Mayr N A, Yuh W T, Zheng J, Ehrhardt J C, Magnotta V A, Sorosky J I, Pelsang R E, Oberley L W, Hussey D H
Department of Radiology, University of Iowa Hospitals and Clinics, Iowa City 52242, USA.
AJR Am J Roentgenol. 1998 Jan;170(1):177-82. doi: 10.2214/ajr.170.1.9423627.
Quantitative analysis of either tumor volume or dynamic enhancement pattern using MR imaging has been reported as useful in the prediction of response to radiation therapy in cancer of the cervix. Because data for both analyses can be obtained in a single MR examination, the purpose of this study was to evaluate whether combining both analyses can further improve the efficacy of using MR imaging to predict tumor control after radiation therapy.
Twenty patients with bulky carcinomas of the cervix, stages bulky IB (n = 2), IIB (n = 6), IIIA (n = 1), IIIB (n = 9), IVA (n = 1), and recurrent (n = 1), were studied. Initial tumor volumes were calculated by outlining the area of tumor in each slice on T2-weighted images and multiplying by the slice profile. Two dynamic contrast-enhanced MR studies were obtained in each patient immediately before the start of radiation therapy and after 20-22 Gy in 2 weeks of radiation therapy. Dynamic enhancement imaging was performed at 3-sec intervals in the sagittal plane for 120 sec after rapid (9 ml/sec) i.v. injection of MR contrast agent (0.1 mmol/kg of gadoteridol) using a power injector. Time and signal intensity curves reflecting the relative signal intensity of contrast enhancement in the tumor region were generated, and the relative signal intensity of the tumor region during the early plateau phase was calculated. Median follow-up was 25 months (range, 11-35 months).
The combined analysis did not improve the prediction rate of local recurrence in small-sized tumors, which responded well to radiation therapy regardless of their dynamic enhancement pattern. However, the combined analysis did improve the prediction rate of local recurrence in intermediate- and large-sized tumors (75% and 80%, respectively) over assessment by either volume analysis (33% and 60%, respectively) or dynamic enhancement pattern analysis (64% and 64%, respectively). The combined analysis was most useful in intermediate-sized tumors (40-99 cm3; 33% recurrence), significantly improving differentiation between high-risk (80% recurrence) and low-risk 10% recurrence) patients (p = .010).
Our preliminary results suggest that the combined data of both tumor morphologic (volume) and microcirculatory (dynamic enhancement pattern) parameters allow more accurate prediction of local failure in patients with advanced cervical cancer than does each individual parameter alone. Combined data appear to have the greatest potential in patients with intermediate-sized tumors, who constitute most patients (60%) and remain a challenge for outcome prediction and management.
据报道，利用磁共振成像（MR）对肿瘤体积或动态增强模式进行定量分析，有助于预测宫颈癌放疗疗效。由于这两种分析的数据可在单次MR检查中获得，本研究旨在评估联合这两种分析能否进一步提高利用MR成像预测放疗后肿瘤控制情况的效能。
研究了20例宫颈巨块型癌患者，分期包括巨块型IB期（n = 2）、IIB期（n = 6）、IIIA期（n = 1）、IIIB期（n = 9）、IVA期（n = 1）及复发癌（n = 1）。通过在T2加权图像上勾勒出各层面肿瘤面积并乘以层面厚度来计算初始肿瘤体积。在放疗开始前及放疗2周达20 - 22 Gy后，对每位患者进行两次动态对比增强MR检查。使用高压注射器经静脉快速（9 ml/秒）注射钆特醇（0.1 mmol/kg）后，在矢状面以3秒间隔进行120秒的动态增强成像。生成反映肿瘤区域对比增强相对信号强度的时间和信号强度曲线，并计算肿瘤区域在早期平台期的相对信号强度。中位随访时间为25个月（范围11 - 35个月）。
联合分析并未提高对放疗反应良好的小肿瘤局部复发的预测率，无论其动态增强模式如何。然而，与单独的体积分析（分别为33%和60%）或动态增强模式分析（分别为64%和64%）相比，联合分析确实提高了中、大肿瘤局部复发的预测率（分别为75%和80%）。联合分析在中等大小肿瘤（40 - 99 cm³；复发率33%）中最有用，显著改善了高危（复发率80%）和低危（复发率10%）患者之间的区分（p = 0.010）。
我们的初步结果表明，与单独的每个参数相比，肿瘤形态学（体积）和微循环（动态增强模式）参数的联合数据能更准确地预测晚期宫颈癌患者的局部治疗失败情况。联合数据在中等大小肿瘤患者中似乎具有最大潜力，这类患者占大多数（60%），仍然是结局预测和管理的挑战。
