Dosimetric comparison of water phantoms,ion chambers,and data acquisition modes for LINAC characterization |
| |
| Institution: | 1. Department of Radiation Oncology, University of Texas Health Science Center San Antonio, TX, USA;2. Landauer Medical Physics, Glenwood, IL, USA;3. Department of Radiation Oncology, University of Arkansas for Medical Sciences, Little Rock, AR, USA;1. Belgian Nuclear Research Centre, Mol, Belgium;2. Iridium Kankernetwerk, University of Antwerp, Antwerp, Belgium;3. Agfa NV, Mortsel, Belgium;4. Landauer, Stillwater Crystal Growth Division, Stillwater, USA;1. Universitätsklinikum Schleswig-Holstein, Klinik für Strahlentherapie, Kiel, Germany;2. Saphir Radiochirurgie Zentrum, Frankfurt und Güstrow, Germany;3. IFCA, Department of Medical Physics and Radiation Oncology, Firenze, Italy;4. TuenMun Hospital, Hong Kong, Hong Kong;5. Greater Poland Cancer Centre, Medical Physics Department, Poznan, Poland;6. IntraOp Medical Corporation, Sunnyvale, USA;7. Schwarzwald-Baar-Klinikum, Klinik für Strahlentherapie, Villingen-Schwenningen, Germany;8. Technische Universität Ilmenau, Ilmenau, Germany;9. Universitätsklinikum Frankfurt am Main, Klinik für Strahlentherapie, Frankfurt, Germany;10. Universitätsklinikum Rostock, Klinik für Strahlentherapie, Rostock, Germany;11. Carl von Ossietzky Universität, Universitätsklinik für Medizinische Strahlenphysik, Campus Pius Hospital, Oldenburg, Germany;1. Division of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany;2. Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), 69120 Heidelberg, Germany;3. Physics Department, Oklahoma State University (OSU), Stillwater, OK 74078, USA;4. Department of Radiation Safety and Security, Paul Scherrer Institut (PSI), 5232 Villigen PSI, Switzerland |
| |
| Abstract: | PurposeIn this study a dosimetric comparison utilizing continuous data acquisition and discrete data acquisition is examined using IBA Blue Phantom (IBA Dosimetry, Schwarzenbruck, Germany) and PTW (PTW, Freiberg, Germany) MP3-M water tanks. The tanks were compared according to several factors including set up time, ease of use, and data acquisition times. A tertiary objective is to study the response of several ionization chambers in the two tanks examined.MethodsMeasurements made using a Varian 23EX LINAC (Varian Medical Systems, Palo Alto, CA) include PDDs and beam profiles for various field sizes with IBA CC13, PTW Semiflex 31010, PTW Pinpoint N31016, and PTW 31013 ion chambers for photons (6, 18 MV) and electrons (6, 9, 12, 15, and 18 MeV). Radial and transverse profile scans were done at depths of maximum dose, 5 cm, 10 cm, and 20 cm using the same set of tanks and detectors for the photon beams. Radial and transverse profile scans were done at depth of maximum dose for the electron beams on the same tanks and chambers. Data processing and analysis was performed using PTW's MEPHYSTO Navigator software and IBA's OmniPro Accept version 6.6 for the respective water tank systems.ResultsPDD values agree to within 1% and dmax to within 1 mm for the PTW MP3-M tank using PTW 31010 and Blue Phantom using IBA CC13 chamber, respectively and larger discrepancy with the PTW PinPoint N31016 chamber at 6 MV. With respect to setup time the PTW MP3-M and IBA Blue phantom tank took about 20 and 40 min, respectively. Scan times were longer by 5–15 min per field size in the PTW MP3-M tank for the square field sizes from 1 cm to 40 cm as compared to the IBA Blue phantom. However, data processing times were higher by 7 min per field size with the IBA system.ConclusionsTank measurements showed little deviation with the higher energy photons as compared to the lower energy photons with regards to the PDD measurements. Chamber construction as well as tank set up may be causing the slight deviation in data. It is important to identify the exact source of the potential errors to ensure that proper tank usage is performed when making such measurements to ensure that patient safety is in compliance. Beam profiles done with different chambers and tanks showed little to no deviation from one to another. With regards to continuous versus discrete data measurements the main difference was in the data processing technique used. Discrete data obtained required less data processing as compared to the continuous data acquired. |
| |
| Keywords: | Water tank Continuous data acquisition Discrete data acquisition Chamber comparison Dosimetry CAX"} {"#name":"keyword" "$":{"id":"kwrd0040"} "$$":[{"#name":"text" "_":"Central axis EPOM"} {"#name":"keyword" "$":{"id":"kwrd0050"} "$$":[{"#name":"text" "_":"Effective point of measurement FWHM"} {"#name":"keyword" "$":{"id":"kwrd0060"} "$$":[{"#name":"text" "_":"Full width at half maximum PDD"} {"#name":"keyword" "$":{"id":"kwrd0070"} "$$":[{"#name":"text" "_":"Percent Depth Dose QA"} {"#name":"keyword" "$":{"id":"kwrd0080"} "$$":[{"#name":"text" "_":"Quality Assurance SBRT"} {"#name":"keyword" "$":{"id":"kwrd0090"} "$$":[{"#name":"text" "_":"stereotactic body radiotherapy SSD"} {"#name":"keyword" "$":{"id":"kwrd0100"} "$$":[{"#name":"text" "_":"Source to surface distance SRS"} {"#name":"keyword" "$":{"id":"kwrd0110"} "$$":[{"#name":"text" "_":"stereotactic radiosurgery |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
