Clinical Trial at Arkansas Cancer Research Center Demonstrates Breast Cancer Treatment Using RITA Medical Systems Radiofrequency Ablation Products Reduces Re-Excision Rates by 86%.

FREMONT, Calif. & LITTLE ROCK, Ark. -- Presentation Made October 18th at the 2005 American College of Surgeons 91st Annual Clinical Congress in San Francisco

RITA Medical Systems, Inc. (Nasdaq:RITA), a publicly-traded medical device company focused solely on cancer therapies, and the University of Arkansas for Medical Sciences today announced that clinical investigators at the University of Arkansas Cancer Research Center reported the results of a clinical trial, Radiofrequency Ablation (RFA)-assisted Lumpectomy, in a paper session at the American College of Surgeons (ACS) 91st Annual Clinical Congress in San Francisco. The presentation reviewed the results of a multiphase clinical trial with 25 patients in which RFA-assisted lumpectomy using RITA's products was shown to reduce the need for re-excision for inadequate margins following lumpectomy by 86%.

V. Suzanne Klimberg, M.D., Professor of Surgery and Pathology at the University of Arkansas for Medical Sciences (UAMS), and the Central Arkansas Veterans Healthcare Systems, Chief of the Division of Breast Surgical Oncology at UAMS, Director of the Breast Cancer Program at UAMS' Arkansas Cancer Research Center, and corresponding author of the clinical abstract commented, "Our short-term follow-up has shown no in-site recurrence of cancer in these patients." Dr. Klimberg continued, "We believe that RFA-assisted lumpectomy is a technique that may give women who choose breast-conserving surgery added assurance that they will not need to endure a second surgical procedure to remove cancer found during pathology examination of the margins of their lumpectomy specimen post-surgery."

In the trial, 25 patients with an average tumor size of 1.8 cm underwent RFA treatment of their lumpectomy excision site in the operating room immediately following breast conserving lumpectomy surgery. The excised lumpectomy specimen was then sent for pathology analysis. Final pathology results found inadequate margins in 28% of the patients. The inadequate margins found in those patients who received RFA at the time of surgery were not re-excised because in a bench trial of 29 mastectomy samples (breast tissue donated by patients undergoing mastectomy surgery) RFA consistently demonstrated a complete zone of ablation to a thickness greater than 5 millimeters.

A finding of "inadequate margin" is made during the post-surgery pathology examination of the lumpectomy specimen when cancer cells are found close to the perimeter of the specimen, indicating that additional cancer cells may remain in the lumpectomy site. Typically, a second operation would be required several days or weeks later to re-excise the inadequate margins in order to reduce the likelihood of in-site breast cancer recurrence. A finding of "positive margin" during the pathology examination is made when cancer cells are found on the perimeter of the lumpectomy specimen. A finding of "negative margin" during the pathology examination is made when no cancer cells are found close to the perimeter of the lumpectomy specimen.

Edward M. Copeland, M.D., Edward R. Woodward Professor, Department of Surgery, University of Florida College of Medicine, and a pioneer in breast conservation therapies for breast cancer commented, "Assuring that lumpectomy margins are negative is one of the keys to preventing recurrence of breast cancer following breast conservation treatment. Were radiofrequency ablation proven to be a safe and cost effective method of obtaining negative margins, it would be a positive addition to the treatment armamentarium of the oncologic surgeon."

Mr. Joseph DeVivo, President and CEO of RITA Medical, commented, "We believe that RFA-assisted lumpectomy holds great promise for women who choose breast conserving surgery."

Mr. DeVivo continued, "We expect Dr. Klimberg and her team to add clinical data to support the use of the RFA-assisted lumpectomy technique. As part of an ongoing pilot study that followed the clinical trial reported at the ACS meeting this week, 8 patients out of 16 treated for breast cancer were found to have inadequate surgical margins after lumpectomy. All 8 patients were spared re-excision because Dr. Klimberg used RFA at the time of lumpectomy."

Mr. DeVivo concluded, "Our goal is to create a well-defined application of RFA in the treatment of breast cancer supported by solid clinical data. As we have previously said, we believe there is a terrific market opportunity for the application of RFA in the treatment of breast cancer."

RFA-assisted lumpectomy utilizes heat with the intent to create an additional tumor-free zone around the lumpectomy cavity. During the trial reported on at ACS this week a RITA RFA probe was deployed 1 cm circumferentially into the walls of the lumpectomy cavity and maintained at 100 degrees C for 15 minutes in 25 patients. In addition to the in-vivo clinical application of RFA, 29 prophylactic mastectomy ablations were performed revealing a 5-10mm ablation zone in 72.4%(21/29), 10-20mm in 24.1%(7/29), and greater than 20mm in 3.5%(1/29). Researchers in the clinical trial reported at ACS this week that they concluded that these ex-vivo ablations reliably created a minimum 5-10 mm zone of ablation.

An abstract of the presentation at the ACS 91st Annual Clinical Congress can be found at the American College of Surgeons website, www.facs.org.

Contributing authors of the presentation abstract include Julie Kepple M.D., oncology fellow, Soheila Korourian M.D., associate professor, Department of Pathology, Ronda S. Henry-Tillman M.D., FACS, associate professor of surgery and director of the UAMS Cancer Control Department, Aaron Margulies M.D. FACS, instructor of surgery and fellow in Diseases of the Breast, Gal Shafirstein Ph.D., assistant professor, Department of Otolaryngology/Head and Neck Surgery, and V. Suzanne Klimberg M.D., FACS.

UAMS and its Arkansas Cancer Research Center are recognized nationally and regionally for their commitment to advancing healthcare and cancer treatment for patients.

About University of Arkansas for Medical Sciences (UAMS)

The University of Arkansas for Medical Sciences (UAMS) is the state's only comprehensive academic health center, with five colleges, a graduate school, a medical center, five centers of excellence and a statewide network of regional centers. UAMS has about 2,320 students and 690 residents and is the state's largest public employer with almost 9,000 employees. UAMS and its affiliates have an economic impact in Arkansas of $4.3 billion a year. UAMS centers of excellence are the Arkansas Cancer Research Center, Harvey and Bernice Jones Eye Institute, Donald W. Reynolds Institute on Aging, Myeloma Institute for Research and Therapy and Jackson T. Stephens Spine & Neurosciences Institute.

About RITA Medical Systems, Inc.

RITA Medical Systems develops manufactures and markets innovative products for cancer patients including radiofrequency ablation (RFA) systems for treating cancerous tumors as well as percutaneous vascular and spinal access systems. The Company's oncology product lines include implantable ports, some of which feature its proprietary Vortex(R) technology; tunneled central venous catheters; safety infusion sets and peripherally inserted central catheters used primarily in cancer treatment protocols. The product line also includes the Habib 4X(TM) surgical resection device which coagulates a "resection plane" and is designed to facilitate surgical resection of highly vascularized tissue with reduced blood loss. The proprietary RITA system uses radiofrequency energy to heat tissue to a high enough temperature to ablate it or cause cell death. In March 2000, RITA became the first RFA Company to receive specific FDA clearance for unresectable liver lesions in addition to its previous general FDA clearance for the ablation of soft tissue. In October 2002, RITA again became the first company to receive specific FDA clearance, this time, for the palliation of pain associated with metastatic lesions involving bone.

The statements in this news release related to the use of the Company's technology, including without limitation the Company's plans to extend its technology to applications for breast cancer and the Company's efforts to extend physician awareness of the Company's technology are forward-looking statements involving risks and uncertainties that could cause actual results to differ materially from those in such forward-looking statements. Such risks and uncertainties include but are not limited to: the Company's ability to compete with companies offering alternative therapies for solid cancerous and benign tumors; the Company's lack of long-term data regarding the safety and efficacy of its RFA products; delay of product introductions or modifications as a result of the FDA regulatory process; and the Company's success in its physician training efforts. Information regarding these risks and other risks and uncertainties is included in the Company's filings with the Securities and Exchange Commission.

UAMS
    http://www.uams.edu

    ACRC
    http://www.acrc.uams.edu

    RITA Medical Systems, Inc.
    http://www.ritamedical.com

NOTE TO EDITORS: Please call to schedule in-person or telephone interview with Dr. Klimberg. BETA-SP video B-Roll of the actual surgery, surgeon and patient interviews is available upon request and by scheduled satellite feed. Contact Juliana Minsky, 805-962-3700.

This video news feed contains surgery, procedure animations & interviews with surgeon and patient.

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