Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia.
Radiol Oncol. 2013 Mar;47(1):32-41. doi: 10.2478/raon-2013-0002. Epub 2013 Feb 1.
Electrochemotherapy (ECT) is an effective and safe method for local treatment of tumors. However, relatively large variability in effectiveness of ECT has been observed, which likely results from different treatment conditions and tumor characteristics. The aim of this study was to investigate the relationship between tumor size and effectiveness of a single-session ECT.
A systematic search of various bibliographic databases was performed and nine studies eligible for this study were extracted. Different statistical methods including meta-analysis were applied to analyze the data.
The results of analysis based on data from 1466 tumors of any histotype show significantly lower effectiveness of ECT on tumors with maximal diameter equal to or larger than 3 cm (complete response (CR) of 33.3%, objective response (OR) of 68.2%) in comparison to smaller tumors (CR% of 59.5%, OR% of 85.7%). The results of meta-analysis indicated that ECT performed on tumors smaller than 3 cm statistically significantly increases the probability of CR by 31.0% and OR by 24.9% on average in comparison to larger tumors. The analysis of raw data about the size and response of tumors showed statistically significant decrease in effectiveness of ECT progressively with increasing tumor diameter. The biggest drop in CR% was detected at tumor diameters as small as 2 cm.
The standard operating procedures for ECT should be reexamined and refined for the treatment of large tumors. We propose that future clinical trials should include accurate ECT treatment planning and/or multiple ECT cycles, besides a prolonged observation for tumor response evaluation.
电化学疗法（ECT）是治疗肿瘤的有效且安全的方法。然而，ECT 的疗效存在较大的变异性，这可能是由于不同的治疗条件和肿瘤特征所致。本研究旨在探讨单次 ECT 与肿瘤大小之间的关系。
对多个文献数据库进行系统检索，提取了 9 项符合条件的研究。采用包括荟萃分析在内的不同统计方法分析数据。
基于来自任何组织类型的 1466 个肿瘤的数据进行分析的结果表明，对于最大直径等于或大于 3cm 的肿瘤（完全缓解（CR）率为 33.3%，客观缓解（OR）率为 68.2%），ECT 的疗效明显低于较小的肿瘤（CR%为 59.5%，OR%为 85.7%）。荟萃分析的结果表明，与较大的肿瘤相比，ECT 治疗小于 3cm 的肿瘤平均可使 CR 的概率增加 31.0%，OR 增加 24.9%。对肿瘤大小和反应的原始数据进行分析表明，随着肿瘤直径的增加，ECT 的疗效呈显著下降趋势。在肿瘤直径小至 2cm 时，CR%的下降幅度最大。
应重新审查和完善 ECT 的标准操作程序，以治疗较大的肿瘤。我们建议未来的临床试验应包括准确的 ECT 治疗计划和/或多次 ECT 循环，以及延长肿瘤反应评估的观察期。
