Prediction of the therapeutic effect of dienogest in ovarian endometrial cysts using the apparent diffusion coefficient

Abstract

The purpose of this study was to investigate whether apparent diffusion coefficient (ADC) mean values can be used for predicting the treatment response in ovarian endometrial cyst patients with dienogest (DNG) administration. Eighteen patients received DNG (2 mg/day, orally) for 60 days, among whom 26 ovarian endometrial cysts were retrospectively identified. Mean ADC values of individual ovarian endometrial cysts were obtained by ADC maps inside the tumor. There was a significant correlation between ADC values and reduction ratio. When calculating the mean ADC values for three groups; more than 50%, 50–25% and less than 25%, ADC values significantly increased with increasing reduction ratio; 2.05 × 10⁻³mm²/s, 1.28 × 10⁻³mm²/s and 0.94 × 10⁻³mm²/s, respectively (p = 0.0180). Multiple regression analysis by reduction ratio (%), ADC mean values (×10⁻³mm²/s), tumor longest diameter (cm) and CA125 (U/ml) revealed that tumor reduction ratio by DNG administration could be predicted by the following equation; R = 19.3 + 24.0x – 0.4y + 0.1z (R: Reduction ratio, x: ADC mean, y: Longest diameter, z: CA125). In conclusion, the ADC mean value is useful for the prediction of the treatment response in ovarian endometrial cyst patients with DNG administration.

Chinese abstract

该研究目的是探讨表面扩散系数（ADC）均值是否可以用来预测卵巢子宫内膜异位囊肿对地诺孕素（DNG）治疗的反应。对18位患者(每天口服DNG 2mg),进行了为期60天的治疗,其中对26个卵巢子宫内膜异位囊肿进行回顾性分析。通过每个肿瘤内的ADC图获得单个卵巢子宫内膜异位囊肿的ADC均值。发现ADC值和减速比（reduction ratio）有显著相关性。把平均ADC值分为三组；超过50%，50-25%，和不到25%时，ADC值随着减速比的增加而明显增加，分别为2.05×10³mm²/s，1.28×10³mm²/s和0.94×10³mm²/s（p=0.0180）。通过对减速比，ADC均值（×10³mm²/s），肿瘤最长径（cm）和CA125(U/ml) 水平的多重线性回归分析发现，使用DNG治疗的肿瘤减速比可以用以下公式表示：R=19.3+24.0x-0.4y+0.1z(R:减速比，x：平均ADC，y:最长经线，z:CA125)。总之，ADC均值对使用DNG治疗卵巢子宫内膜异位囊肿的疗效预测是非常有用的。

• ADC
• dienogest
• endometriosis
• MR imaging
• ovarian endometrial cyst