A Single-Institution Retrospective Study of Three-Fraction HDR Accelerated Partial Breast Irradiation

Eric M Chung; Anthony T Nguyen; Amin Mirhadi; Jennifer M Steers; Tiffany Phillips; Katelyn M Atkins; Michele Burnison; Stephen L Shiao; Mitchell Kamrava

doi:10.1016/j.brachy.2023.02.006

A Single-Institution Retrospective Study of Three-Fraction HDR Accelerated Partial Breast Irradiation

Brachytherapy. 2023 May-Jun;22(3):361-367. doi: 10.1016/j.brachy.2023.02.006. Epub 2023 Mar 28.

Authors

Eric M Chung¹, Anthony T Nguyen¹, Amin Mirhadi¹, Jennifer M Steers¹, Tiffany Phillips¹, Katelyn M Atkins¹, Michele Burnison¹, Stephen L Shiao¹, Mitchell Kamrava²

Affiliations

¹ Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA; Cedars-Sinai Medical Center, Samuel Oschin Comprehensive Cancer Institute, Los Angeles, CA.
² Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA; Cedars-Sinai Medical Center, Samuel Oschin Comprehensive Cancer Institute, Los Angeles, CA. Electronic address: mitchell.kamrava@cshs.org.

PMID: 36997449
DOI: 10.1016/j.brachy.2023.02.006

Abstract

Purpose: Accelerated partial breast irradiation (APBI) delivered with high-dose-rate brachytherapy is a standard of care treatment typically delivered over 10 fractions. The TRIUMPH-T multi-institutional study recently demonstrated promising results using a shorter three fraction regimen, however there are limited additional published series using this regimen. Here, we report our experience and outcomes for patients treated as per the TRIUMPH-T regimen.

Methods and materials: This study was a retrospective single-institution analysis of patients who underwent lumpectomy followed by APBI (22.5 Gy in 3 fractions delivered over 2-3 days) using a Strut Adjusted Volume Implant (SAVI) applicator between November 2016 and January 2021. Dose-volume metrics were obtained from the clinically treated plan. Chart review was performed to determine locoregional recurrence and toxicities according to CTCAE v5.0.

Results: Between 2016 and 2021, 31 patients were treated per the TRIUMPH-T protocol. Median followup was 31 months from completion of brachytherapy. There were no acute/late Grade 3 or higher toxicities. Cumulative late Grade 1 and 2 toxicities were seen in 58.1% and 9.7% of patients, respectively. Of note, four patients experienced locoregional recurrence: three ipsilateral breast tumor recurrences and one nodal recurrence. All three ipsilateral breast tumor recurrences occurred in patients who would be classified as "cautionary" based on ASTRO consensus guidelines due to age ≤50, lobular histology, or high grade.

Conclusions: Three-fraction HDR brachytherapy APBI was well-tolerated with no grade 3 or higher toxicities and an acceptably small percentage of grade 2 toxicities. Given the small sample size, the number of recurrences suggests that attention to appropriate patient selection is necessary until more long-term followup data is available.

Keywords: Accelerated partial breast irradiation; Brachytherapy; Breast cancer.

MeSH terms

Brachytherapy* / methods
Breast Neoplasms* / radiotherapy
Female
Humans
Mastectomy, Segmental
Neoplasm Recurrence, Local / etiology
Neoplasm Recurrence, Local / radiotherapy
Radiotherapy Dosage
Retrospective Studies