Loncaster Juliette A, Carrington Bernadette M, Sykes Johnathan R, Jones Andrew P, Todd Susan M, Cooper Rachel, Buckley David L, Davidson Susan E, Logue John P, Hunter Robin D, West Catharine M L
Academic Department of Radiation Oncology, Christie Hospital NHS Trust, Manchester, UK.
Int J Radiat Oncol Biol Phys. 2002 Nov 1;54(3):759-67. doi: 10.1016/s0360-3016(02)02972-3.
To investigate whether analysis of MRI enhancement data using a pharmacokinetic model improved a previously found correlation between contrast enhancement and tumor oxygenation measured using PO2 histograph. To evaluate the prognostic value of gadolinium enhancement data for radiotherapy outcome, and to study the efficacy of combined enhancement and MRI volume data.
Fifty patients underwent dynamic gadolinium-enhanced MRI as part of their initial staging investigations before treatment. Gadolinium enhancement was analyzed using the Brix pharmacokinetic model to obtain the parameters amplitude and rate of contrast enhancement. Pretreatment tumor oxygen measurements (Eppendorf PO2 histograph) were available for 35 patients.
Both standard and pharmacokinetic-derived enhancement data correlated with tumor oxygenation measurements, and poorly enhancing tumors had low tumor oxygen levels. However, only the pharmacokinetic-analyzed data correlated with patient outcome and patients with poorly (amplitude less than median) vs. well-enhancing tumors had significantly worse disease-specific survival (p = 0.024). For the 50 patients studied, no relationship was found between enhancement and volume data. Combining MRI volume and enhancement information highlighted large differences in outcome (p = 0.0054). At the time of analysis, only 55% of patients with large, poorly enhanced tumors were alive compared with 92% of patients with small, well-enhanced tumors.
These preliminary results suggest that pharmacokinetic modeling of dynamic contrast-enhanced MRI provides data that reflect tumor oxygenation and yields useful prognostic information in patients with locally advanced carcinoma of the cervix. Combining MRI-derived enhancement and volume data delineates large differences in radiotherapy outcome.
研究使用药代动力学模型分析MRI增强数据是否能改善先前发现的使用PO2组织血氧仪测量的对比增强与肿瘤氧合之间的相关性。评估钆增强数据对放疗结果的预后价值，并研究增强数据与MRI体积数据联合使用的效果。
50例患者在治疗前进行了动态钆增强MRI检查，作为其初始分期检查的一部分。使用Brix药代动力学模型分析钆增强情况，以获得对比增强的幅度和速率参数。35例患者有治疗前肿瘤氧测量值（Eppendorf PO2组织血氧仪测量）。
标准增强数据和药代动力学衍生的增强数据均与肿瘤氧测量值相关，增强不佳的肿瘤具有低肿瘤氧水平。然而，只有药代动力学分析的数据与患者预后相关，增强不佳（幅度小于中位数）与增强良好的肿瘤患者相比，疾病特异性生存率显著更差（p = 0.024）。对于所研究的50例患者，未发现增强与体积数据之间的关系。结合MRI体积和增强信息突出了结果的巨大差异（p = 0.0054）。在分析时，大的、增强不佳的肿瘤患者中只有55%存活，而小的、增强良好的肿瘤患者中这一比例为92%。
这些初步结果表明，动态对比增强MRI的药代动力学建模提供了反映肿瘤氧合的数据，并为局部晚期宫颈癌患者提供了有用的预后信息。结合MRI衍生的增强和体积数据可描绘出放疗结果的巨大差异。
