Combination treatments of tumors with thermoablation: principles and review of preclinical studies

Thermoablation is a widely used method to treat unresectable tumors. It consists in heating or cooling the tissue to eradicate the malignant cells. Several methods of thermoablation exist, including radiofrequency (RFA), microwave, high intensity focused ultrasound (HIFU), laser and cryoablation. Thermoablation has been shown to be effective and safe to remove unresectable tumors. However, all methods have limitations concerning the volume of tissue that can be removed, the homogeneity of cellular death within the ablation zone and the risk of recurrence after the treatment. To overcome these drawbacks, thermoablation techniques can be combined with other types of treatments, such as chemotherapy and radiotherapy. Thermoablation can also be used as an adjuvant technique in immunotherapy. Three techniques (RFA, HIFU and cryoablation) used by themselves or in combination with other types of treatments are reviewed.