Indications of external radiotherapy for hepatocellular carcinoma from updated clinical guidelines: Diverse global viewpoints

The etiology and disease patterns of hepatocellular carcinoma (HCC) significantly vary among regions. Modern standard treatments commonly require multidisciplinary approaches, including applications of up-to date medicine and advanced procedures, and necessitate the support of socioeconomic systems. For these reasons, a number of clinical guidelines for HCC from different associations and regions have been presented. External beam radiation therapy was contraindicated for HCC until a few decades ago, but with the development of new technologies, its application has rapidly increased as selective irradiation for tumorous lesions became possible. Most of the guidelines had been opposed or indifferent to radiotherapy in the past, but several guidelines have introduced indications and recommendations for radiotherapy in their updated versions. This review will discuss the characteristics of important guidelines and their contents regarding radiotherapy and will also provide guidance to physicians who are considering applications of locoregional modalities that include radiotherapy.