The recently FDA-cleared breast brachytherapy device from North American Scientific is designed to allow for either low dose rate or high dose rate accelerated partial breast irradiation therapy. Both treatment options would be delivered over four or five days compared to the six-to-eight week whole breast irradiation treatment. The multichannel catheter device will be placed through a single incision, but will offer the unique ability to better conform to the resection cavity, allowing for more conformal dose distributions during treatment. The low dose rate option may be preferred by physicians and patients who wish to minimize the dose to surrounding tissue and critical structures.