# Application of Intraoperative Radiotherapy in Early-Stage Breast Cancer Patients in a Clinical Setting

## TL;DR

This study shows that intraoperative radiation therapy for early-stage breast cancer leads to low recurrence and metastasis rates in a multiethnic patient group.

## Contribution

The paper presents 43-month clinical outcomes of IORT in a real-world multiethnic cohort of early-stage breast cancer patients.

## Key findings

- The overall recurrence rate was 1.4% with 0.5% local recurrence and 0.9% metastasis.
- Patient outcomes were excellent with one death from metastasis in 211 patients followed for 43.4 months on average.
- No significant differences in tumor size or age were found between Jewish and Bedouin patients.

## Abstract

Background: Intraoperative radiation therapy (IORT) has gained popularity in recent years as an alternative to external beam whole breast radiation therapy (WBRT) for early-stage breast cancer. Here, we report 43-month recurrence and survival outcomes in a multiethnic cohort treated with IORT in a clinical context.

Method: Two hundred and eleven patients with low-risk features were treated with IORT for early-stage breast cancer from 2014 to 2021. Selection criteria were based on Group Europeen de Curietherapie-European Society for Therapeutic Radiology and Oncology (GEC-ESTRO) guidelines: preferably unifocal intraductal carcinoma (IDC), aged > 50, tumor size ≤ 2.0 cm, and without lymph node involvement. All patients received 20 Gy of radiation dose during the lumpectomy. Information on patient and tumor characteristics was collected.

Results: The mean age of this cohort was 67.5 years; 95.2% of patients are Jewish, and the rest are Bedouins (4.7%). Most tumors were intraductal carcinoma (97.2%) and stage 1 (94.8%). The mean follow-up time was 43.4 months. Bedouins had larger tumor sizes (mean 1.21 vs. 1.13 cm) and were younger at diagnosis than Jewish patients (mean 65.4 vs. 67.6 years), although the differences are not significant. The overall recurrence rate was 1.4%. One case of local recurrence (0.5%) and two cases of metastasis (0.9%) were observed during the study period. One patient died from metastasis.

Conclusion: Our findings suggest that IORT in selected low-risk patients can achieve an excellent prognosis with low rates of recurrence and metastasis.