This work aimed to create a mailable and OSLD-based phantom with accuracy suitable for RPC audits of HDR brachytherapy sources at institutions participating in NCI-funded cooperative clinical trials. An 8 × 8 × 10 cm3 prototype with two slots capable of holding nanoDot Al2O3:C OSL dosimeters (Landauer, Glenwood, IL) was designed and built. The phantom has a single channel capable of accepting all 192Ir HDR brachytherapy sources in current clinical use in the United States. Irradiations were performed with an 192Ir HDR source to determine correction factors for linearity with dose, dose rate, and the combined effect of irradiation energy and phantom construction. The uncertainties introduced by source positioning in the phantom and timer resolution limitations were also investigated. It was found that the linearity correction factor was where dose is in cGy, which differed from that determined by the RPC for the same batch of dosimeters under 60Co irradiation. There was no significant dose rate effect. Separate energy+block correction factors were determined for both models of 192Ir sources currently in clinical use and these vendor-specific correction factors differed by almost 2.6%. For Nucletron sources, this correction factor was 1.026±0.004 (99% Confidence Interval) and for Varian sources it was 1.000±0.007 (99% CI). Reasonable deviations in source positioning within the phantom and the limited resolution of the source timer had insignificant effects on the ability to measure dose. Overall measurement uncertainty of the system was estimated to be ±2.5% for both Nucletron and Varian source audits (95% CI). This uncertainty was sufficient to establish a ±5% acceptance criterion for source strength audits under a formal RPC audit program. Trial audits of eight participating institutions resulted in an average RPC-to-institution dose ratio of 1.000 with a standard deviation of 0.011.
","abstract_html":"<p>This work aimed to create a mailable and OSLD-based phantom with accuracy suitable for RPC audits of HDR brachytherapy sources at institutions participating in NCI-funded cooperative clinical trials. An 8 × 8 × 10 cm<sup>3</sup> prototype with two slots capable of holding nanoDot Al<sub>2</sub>O<sub>3</sub>:C OSL dosimeters (Landauer, Glenwood, IL) was designed and built. The phantom has a single channel capable of accepting all <sup>192</sup>Ir HDR brachytherapy sources in current clinical use in the United States. Irradiations were performed with an <sup>192</sup>Ir HDR source to determine correction factors for linearity with dose, dose rate, and the combined effect of irradiation energy and phantom construction. The uncertainties introduced by source positioning in the phantom and timer resolution limitations were also investigated. It was found that the linearity correction factor was where <em>dose</em> is in cGy, which differed from that determined by the RPC for the same batch of dosimeters under <sup>60</sup>Co irradiation. There was no significant dose rate effect. Separate energy+block correction factors were determined for both models of <sup>192</sup>Ir sources currently in clinical use and these vendor-specific correction factors differed by almost 2.6%. For Nucletron sources, this correction factor was 1.026±0.004 (99% Confidence Interval) and for Varian sources it was 1.000±0.007 (99% CI). Reasonable deviations in source positioning within the phantom and the limited resolution of the source timer had insignificant effects on the ability to measure dose. Overall measurement uncertainty of the system was estimated to be ±2.5% for both Nucletron and Varian source audits (95% CI). This uncertainty was sufficient to establish a ±5% acceptance criterion for source strength audits under a formal RPC audit program. Trial audits of eight participating institutions resulted in an average RPC-to-institution dose ratio of 1.000 with a standard deviation of 0.011.</p>","abstract_has_math":false,"creators":["Casey, Kevin"],"institution":null,"degree_name":"Masters of Science (MS)","degree_level":"Thesis (MS)","degree_discipline":null,"degree_department":null,"school":null,"contributors":["David Followill, Ph.D.","Paola Alvarez, M.S.","Stephen Kry, Ph.D."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2012,"date_issued":"2012-08-01T07:00:00Z","date_published":"2012-08-01T07:00:00Z","updated_at":"2026-07-24T05:50:38Z","subjects":["HDR","high dose rate","brachytherapy","dosimetry","OSLD","OSL","RPC","Radological Physics Center","remote audit","Other Medical Sciences","Other Physics"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://digitalcommons.library.tmc.edu/utgsbs_dissertations/249","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["David Followill, Ph.D.","Paola Alvarez, M.S.","Stephen Kry, Ph.D."]},{"key":"dc:creator","label":"Author","values":["Casey, Kevin"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.available","label":"Dc Date Available","values":["2012-07-26T07:00:00Z"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis (MS)"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Masters of Science (MS)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["HDR","high dose rate","brachytherapy","dosimetry","OSLD","OSL","RPC","Radological Physics Center","remote audit","Other Medical Sciences","Other Physics"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://digitalcommons.library.tmc.edu/utgsbs_dissertations/249"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["This work aimed to create a mailable and OSLD-based phantom with accuracy suitable for RPC audits of HDR brachytherapy sources at institutions participating in NCI-funded cooperative clinical trials. An 8 × 8 × 10 cm3 prototype with two slots capable of holding nanoDot Al2O3:C OSL dosimeters (Landauer, Glenwood, IL) was designed and built. The phantom has a single channel capable of accepting all 192Ir HDR brachytherapy sources in current clinical use in the United States. Irradiations were performed with an 192Ir HDR source to determine correction factors for linearity with dose, dose rate, and the combined effect of irradiation energy and phantom construction. The uncertainties introduced by source positioning in the phantom and timer resolution limitations were also investigated. It was found that the linearity correction factor was where dose is in cGy, which differed from that determined by the RPC for the same batch of dosimeters under 60Co irradiation. There was no significant dose rate effect. Separate energy+block correction factors were determined for both models of 192Ir sources currently in clinical use and these vendor-specific correction factors differed by almost 2.6%. For Nucletron sources, this correction factor was 1.026±0.004 (99% Confidence Interval) and for Varian sources it was 1.000±0.007 (99% CI). Reasonable deviations in source positioning within the phantom and the limited resolution of the source timer had insignificant effects on the ability to measure dose. Overall measurement uncertainty of the system was estimated to be ±2.5% for both Nucletron and Varian source audits (95% CI). This uncertainty was sufficient to establish a ±5% acceptance criterion for source strength audits under a formal RPC audit program. Trial audits of eight participating institutions resulted in an average RPC-to-institution dose ratio of 1.000 with a standard deviation of 0.011.
"]},{"key":"dc:title","label":"Title","values":["Development and Implementation of A Remote Audit to ol For High Dose Rate (Hdr) 192Ir Brachytherapy Using Optically Stimulated Luminescence Dosimetry"]}]}],"canonical_facts":{"dc:contributor":["David Followill, Ph.D.","Paola Alvarez, M.S.","Stephen Kry, Ph.D."],"dc:creator":["Casey, Kevin"],"dc:date.available":["2012-07-26T07:00:00Z"],"dc:description.abstract":["This work aimed to create a mailable and OSLD-based phantom with accuracy suitable for RPC audits of HDR brachytherapy sources at institutions participating in NCI-funded cooperative clinical trials. An 8 × 8 × 10 cm3 prototype with two slots capable of holding nanoDot Al2O3:C OSL dosimeters (Landauer, Glenwood, IL) was designed and built. The phantom has a single channel capable of accepting all 192Ir HDR brachytherapy sources in current clinical use in the United States. Irradiations were performed with an 192Ir HDR source to determine correction factors for linearity with dose, dose rate, and the combined effect of irradiation energy and phantom construction. The uncertainties introduced by source positioning in the phantom and timer resolution limitations were also investigated. It was found that the linearity correction factor was where dose is in cGy, which differed from that determined by the RPC for the same batch of dosimeters under 60Co irradiation. There was no significant dose rate effect. Separate energy+block correction factors were determined for both models of 192Ir sources currently in clinical use and these vendor-specific correction factors differed by almost 2.6%. For Nucletron sources, this correction factor was 1.026±0.004 (99% Confidence Interval) and for Varian sources it was 1.000±0.007 (99% CI). Reasonable deviations in source positioning within the phantom and the limited resolution of the source timer had insignificant effects on the ability to measure dose. Overall measurement uncertainty of the system was estimated to be ±2.5% for both Nucletron and Varian source audits (95% CI). This uncertainty was sufficient to establish a ±5% acceptance criterion for source strength audits under a formal RPC audit program. Trial audits of eight participating institutions resulted in an average RPC-to-institution dose ratio of 1.000 with a standard deviation of 0.011.
"],"dc:identifier":["https://digitalcommons.library.tmc.edu/utgsbs_dissertations/249"],"dc:subject":["HDR","high dose rate","brachytherapy","dosimetry","OSLD","OSL","RPC","Radological Physics Center","remote audit","Other Medical Sciences","Other Physics"],"dc:title":["Development and Implementation of A Remote Audit to ol For High Dose Rate (Hdr) 192Ir Brachytherapy Using Optically Stimulated Luminescence Dosimetry"],"thesis:degree_level":["Thesis (MS)"],"thesis:degree_name":["Masters of Science (MS)"]},"updated_at":"2026-07-24T05:50:38Z"}