1. Establishing a fingerprinting method for fast catheter identification in HDR brachytherapy in vivo dosimetry.
- Author
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Tho D, Bélanger C, Jørgensen EB, Tanguay J, Rosales HML, Beddar S, Johansen JG, Kertzscher G, Lavallée MC, and Beaulieu L
- Subjects
- Male, Humans, Radiotherapy Dosage, Phantoms, Imaging, Catheters, Radiotherapy Planning, Computer-Assisted methods, In Vivo Dosimetry, Brachytherapy methods
- Abstract
Purpose: To use quantities measurable during in vivo dosimetry to build unique channel identifiers, that enable detection of brachytherapy errors., Materials and Methods: Treatment plan of 360 patients with prostate cancer who underwent high-dose-rate brachytherapy (range, 16-25 catheters; mean, 17) were used. A single point virtual dosimeter was placed at multiple positions within the treatment geometry, and the source-dosimeter distance and dwell time were determined for each dwell position in each catheter. These values were compared across all catheters, dwell position by dwell position, simulating a treatment delivery. A catheter was considered uniquely identified if, for a given dwell position, no other catheters had the same measured values. The minimum number of dwell positions needed to identify a specific catheter and the optimal dosimeter location uniquely were determined. The radial (r) and vertical (z) dimensions of the source-dosimeter distance were also examined for their utility in discriminating catheters., Results: Using a virtual dosimeter with no uncertainties, all catheters were identified in 359 of the 360 cases with 9 dwell position measurements. When only the dwell time were measured, all catheters were uniquely identified after 1 dwell position. With a 2-mm spatial accuracy (r,z), all catheters were identified in 94% of the plans. Simultaneous measurement of source-dosimeter distance and dwell time ensured full catheter identification in all plans ranging from 2 to 6 dwell positions. The number of dwell positions needed to uniquely identify all catheters was lower when the distance from the implant center was higher., Conclusions: The most efficient fingerprinting approach involved combining source-dosimeter distance (i.e., source tracking) and dwell time. The further the dosimeter is placed from the center of the implant the better it can uniquely identify catheters., (Copyright © 2024. Published by Elsevier Inc.)
- Published
- 2024
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