Estimating dose to implantable cardioverter-defibrillator outside the treatment fields using a skin QED diode, optically stimulated luminescent dosimeters, and LiF thermoluminescent dosimeters Journal Article
| Authors: | Chan, M. F.; Song, Y.; Dauer, L. T.; Li, J.; Huang, D.; Burman, C. |
| Article Title: | Estimating dose to implantable cardioverter-defibrillator outside the treatment fields using a skin QED diode, optically stimulated luminescent dosimeters, and LiF thermoluminescent dosimeters |
| Abstract: | The purpose of this work was to determine the relative sensitivity of skin QED diodes, optically stimulated luminescent dosimeters (OSLDs) (microStar™ DOT, Landauer), and LiF thermoluminescent dosimeters (TLDs) as a function of distance from a photon beam field edge when applied to measure dose at out-of-field points. These detectors have been used to estimate radiation dose to patients' implantable cardioverter-defibrillators (ICDs) located outside the treatment field. The ICDs have a thin outer case made of 0.4- to 0.6-mm-thick titanium (~2.4-mm tissue equivalent). A 5-mm bolus, being the equivalent depth of the devices under the patient's skin, was placed over the ICDs. Response per unit absorbed dose-to-water was measured for each of the dosimeters with and without bolus on the beam central axis (CAX) and at a distance up to 20 cm from the CAX. Doses were measured with an ionization chamber at various depths for 6- and 15-MV x-rays on a Varian Clinac-iX linear accelerator. Relative sensitivity of the detectors was determined as the ratio of the sensitivity at each off-axis distance to that at the CAX. The detector sensitivity as a function of the distance from the field edge changed by ± 3% (1-11%) for LiF TLD-700, decreased by 10% (5-21%) for OSLD, and increased by 16% (11-19%) for the skin QED diode (Sun Nuclear Corp.) at the equivalent depth of 5 mm for 6- or 15-MV photon energies. Our results showed that the use of bolus with proper thickness (i.e., ~d max of the photon energy) on the top of the ICD would reduce the scattered dose to a lower level. Dosimeters should be calibrated out-of-field and preferably with bolus equal in thickness to the depth of interest. This can be readily performed in clinic. © 2012 American Association of Medical Dosimetrists. |
| Keywords: | sensitivity and specificity; sensitivity analysis; reproducibility of results; radiation response; radiation dosage; skin; dosimetry; radiotherapy, conformal; equipment design; ionization chamber; skin physiological phenomena; defibrillator; photon; radiation field; defibrillators, implantable; diode; thermoluminescence dosimeter; linear accelerator; titanium; equipment failure analysis; radiation detector; thickness; radiation absorption; thermoluminescent dosimetry; semiconductors; diodes; osld; out-of-field dosimetry; tld; lithium fluoride; optically stimulated luminescent dosimeter; qed diode; optically stimulated luminescence dosimetry |
| Journal Title: | Medical Dosimetry |
| Volume: | 37 |
| Issue: | 3 |
| ISSN: | 0958-3947 |
| Publisher: | Elsevier Science, Inc. |
| Date Published: | 2012-01-01 |
| Start Page: | 334 |
| End Page: | 338 |
| Language: | English |
| DOI: | 10.1016/j.meddos.2011.11.007 |
| PROVIDER: | scopus |
| PUBMED: | 22296877 |
| DOI/URL: | |
| Notes: | The publisher's record lists the publication date as Autumn -- "Export Date: 4 September 2012" -- "CODEN: MEDOE" -- "Source: Scopus" |
Altmetric
Citation Impact
BMJ Impact Analytics
Related MSK Work