Bodács István, Polgár Csaba, Major Tibor
Sugárterápiás Központ, Országos Onkológiai Intézet, Budapest, Hungary.
Magy Onkol. 2014 Jun;58(2):108-15. Epub 2014 Feb 5.
Different techniques exist for the delivery of radiotherapy after breast conserving surgery. The conventional method is whole breast irradiation. However, in selected patients partial breast irradiation can be performed, either with external beams or brachytherapy. In the current study three irradiation techniques are compared regarding dosimetric aspects. Treatment plans of thirty women treated with external beam conformal partial breast irradiation (CONF) were evaluated using dose-volume histograms. For the same patients whole breast irradiation plans (WBI) were made and compared with the CONF ones. Breast and lung of both sides, and heart at left sided lesions were contoured as organs at risk. After this, dose plans of another thirty patients treated with interstitial brachytherapy (IBT) were analyzed and compared with the CONF plans. According to our results the 90% isodose curve covered at least 97% of the target volume at all three techniques, and this value was 100% for CONF. The maximal dose within target volume was 106% in CONF and 115% in WBI plans. Volume of ipsilateral breast receiving the prescribed dose was 66%, 15% and 13% in the WBI, CONF and IBT plans, respectively. The dose to the contralateral breast was less for CONF compared to WBI. Volume of the ipsilateral lung receiving 30% of the prescribed dose was 15%, 8% and 1%, the maximal dose was 105%, 94% and 47% in the WBI, CONF and IBT plans, respectively. In the same order the maximal dose to the heart was 82%, 49% and 25%, while the dose irradiated to 5% of the heart volume was 27%, 19% and 14% at left sided lesions. Regarding target coverage, the conformal technique was the best, and the dose was more homogeneous than at WBI. With respect to dose to organs at risk the partial breast irradiation techniques were much more favorable than WBI, and the lowest doses occurred in the IBT treatment plans.
保乳手术后有多种放疗技术。传统方法是全乳照射。然而，对于部分选定患者，可采用外照射或近距离放疗进行部分乳腺照射。在本研究中，对三种照射技术的剂量学方面进行了比较。使用剂量体积直方图评估了30例接受外照射适形部分乳腺照射（CONF）治疗的女性的治疗计划。针对相同患者制定了全乳照射计划（WBI）并与CONF计划进行比较。双侧乳腺和肺部以及左侧病变处的心脏被勾勒为危及器官。此后，分析了另外30例接受组织间近距离放疗（IBT）治疗的患者的剂量计划，并与CONF计划进行比较。根据我们的结果，在所有三种技术中，90%等剂量曲线至少覆盖97%的靶体积，CONF技术该值为100%。靶体积内的最大剂量在CONF计划中为106%，在WBI计划中为115%。接受规定剂量的同侧乳腺体积在WBI、CONF和IBT计划中分别为66%、15%和13%。与WBI相比，CONF对侧乳腺的剂量更低。接受30%规定剂量的同侧肺体积在WBI、CONF和IBT计划中分别为15%、8%和1%，最大剂量分别为105%、94%和47%。按相同顺序，心脏的最大剂量分别为82%、49%和25%，而在左侧病变处，照射到5%心脏体积的剂量分别为27%、19%和14%。关于靶区覆盖，适形技术最佳，且剂量比WBI更均匀。就危及器官的剂量而言，部分乳腺照射技术比WBI更有利，且最低剂量出现在IBT治疗计划中。
