Rita Medical Highlights Recent Clinical Data Updating Study of Radiofrequency Ablation in the Treatment of Breast Cancer

Rita Medical Highlights Recent Clinical Data Updating Study of Radiofrequency Ablation in the Treatment of Breast Cancer

91% Reduction in Need for Re-Excision due to Inadequate Margins Reported in Presentation at 92nd Annual Clinical Congress of the American College of Surgeons

FREMONT, Calif. and CHICAGO, Oct. 11 /PRNewswire-FirstCall/ -- RITA Medical Systems, Inc. (Nasdaq: RITA), a publicly-traded medical device company focused solely on cancer therapies, today highlighted the presentation of recently published results of patient follow-up data after multimodal treatment for breast cancer that included radiofrequency ablation (RFA). Forty-one patients in the trial were treated with traditional lumpectomy breast conserving surgical excision, followed intraoperatively by radiofrequency ablation (eRFA). The authors indicated that eRFA reduced the need for re-excision for inadequate margins by 91% (10 of 11 patients with inadequate margins).

On October 10, 2006, at the 92nd Annual Clinical Congress of the American College of Surgeons, in Chicago, Illinois, V. Suzanne Klimberg, M.D., Professor of Surgery and Pathology at the University of Arkansas for Medical Sciences presented the results of a multiphase eRFA trial in an educational session entitled, "Evolving Options in Breast Preserving Treatment of Breast Cancer -- 'Percutaneous Excision and Ablation for Breast Cancers -- The Future.'"

Dr. Klimberg and her colleagues at the University of Arkansas for Medical Sciences also reported on the findings of their multiphase trial in an article titled, "eRFA: Excision Followed by RFA - A New Technique to Improve Local Control in Breast Cancer," peer-reviewed and published in the October 2006 issue of the Annals of Surgical Oncology.

Dr. Klimberg commented, "I believe eRFA represents an important area for further research because of the potential patient benefits and the ease with which it can be learned and practiced by the surgical community. Our early results demonstrate that eRFA has the potential to reduce the rate of re- excision due to positive or close margins, and provide therapeutic outcomes potentially equivalent to brachytherapy in favorable tumors, all with better cosmetic results for our patients."

Breast cancer is the most common cancer in women in the U.S. In 2006, it is estimated that over 210,000 patients will be diagnosed with breast cancer. One of the leading concerns in patients who choose to have a lumpectomy procedure to remove a tumor in the breast is to obtain a negative margin (tumor-free zone) around the lumpectomy cavity to minimize the chance of local tumor recurrence. Breast irradiation is often used as a follow-up to prevent recurrence. However, inadequate margins are found at the first operation in 20% to 55% of breast cancers removed by lumpectomy. In addition, 75% to 90% of recurrences occur at the site of the original lumpectomy.

Joseph DeVivo, President and Chief Executive Officer of RITA Medical Systems said, "Dr. Klimberg's research is very encouraging in terms of demonstrating the potential benefits of eRFA treatment in women who have received lumpectomies in the treatment of their breast cancer." He continued, "In the trial, eRFA provided safe margins around the lumpectomy site, sparing patients from additional surgeries, which we believe confirms the important role that RITA's RFA devices can play in the treatment of breast cancer."

eRFA: Excision Followed by RFA -- A New Technique to Improve Local Control in Breast Cancer (V. Suzanne Klimberg, M.D. et al, Annals of Surgical Oncology)

The multiphase trial, conducted at the University of Arkansas for Medical Services from July 2002 to January 2005, included RFA of prophylactic mastectomy specimens and RFA in patients desiring lumpectomy. In both models, a lumpectomy was performed. The RFA probe was deployed 1 cm circumferentially into the walls of the lumpectomy cavity and maintained at 100 degrees C for 15 minutes. Whole mount slides were used to measure the zone of ablation for ex-vivo specimens.

Forty-one patients with an average age of 63 and an average tumor size of 1.6 cm participated in the study. Each underwent in-vivo eRFA, and 25% (11 patients) had inadequate margins. 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.

The ex-vivo ablation model for those who had inadequate margins reliably created a 5-10 mm perimeter of ablation. In-vivo, this 5-10 mm perimeter zone reduced the need for re-excision for inadequate margins by 91% (10/11 patients). The researchers conclude that short-term follow-up suggests that eRFA could reduce re-excision surgery and local recurrence.

V. Suzanne Klimberg, M.D., is a professor of surgery and pathology at the University of Arkansas for Medical Sciences (UAMS). UAMS and its Arkansas Cancer Research Center are recognized nationally and regionally for their commitment to advancing healthcare and cancer treatment for patients. To view a copy of the study, please contact the publisher, Springer New York.

About RITA Medical Systems, Inc.

RITA Medical Systems develops, manufactures and markets innovative products for cancer patients including radiofrequency ablation (RFA) systems and embolization products 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^® technology; tunneled central venous catheters; and safety infusion sets and peripherally inserted central catheters used primarily in cancer treatment protocols. The radiofrequency product line also includes the HABIB 4X resection device which coagulates a "surgical resection plane" and is designed to facilitate a fast dissection in order to minimize blood loss and blood transfusion during surgery. The proprietary RITA RFA 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 Company also distributes LC Bead embolic microspheres in the United States. The LC Bead microspheres are injected into selected vessels to block the blood flow feeding a tumor, causing it to shrink over time, and are often used in combination with radiofrequency ablation (RFA). The RITA Medical Systems website is at www.ritamedical.com.

The statements in this news release related to the number of patients in the United States diagnosed with breast cancer; the ability of eRFA treatment to reduce the need for re-excision due to inadequate margins; the ability of eRFA treatment to provide better cosmetic results; and the outcomes of breast cancer patients treated with eRFA 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 ability to develop new radiofrequency products; the Company's lack of long-term data regarding the safety and efficacy of its radiofrequency 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.

SOURCE RITA Medical Systems, Inc.


10/11/2006

CONTACT: Stephen Pedroff, VP Marketing Communications of RITA Medical
Systems, Inc., +1-510-771-0400, or spedroff@ritamed.com; or investors, Doug
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Steve DiMattia, +1-646-277-8706, or sdimattia@evcgroup.com, both of EVC Group,
for RITA Medical Systems, Inc.
/Web site: http://www.ritamedical.com


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