乳腺癌改良根治术后三种放疗技术的剂量学对比研究

目的:分析比较容积调强弧形治疗(VMAT)与固定野调强放疗(F_IMRT)、电子束联合VMAT (E&VMAT)技术在乳腺癌改良根治术后放疗中的剂量学差异，为临床选择治疗方案提供参考。方法:随机选择乳腺癌改良根治术后放疗的左乳腺癌患者10例，靶区包括患侧胸壁和锁骨上淋巴引流区，处方剂量43.5 Gy (2.9 Gy/次...

Dosimetric comparison of three techniques in radiotherapy for breast cancer after modified mastectomy

Objective To analyze and compare the dosimetric differences based on volumetric-modulated arc therapy (VMAT), fixed field intensity-modulated radiotherapy (F_IMRT), and electron irradiation combined with VMAT (E&VMAT) in radiotherapy for breast cancer after modified mastectomy, aiming to provide reference for clinical selection of treatment plan. Methods Ten patients with the left breast cancer who received radiotherapy after modified mastectomy were randomly selected. The target areas included chest wall and supraclavicular region, and the prescribed dose was 43.5Gy in 15 fractions (2.9Gy/F). Based on the Pinnacle³ planning system, the VMAT, F_IMRT and E&VMAT plans (electron beam for chest wall, VMAT for supraclavicular area) were designed for each patient. The conformity and homogeneity of the target areas, the dose of organs at risk and treatment time were compared. Results The VMAT plan could improve the dose distribution of the target areas. The conformity index and homogeneity index of the target dose were significantly better than those of the F_IMRT and E&VMAT plans (all P<0.05). The average dose, V30Gy, V20Gy, V10Gy of the left lung in the VMAT plan were significantly better than those in the F_IMRT and E&VMAT plans (all P<0.05). The V5Gy of the left lung in the VMAT plan was significantly better than that in the F_IMRT plan (P<0.05). There was no statistical difference in the V5Gy of the left lung between the VMAT and E&VMAT plans (P>0.05). The heart, right breast and right lung of the VMAT plan could meet the clinical dose limit requirements. The treatment time of the VMAT, F_IMRT and E&VMAT plans was (326±27) s,(1 082±169) s, and (562±48) s, respectively. Conclusions Compared with the F_IMRT and E&VMAT plans, the VMAT plan has better quality and shorter treatment time. VMAT plan has higher value in clinical application compared with the F_IMRT and E&VMAT plans.