PROBLEM TO BE SOLVED: To provide a more accurate system and method for inserting a needle into an animal body for radiotherapy. SOLUTION: The system and the method is described below. The system comprises a template, a needle-drive means and a real-time imaging means. The template positions a needle for insertion. The needle-drive means drives the needle toward the target position in a body by means of the template. The real-time imaging means creates and presents the image of the target position and the position of the needle during the insertion of the needle. A need arises for a needle more accurately to be inserted in view of the fact that the needle slips off 'the insertion or movement line' due to the inclined leading tip of the hollow needle structure, resulting in the shifting off from the actual target position of the animal body, which can cause undesirable effects upon the quality of the dosimetry of the implanted seeds. The system is also provided with an adjusting means to adjust the movement of the needle toward the target position during the insertion thereof. COPYRIGHT: (C)2003,JPO