Boost by Brachytherapy in Breast Cancer: Experience of the Radiotherapy Department at CHU Hassan II of Fès

Research Article

Abstract

Introduction: Breast-conserving surgery combined with external beam radiotherapy (EBRT) is widely recognized as an effective treatment for localized breast cancer. To improve local control, a boost dose to the tumor bed is frequently recommended, particularly for patients at higher risk of recurrence. High-dose-rate (HDR) interstitial brachytherapy enables precise boost delivery while reducing radiation exposure to surrounding healthy tissues.

Objective: To evaluate the efficacy and safety of HDR interstitial brachytherapy as a boost following EBRT in patients with T1-T2 breast cancer.

Method: This retrospective study included 21 patients with T1-T2 breast cancer treated at the Radiotherapy Department of CHU Hassan II of Fez from October 2016 to December 2023. Patients underwent lumpectomy and were selected based on GEC-ESTRO and ASTRO inclusion criteria. Initial EBRT was delivered via conventional fractionation (50 Gray in 25 fractions) or hypofractionation (42 Gray in 15 fractions), followed by an HDR brachytherapy boost of 8-10 Gray administered in two fractions with a minimum 6-hour interval. Clinical and radiological follow-ups were conducted to assess local control, side effects, and survival.

Results: The median age was 44 years, with a median follow-up of 55 months. Among the 21 patients, 11 presented with T1 stage cancer, and 10 with T2 stage. The local recurrence rate was 4.76%. Mean disease-free survival was 54.4 months, and overall survival was 56 months. HDR brachytherapy showed strong local control, with minimal recurrence rates and favorable survival outcomes.

Conclusion: HDR interstitial brachytherapy as a boost following EBRT in breast-conserving surgery appears to be an effective approach for enhancing local control in T1-T2 breast cancer, with low recurrence and good survival outcomes. These findings support HDR brachytherapy as a viable, tissue-sparing option for boosting tumor bed dose in this patient group.