Conformal and stereotactic radiotherapy in hepatocellular carcinoma

Historically, Radiation Therapy (RT) has played a minor role in the treatment of hepatocellular carcinoma, especially because of toxicity related to conventional techniques. However, high radiation doses can now be given safely by means of 3D-conformal techniques and other more specialized techniques. 3D-conformal RT, in which both target definition and treatment planning are based on three-dimensional image data sets, provided good local control in several series. As an evolution of cranial radiosurgery, stereotactic body radiation therapy (SBRT) is currently being employed as a new tool for the treatment of HCC, as it offers the opportunity of achieving radioablation for tumors up to 6 cm in diameter with a minimal risk of radiation induced liver disease. SBRT is distinguished by the fact that both planning and treatment are guided by reference to a system of external stereotactic coordinates. As a consequence, SBRT may succeed in minimizing geometric treatment uncertainties, thus allowing the delivery of high doses to the target, given in a small number of fractions. In several published series of SBRT for HCC, actuarial 5-year local control rates higher than 80% have been achieved In short, radiation therapy should be considered as a useful addition to the treatment spectrum of HCC.