The present invention provides a catheter apparatus including: a multi-lumen tubing structure integrally formed and having a proximal end direction and a distal end direction, wherein the multi-lumen tubing structure includes a tubular structure and a plurality of fluid flowing tube structures, the tubular structure and the fluid flowing tube structures are disposed along the first axis direction of the multi-lumen tubing structure； at least one tube sleeve membrane element covering the outer periphery of the multi-lumen tubing structure, wherein the at least one tube sleeve membrane element includes a reinforcing structure and/or a cushion structure； and a pointed end which engages the multi-lumen tubing structure so that the pointed end can be firmly fixed at the multi-lumen tubing structure. The present invention also provides a brachytherapy system that adopts the catheter apparatus and can be used to treat intracavitary tumors such as esophageal cancer, etc..本發明提供了一種導管裝置，其包括：一多管腔管路結構，為一體成型，具有一近端方向及一遠端方向，其中，所述多管腔管路結構包括一管狀結構及複數個流體流管結構，所述管狀結構及所述複數個流體流管結構沿著所述多管腔管路結構的一第一軸方向設置；至少一管套膜元件，包覆所述多管腔管路結構之外緣，其中，所述至少一管套膜元件包括一強化結構和/或一緩衝結構；以及一尖端，所述尖端接合於所述多管腔管路結構，使所述尖端牢牢固定於所述多管腔管路結構。本發明還提供了一種採用該導管裝置的近接治療系統，可用於治療食道癌等腔內腫瘤。
