根据本底半自动化确定肿瘤内靶区:模型实验  

Estimation of Internal Tumor Volume: A Phantom Study Based on Semiautomatic Standardized Uptake Value of the Background

作　　者：陈仰纯[1] 陈向荣[1] 刘吉安[1] 李凡勇[1] 

机构地区：[1]福建医科大学附属泉州第一医院核医学科,福建泉州362000

出　　处：《中国医学影像学杂志》2015年第2期91-95,共5页Chinese Journal of Medical Imaging

基　　金：国家自然科学基金项目(30800274)

摘　　要：目的 根据本底标准化摄取值（SUV）计算肺肿瘤内靶区（ITV）SUV阈值,并评价其可行性。材料与方法 3个空心插件固定在圆桶底部,空心插件与圆桶分别充满55.06 kBq/ml和5.37 kBq/ml18F-FDG溶液以模拟肿瘤与肺组织。以三维运动滑台驱动该模型模拟呼吸运动,最大位移10.9 mm、21.8 mm、43.7 mm。采集模型二维PET/CT图像。记肺本底SUV为±SD,以＋3SD作为确定ITV的阈值,以真实ITV和测量ITV的Dice相似系数（DSC）和容积恢复系数（VRC）为评价指标,并与SUV2.5、35%SUVmax、41%SUVmax、a×mSUV70＋b×、0.42×（SUVmax＋）及Riegel等根据肿瘤体积、靶本底比及肿瘤运动幅度确定SUV阈值的方法进行比较,分析各方法的ITV、DSC和VRC。结果 3个肿瘤模型共9个ITV真实值分别为134.3 ml、166.1 ml、223.5 ml、86.6 ml、108.5 ml、150.7 ml、32.3 ml、43.8 ml、63.6 ml。采用Riegel等的方法测得ITV与真实值差异无统计学意义（t=-0.48,P〉0.05）。其他6种SUV阈值法测量ITV与真实值差异有统计学意义（t=-5.11~2.76,P〈0.05）。＋3SD和Riegel等的方法制订的ITV的DSC和VRC分别为0.75~0.92、0.69~0.93和0.82~0.97、0.74~0.96,差异无统计学意义（t=-0.73,P〉0.05）,但大于其他5种方法所得值。结论 根据本底确定的SUV阈值（＋3SD）具有描绘肺癌ITV的潜力,可以为放射治疗提供ITV的参考范围。Purpose To estimate and discuss the feasibility of the threshold value of the internal tumor volume （ITV） of lung cancer based on the standardized uptake value （SUV） of the background.Materials and Methods The phantom was designed with 3 vacuous models fixed at the bottom of a barrel. The 3 vacuous models were filled with18F-FDG （55.0 kBq/ml） which represented a tumor and the barrel was filled with18F-FDG （5.9 kBq/ml）, which represented the background of the lung. The barrel moved sinusoidally with distances of 10.9 mm, 21.8 mm, and 43.7 mm to simulate breathing, and then the phantom 2D PET/CT data were acquired. The SUV in the background was recorded as ±SD, and＋3SD was regarded as threshold value to obtain the measured ITVs. The Dice similarity coefficient （DSC） and volume recovery coefficient （VRC） were used to evaluate the accuracy of the ITVs measured by seven methods, including that by SUV 2.5, 35% SUVmax, 41% SUVmax, a×mSUV70＋b×, 0.42×（SUVmax＋） and Riegel et al. computed threshold value followed the gross tumor volume, tumor-to-nontumor ratio and motion extent.Results Nine ITVs of three lung cancer models were 134.3 ml, 166.1 ml, 223.5 ml, 86.6 ml, 108.5 ml, 150.7 ml, 32.3 ml, 43.8 ml and 63.6 ml, respectively. The ITV measured by Riegel et al. showed no difference with the real ITV （t=-0.48,P〉0.05）. The ITVs measured by the other six methods were significantly different from the real ITVs （t=-5.11-2.76,P〈0.05）. The DSC of the ITV measured by＋3SD and the method of Riegel et al. were 0.75-0.92 and 0.69-0.93, respectively; and the VRC were 0.82-0.97 and 0.74-0.96, respectively （differences without significance：t=-0.73,P〉0.05）. Moreover, they surpassed the results of the other five methods.Conclusion The threshold value （＋3SD） of the SUV determined by the background has potential value in the description of the ITV of lung cancer, so as to provide reference for radiotherapy.

关 键 词：癌 非小细胞肺 正电子发射断层显像术 体层摄影术 X线计算机 氟脱氧葡萄糖F18 标准化摄取值 肿瘤内靶区 

分 类 号：R-33[医药卫生] R730.44