A new guideline from the American Society for Radiation Oncology (ASTRO) provides guidance on the use of radiation therapy to treat adult patients with primary liver cancer using external beam radiation therapy (EBRT). The evidence-based recommendations describe the indications and optimal dosage of EBRT, techniques and treatment planning for patients with hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (IHC), with a strong emphasis on multidisciplinary care. The guideline, ASTRO’s first for primary liver cancer, is published in Practical radiation oncology.
Primary liver cancers are among the most frequently diagnosed types of cancer and the fourth leading cause of cancer death worldwide. Incidence rates in the United States have more than tripled since 1980, increasing by about 2% each year for the past two decades; an estimated 42,230 new cases were diagnosed last year. Mortality rates from HCC and IHC also continue to rise despite the increasing availability of HCC screening and improved prevention and treatment of diseases that lead to liver cancer (e.g., hepatitis B, hepatitis C, non-alcoholic fatty liver disease).
Multidisciplinary involvement is particularly important for the primary treatment of liver cancer, due to the complexity of diagnosis and staging, the availability of a wide range of treatment options, and the need to consider Medical comorbidities such as underlying cirrhosis, which is present in approximately 90% of patients with HCC.
Common treatment options for primary HCC include liver transplantation, surgical removal of the tumor, thermal ablation and catheter therapy for patients whose disease is confined to the liver, and systemic therapy (targeted therapy and / or immunotherapy) for those with more advanced disease. For IHC, standard treatment includes a combination of surgery and chemotherapy, with or without radiation therapy. EBRT, which targets high doses of targeted radiation at tumor sites outside the body with non-invasive techniques, has historically been used less frequently than other approaches; for example, a recent study found that only 4% of eligible patients received EBRT as a bridging therapy before liver transplant.
“Historically, low rates of external radiation use were due to technological limitations that made it difficult to avoid healthy liver tissue. radiation, we now have a growing body of clinical evidence on the role EBRT can play for patients with these conditions, ”said Higinia Cardenes, MD, PhD, chair of the guidelines working group and professor of clinical radiation oncology at Weill Cornell Medicine in New York.
Patients diagnosed with liver cancer often have a number of treatment options available to them, and each one should be presented to them before deciding on treatment. The different disciplines -; hepatology, surgical oncology, interventional radiology and radio-oncology -; should all be involved in multidisciplinary treatment discussions to determine what might be best for each patient. We believe this guideline is an important step in the management of primary liver cancers, as we hope to provide practitioners and the public with a systematic, evidence-based foundation of where EBRT might fit into the complex treatment picture. of these difficult cases. “
Smith Apisarnthanarax, MD, vice chair of the guidelines working group, medical director of the Seattle Cancer Care Alliance, and professor of radiation oncology at the University of Washington in Seattle
The guideline recommendations address patient selection, as well as techniques for planning and administering EBRT in a range of clinical situations, including definitive / non-transplant, consolidation, recovery, preoperative (including bridge-transplantation), postoperative and palliative treatment settings. With an emphasis on multidisciplinary discussion and planning, the main recommendations are as follows:
- EBRT is strongly recommended (a) as a potential first-line treatment for patients with liver-confined HCC who are not candidates for curative therapy; (b) as consolidation therapy for patients with incomplete responses to other therapies directed against the liver; and (c) as a lifesaving therapeutic option for patients with local recurrence after further treatment.
- EBRT is conditionally recommended for (a) patients with multifocal or unresectable HCC confined to the liver, or (b) patients with macrovascular invasion, when sequenced with systemic or catheter-based therapies. The guideline includes treatment algorithms for the management of HCC confined to the liver and HCC with macrovascular invasion.
- EBRT is conditionally recommended as part of palliative care for symptomatic primary HCC and / or HCC that has invaded a blood vessel. It is also recommended under certain conditions as a bridging treatment before liver transplantation or before surgery in carefully selected patients.
- For patients with unresectable IHC, EBRT with or without chemotherapy should be considered, usually after systemic therapy. For patients with resected IHC and high-risk characteristics, adjuvant EBRT is recommended under certain conditions. The guideline includes treatment algorithms for unresectable and resectable IHC.
- The guideline also discusses the optimal dosage, fractionation, treatment planning and administration techniques of EBRT, emphasizing that treatment should be based on individual factors, including the extent and location of the cancer, the underlying liver function and available treatment technologies.
About the guideline
The guideline was based on a systematic literature review of articles published from January 2000 to February 2020. The multidisciplinary working group included radiotherapists, medical and surgical oncologists, medical physicists, a hepatologist, a transplant surgeon, and a transplant surgeon. resident in radiation oncology. The guideline was developed in collaboration with the American Society of Clinical Oncology, the American Society of Transplant Surgeons, and the Society of Surgical Oncology. Dr Cardenes and Dr Apisarnthanarax also recorded a podcast on recommendations for Practical radiation oncology.
ASTRO’s clinical guidelines are designed as tools to promote appropriate shared and individualized decision-making between physicians and patients. None should be interpreted as being strict or replacing the properly informed and considered judgments of physicians and patients.
American Society of Radiation Oncology
Apisarnthanarax, S., et al. (2021) External beam radiation therapy for primary liver cancers: an ASTRO clinical practice guideline. Practical radiation oncology. doi.org/10.1016/j.prro.2021.09.004.