| Zugriffsnummer | 34360 |
| Dokumenttyp | Zeitschriftenartikel |
| Peer Review | unbekannt |
| Sprache | Englisch |
| Titel | A radiation quality correction factor kQ for well-type ionization chambers for the measurement of the reference air kerma rate of Co-60 HDR brachytherapy sources |
| Autor(in); Institution |
Schüller, Andreas; 6.2, Dosimetrie für Strahlentherapie und Röntgendiagnostik, PTB-Braunschweig
Meier, Markus; 6.2, Dosimetrie für Strahlentherapie und Röntgendiagnostik, PTB-Braunschweig
Selbach, Hans-Joachim; 6.2, Dosimetrie für Strahlentherapie und Röntgendiagnostik, PTB-Braunschweig
Ankerhold, Ulrike; 6.2, Dosimetrie für Strahlentherapie und Röntgendiagnostik, PTB-Braunschweig
|
| Quelle/Jahr | Medical Physics: 42 (2015), 7, 4285 - 4294 |
| ISSN | 0094-2405 |
| DOI | |
| Verlag | New York, NY: AAPM |
| Freie Schlagworte | HDR brachytherapy sources ; well-type ionization chamber ; high dose rate cobalt-60 sources ; high dose rate iridium-192 sources ; source calibration |
| Zusammenfassung | Purpose: The aim of this study was to investigate whether a chamber-type-specific radiation quality correction factor k_Q can be determined in order to measure the reference air kerma rate of Co-60 high-dose-rate (HDR) brachytherapy sources with acceptable uncertainty by means of a well-type ionization chamber calibrated for Ir-192 HDR sources. Methods: The calibration coefficients of 35 well-type ionization chambers of two different chamber types for radiation fields of Co-60 and Ir-192 HDR brachytherapy sources were determined experimentally. A radiation quality correction factor kQ was determined as the ratio of the calibration coefficients for Co-60 and Ir-192. The dependence on chamber-to-chamber variations, source-to-source variations, and source strength was investigated. Results: For the PTW Tx33004 (Nucletron source dosimetry system (SDS)) well-type chamber, the type-specific radiation quality correction factor kQ is 1.19. Note that this value is valid for chambers with the serial number, SN ≥ 315 (Nucletron SDS SN ≥ 548) onward only. For the Standard Imaging HDR 1000 Plus well-type chambers, the type-specific correction factor kQ is 1.05. Both kQ values are independent of the source strengths in the complete clinically relevant range. The relative expanded uncertainty (k =2) of kQ is UkQ=2.1% for both chamber types. Conclusions: The calibration coefficient of a well-type chamber for radiation fields of Co-60 HDR brachytherapy sources can be calculated from a given calibration coefficient for Ir-192 radiation by using a chamber-type-specific radiation quality correction factor kQ. However, the uncertainty of a Co-60 calibration coefficient calculated via kQ is at least twice as large as that for a direct calibration with a Co-60 source. |
| Kostenfreier Zugang | Open Access Hybrid |
| Rechteinformation | CC BY 3.0 ; Creative Commons Attribution 3.0 License ; Original article: under a Creative Commons Attribution 3.0 Unported License |
Zitierung
Schüller, A., Meier, M., Selbach, H.-J., & Ankerhold, U. (2015). A radiation quality correction factor kQ for well-type ionization chambers for the measurement of the reference air kerma rate of Co-60 HDR brachytherapy sources. Medical Physics, 42(7), 4285–4294. https://doi.org/10.1118/1.4922684