A Comparative Study of Daily 3-Gy Hypofractionated and 1.8-Gy Conventional Breast Irradiation in Early-Stage Breast Cancer

Abstract

We retrospectively compared accelerated hypofractionation (AHF) with conventional fractionation (CF) in the radiation therapy (RT) for early-stage breast cancer patients.Three hundred seventy-nine early-stage (pT1–2 and pN0–1a) breast cancer patients who received RT with AHF after breast-conserving surgery (BCS) were included. These patients were matched with 379 corresponding patients who received BCS and RT with CF at a different center with respect to the year BCS was performed, patient age (±3 years), and cancer stage. The AHF regimen consisted of 39 Gy in 13 fractions to the whole breast and a consecutive boost of 9 to 12 Gy in 3 to 4 fractions to the tumor bed. CF comprised whole-breast irradiation up to 50.4 Gy in 28 fractions and a boost of 9 to 14 Gy in 5 to 7 fractions to the tumor bed.The median follow-up period was 75 months (range, 3.8–110.8 months). There was no statistically significant difference between the AHF and CF groups in terms of age distribution, T and N stage, resection margin, and histologic grade. There were 5 ipsilateral breast tumor relapse (IBTR) cases in the AHF group compared with 7 cases in the CF group. Seven and eight locoregional relapse (LRR) cases were observed in the AHF and CF groups, respectively. The 7-year rates of IBTR-free survival, LRR-free survival, and disease-free survival were 98.9%, 98.4%, and 97.1% in the AHF group and 98.1%, 97.9%, and 96.0% in the CF group, respectively (P > 0.05). The incident rates of grade 3 edema, hyperpigmentation, or wet desquamation at the end of RT were higher in the CF group than in the AHF group (16.4% vs 0.2%, respectively; P < 0.01).AHF RT of 39 Gy to the whole breast plus a 9-Gy boost in 16 fractions showed excellent tumor control and tolerable skin toxicity, a finding that is comparable to CF RT in patients with early-stage breast cancer.

Whole-breast Radiotherapy With Boost for Node-negative Breast Cancer: Conventionalvs. Hypo-fractionation

“…Also, the fourth trial investigated only acute and short-term toxicities (14). Three other studies were identified that compared HF+boost and CF+boost (13,15,16). However, in one of these studies, median follow-up was limited to 16 months, and one study evaluated only acute toxicity (13,15).…”

“…However, in one of these studies, median follow-up was limited to 16 months, and one study evaluated only acute toxicity (13,15). The third of these studies provided longerterm (5-year) results of LC, MF, and OS (16). However, its results regarding acute skin toxicity were conflicting.…”

Comparison of the Oncological Efficacy Between Intraoperative Radiotherapy With Whole-Breast Irradiation for Early Breast Cancer: A Meta-Analysis

“…After full-text scrutinization, 35 of them were further omitted for the following reasons: (1) no provision of the 5-year outcomes in 15 potential articles for calculating the weighted average proportion; (2) no application of a 10-16 Gy boost to the patient in 13 potential studies for calculating the weighted average proportion in the WBI cohort; (4) no usage of a single dose of 21 Gy in five potential studies for calculating the weighted average proportion in the IORT cohort; and (5) 2 articles with other reasons. Ultimately, 38 articles with 30,225 early breast cancer patients were involved (9-12, 15-20, 26-53), in which 18 exclusively analyzed the 5-year oncological efficacy in the WBI cohort (15,16,(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40)(41), 9 exclusively analyzed that in the IORT cohort (9,12,17,(42)(43)(44)(45)(46)(47), and 11 compared the oncological efficacy between the cohorts (10,11,(18)(19)(20)(48)(49)(50)(51)(52)(53). Three of the 11 studies for the comparative meta-analysis had the available data to calculate the weighted average 5-year oncological efficacy in the non-comparative meta-analysis (10,…”

Radiation Boost After Adjuvant Whole Breast Radiotherapy: Does Evidence Support Practice for Close Margin and Altered Fractionation?

“…More importantly, cosmetic outcomes are similar when a boost is used in combination with hypofractionated vs. conventional WBI (33)(34)(35)(36)(37)(38)(39). In their 120-patient study comparing addition of a boost to conventional fractionation (50 Gy/25 fractions) vs. hypofractionation (42.5 Gy/16 fractions), De Felice et al (34) found no difference in long-term breast fibrosis.…”

“…Next, with regards to cancer control, conventional and hypofractionation regiments have been shown to produce similar outcomes ( 33 ). Within conventional fractionation, the improved local control provided by a boost is well-documented ( 40 ).…”