INDEPENDENT TECHNIQUE OF VERIFYING HIGH-DOSE-RATE (HDR) BRACHYTHERAPYTREATMENT PLANS

Purpose: An independent technique for verifying high-dose rate (HDR) b rachytherapy treatment plans has been formulated and validated clinica lly, Methods and Materials: In HDR brachytherapy, dwell times at respe ctive dwell positions are computed, using an optimization algorithm in a HDR treatment-planning system to deliver a specified dose to many t arget points simultaneousty. Because of the variability of dwell times , concerns have been expressed regarding the ability of the algorithm to compute the correct dose, To address this concern, a commercially a vailable low-dose rate (LDR) algorithm was used to compute the doses a t defined distances, based on the dwell times obtained from the HDR tr eatment plans, The percent deviation between doses computed using the HDR and LDR algorithms were reviewed for HDR procedures performed over the last year, Results: In this retrospective study, the difference b etween computed doses using the HDR and LDR algorithms was found to be within 5% for about 80% of the HDR procedures, All of the reviewed pr ocedures have dose differences of less than 10%, Conclusion: An indepe ndent technique for verifying HDR brachytherapy treatment plans has be en validated based on clinical data, Provided both systems are availab le, this technique is universal in its applications and not limited to either a particular implant applicator, implant site, or implant type . (C) 1998 Elsevier Science Inc.