Patients with head and neck, rectal, and recurring prostate cancer are first to benefit from new technology for fast delivery of image-guided intensity-modulated radiotherapy (IMRT)

GUATEMALA CITY, Dec. 22 /PRNewswire-FirstCall/ -- Four cancer patients became the first in Latin America to receive treatment using a fast form of image-guided radiotherapy that potentially enables doctors to improve outcomes while extending modern care to more patients. Doctors at Hope International Centro de Radioterapia of Guatemala are now treating four patients using RapidArc® radiotherapy technology from Varian Medical Systems (NYSE: VAR), one with recurring prostate cancer, one with a nasal cavity tumor, one with rectal cancer, and one with recurring glioblastoma multiforme--an aggressive type of brain tumor.

Clinicians at the center, which treats patients from across Central America, carried out the first treatment for a 66-year-old attorney whose prostate cancer recurred a year after it was first treated using robotic surgery. His first RapidArc treatment was delivered in 3.16 minutes using two arcs, or rotations, of the machine around the patient. By comparison, conventional IMRT (intensity-modulated radiation therapy) treatments would have taken eight to ten minutes.

Using the image-guidance technology that is integral to the RapidArc treatment process, clinicians were able to detect a 2-3 millimeter displacement of the targeted tumor after they positioned the patient for his first treatment. "We could then make a very fine adjustment in the patient's position, to ensure that we were accurately targeting the tumor and sparing surrounding tissues to the greatest extent possible," said Luis A. Linares, MD, Medical Director.

Linares and his medical team generated conventional IMRT treatment plans as well as RapidArc plans for all four patients, in order to compare and choose the one most likely to result in the best possible outcome. "In every case, the RapidArc plans were superior, as far as quality of the dose distribution was concerned," Dr. Linares said. "We saw better coverage of the targeted tumor, and better normal tissue sparing. For the rectal cancer patient, doses to the bladder and femoral heads were significantly lower with the RapidArc plan. For the prostate cancer patient, RapidArc did a better job of protecting both the bladder and the rectum. And for the patient with recurrent glioblastoma, we saw a definite advantage to the RapidArc plan, in terms of protecting the optic nerve and optic chiasm."

RapidArc delivers a precise and efficient treatment in single or multiple arcs of the treatment machine around the patient and makes it possible to deliver advanced image-guided intensity

modulated radiotherapy (IMRT) up to eight times faster than is possible with conventional IMRT. RapidArc technology directs the treatment beam at a tumor while continuously rotating around the patient. Conventional IMRT treatments are slower because they target tumors using a complex sequence of fixed beams from multiple angles.

"Faster treatments have the potential to be even more precise, since there is less chance of the patient or tumor moving during treatment," Dr. Linares said.

"We are pleased to hear that the first RapidArc treatments have now been delivered at this important cancer treatment facility in Central America," said James Miles, Varian's director of operations for Latin American and the Caribbean. "RapidArc is enabling more and more cancer centers around the world to offer patients the most modern treatments available."

Selected studies showing improved outcomes for prostate and head and neck cancer patients treated with IMRT as compared with other forms of radiotherapy, and demonstrating the magnitude of tumor motion that can take place during a prostate cancer treatment.

• Namiki S et al. Five-year follow-up of health-related quality of life after intensity-modulated radiation therapy for prostate cancer. Jpn J Clin Oncol. 2009 Nov;39(11):732-8.
• Liauw SL et al. Biochemical control and toxicity after intensity-modulated radiation therapy for prostate cancer. Technol Cancer Res Treat. 2009 Jun;8(3):201-6.
• Zelefsky MJ et al. Incidence of late rectal and urinary toxicities after three-dimensional conformal radiotherapy and intensity-modulated radiotherapy for localized prostate cancer. Int J Radiat Oncol Biol Phys. 2008 Mar 15;70(4):1124-9.
• Lee NY et al. Intensity-modulated radiation therapy with or without chemotherapy for nasopharyngeal carcinoma: radiation therapy oncology group phase II trial 0225. J Clin Oncol. 2009 Aug 1;27:3684-90.
• Wong FCS et al. Whole-field simultaneous integrated-boost intensity-modulated radiotherapy for patients with nasopharyngeal carcinoma. Int J Radiat Oncol Biol Phys. In press.
• Li HS et al. Dosimetric consequences of intrafraction prostate motion. Int J Radiat Oncol Biol Phys. 2008 Jul 1;71(3):801-12. Epub 2008 Jan 30.

About Hope International

Hope International Centro de Radioterapia in Guatemala City is a modern, warm facility located within 15 minutes of the international airport in Aurora, close to hotels and tourist services. The center's mission is to offer internal and external forms of radiotherapy in the treatment of cancer, using state-of-the-art technology. Patients receive attentive care in a friendly, pleasant atmosphere. For more information, visit http://www.hoperadioterapia.com.

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, China and Europe and in its 79 sales and support offices around the world. For more information, visit http://www.varian.com/.

    FOR INFORMATION CONTACT:
    Meryl Ginsberg, Varian Medical Systems
    650-424-6444 or meryl.ginsberg@varian.com

    Pablo Aparicio, Hope International
    (502) 2311-0400 or paparicio@hoperadiotherapy.com

SOURCE Varian Medical Systems, Inc.

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