Third time re-irradiation of liver metastasis with robotic radiosurgery: a case series

Re-irradiation (Re-RT) in liver tumours is rarely reported owing to poor tolerance of liver and high incidence of radiation induced liver disease incidence. Fiducial based robotic radiosurgery allows to deliver high dose radiation to the liver tumour and restricts the dose to healthy uninvolved liver, thereby increasing the potential for Re-RT. Tolerance to radiation is low for entire liver and hence re-radiation is a challenge. On the other hand, as regenerative potential of hepatocytes is rapid, replacement of necrotic liver tissue occurs with regenerated hepatocytes. These regenerated hepatocytes are radiation naïve, do not have “memory” of radation therapy treatment and hence have potential of Re-RT. We are reporting a series of two breast cancer patients presented with liver oligometastasis treated with fiducial based CyberKnife system (CK). Both the patients were treated multiple times with CK and had long-term survival (> 2 years) without any clinical features of radiation induced liver injury. Appropriately selected patients are suitable for multiple sessions of CK for liver lesions with long-term outcome