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.
ABSTRACT
Objective: To conduct a Meta-analysis to analyze the short-term and long-term preventive effects of whole breast irradiation combined with tumor bed boost on short- and long-term local recurrence rates and local recurrence rate of ipsilateral invasive breast cancer in patients with breast ductal carcinoma in situ (DCIS) after breast conserving-surgery (BCS). Methods: A computer-based online search of PubMed, China Journal Full-text Database (CJFD), China Biology Medicine disc (CBMdisc), Embase and Cochrane Library was performed to include eligible studies in accordance with the inclusion and exclusion criteria. Newcastle Ottawa Quality Assessment Scale was used for quality assessment of included articles. RevMan 5.3 software was used for Meta-analysis. Results: A total of 14 non-randomized controlled trials (13 were cohort study, and 1 was nonsimultaneous controlled trial) involving 8679 patients with breast DCIS were included. The results of this Meta-analysis showed that no statistically significant differences between whole breast irradiation and whole breast irradiation combined with tumor bed boost in terms of 5-year local recurrence rate [odds ratio (OR) = 0.92, 95% confidence interval (CI): 0.46-1.82; P = 0.81], 7-year local recurrence rate (OR = 0.70, 95% CI: 0.45-1.09; P = 0.11), ≥ 10-year local recurrence rate (OR = 0.95, 95% CI: 0.79-1.15; P= 0.62) and the local recurrence rate of ipsilateral invasive breast cancer (OR = 0.89, 95% CI: 0.62-1.29; P = 0.55). Conclusion: As compared with whole breast irradiation, the whole breast irradiation combined with tumor bed boost in patients with DCIS after BCS can not obviously decrease the 5-year, 7-year and ≥ 10-year local recurrence rates, as well as the local recurrence rate of ipsilateral invasive breast cancer.
ABSTRACT
Objective To determine the change of tumor bed volume during whole breast irradiation by repeated computed tomography scanning and to analyze the dosimetric impact of boost-planning on different CT images. Methods From July 2008 to Jan 2009, sixteen patients with early-stage breast cancer underwent breast conservative surgery (BCS) were enrolled in the study. All patients received whole breast irradiation and tumor bed boost, no adjuvant chemotherapy was given. Two additional CT scans were acquired in addition to the planning CT ( CT1 ), one in the course of radiotherapy ( CT2 ) and the other before the boost (CT3). Tumor beds were contoured in all CT images. Three-dimensional conformal radiotherapy planning for tumor bed boost was done on CT1 and CT3 respectively. Results The mean tumor bed volume on CT1, CT2 and CT3 were 49.5 cm3, 25.6 cm3 and 22. 2 cm3 ( F = 5. 63, P = 0. 007 ),respectively. Further analysis found statistically significant difference between CT1 and CT2 ( q = 0. 03, P =0. 010), CT1 and CT3 ( q = 0. 01, P = 0. 004), but not between CT2 and CT3 ( q = 1.00, P = 0. 333 ). The average reduction of tumor bed volume from CT1 to CT3 was 43.4%. A reduction of 20% or above was found in 88% of the patients ( n = 14), 50% or above in 38% of the patients (n = 6). In the boost-planning, the volume of the ipsilateral breast receiving 100% prescribed dose (V100%) on CT1 and CT3 was 183.5 cm3 and 144. 5 cm3, respectively ( t = 3.06, P = 0. 008 ). Conclusions Volume of tumor bed is dynamically reduced in the course of whole breast irradiation after BCS, with more important reduction in the early weeks after the beginning of irradiation. A second CT scan before tumor bed boost is warranted.