SU-D-108-03: Evaluation of the Feasibility of a Novel Radiochromic Dosimetry System for In-Vivo Dose Verification in Organs at Risk in HDR Intracavitary Gynecological Brachytherapy.

Journal Article (Journal Article)

PURPOSE: To evaluate the feasibility of a novel radiochromic dosimetry system for in-vivo dose verification in organs at risk in HDR intracavitary gynecological brachytherapy. METHODS: Novel, small cylindrical PRESAGE dosimeters (4mm in diameter by 20mm in height) were attached to intracavitary HDR brachytherapy applicators near the rectum and bladder of three patients undergoing Ir-192 HDR brachytherapy treatments. Two methods of dose-readout were investigated (i) a volume averaged readout by spectrophotometer, and (ii) 2D projection imaging in a high-resolution (50 micron) telecentric optical system. Both readout techniques were benchmarked against a gold standard. The gold standard consisted of spectrophotometer readout of precision 1×1×4cm optical cuvettes filled with PRESAGE, and irradiated to known doses in a 6 MV photon beam. Temperature corrections were required to account for increased PRESAGE sensitivity at body temperature. Estimated doses were compared with measured dose distributions in Eclipse. RESULTS: Examination of the change in optical density between dosimeters and cuvettes shows a linear relationship in sensitivity between 1-15 Gy with a 95% confidence interval in the slope (0.8703 +/- 0.0192). Patient data showed a 0 % and 2.8% difference in estimated doses vs. Eclipse measurements in the bladder and rectum, respectively. CONCLUSION: This work presents the spectrophotometer/optical scanning system as a viable dosimetry system, which can provide in-vivo dose verification in intracavitary HDR brachytherapy. Further work needs to be done in regard to dosimeter positioning in patient treatments. NIH Grant RO1CA100835.

Full Text

Duke Authors

Cited Authors

  • Vidovic, A; Juang, ; Steffey, B; Meltsner, S; Adamovics, J; Chino, J; Craciunescu, O; Oldham, M

Published Date

  • June 2013

Published In

Volume / Issue

  • 40 / 6Part3

Start / End Page

  • 104 -

PubMed ID

  • 28519546

Electronic International Standard Serial Number (EISSN)

  • 2473-4209

Digital Object Identifier (DOI)

  • 10.1118/1.4814013


  • eng

Conference Location

  • United States