgery followed by whole breast irradiation (WBI)
Since 1990, conservative surgery and adjuvant WBI have been the standard of care for early-stage breast cancer [3]; this approach was shown to achieve good local control with satisfactory cosmetic results while preserving the mammary gland

Summary

Introduction

Breast cancer is the most common malignant disease among women, and it still represents the leading cause of death from cancer among them (28% in patients under 50 years, 21% in those between 50 and 69 years, and 14% in those older than 70), even though there has been a downward trend in the mortality (0.8%/year) in recent years, due to the spread of screening programs, early diagnosis and therapeutic progress [1,2]. The standard treatment for early breast cancer includes breast conserving surgery, such as quadrantectomy, wide excision or lumpectomy, plus sentinel lymph node biopsy or, if necessary, axillary lymph node dissection, followed by postoperative whole breast irradiation (WBI) ± adjuvant systemic treatment. Adjuvant WBI is currently considered the standard treatment after breast conservative surgery and plays an important role to reduce local recurrences (LR) and to improve disease-free survival (DFS) and overall survival (OS) [3]. The most widely used dose was 50–50.4 Gy in daily fractions of 2–1.8 Gy in 5–5.5 weeks, generally using two fields tangent to the chest wall with or without a boost with either electrons or photons or brachytherapy to the tumor bed, which is regarded as the site with the highest probability of local recurrence. The LR rate turned out to be even superior to that of the conventional schedule, while maintaining equal or even better long-term cosmetic results and toxicity [4,5]

Methods

Results

Discussion

Conclusion