Results of intraoperative radiotherapy given as a boost after breast conserving-surgery
Kraiwut Onthong, Chakapong Chakkabat, Chonnipa Nantavithya, Kanjana Shotelersuk, Sikrit Denariyakoon, Mawin Vongsaisuwon, Adhisabandh Chulakadabbav, Kris Chatamra, Kitwadee Saksornchai, Kraiwut Onthong, Chakapong Chakkabat, Chonnipa Nantavithya, Kanjana Shotelersuk, Sikrit Denariyakoon, Mawin Vongsaisuwon, Adhisabandh Chulakadabbav, Kris Chatamra, Kitwadee Saksornchai
Abstract
Background: Whole breast irradiation after breast-conserving surgery (BCS) with an external beam boost of 10-16 Gy is currently the standard treatment in breast cancer. Various modalities have been used for tumor bed boost irradiation. This study aimed to evaluate the local recurrence rate, overall survival rate (OSR), toxicity and cosmetic outcome of intraoperative radiotherapy (IORT) as a boost followed by whole breast irradiation in patients who received BCS.
Methods: This is a retrospective study. Between December 2009 and March 2017, 81 patients who underwent BCS with IORT as a boost were enrolled in this study. For IORT, a single dose of 20 Gy was delivered using a 30-50 kV photon beam, intraoperatively. All patients received whole breast radiation therapy (WBRT) of 42.5-50 Gy over 4-5 weeks. The primary endpoint was a 3-year local recurrence rate. Secondary endpoints included the OSR, toxicity and cosmetic outcome at 6 months after radiation treatment.
Results: At a median follow-up of 43 months, ipsilateral local recurrence was observed in one of the 81 patients (1.2%) which occurred in the same quadrant of the breast index. The 3-year OSR was 89.8%. Treatment was well-tolerated with no grade 3-4 acute and late toxicity, and 87% of patients were recorded as excellent-good cosmesis.
Conclusions: The use of BCS with IORT as a boost resulted in a low local recurrence rate and excellent cosmetic outcome in early breast cancer. Thus, IORT as a boost could be considered as an alternative to an external beam boost. Prospective studies are needed to confirm this data.
Keywords: Intraoperative radiotherapy (IORT); boost; cosmetic outcomes; early breast cancer; local recurrence; whole breast irradiation.
Conflict of interest statement
Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at http://dx.doi.org/10.21037/gs-20-249). The authors have no conflicts of interest to declare.
2020 Gland Surgery. All rights reserved.
Source: PubMed