| Zugriffsnummer | 49374 |
| Dokumenttyp | Zeitschriftenartikel |
| Peer Review | mit Peer Review |
| Sprache | Englisch |
| Titel | Calorimeter measurements of absolute dose in aluminum, a surrogate of bone, to validate dose-to-medium in Acuros XB |
| Autor(in); Institution |
Szpala, Stanislaw; BC cancer surrey, Physics, Surrey BC, CANADA
Renaud, James; Medical and Industrial Dosimetry, National Research Council of Canada (NRC) Ottawa, Ontario, CANADA
Muir, Bryan Richard; Medical and Industrial Dosimetry, National Research Council of Canada (NRC) Ottawa, Ontario, CANADA
Singh Kohli, Kirpal; BC cancer surrey, Physics, Surrey BC, CANADA
McEwen, Malcom R; Medical and Industrial Dosimetry, National Research Council of Canada (NRC) Ottawa, Ontario, CANADA
|
| Quelle/Jahr | Physics in Medicine and Biology: 68 (2022), 1, 1 - 12 |
| Artikelnummer | 015019 |
| ISSN | 0031-9155 (print) ; 1361-6560 (online) |
| DOI | |
| Verlag | Bristol: IOP Publishing |
| Freie Schlagworte | Acuros XB ; dose-to-medium and dose-to-water in bone ; Aluminum calorimeter |
| Zusammenfassung | Objective: While the accuracy of dose calculations in water with Acuros XB is well established, experimental validation of dose in bone is limited. Acuros XB reports both dose-to-medium and dose-to-water, and these values differ in bone, but there are no reports of direct measurements validating these values in bone. This work compares Acuros XB calculations to direct measurements of absolute dose in aluminum (medium similar to bone). The validity of using selected relative dosimeters in aluminum is also investigated. Approach: A calorimeter with an aluminum core embedded in an aluminum phantom was selected as bone surrogate for the direct measurement of absolute dose. Matching the medium of the core to the medium of the phantom allowed eliminating the calculation of the conversion between media. The dose was measured at the fixed depth of 3.3 cm (˜9 g·cm-2) with 6X, 10X, 6FFF and 10FFF photon beams from a TrueBeam Varian linac. In addition, experimental cross-calibration between water and aluminum was performed for an IBA CC13 ionization chamber, a PTW microDiamond and EBT3 Gafchromic film. Main results: Calculations with Acuros XB dose-to-medium in aluminum agreed with the calorimetry data within -2.8% to -3.6%, depending on the beam. Use of dose-to-water would have resulted in about 28% discrepancy. The cross calibration coefficient between water and aluminum yielded values of about 0.87 for the CC13 chamber, 0.91 for the microDiamond, and 0.88 for the EBT3 film, and independent of the beam within about ±1%. Significance: It was demonstrated that dose-to-medium reporting in Acuros XB agrees with calorimeter-based direct measurements of absolute dose in aluminum, and the discrepancy is significant when dose-to-water is used instead. It was also shown that the use of an ionization chamber, a microDiamond and Gafchromic film in aluminum (a bone surrogate) requires a considerable correction from calibration in water. |
Zitierung
Szpala, S., Renaud, J., Muir, B. R., Bourgouin, A., Singh Kohli, K., & McEwen, M. R. (2022). Calorimeter measurements of absolute dose in aluminum, a surrogate of bone, to validate dose-to-medium in Acuros XB. Physics in Medicine and Biology, 68(1), 1–12. https://doi.org/10.1088/1361-6560/aca869