EGSnrc Monte Carlo-aided dosimetric studies of the new BEBIG (60)Co HDR brachytherapy source.

Purpose: The purpose of this study is to obtain the dosimetric parameters of the new BEBIG (60)Co brachytherapy source following by TG-43U1 recommendation with appropriate electron cutoff energy (0.521 MeV).

Material And Methods: The new BEBIG (60)Co brachytherapy source is used to calculate the TG-43U1 parameters.

Dosimetric verification of source strength for HDR afterloading units with Ir-192 and Co-60 photon sources: Comparison of three different international protocols.

Before clinical use of a brachytherapy source, regulations or recommendations by medical physics societies require an independent measurement of its air kerma strength by a qualified medical physicist. Currently, in addition to Ir-192, also HDR-Co-60 sources are increasingly coming into operation. However, the existing dosimetry protocols do not provide any guidelines for Co-60 sources.

[Dosimetry of HDR afterloading machines with Ir-192- und Co-60-sources: comparison of different international protocols].

The air kerma rate in air at a reference distance of 1 meter from the source is the recommended quantity for the specification of gamma ray source in brachytherapy. The absorbed dose for the patients is directly proportional to the air kerma rate. Therefore the air kerma rate should be determined before the first use of the source on patients by a medical physicist who is independent from the source manufacturer.

Experimental determination of the effective point of measurement of cylindrical ionization chambers for high-energy photon and electron beams.

Measurements of depth-dose curves in water phantom using a cylindrical ionization chamber require that its effective point of measurement is located at the measuring depth. Recommendations for the position of the effective point of measurement with respect to the central axis valid for high-energy electron and photon beams are given in dosimetry protocols. According to these protocols, the use of a constant shift P(eff) is currently recommended.

Determination of absorbed dose to water for high-energy photon and electron beams-comparison of the standards DIN 6800-2 (1997), IAEA TRS 398 (2000) and DIN 6800-2 (2006).

For the determination of the absorbed dose to water for high-energy photon and electron beams the IAEA code of practice TRS-398 (2000) is applied internationally. In Germany, the German dosimetry protocol DIN 6800-2 (1997) is used. Recently, the DIN standard has been revised and published as Draft National Standard DIN 6800-2 (2006).

[Determination of absorbed dose to water for high energy photon and electron beams--comparison of different dosimetry protocols].

The determination of absorbed dose to water for high-energy photon and electron beams is performed in Germany according to the dosimetry protocol DIN 6800-2 (1997). At an international level, the main protocols used are the AAPM dosimetry protocol TG-51 (1999) and the IAEA Code of Practice TRS-398 (2000). The present paper systematically compares these three dosimetry protocols, and identifies similarities and differences.

[Dose distribution of asymmetric fields: comparison of the Helax-TMS with our developed 2D-program ASYMM].

The purpose of this investigation was to compare the commercial 3D-treatment planning system Helax TMS to a simple 2D program ASYMM, concerning the calculation of dose distributions for asymmetric fields. The dose calculation algorithm in Helax-TMS is based on the polyenergetic pencil beam model of Ahnesjö. Our own developed 2D treatment planning program ASYMM, based on the Thomas and Thomas method for asymmetric open fields, has been extended to calculate the dose distributions for open and wedged fields.