主动呼吸控制技术(ABC)在肺癌放射治疗中的应用

The Use of Active Breathing Control (ABC) in Radiotherapy of Lung Cancer

目的:使用主动呼吸控制技术(activebreathingcontrol,ABC)治疗非小细胞肺癌患者,评价呼吸运动对肺部肿瘤动度的影响及ABC技术的优势和可行性,并评价近期疗效和急性放射反应。方法:选择9例使用ABC技术联合三维适形放疗技术治疗的非小细胞肺癌患者进行分析。CT定位扫描时分别采集ABC和自由呼吸(freebreath,FB)状态下的图像,评价呼吸运动对肺部肿瘤动度和PTV边界的影响程度;并比较两种计划的DVH。放疗剂量为54～60Gy/18～20次,3Gy/次,1次/天,5天/周。定期随访,评价近期疗效及急性放射反应。结果:应用ABC技术后,膈肌的平均位移从FB时的24.5mm(20.0～32.0mm)降低为3.6mm(0.5～7.2mm),胸壁的侧方位移从FB时的3.2mm(2.8～4.0mm)降低为1.2mm(0.5～1.6mm)。PTV边界可以从FB时的1.5cm减少为0.75cm;肺的V20从21.8%降低为15.0%,减少了30.6%。中位随访6个月时,9例患者中有6例CR,3例PR。急性放射副反应都很轻微,仅为Ⅰ°～Ⅱ°。结论:在肺癌的精确放射治疗中,呼吸动度的影响不可忽视。而ABC系统可以有效的降低呼吸运动对治疗的影响,提高放疗的精确性,减少副反应。但该系统使用较为复杂,延长了治疗的时间,个别患者不能耐受。

To use the technique of active breathing control （ABC） for treatment of non-small cell lung canner （NSCLC）, to evaluate the effect of respirator）, movement on mubilily of the pulmonary tumor, and to examine the predominance and feasibility of ABC technology, as well as the short term curative effect and acute radioreaction. Methods： Nine advanced NSCLC patients were cho sen to he treated with the ABC method and three-dimensionaL canformal radiotherapy （3D-CRT）. Each patient received computed tomography （CT） scans under two respiration conditions： free breath （FB） and active breath-hold. The effect of respirator＇ movement on mobility of the lung tumor was evaluated, and planning target volume （PTV） margin and duse-volume histograms （DVH） were also exaulined. A dose of 54-60 GY/18-20 fractions, 3 GY/fraction, 1 f/d and 5 d/w was used and the short-term effect was evaluated. The adverse effects of radiotherapy were also evaluated during the treatment. Results： With use of the ABC, the boundary picture of the pulmonary, diaphragm at flee breath （FB） was observed to be 24.5 mm （20.0-32.0 nun） to 3.64 mm （0.5-7.2 ram）, and the lung-chestwall boundary was observed to be 3.2 mm （2.8-4 mm） to 1.2 mm （0.5-1.6 ram）. PTV margin can then be reduced from 1.5 cm to 0.75 cm. The V20 was lowered from 21.8% lu 15.0% when using ABC, and on average V20 were reduced 30.6%. The short-term effects include 6 CR and 3 PR. Acute toxicity is mild. Conclusion： In the precise radiotherapy of lung eaneer, the influence of breathing can not be ignored. The ABC system reduced the influence of breathing, improved the precision of the radiotherapy and reduced the toxicity.But it is also rather complex, it prolongs the treatment time, and some patients can not tolerate the treatment.