低剂量螺旋CT扫描在肺癌放疗随访中的价值

目的评价低剂量螺旋CT扫描在肺癌放疗随访中的应用价值。方法本研究共包括15例病理证实且均行放疗的肺癌患者。放疗一个疗程后行CT复查,先对肺部病灶行常规剂量螺旋CT扫描,然后行低剂量CT扫描。低剂量扫描参数为层厚8mm,螺距1.5,管电压120kV,管电流分别降为20、40mA。常规剂量扫描除管电流为120mA外,其余同低剂量扫描。将照片上所有扫描条件遮盖,由二位不知道详细资料的影像科医师对放疗前后病灶特征做出评价。结果15例肺癌中8例为周围型,7例为中央型。两组低剂量和常规剂量扫描对肿瘤放疗前后大小、支气管狭窄、胸膜侵犯和纵隔淋巴结肿大检出率相同,常规剂量组、40mA组检出空洞坏死7例,20mA组检出6例。结论低剂量扫描在明显降低辐射的同时,与常规剂量扫描对肺癌放疗前后特征的检出情况基本相同,可作为临床肺癌放疗随访的一种选择。

Clinical Value of Low-dose Spiral CT Scan in Follow-up of Patients with Lung Carcinoma During Radiotherapy

Objective To study the value of low-dose spiral CT in follow-up during radiotherapy of lung carcinoma.Methods The study included 15 patients with lung cancer confirmed by pathology.After a course of radiotherapy,all patients underwent routine-dose CT scan,then followed with low-dose CT scan.Parameters of low-dose CT scan were slice thickness 8mm,helical pitch 1.5,tube voltage 120kV,tube current 20 or 40 mA.As for routine dose,parameters were the same with the low-dose scan except for tube current at 120 mA.CT findings were evaluated by two radiologists who did not know the findings or imaging methods. Results Fifteen patients included 8 cases of peripheral lung cancer and 7 cases of central type.Detection of two low-dose CT scan and routine-dose CT scan about the size,bronchial stenosis,invasion to pleural membrane and mediastinal lymphadenectasis before and after radiotherapy was similar.Cavitas and necrosis in 7 patients were detected by routine-dose group and 40mA group,while 6 patients were detected in 20mA group. Conclusions Low-dose CT scan decreases radiation significantly,and the detection of features of lung cancer before and after radiotherapy is similar with routine-dose scan.Low-dose CT scan can be a choice of follow-up of lung carcinoma during radiotherapy.