MOUNTAIN VIEW, Calif., Dec. 5 /PRNewswire-FirstCall/ -- RITA Medical Systems, Inc. (Nasdaq: RITA) announced today that the results of a clinical study on the use of its proprietary radiofrequency (RF) ablation technology confirm that the minimally invasive treatment appears to be effective in treating cancerous lung tumors when surgery is not an option, which is the case for the majority of lung cancer patients. Data from the study were presented at the Radiology Society of North America (RSNA) 88th Scientific Assembly and Annual Meeting, being held in Chicago December 1-6, by Professor Riccardo Lencioni, M.D. Professor Lencioni is a Professor of Diagnostic and Interventional Radiology at the University of Pisa in Italy. Earlier results from this study had been presented at European Congress of Radiology, held in Vienna, Austria in March 2002.

The clinical study included 62 patients who had primary lung cancer or lung metastases (cancer which has spread to the lung) and who were not surgical candidates. These patients were treated using RITA Medical Systems' radiofrequency ablation system. This system enables physicians to deliver monitored and controlled levels of radiofrequency energy into the cancerous tissue through an array of thin electrodes, which heat and destroy, or ablate, the targeted tissue. In many cases, this minimally invasive procedure can be performed using only a local anesthetic and IV sedation.

Following treatment with the RITA System, the patients' progress is assessed over a one year period using CT imaging. For 25 patients who had been followed for at least six months, 93 percent of tumors had stabilized or decreased in size at that point in time. Over this period, these tumors would typically be expected to at least double in size. There were no major complications reported.

"These results are very impressive. The data presented here clearly show that RITA can offer a new approach in the treatment of lung cancer for the majority of patients who cannot have surgery," said Professor Lencioni.

Barry Cheskin, RITA's President and Chief Executive Officer commented, "With these results, we are officially launching our products for treating lung cancer outside the United States, as planned. While we expect limited revenue from this application in 2003 as we pioneer this market with key thought leaders, this represents the third application of our technology to be commercialized, in addition to our liver and bone applications." He added that the Company estimates the market opportunity for treating unresectable lung tumors is approximately $400 million in addition to other market opportunities of $500 million for unresectable liver cancer and $600 million for painful bone metastases.

The study was conducted at UCLA, Pisa University Hospital in Pisa, Italy, St. George Hospital in Sydney, Australia, University of Munich-Grosshadern in Munich, Germany, University Hospital Essen in Essen, Germany, Institute for Research and Treatment of Cancer in Turin, Italy and Middlesex Hospital in London, England.

About RITA Medical Systems, Inc.

RITA Medical Systems develops, manufactures and markets innovative products for patients with solid cancerous or benign tumors. The proprietary RITA system uses radiofrequency energy to heat tissue to a high enough temperature to ablate it or cause cell death. While the Company's current focus is on liver cancer and metastatic bone cancer, the Company believes that its minimally invasive technology may in the future be applied to other types of tumors, including tumors of the lung, breast, uterus, prostate and kidney. The Company has received regulatory clearance in major markets worldwide, including the United States. In March 2000, RITA became the first radiofrequency ablation 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 has sold over 40,000 of its disposable devices throughout the world.

The statements in this news release related to the company's plans to extend its technology to applications beyond the liver, sales in 2003 and the company's projections of the market potential related to liver and non-liver applications are forward-looking statements involving risks and uncertainties that could cause actual results to differ materially from those in such forward-looking statements. Information regarding these and other risks is included in the Company's filings with the Securities and Exchange Commission.

RITA is a trademark of RITA Medical Systems, Inc.

For further information, please contact Matt Clawson (investors), matt@allencaron.com, or Len Hall (media), len@allencaron.com, both of Allen & Caron Inc, +1-949-474-4300, for RITA Medical Systems, Inc.; or Don Stewart, Chief Financial Officer of RITA Medical Systems, Inc., +1-650-314-3400, dstewart@ritamed.com.

SOURCE RITA Medical Systems, Inc.