Impact of magnetic fields on dose measurement with small ion chambers illustrated in high-resolution response maps.

Purpose: Dosimetry of ionizing radiation in the presence of strong magnetic fields is gaining increased relevance in light of advances for MRI-guided radiation therapy. While the impact of strong magnetic fields on the overall response of ionization chambers has been simulated and measured before, this work investigates the local impact of the magnetic field on dose response in an ion chamber. High-resolution 1D and 2D response maps have been created for two small clinical thimble ionization chambers, the PinPoint chambers 31006 and 31014 (Physikalisch Technische Werkstaetten Freiburg, Germany).

Comparative toxicity of synchrotron and conventional radiation therapy based on total and partial body irradiation in a murine model.

Synchrotron radiation can facilitate novel radiation therapy modalities such as microbeam radiation therapy (MRT) and high dose-rate synchrotron broad-beam radiation therapy (SBBR). Both of these modalities have unique physical properties that could be exploited for an improved therapeutic effect. While pre-clinical studies report promising normal tissue sparing phenomena, systematic toxicity data are still required.

Establishing IAEA TRS-457 diagnostic X-ray beam qualities at the Australian primary standard dosimetry laboratory.

This paper reports the process and findings in establishing the diagnostic beam qualities for the calibration of diagnostic dose meters in the Australian primary standard dosimetry laboratory at the Australian Radiation Protection and Nuclear Safety Agency, ARPANSA. A novel iterative method to achieve the RQR beam quality requirements described by IEC 61267 is presented. The correction factors for the primary standard free-air chamber and their uncertainties are reported.

Commissioning of a PTW 34070 large-area plane-parallel ionization chamber for small field megavoltage photon dosimetry.

Purpose: This study investigates a large-area plane-parallel ionization chamber (LAC) for measurements of dose-area product in water (DAP ) in megavoltage (MV) photon fields.

Methods: Uniformity of electrode separation of the LAC (PTW34070 Bragg Peak Chamber, sensitive volume diameter: 8.16 cm) was measured using high-resolution microCT.