Effective treatment of metastatic cancer by an innovative intratumoral alpha particle-mediated radiotherapy in combination with immunotherapy: A short review

Alpha radiation is a lethal form of radiation whose short range limits its use for cancer treatment. A unique intra-Tumoral alpha radiation-based tumor ablation treatment termed Diffusing Alpha emitters Radiation Therapy (DaRT) was developed and tested for tumor ablation and stimulation of anti-Tumor immunity. Radium-224 loaded wires (Alpha DaRT seeds) are inserted into the tumors and release by recoil short-lived alpha-emitting atoms. These atoms disperse in the tumor at least 5 mm from the source and spray it with highly destructive alpha radiation. DaRT was found to destroy solid malignant tumors experimental animals and in patients with cutaneous malignancies. Tumor destruction resulted in activation of specific antitumor immunity. DaRT provides, for the first time, an efficient method for treatment of the entire volume of solid tumors by alpha radiation, and could be used not only as a local treatment but also as a therapeutic strategy to induce strong systemic antitumor immune responses, which will eliminate residual disease and metastases in distant sites. This combined treatment modality holds significant potential for the treatment of non-resectable human cancers.