Abstract：
OBJECTIVE: This study compared the dosimetric parameters of field-in-field forward intensity-modulated radiotherapy (FIF-IMRT) and fixed-field inversely optimized intensity-modulated radiotherapy (FFIO-IMRT) for the whole-breast irradiation of patients undergoing right-breast lumpectomy.
METHODS: A total of 30 patients with pT1-2N0M0 right-breast invasive ductal carcinoma were enrolled in this study. Two different treatment plans, i.e., FIF-IMRT and FFIO-IMRT, were designed for each patient. The dosimetric parameters of the two treatment plans were compared including ipsilateral lung and heart, conformity index (CI), and the homogeneity index (HI) of the planning target volume (PTV).
RESULTS: Fixed-field inversely optimized intensity-modulated radiotherapy was found to significantly improve CI (83.302% vs. 60.146%) and HI (11.837% vs. 19.280%), and significantly reduced V25 (18.038% vs. 19.653%) and V30 (15.790% vs. 18.492%) of the ipsilateral lung. It also significantly increased V5 (69.791% vs. 32.615%) of the ipsilateral lung and V5 (61.579% vs. 3.829%), V10 (14.130% vs. 0.381%), V20 (1.843% vs. 0.051%), and Dmean (5.211Gy vs. 1.870Gy) of the heart.
CONCLUSIONS: Regardless of improving the conformity and homogeneity of PTV and reducing the ipsilateral lung irradiation volume at high doses, FFIO-IMRT significantly raised the ipsilateral lung irradiated volume at low doses, as well as the irradiation volume and mean radiation doses to the heart. This limits its use in patients with early-stage right breast cancer.
METHODS: A total of 30 patients with pT1-2N0M0 right-breast invasive ductal carcinoma were enrolled in this study. Two different treatment plans, i.e., FIF-IMRT and FFIO-IMRT, were designed for each patient. The dosimetric parameters of the two treatment plans were compared including ipsilateral lung and heart, conformity index (CI), and the homogeneity index (HI) of the planning target volume (PTV).
RESULTS: Fixed-field inversely optimized intensity-modulated radiotherapy was found to significantly improve CI (83.302% vs. 60.146%) and HI (11.837% vs. 19.280%), and significantly reduced V25 (18.038% vs. 19.653%) and V30 (15.790% vs. 18.492%) of the ipsilateral lung. It also significantly increased V5 (69.791% vs. 32.615%) of the ipsilateral lung and V5 (61.579% vs. 3.829%), V10 (14.130% vs. 0.381%), V20 (1.843% vs. 0.051%), and Dmean (5.211Gy vs. 1.870Gy) of the heart.
CONCLUSIONS: Regardless of improving the conformity and homogeneity of PTV and reducing the ipsilateral lung irradiation volume at high doses, FFIO-IMRT significantly raised the ipsilateral lung irradiated volume at low doses, as well as the irradiation volume and mean radiation doses to the heart. This limits its use in patients with early-stage right breast cancer.
摘要：
目的：本研究比较了场内正向调强放疗（FIF-IMRT）和固定场逆向优化调强放疗（FFIO-IMRT）的剂量学参数对右乳腺肿块切除术患者的全乳房照射。
方法：本研究共纳入30例pT1-2N0M0右乳浸润性导管癌患者。两种不同的治疗方案,即，FIF-IMRT和FFIO-IMRT,是为每个病人设计的。比较两种治疗方案的剂量参数，包括同侧肺和心脏，合格指数(CI)，和规划目标体积(PTV)的均匀性指数(HI)。
结果：发现固定场反向优化调强放疗显着提高CI（83.302%vs.60.146%）和HI（11.837%与19.280%），并显著降低V25(18.038%vs.19.653%）和V30（15.790%与18.492%)的同侧肺。它还显着增加了V5（69.791％与32.615％）的同侧肺和V5（61.579％vs.3.829%)，V10（14.130%与0.381%），V20（1.843%与0.051%)，和Dmean（5.211Gyvs.1.870Gy）的心脏。
结论：无论提高PTV的一致性和均匀性，还是减少高剂量同侧肺照射量，FFIO-IMRT在低剂量下显着提高了同侧肺的照射体积，以及心脏的照射量和平均辐射剂量。这限制了其在早期右乳腺癌患者中的使用。
方法：本研究共纳入30例pT1-2N0M0右乳浸润性导管癌患者。两种不同的治疗方案,即，FIF-IMRT和FFIO-IMRT,是为每个病人设计的。比较两种治疗方案的剂量参数，包括同侧肺和心脏，合格指数(CI)，和规划目标体积(PTV)的均匀性指数(HI)。
结果：发现固定场反向优化调强放疗显着提高CI（83.302%vs.60.146%）和HI（11.837%与19.280%），并显著降低V25(18.038%vs.19.653%）和V30（15.790%与18.492%)的同侧肺。它还显着增加了V5（69.791％与32.615％）的同侧肺和V5（61.579％vs.3.829%)，V10（14.130%与0.381%），V20（1.843%与0.051%)，和Dmean（5.211Gyvs.1.870Gy）的心脏。
结论：无论提高PTV的一致性和均匀性，还是减少高剂量同侧肺照射量，FFIO-IMRT在低剂量下显着提高了同侧肺的照射体积，以及心脏的照射量和平均辐射剂量。这限制了其在早期右乳腺癌患者中的使用。
