CT-guided intervention using a patient laser marker system

To prove the usefulness of a simple laser marker system (LMS) in target def inition as well as examination procedure for CT-guided interventions, 130 c ases of diagnostic biopsies and lumbal sympathectomies were compared. In 75 cases LMS and in 55 cases a simple crossgrid was used. Taking advantage of the LMS, the parameters of intervention (cutaneous location, length, and a ngle) can be planned, exactly demonstrated, and it is possible to check the needle position during the whole procedure. Thus, the number of necessary control scans decreased to 30 %, and corrections of needle location were re duced to approximately 30 %. Moreover, the average target deviation of the needle decreased below 5 mm in 50 % of cases, and the duration of intervent ional procedure was reduced considerably. It can be concluded that LMSs are recommended in CT-guided interventions for quality assurance, dose reducti on, and improvement of handling. It will be especially advantageous in case s of small target volume, oblique needle path, and tilted gantry.