North American Scientific Announces FDA Clearance of Low-Dose Breast Brachytherapy Product; Company Plans Launch in November 2006.

CHATSWORTH, Calif. -- North American Scientific, Inc. (Nasdaq:NASI), a leading manufacturer of brachytherapy sources, announced today that the Company has received 510(k) clearance from the United States Food and Drug Administration (FDA) to market the low-dose rate radiation treatment design of its recently announced breast brachytherapy product. The product is designed to enhance current accelerated partial breast irradiation (APBI) treatment options, an estimated $500 million U.S. market.

This approval marks a significant milestone in the Company's Breast Brachytherapy Program, announced in March 2006, which is designed to offer a new treatment alternative to women electing APBI as part of their Breast Conserving Therapy (BCT). The Company's unique multi-channel catheter system is designed to allow for either low-dose therapy, using the Company's existing Prospera(R) I-125 seeds, or high-dose rate treatments. The Company expects to file a second 510(k) application with the FDA to market a similar device for the high-dose rate procedure. The Company plans to launch both new APBI devices in November 2006 at the 48th annual meeting of the American Society of Therapeutic Radiology and Oncology (ASTRO).

"Today's approval is a key step toward executing on our Breast Brachytherapy strategy," said L. Michael Cutrer, President & Chief Executive Officer of North American Scientific. "While we announced this as an initiative last month, considerable work on the product's design had been done. Our new system is designed to offer the physician greater flexibility in treatment planning and delivery while offering patients new alternatives to whole breast irradiation. While devices currently on the market utilize high-dose rate treatment, we believe that offering a low-dose rate option for primary treatment or in combination with high-dose rate therapy could prove to be an important option for breast cancer treatment. While we may see the first patients utilizing our device as a low-dose rate treatment, we feel it is equally important that a high-dose rate option is also available to the market and we plan to submit the 510(k) for this design later this summer with both designs being targeted for release in November."

Brachytherapy, or internal radiation therapy, makes use of radioactive sources or seeds and has emerged as one of the most common treatments of prostate cancer. Recently, brachytherapy has been applied to the treatment of breast cancer through APBI, with two approaches gaining market acceptance. The first approach involves the placement of 15-20 needle/catheters through the breast followed by high-dose rate therapy. The second approach utilizes a single catheter device with a balloon followed by high-dose rate therapy and, though it is less invasive, has limitations such as conformity and tissue compression. Both methods offer only high-dose rate treatments.

About North American Scientific

North American Scientific is a leader in radiation therapy products and services in the fight against cancer. Its innovative products provide physicians with a set of tools for the treatment of various types of cancers. They include radioisotope-based brachytherapy seeds, used primarily in the treatment of prostate cancer, marketed under the trade name Prospera(R); Intensity Modulated Radiation Therapy (IMRT); and Image Guided Radiation Therapy (IGRT). IMRT allows an escalated radiation dose to be delivered to a tumor while limiting exposure and damage to nearby healthy tissue. The Company's principal IMRT products are marketed under the trade names PEACOCK(R) and CORVUS. The Company's IGRT products, BAT(R), BATCAM(TM) and nTRAK(TM) provide fast and accurate targeting and localization of a treatment volume on a daily basis. Over 500 hospitals and research sites worldwide are equipped with the Company's clinically proven PEACOCK, CORVUS (our proprietary treatment planning software), BAT, BATCAM, and ancillary treatment solutions. Please visit www.nasmedical.com for more information.

Statements included in this release that are not historical facts may be considered forward-looking statements that are subject to a variety of risks and uncertainties. There are a number of important factors that could cause actual results to differ materially from those expressed in any forward-looking statements made by the Company including, but not limited to, the impact of competitive products and pricing, technological changes, changes in relationships with strategic partners and dependence upon strategic partners for the performance of critical activities under collaborative agreements, the ability of the Company to successfully directly market and sell its products, uncertainties relating to patent protection and regulatory approval, the stable supply of appropriate isotopes, research and development estimates, market opportunities, risks associated with strategic opportunities or acquisitions the Company may pursue and the risk factors included in the Company's filings with the Securities and Exchange Commission. Any forward-looking statements contained in this news release speak only as of the date of this release, and the Company undertakes no obligation to revise or update any forward-looking statements, whether as a result of new information, future results or otherwise.