Abstract: Embodiments of the disclosure may be drawn to brachytherapy applicators. Exemplary applicators may include an interstitial tube having a body with a proximal end and a distal end and a central conduit extending from the distal end of the body, wherein the central conduit includes a proximal opening, a distal opening, and a channel extending from the proximal opening to the distal opening, and wherein the proximal opening is offset from an axis of the body. The proximal opening may be configured to fluidly connect to a brachytherapy guide tube, and the channel of the central conduit may be dimensioned to receive at least one of a needle or a catheter therethrough.

Abstract: A guiding sheath exchange system comprises first and second guiding sheaths and an exchange dilator. Each guiding sheath has a lumen extending therethrough. The first guiding sheath has a first predefined curve at its distal end and the second guiding sheath has a second predefined curve at its distal end different from the first predefined curve. The exchange dilator comprises a flexible tubing having a generally constant diameter along its length, two tapered ends and a lumen therethrough. The guiding sheath exchange system is used for replacing the first guiding sheath having a distal end that is in the patient's heart with the second guiding sheath. The replacement method comprises inserting the distal end of the exchange dilator into the proximal end of the lumen of the first guiding sheath and feeding the distal end of the exchange dilator through the lumen so that it extends distal the distal end of the first guiding sheath.