影像引导对乳腺癌调强放射治疗精度的影响

目的：分析在乳腺癌图像引导放射治疗（IGRT）过程中，图像引导对于放射治疗的精确度的影响；同时观察图像引导放射治疗的毒性反应及放射治疗近期的治疗效果。方法：搜集2012年1月-2013年2月间，于哈尔滨医科大学附属第三医院放疗科收治的乳腺癌患者25例。使用医科达SynergyTM锥形束CT（CBCT）进行治疗前扫描，通过图像引导放射治疗技术对25例患者进行误差纠正，调整后行调强放疗。患者在进行放疗前，用锥形柬CT对射野的偏差进行校正，其偏差利用锥形束CT图像与计划螺旋CT图像进行手动匹配，在X、Y、Z三个方向上进行调整。根据误差调整治疗床位置后治疗。对急性放射性反应采用RTOG5级评价标准进行评价：急性放射性皮肤反应、急性放射性肺损伤及急性放射性心脏损伤。结果：25例乳腺癌患者治疗前经锥形束CT扫描采集的图像与计划参考图像比较在X、Y、Z方向上平均误差分别为0．429±1．683mm、0．431±1．728mm、0．583±2．041mm：摆位误差纠正后，误差值分别为：0．068±0．429、0．019±0．438、0．158±0．697，调整后摆位误差控制在1mm之内进行治疗。放疗后2周急性皮肤反应为0级23例、1级2例；4周为0级21例、1级4例。无急性放射性肺损伤及心脏损伤的病例出现。结论：目前调强放疗是乳腺癌临床放射治疗的重要手段，图像引导放射治疗的应用能够使放疗精度显著提高。

Using Image Guide Radiotherapy Enhanced the Radiotherapy Precision of Breast Cancer in Intensity Modulated Radiotherapy

Objective： To analyze the influence of image-guided radiation therapy （IGRT） on the accuracy in breast cancer radiotherapy, and to observe the toxicity and therapeutic effect after image-guided radiation therapy. Methods： 25 patients with breast cancer were collected from January 2012 to February 2013 in department of radiation oncology of the third affiliated hospital of Harbin medical university. Using ELEKTA SynergyTM of the cone-beam CT （CBCT） to scan 25 cases of breast cancer patients and treating patients with IMRT. Before each radiation, field size bias was corrected by using CBCT. The deviation was obtained from CBCT image with the project on the spiral CT images on X, Y, and Z directions. The treatment began after the adjustment of the location of the treatment bed. Acute radiation skin response was recorded and local radioactive lung injury and acute radioactive cardiac injuries. Results： The average errors of 12 cases of Breast cancer in LR, SI, and AP directions were 0.429＋ 1.683mm, 0.431 ± 1.728mm, and 0.583±2.041 mm for the first CBCT scan, respectively. After correction, the deviations were： 0.068 ± 0.429, 0.019 ± 0.438 and 0.158 ± 0.697, the adjusted position deviation was controlled within lmm treatment. Grade 0 of acute radiation skin reaction was seen in 23 patients in lweek and grade 1 in 2 patients 2 weeks later. Conclusions： Currently intensity-modulated radiotherapy is to meet the standards of clinical breast cancer, the best plan IGRT auxiliary can achieve this goal by improving the accuracy.