North American Scientific Inc. said it agreed to sell its prostate brachytherapy product line to Best Theratronics Ltd. for $5 million so that it can better concentrate on its similar therapy for breast cancer.

Brachytherapy involves inserting tiny radioactive metal seeds around the tumor to kill it with less chance of hurting healthy cells.

“This divestiture allows us to focus exclusively on our implantable ClearPath devices which were developed to optimize local radiation delivery for the treatment of breast cancer,” Chief Executive John Rush said in a statement. “We believe that a focused effort on this exciting women’s health opportunity will give us the best chance to deliver the shareholder value that we strive for.”

Ottawa, Canada-based Best Theratronics, part of the TeamBest Family of Companies, will acquire Prospera brachytherapy seeds, SurTRAK needles and strands and various accessories used primarily in the treatment of prostate cancer.

North American Scientific of Chatsworth will receive $5 million for the product line, with $2 million being paid at the closing of the transaction and the remaining $3 million being paid in installments over 12 months.

The deal approved by North American Scientific’s board will be put to a shareholders vote at a special meeting. The company hopes to close the deal by April.

North American Scientific shares fell 2 cents, or 10 percent, to 17 cents in morning trading on the Nasdaq.