Role and Future Directions of External Beam Radiotherapy for Primary Liver Cancer

Abstract

The incidence of primary liver cancers continues to increase in the United States and worldwide. The majority of patients with primary liver cancer are not candidates for curative therapies such as surgical resection or orthotopic liver transplantation due to tumor size, vascular invasion, or underlying comorbidities. Therefore, while primary liver cancer is the sixth-most common cancer diagnosis worldwide, it represents the second leading cause of cancer-related deaths. Radiotherapy traditionally played a limited role in the treatment of primary liver cancer due to concerns over hepatic tolerance and the inability to deliver a tumoricidal dose of radiotherapy while still sparing normal hepatic parenchyma. However, the development of modern radiotherapy techniques has made liver-directed radiotherapy a safe and effective treatment option for both hepatocellular carcinoma and intrahepatic cholangiocarcinoma. An increasing body of literature has demonstrated the excellent local control and survival rates associated with liver-directed radiotherapy. These data include multiple radiotherapy techniques and modalities, including stereotactic body radiotherapy (SBRT), intensity modulated radiotherapy (IMRT), and charged particle therapy, including proton therapy. In this review, we discuss the development of liver-directed radiotherapy and evidence in support of its use, particularly in patients who are not candidates for resection or orthotopic liver transplantation. We also discuss future directions for its role in the management of primary liver cancers.

Protons versus Photons for Unresectable Hepatocellular Carcinoma: Liver Decompensation and Overall Survival

“…1,2 Over the last decade, technological refinements in target delineation, treatment planning and image-guided setup verification have enabled safer delivery of ablative radiation therapy doses, which is being used increasingly for HCC. 3 The more commonly available treatment modality for ablative radiation therapy is with photons, which continues to deposit dose along the exit beam path beyond the target volume, leading to unwanted dose to nontarget liver and other healthy tissues. In contrast, proton beam therapy uses charged particles that come to rest within the patient and have no exit dose beyond a prespecified target range because of the characteristic proton Bragg peak, beyond which there is no additional proton radiation dose.…”

Enhancing liver tumor localization accuracy by prior-knowledge-guided motion modeling and a biomechanical model

“…In Eq. [3], the first two terms quantify the change of the Mooney-Rivlin material's shape towards stress. The third term quantifies the change of the material's volume towards stress.…”

“…Liver is also an organ highly susceptible to metastasis from other primary cancers (2). Radiation therapy has become increasingly popular in primary liver cancer and liver metastasis management, especially with the advent of highly-focused stereotactic body radiation therapy (SBRT) (3,4). However, the normal liver tissue has long been known for its low tolerance to radiation.…”

JMJD6–BRD4 complex stimulates lncRNA HOTAIR transcription by binding to the promoter region of HOTAIR and induces radioresistance in liver cancer stem cells

“…However, because of indistinguishable or delayed appearance of clinical symptoms, few patients could receive above-mentioned managements [ 6 ]. Notably, the development of radiotherapy techniques has shown satisfied local–regional control effect for tumor cells, offering a promising option for most patients with advanced liver cancer [ 7 ]. But radio-resistance acquisition remains a serious obstacle for the successful treatment of liver cancer patients [ 8 ].…”