Transcranial direct current stimulation in the management of pain in oncology patients. A systematic review and meta-analysis with meta-regression of randomized controlled trials.

Abstract

To evaluate the efficacy of transcranial direct current stimulation (tDCS) in pain management in subjects with oncologic process. Several databases were searched in December 2023. Randomized Controlled Trials that evaluated the application of tDCS on pain in adults with oncologic process were selected. Random-effects meta-analysis with 95%CI were used to quantify the change scores in pain between tDCS and control groups. Six trials with 482 participants were included. There were significant differences in favor of tDCS in pain intensity in surgical oncology patients compared to sham stimulation (<i>p</i> < 0.001). Non-surgical patients showed no significant effect. Meta-regression analysis in this group of patients showed that the timing of the evaluation moderated the effect of tDCS on pain (<i>p</i>= .042), with longer time after tDCS being associated with greater pain reduction. The application of a-tDCS for at least 20 min, with a current density higher than 0.057 mA/cm2, applied over M1, left DLPFC, or the insula area, between 2-5 sessions appears to be an effective and safe treatment of pain in surgical oncology patients compared to sham. The tDCS appears to be more effective for high-intensity pain, and in the long term.