HANGZHOU, China, Oct. 18 /PRNewswire/ -- Lung cancer is a major and growing global epidemic, according to Billy W. Loo, Jr., M.D., assistant professor of radiation oncology at Stanford University in Palo Alto, California. Dr. Loo was one of three preeminent experts who made presentations at a special symposium for Chinese radiation oncology professionals sponsored by Varian and held in connection with the 2nd Chinese Society of Therapeutic Radiology and Oncology and Sino-American Network for Therapeutic Radiology and Oncology (CSTRO/SANTRO ) Joint Meeting in Hangzhou, China earlier this month.
"Early stage cases, and especially those patients who are unfit for surgery, can be effectively treated using stereotactic ablative radiotherapy (SABR), a very fast, image-guided, arc-based approach," said Dr. Loo. "Varian's technologies for this type of treatment—the Trilogy and TrueBeam systems for image-guided radiotherapy—are an attractive way to deliver SABR."
SABR, which is also referred to as stereotactic body radiotherapy (SBRT), involves the use of highly focused radiation concentrated on small tumors that have been discovered early, so it depends on early detection, said Dr. Loo, who uses Varian's Trilogy® and TrueBeam® systems to deliver these sophisticated treatments. "A large dose is given in one or just a few treatment sessions. Dose delivery is extremely accurate and precise, due to image-guidance, patient immobilization, and other technologies designed to ensure accuracy," he added.
Dr. Loo noted that studies conducted by researchers around the world have shown that SABR produces better tumor control rates, and higher overall survival rates, than conventional radiotherapy.(1)
To deliver SABR treatments at Stanford, Dr. Loo and his colleagues depend on the full spectrum of capabilities available to them with their Trilogy and TrueBeam systems, including fluoroscopic imaging for determining the extent of tumor motion, cone-beam CT imaging for pre-treatment patient positioning, respiratory gating for motion management, high dose delivery rates for efficiency, and RapidArc to attack the tumor from all angles in a 360-degree arc.
"SABR for early stage lung cancer is rapidly maturing, with promising early results," Dr. Loo concluded.
Another presentation, by Maria Chan, Ph.D., of Memorial Sloan Kettering Cancer Center, focused on the use of Varian's On-Board Imager® device to perform IGRT. The On-Board Imager is a standard component of Varian's high-energy linear accelerators for the treatment of cancer. It is used to generate radiographic (2-D), cone-beam CT (3-D) or fluoroscopic images that show how a tumor moves as a patient breathes in and out. These images make it possible to accurately pinpoint the tumor and adjust the patient's position just prior to each treatment.
A third presenter, Christopher Willett, M.D., of Duke University, discussed his clinical team's use of RapidArc® technology to deliver precise image-guided treatments quickly by delivering the dose continuously from 360 degrees around the patient while shaping the treatment beam to match the shape of the tumor from every angle. RapidArc makes it possible to complete an image-guided treatment two to eight times faster than is possible with conventional approaches to beam delivery.
"Varian Medical Systems has a corporate mission of helping radiation oncology professionals to save another 100,000 lives every year," said Thomas P. Duffy, Varian's vice president of sales and marketing for the Asia Pacific region. "To that end, we are committed to supporting the clinical adoption of advanced forms of radiotherapy across China. We sponsored this symposium as part of our commitment to facilitating the transfer of best clinical practices between the east and the west."
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, proton therapy, 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 and digital detectors for X- ray imaging in medical, scientific, and industrial applications and also supplies X-ray imaging products for cargo screening and industrial inspection. Varian Medical Systems employs approximately 5,100 people who are located at manufacturing sites in North America, Europe, and China and approximately 79 sales and support offices around the world. For more information, visit http://www.varian.com.
(1) Published papers on this topic:
Blomgren H et al. Stereotactic high dose fraction radiation therapy of extracranial tumors using an accelerator. Clinical experience of the first thirty-one patients. Acta Oncol. 1995;34:861–870.
Chang J et al. Stereotactic Body Radiation Therapy in Centrally and Superiorly Located Stage I or Isolated Recurrent Non–Small-Cell Lung Cancer. International Journal of Radiation Oncology * Biology * Physics, 15 November 2008 (Vol. 72, Issue 4, Pages 967-971.
Lagerwaard F et al. Outcomes of Risk-Adapted Fractionated Stereotactic Radiotherapy for Stage I Non–Small-Cell Lung Cancer. International Journal of Radiation Oncology * Biology * Physics, 1 March 2008 (Vol. 70, Issue 3, Pages 685-692).
Timmerman R et al. Stereotactic Body Radiation Therapy for Inoperable Early Stage Lung Cancer JAMA. 2010 March 17; 303(11): 1070–1076.
Uematsu M, et al. Focal, high dose, and fractionated modified stereotactic radiation therapy for lung carcinoma patients: a preliminary experience. Cancer. 1998 Mar 15;82(6):1062-70.
Whyte RI et al. Stereotactic radiosurgery for lung tumors:preliminary report of a phase I trial. Ann Thorac Surg. 2003;75:1097–101. doi: 10.1016/S0003-4975(02)04681-7.
Ling Zhang, M.D.
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