Cancer Experts Detail New Approaches to Liver Cancer Treatment with Stereotactic Ablative Radiotherapy

Taiwan Medical Meeting Offers Promising Findings with New technology to Treat Liver Cancer.

Presentations on noninvasive radiosurgical approaches to treating hepatocellular carcinoma (HCC) were made by leading clinicians in August 2013 at a meeting organized by the Taiwan Society for Therapeutic Radiology and Oncology and Taiwan Liver Cancer Association, held in Taipei City (Taiwan).

HCC, the most common type of liver cancer, is globally the third leading cause of cancer deaths after lung and stomach cancer, and a significant problem in mainland China, Taiwan, and other parts of Asia. “Most patients with HCC are not eligible for surgery or liver transplant,” said Theodore Lawrence, MD, PhD, professor and chairman of the department of radiation oncology at the University of Michigan (Ann Arbor, USA). “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].”

SABR is a type of radiosurgery that involves the careful use of modern technologies for three-dimensional (3D) image guidance, motion management, and beam shaping. Dr. Lawrence and colleagues personalized their use of SABR for each patient to a predictive model they have developed based on treatment data from over 400 HCC patients. 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.

Carlo Greco, MD, professor and director of clinical research at the Champalimaud Foundation (Lisbon, Portugal), discussed advances in imaging and biologic 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, developed by Varian Medical Systems (Palo Alto, CA, USA), 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 12 months following treatment.”

Marta Scorsetti, MD, director of the department of radiation oncology and radiosurgery at the Humanitas Cancer Center (Milan, Italy), presented her research findings assessing the viability and effectiveness 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.

Whereas individual local tumor control and overall survival results varied, after an average 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.

Po-Ming Wang, MD, chief radiation oncologist from Cheng Ching General Hospital (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 continually shaping and reshaping the treatment beam to correspond to 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, PhD, 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.”

Related Links:
University of Michigan
Champalimaud Foundation
Varian Medical Systems