【摘要】 目的 探讨采用部分射束回避容积旋转调强在左乳癌根治术后放疗中的剂量学优势。方法 选取2023年1月至2024年3月嘉兴市第二医院经改良根治性乳房切除术并接受放疗的左乳癌女性患者45例，每例患者分别设计射束回避A组计划和无射束回避B组计划，评估两组方案在靶区适形指数与均匀指数、健侧乳、双侧肺、心脏的剂量学差异及机器跳数。结果 所有患者的两组计划都符合临床处方剂量要求，A组计划靶体积（PTV）的D2%明显高于B组（P<0.05）;CI和HI比较，差异均无统计学意义（1.12±0.04 vs. 1.10±0.02, P=0.192;0.13±0.02 vs. 0.10±0.03, P=0.426）。两组患侧肺的平均剂量D_mean相近（P=0.549）,A组的V30Gy明显高于B组（P<0.05），但V_5Gy、V_10Gy、V_20Gy较B组均有相应减少（P>0.05）。A组较B组明显减少了健侧肺的Dmean、V_5Gy、V_10Gy，平均值分别为51.5%（P<0.05）、36.4%（P<0.05）、80.2%（P<0.05）、70.4%（P<0.05）。A组健侧乳和心脏各项评估参数的平均值均低于B组，其中健侧乳D_mean、V_5Gy和心脏D_mean、V_5Gy、V_10Gy的平均值差异均有统计学意义（P<0.05），且心脏的平均剂量较B组减少了26.3%。A组的平均机器跳数明显低于B组（P<0.05）。结论 左乳癌根治术后的放疗患者采用部分射束回避的多弧容积旋转调强治疗不仅能充分保证靶区剂量，还能有效减少健侧肺、健侧乳和心脏的低剂量照射，从而降低辐射诱发第二癌症的风险。更多还原

【Abstract】 【Objective】 To investigate the dosimetric advantages of partial beam avoidance volume rotation intensity modulation in radiotherapy after radical mastectomy for left breast cancer. 【Methods】 A total of 45 female patients（aged 38 to 68years, median age 50.1 years） with left breast cancer who underwent modified radical mastectomy and radiotherapy were selected.Beam avoidance group A plans and non-beam avoidance group B plans were designed for each patient to assess the dosimetric differences and machine hops between the two groups of plans in target conformity index and uniformity index, unaffected breast,bilateral lung, and heart. 【Results】 All patients met the clinical prescribed dose requirements in both groups, D2% of planning target volume（PTV） in group A was significantly higher than that in group B（P=0.001）; there were no significant differences in conformity index（CI） and homogeneity index（HI）（1.12±0.04 vs. 1.10±0.02, P=0.192; 0.13±0.02 vs. 0.10±0.03, P=0.426）. The mean dose Dmean of the affected lung was similar between the two groups（P=0.549）, and V_30Gy in group A was significantly higher than that in group B（P<0.05）, but V_5Gy, V_10Gy, and V20Gy were correspondingly reduced compared with group B（P>0.05）. Group A significantly reduced Dmean, V_5Gy, and V_10Gy in the unaffected lung compared with group B, with mean values of 51.5%（P<0.05）,36.4%（P<0.05）, 80.2%（P<0.05）, and 70.4%（P<0.05）, respectively. The mean values of all assessed parameters of the unaffected breast and heart in group A were lower than those in group B, in which there were significant differences in the mean values of D_mean,V_5Gy and cardiac Dmean, V_5Gy, and V_10Gy in the unaffected breast（P<0.05）, and the mean dose to the heart was reduced by 26.3%compared with group B. The mean number of machine units in group A was significantly lower than that in group B（P<0.05）.【Conclusion】 Multi-arc volumetric rotational intensity modulated radiation therapy with partial beam avoidance can not only fully ensure the target dose, but also effectively reduce the low-dose irradiation of the unaffected lung, unaffected breast and heart in patients undergoing radiotherapy after radical resection of left breast cancer, thereby reducing the risk of radiation-induced second cancer.更多还原