CLINICAL-RESULTS OF COMPUTERIZED TOMOGRAPHY-BASED SIMULATION WITH LASER PATIENT MARKING

Purpose: Accuracy of a patient treatment portal marking device and com puterized tomography (CT) simulation have been clinically tested. Meth ods and Materials: A CT-based simulator has been assembled based on a commercial CT scanner, This includes visualization software and a comp uter-controlled laser drawing device, This laser drawing device is use d to transfer the setup, central aids, and/or radiation portals from t he CT simulator to the patient for appropriate patient skin marking, A protocol for clinical testing is reported, Twenty-five prospectively, sequentially accessioned patients have been analyzed. Results: The si mulation process can be completed in an average time of 62 min, Under many cases, the treatment portals can be designed and the patient mark ed in one session, Mechanical accuracy of the system was found to be w ithin +/- 1 mm, The portal projection accuracy in clinical cases is ob served to be better than +/- 1.2 mm, Operating costs are equivalent to the conventional simulation process it replaces. Conclusion: Computed tomography simulation is a clinically accurate substitute for convent ional simulation when used with an appropriate patient marking system and digitally reconstructed radiographs. Personnel time spent in CT si mulation is equivalent to time in conventional simulation.