Yamashita Shimpei, Kohjimoto Yasuo, Iguchi Takashi, Nishizawa Satoshi, Iba Akinori, Kikkawa Kazuro, Hara Isao
Department of Urology, Wakayama Medical University , Wakayama, Japan .
J Endourol. 2017 Apr;31(4):384-390. doi: 10.1089/end.2016.0719. Epub 2017 Feb 2.
Although previous studies have indicated that stone heterogeneity can affect extracorporeal shockwave lithotripsy (SWL) outcomes, there is no established measurement of stone heterogeneity on CT imagery. We investigated whether variation coefficient of stone density (VCSD) can predict shockwave success.
We conducted a retrospective review of 245 patients with urinary calculi who had undergone SWL. We compared the predictive powers of treatment success between VCSD and other parameters associated with CT attenuation. In addition, we performed logistic regression analysis to identify the factors contributing to treatment success. Treatment success was determined within 3 months after first treatment using noncontrast CT.
The treatment success rate was 47.8% (117/245 cases). From receiver operating characteristic curves for treatment success, area under curve of VCSD (0.7181) was larger than that of mean stone density (MSD) (0.6384, p = 0.09) and standard deviation of stone density (0.5412, p < 0.01). Multivariate analysis revealed that MSD (p = 0.028) and VCSD (p < 0.001) independently predicted the outcome. Categorized by stone location, VCSD was the independent significant predictor for SWL outcomes in both kidney (p = 0.047) and ureteral calculi (p < 0.001).
We found that VCSD can be a novel predictor of SWL success. The development of nomograms or scoring systems, including VCSD, can assist in the decision process for patients and minimize unnecessary delay in treatment of urolithiasis.
尽管先前的研究表明结石异质性会影响体外冲击波碎石术（SWL）的效果，但在CT图像上尚无确定的结石异质性测量方法。我们研究了结石密度变异系数（VCSD）是否能预测冲击波治疗的成功率。
我们对245例行SWL的尿石症患者进行了回顾性研究。我们比较了VCSD与其他CT衰减相关参数对治疗成功的预测能力。此外，我们进行了逻辑回归分析以确定促成治疗成功的因素。首次治疗后3个月内使用非增强CT确定治疗是否成功。
治疗成功率为47.8%（117/245例）。从治疗成功的受试者工作特征曲线来看，VCSD的曲线下面积（0.7181）大于平均结石密度（MSD）的曲线下面积（0.6384，p = 0.09）和结石密度标准差的曲线下面积（0.5412，p < 0.01）。多变量分析显示，MSD（p = 0.028）和VCSD（p < 0.001）独立预测治疗结果。按结石位置分类，VCSD是肾（p = 0.047）和输尿管结石（p < 0.001）SWL结果的独立显著预测因素。
我们发现VCSD可以成为SWL成功的一种新的预测指标。开发包括VCSD的列线图或评分系统，可以辅助患者的决策过程，并尽量减少尿石症治疗中不必要的延误。
