Fig. 2

Schematic diagram of ¹²⁵I seed strand (ISS) production and release process. A narrow catheter port was placed 2 cm away from the head end of the 3F medical catheter by burring methods. A small guidewire hole was opened 1.5 cm away from the head end, which accommodates the passage of a 0.035 inch guide wire. The ¹²⁵I seeds were arranged one by one behind the narrow catheter, and the non-¹²⁵I seed-filled part was fixed with a 0.018 inch soft filling guidewire to prevent.¹²⁵I seed displacement (A). Double guidewires were inserted into the bile duct through a 9F short sheath (B). The ISS and drainage catheter were advanced by two guidewires (C). The 8.5F drainage catheter and ISS were distributed in parallel across the tumor obstruction (D)