TAIPEI CITY, Taiwan, Sept. 3, 2013 /PRNewswire/ -- Clinical experts outlined promising new approaches to treating liver cancer using radiosurgery with advanced imaging and motion management technology. Presentations on non-invasive radiosurgical approaches to treating hepatocellular carcinoma (HCC) were made by leading clinicians here last week at a meeting organized by the Taiwan Society for Therapeutic Radiology and Oncology and Taiwan Liver Cancer Association.
HCC, the most common type of liver cancer, is globally the third leading cause of cancer mortality after lung and stomach cancer, and a significant problem in Taiwan, mainland China, and other parts of Asia.1
"Most patients with HCC are not eligible for surgery or liver transplant," said Theodore Lawrence, M.D., Ph.D., professor and chairman of the Department of Radiation Oncology at the University of Michigan. "Historically we couldn't do much for them with radiotherapy because we lacked the ability to focus the dose on the tumor and minimize exposure of the rest of the liver. That has changed with advanced approaches like stereotactic ablative radiotherapy (SABR)."
Stereotactic ablative radiotherapy (SABR) is a type of radiosurgery that involves the careful use of modern technologies for 3-D image guidance, motion management, and beam shaping. Dr. Lawrence and his clinical team customize their use of SABR for each patient according to a predictive model they have developed based on treatment data from over 400 HCC cases. This model helps them determine the optimal radiation dose to use given the volume of liver to be treated. "High doses can be given safely if enough normal liver can be spared," he explained.
Single-Dose Image-Guided Treatments
Carlo Greco, MD, professor and director of clinical research at the Champalimaud Foundation in Lisbon, Portugal, discussed advances in imaging and biological targeting that enable high precision single-dose image-guided radiotherapy (SD-IGRT) for treating metastatic lesions in the liver as well as elsewhere in the body. "These treatments depend on our ability to accurately position patients for treatment, use imaging for precise targeting, and manage motion during treatment," said Dr. Greco.
The TrueBeam™ platform from Varian Medical Systems (NYSE: VAR), with its high dose delivery rate, enables fast completion of these otherwise time-consuming treatments. "Since we installed the TrueBeam machine in early 2012, we have treated over 400 metastatic lesions with high dose SD-IGRT," Dr. Greco said. "Lung, bone, liver, adrenal gland and lymph node lesions have been the focus of our experience. Based on follow-up imaging studies, we're seeing outstanding early local control rates, with 95% of lesions free of relapse at twelve months following treatment."
Encouraging Outcomes Reported From Milan
Marta Scorsetti, M.D., director of the Department of Radiation Oncology and Radiosurgery at the Humanitas Cancer Center in Milan, Italy, presented her work evaluating the feasibility and efficacy of SABR in the treatment of both inoperable primary liver cancer and liver metastases. She reported on the results obtained with 67 patients treated for metastatic lesions, and 18 patients with primary HCC lesions.
While specific local tumor control and overall survival results varied, after a median follow-up of 12 months all groups showed acceptable rates of local tumor control and very little treatment related toxicity. No radiation induced liver disease (RILD) was detected, Dr. Scorsetti reported.
Gated RapidArc for Treating Liver Cancer
Po-Ming Wang, M.D., chief radiation oncologist at Cheng Ching General Hospital in Taichung, Taiwan, summarized his experience using Varian's TrueBeam STx system to deliver gated RapidArc radiosurgery in the treatment of liver cancer. RapidArc speeds up highly precise radiosurgery treatments by constantly shaping and reshaping the treatment beam to match the shape of the tumor while delivering dose continuously as the treatment machine rotates around the patient. Gated RapidArc makes it possible to monitor patient breathing and compensate for tumor motion during a RapidArc treatment.
"With the TrueBeam STx, we are able to image the tumor during the treatment and adapt the treatment delivery in 'real time' based on observable changes," said Dr. Wang. "This helps us to better target the liver tumor and minimize the impact on surrounding critical organs like the duodenum or stomach. The gated RapidArc technique also helps to preserve more of the patient's normal liver volume."
"Varian was pleased to provide financial support for this important meeting, which was the first liver-specific SABR meeting to take place in the Asia Pacific region," said Clif Ling, Ph.D., director of advanced clinical research for Varian. "The meeting was attended by radiation oncology and hepatology professionals and designed to provide a platform for liver cancer experts in Taiwan to begin to form a consensus about how to use SABR—a relatively new capability in radiation oncology—to treat HCC. We hope that better understanding of the use of SABR for HCC will lead to improved treatment results."
1World Cancer Report 2008, Boyle P & Levin P eds., World Health Organization: International Agency for Research on Cancer; Lyon, France http://www.iarc.fr/en/publications/pdfs-online/wcr/2008/wcr_2008.pdf.
The presentations summarized here were made by researchers at a scientific society meeting sponsored by Varian and its local distributor designed to share clinical experience using modern radiotherapy technology to treat hepatocellular carcinoma with stereotactic ablative radiotherapy (SABR). Treatment outcomes described in the presentations are generally preliminary and limited to a single institution and are not intended to represent typical outcomes in a general patient population undergoing SABR treatment. Varian's devices that deliver SABR treatments, including the TrueBeam™ machine, have been cleared by the U.S. Food and Drug Administration (FDA) for treating lesions, tumors, and conditions anywhere in the body when radiation treatment is indicated.
Important Safety Information: Radiation treatments may cause side effects that can vary depending on the part of the body being treated. The most frequent ones are typically temporary and may include, but are not limited to, irritation to the respiratory, digestive, urinary or reproductive systems, fatigue, nausea, skin irritation, and hair loss. In some patients, they can be severe, and can include but are not limited to radiation induced liver disease (or radiation hepatitis), fractured ribs and persistent nausea. Treatment sessions may vary in complexity and time. Radiation treatment is not appropriate for all cancers. Cancer patients should discuss the potential for side effects and their severity as well as the benefits of radiation with their doctors to determine if radiation treatments are right for them.
About Varian Medical Systems
Varian Medical Systems, Inc., of Palo Alto, California, is the world's leading manufacturer of medical devices and software for treating cancer and other medical conditions with radiotherapy, radiosurgery, and brachytherapy. The company supplies informatics software for managing comprehensive cancer clinics, radiotherapy centers and medical oncology practices. Varian is a premier supplier of tubes, digital detectors, and image processing workstations for X-ray imaging in medical, scientific, and industrial applications and also supplies high-energy X-ray devices for cargo screening and non-destructive testing applications. Varian Medical Systems employs approximately 6,350 people who are located at manufacturing sites in North America, Europe, and China and approximately 70 sales and support offices around the world. For more information, visit http://www.varian.com or follow us on Twitter.
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