Evaluation of intraoperative breast radiotherapy on local recurrence: a Brazilian cohort

Abstract

Purpose

Assess the local recurrence rate and global survival rate among women diagnosed with breast cancer who underwent intraoperative electron radiotherapy (IOERT) between 2007 and 2017, in a single private healthcare setting in Belo Horizonte, Brazil.

Material and Methods

This is a retrospective study based on medical records about the outcomes of patients submitted to breast-conserving surgery followed by IOERT. The collected variables included the patient’s profile and tumor features, IOERT isodose, and outcomes. The quantitative data were presented in tables of frequency. The survival curves were created with the Kaplan-Meier method. In all tests, the adopted relevance level was 5%. The analyses were carried out with SPSS version 25.0.

Results and Conclusions

The samples consisted of 78 patients, among which a total of 14 (17.9%) recurrences were observed. The median time of recurrence was 49 months after the IOERT was performed. Of the 78 patients analyzed, 13 (16.7%) died, 5 (6.4%) of which were due to breast cancer. The global survival rate in 5 years was 94.9% and 90.4% in 10 years. The local recurrence rate in 5 years was 89.7% and 86.4% in 10 years. Our findings revealed a higher local recurrence rate than the literature data. However, our results also showed that patients classified as low-risk had an overall survival of 5 and 10 years similar to other studies in the literature, reaffirming that low-risk women can benefit from IOERT. Given this finding, it is reaffirmed that rigorous eligibility criteria for IOERT are critical to reducing local recurrence.

Keywords:

• Accelerated partial breast irradiation
• breast-conservation therapy
• iOERT
• low-risk breast cancer
• radiation therapy

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.

Notes on contributors

Cintia Melo Sousa

Cintia Melo Sousa, RN is the coordinator of Radiation Services in the Research Institution.

Izabella Nobre Queiroz

Izabella Nobre Queiroz, MD, is an radio-oncologist in the Research Institution.

Ana Paula Drummond-Lage

Ana Paula Drummond-Lage, PharmD, MSc, Ph.D., is an Adjunct Professor (Docent) of Oncology and a Senior Researcher at the Post-Graduation Department, Faculdade Ciências Médicas de Minas Gerais, Belo Horizonte, Brazil.