Tumor size and effectiveness of electrochemotherapy

  • Barbara Mali Faculty of Electrical Engineering, University of Ljubljana
  • Damijan Miklavcic Faculty of Electrical Engineering, University of Ljubljana
  • Luca Giovanni Campana Sarcoma and Melanoma Unit, Veneto Region Oncology Research Institute (IOV-IRCCS), Padova
  • Maja Cemazar Institute of Oncology Ljubljana
  • Gregor Sersa Institute of Oncology Ljubljana
  • Marko Snoj Institute of Oncology Ljubljana
  • Tomaz Jarm Faculty of Electrical Engineering, University of Ljubljana


Background. 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.

Materials and methods. 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.

Results. 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 (CR% of 33.3%, 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.

Conclusions. 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.

How to Cite
Mali, B., Miklavcic, D., Campana, L. G., Cemazar, M., Sersa, G., Snoj, M., & Jarm, T. (2013). Tumor size and effectiveness of electrochemotherapy. Radiology and Oncology, 47(1). Retrieved from https://www.radioloncol.com/index.php/ro/article/view/909
Experimental oncology