AbstractA new method for ultrasonically guided percutaneous interstitial implantation of125I seeds in abdominal tumours is described. A linear array puncture transducer mounted on a specialx-y-zco-ordinate frame is used in combination with a special insertion technique. Followingin vitroexperiments the technique was applied in two patients with pancreatic cancer. There were no immediate complications after the implantation of 36 and 37125I seeds.