North American Scientific Inc. said on Tuesday that the Chatsworth-based brachytherapy company had received clearance from the U.S. Food and Drug Administration to market a low-dose rate radiation treatment version of its recently announced breast brachytherapy product.

The product is designed to enhance accelerated partial breast irradiation treatments, an estimated $500 million U.S. market. Brachytherapy is a minimally invasive procedure in which radioactive material, sealed in titanium capsules the size of a grain of rice, are implanted into cancerous tissue to deliver a short-range dose of therapeutic radiation. The targeted approach minimizes the amount of radiation that surrounding healthy tissue might receive.

North American Scientific designed a multi-channel catheter system that is less invasive, in part because of the fewer incisions needed for treatment. Breast brachytherapy generally would be used in conjunction with surgery and chemotherapy.

After soaring 28.7 percent on the news Tuesday, shares of the Chatsworth-based medical device company closed up 12 percent to $2.46. The company has been facing delisting from the Nasdaq National Market because of problems in maintaining the minimum $10 million stockholders equity requirement or a $50 million market capitalization. Chief Executive Michael Cutrer said the later requirement could be met if the company’s share price could be kept around $2.90.

The company is concluding studies on a high-dose rate procedure and expects to file a second 510(k) application with the FDA by June, Cutrer said. The company hopes to launch both devices in November at the annual meeting of the American Society of Therapeutic Radiology and Oncology.

“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,” Cutrer said.