A new method for the placement of brachytherapy probes in paranasal sinus and nasopharynx neoplasms

Purpose: In afterloading therapy, the exact placement of the applicator Is crucial for the result of radiotherapy. A deviation of few millimeters from the target leads to a significant reduction of radiation energy to the tum or. Methods and Materials: We present a new method using a computer-assisted de vice for three-dimensional placing of afterloading probes based on CT scans that allows for the exact placement. Results: Target points have been reached with an accuracy of 0.6 mm, Since 1991 we have used this technique for 24 clinical applications in 11 patient s with recurrent neoplasms in the region of the paranasal sinuses and nasop harynx for palliative treatment. Conclusions: The presented method is a reliable and precise procedure for t he positioning of afterloading probes, avoiding the inaccuracy of the tradi tional methods. (C) 1999 Elsevier Science Inc.