TKT and esophageal cancer: In recent years, a series studies by Yang et al. showed that a direct intra-tumoral injection of high-dose HSV-TK/lentivirus genes, via a multifunctional thermal perfusion RFA electrode, could improve the HSV-TK gene transfection, and that RFH treatment at 42 °C with 30 min could further significantly enhance the HSV-TK gene transfection, achieving an excellent therapeutic effect on liver cancer, lung cancer, ovarian cancer, and esophageal cancer in animal models [[77], [78], [79], [80], [81]].