Comparison of survival effects between using electron and modulated X-ray beams for boosting irradiation in breast cancer patients after breast-conserving surgery and postoperative radiotherapy / 中华放射医学与防护杂志

ABSTRACT

Objective To compare the survival effects between using electron beams (EB) and modulated X-ray beams (XB) for boosting irradiation in breast cancer patients after breast-conserving surgery and postoperative radiotherapy.Methods This study retrospectively included 485 breast cancer patients who underwent breast-conserving surgery at Beijing Cancer Hospital.All patients underwent either EB or XB for tumor bed boost irradiation (10-16 Gy/5-8 fractions) after whole-breast irradiation of 46-50 Gy/23-25 fractions.Results Median follow-up time for the cohort was 96.04 months.Statistically significant increase of local recurrence free Survival (LRFS) was observed in XB group than in EB group.The 5-year and 10-year LRFS was both 98.4％ in XB group,as well as 94.2％ and 93.2％ in EB group,respectively (x2 =4.190,P ＜ 0.05).But there was not statistically significant difference in 5-year and 10-year overall survival (OS) between XB group(96.7％ and 95.8％) and EB group(94.9％ and 89.4％),respectively (P ＞ 0.05).The multivariate analysis showed that LRFS was significantly correlated with age≤40,positive pathological lymph nodes and positive expression of Her-2 receptor.But boost irradiation method was not independent prognostic factor for LRFS and OS (P ＞ 0.05).Conclusions For cancer patients treated with breast-conserving surgery and whole-breast postoperative radiation followed by a boost irradiation to tumor bed,XB irradiation was superior to EB irradiation in term of LRFS,yet no difference of OS was observed in both groups.