Über das Auflösungsvermögen und die Empfindlichkeit eines zweidimensionalen Ionisationskammer-Arrays (PTW: Typ 10024)

Poppe, Björn; Atung, Zanzem; Chofor, George; Blechschmidt, Arne; Djouguela, Armand; Kollhoff, Ralf; Rubach, A; Harder, Dietrich

doi:10.1078/0939-3889-00261

Cited by 5 publications

(3 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The comparable device 2D ARRAY described by Poppe et al (2005Poppe et al ( , 2006 consists of 27 × 27 chambers with a centre-to-centre distance of 1 cm that allows a simple association of the leaves of a standard MLC only in the isocentre. This fact complicates the use of the detector for quality assurance of dynamic radiation techniques.…”

Section: Discussionmentioning

confidence: 99%

“…The lateral response of a single chamber can be characterized by the line-spread function (LSF). This LSF can be determined using a narrow slit shifted stepwise over the device (Poppe et al describe an analogue procedure in Poppe et al (2006Poppe et al ( , 2005 for a similar device (PTW, Freiburg, Germany)). Figure 1 shows the set-up for this measurement: the slit was generated by tungsten blocks of 1 × 10 × 10 cm 3 placed on a thin plate of solid water in the central beam in order to use the almost parallel beam for the measurement.…”

Section: Lateral Response Function and Spatial Resolution Of A Single...mentioning

confidence: 99%

See 1 more Smart Citation

Dosimetric evaluation of a 2D pixel ionization chamber for implementation in clinical routine

et al. 2007

View full text Add to dashboard Cite

In this paper we present the results of a dosimetric evaluation of a 2D ionization chamber array with the objective of its implementation for quality assurance in clinical routine. The pixel ionization chamber MatriXX (Scanditronix Wellhofer, Germany) consists of 32x32 chambers with a distance of 7.6 mm between chamber centres. The effective depth of measurement under the surface of the detector was determined. The dose and energy dependence, the behaviour of the device during its initial phase and its time stability as well as the lateral response of a single chamber of the detector in cross-plane and diagonal directions were analysed. It could be shown, that the detector's response is linear with dose and energy independent. Taking the lateral response into account, two different dose profiles, for a pyramidal and an IMRT dose distribution, were applied to compare the data generated by a treatment planning system with measurements. From these investigations it can be concluded that the detector is a suitable device for quality assurance and 2D dose verifications.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Lateral Response Function and Spatial Resolution Of A Single...mentioning

confidence: 99%

Dosimetric evaluation of a 2D pixel ionization chamber for implementation in clinical routine

et al. 2007

View full text Add to dashboard Cite

show abstract

“…Since certain measurement tasks, such as acquiring percent depth‐dose curves or the localization scan at the beginning of a CT examination, are done with a stationary X‐ray tube, these detectors can still be used. General physical properties of the 2D‐Array seven29 have been investigated and described by Poppe et al 29 , 30 , 31 …”

Section: Methodsmentioning

confidence: 99%

Computed tomography dosimetry with high‐resolution detectors commonly used in radiotherapy — an energy dependence study

Liebmann

Poppe

Boetticher

2015

J Applied Clin Med Phys

View full text Add to dashboard Cite

New methods of dosimetry in computed tomography (CT) X‐ray fields require the use of high‐resolution detectors instead of pencil‐type ionization chambers typically used for CT dose index (CTDI) measurements. This paper presents a study on the suitability of a wide range of ionization chambers, diodes, and a two‐dimensional detector array, used primarily in radiation therapy, for CT and cone‐beam CT dosimetry. Specifically, the energy dependence of these detectors from 50 kVp up to 125 kVp is reported. All measurements were performed in reference to a calibrated diode for use in this energy region. The radiation quality correction factors provided by the manufacturer were used, depending on the measured half‐value layer (HVL) for the particular X‐ray beam. Our study demonstrated the general usability of thimble ionization chambers. These thimble ionization chambers showed a maximum variation in energy response of 5%. Ionization chambers with even smaller sensitive volume, and which exhibit similar variation in energy dependence, can be used if higher spatial resolution is required. Furthermore, the investigated detectors are better suited for dosimetry at CT and CBCT units than conventional large volume or flat detectors, due to their rotational symmetry. Nevertheless, a flat detector can be used for certain measurement tasks, such as the acquisition of percent depth‐dose curves or beam profiles for nonrotating beams, which are important for beam characterization.PACS numbers: 87.57.uq, 87.56.Da, 87.57.Q‐

show abstract

Impact of a monolithic silicon detector operating in transmission mode on clinical photon beams

et al. 2017

View full text Add to dashboard Cite

show abstract

Über das Auflösungsvermögen und die Empfindlichkeit eines zweidimensionalen Ionisationskammer-Arrays (PTW: Typ 10024)

Cited by 5 publications

References 7 publications

Dosimetric evaluation of a 2D pixel ionization chamber for implementation in clinical routine

Dosimetric evaluation of a 2D pixel ionization chamber for implementation in clinical routine

Computed tomography dosimetry with high‐resolution detectors commonly used in radiotherapy — an energy dependence study

Impact of a monolithic silicon detector operating in transmission mode on clinical photon beams

Contact Info

Product

Resources

About