Meta-Analysis of Modulated Electro-Hyperthermia and Tumor Treating Fields in the Treatment of Glioblastomas

Simple Summary
Glioblastoma is a highly aggressive brain tumor, which has a very poor 5-year survival rate (<5%). In the last decades, the concomitant use of two non-invasive, electromagnetic devices, modulated electro-hyperthermia (mEHT) and Tumor Treating Fields (TTF) has been introduced. Both mEHT and TTF have specific anti-tumor effects, which can help to achieve a more efficient
treatment of patients and a higher rate of therapeutic response. In this meta-analysis we investigated how patient survival rates change if either device is used. The significant difference in the 1-year survival rates between the treated (>60%) and untreated groups (historical data: <40%) confirms the observation that the use of both mEHT and TTF in the treatment of glioblastomas benefits patients. In addition, it is important to emphasize that most studies have proven that the mEHT or TTF-treated patients’ quality of life is much better than that of the untreated patients.

Abstract
Background: Glioblastoma is one of the most difficult to treat and most aggressive brain tumors, having a poor survival rate. The use of non-invasive modulated electro-hyperthermia (mEHT) and Tumor Treating Fields (TTF) devices has been introduced in the last few decades, both of which having proven anti-tumor effects. Methods: A meta-analysis of randomized and observational studies about mEHT and TTF was conducted. Results: A total of seven and fourteen studies about mEHT and TTF were included, with a total number of 450 and 1309 cases, respectively. A 42% [95% confidence interval (95% CI): 25–59%] 1-year survival rate was found for mEHT, which was raised to 61% (95% CI: 32–89%) if only the studies conducted after 2008 were investigated. In the case of TTF, 1-year survival was 67% (95% CI: 53–81%). Subgroup analyses revealed that newly diagnosed patients might get extra benefits from the early introduction of the devices (mEHT all studies: 73% vs. 37%, p = 0.0021; mEHT studies after 2008: 73% vs. 54%, p = 0.4214; TTF studies: 83% vs. 52%, p = 0.0083), compared with recurrent glioblastoma. Conclusions: Our meta-analysis showed that both mEHT and TTF can improve glioblastoma survival, and the most benefit may be achieved in newly diagnosed cases.

Keywords: astrocytoma; glioblastoma; modulated electro-hyperthermia; tumor treating fields