Commissioning of a Versa HD linear accelerator for three commercial treatment planning systems.

In a mixed-vendor radiation oncology environment, it is advantageous if the department's treatment planning system (TPS) supports the linear accelerators of different vendors. In this publication beam data collection and modeling for the Versa HD linear accelerator in Monaco, Pinnacle, and Eclipse are discussed. In each TPS static field, Intensity-Modulated Radiation Therapy (IMRT) step and shoot, and Volumetric-Modulated Arc Therapy (VMAT) plans for flattened and flattening-filter free photon beams of all available energies were evaluated for field sizes >3 × 3.

Clinical radiation therapy measurements with a new commercial synthetic single crystal diamond detector.

A commercial version of a synthetic single crystal diamond detector (SCDD) in a Schottky diode configuration was recently released as the new type 60019 microDiamond detector (PTW-Freiburg, Germany). In this study we investigate the dosimetric properties of this detector to independently confirm that findings from the developing group of the SCDDs still hold true for the commercial version of the SCDDs. We further explore if the use of the microDiamond detector can be expanded to high-energy photon beams of up to 15 MV and to large field measure- ments.

Circumferential or sectored beam arrangements for stereotactic body radiation therapy (SBRT) of primary lung tumors: effect on target and normal-structure dose-volume metrics.

To compare 2 beam arrangements, sectored (beam entry over ipsilateral hemithorax) vs circumferential (beam entry over both ipsilateral and contralateral lungs), for static-gantry intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) delivery techniques with respect to target and organs-at-risk (OAR) dose-volume metrics, as well as treatment delivery efficiency. Data from 60 consecutive patients treated using stereotactic body radiation therapy (SBRT) for primary non-small-cell lung cancer (NSCLC) formed the basis of this study. Four treatment plans were generated per data set: IMRT/VMAT plans using sectored (-s) and circumferential (-c) configurations.

Monte Carlo dose calculations in the treatment of a pelvis with implant and comparison with pencil-beam calculations.

In the present paper, dose distribution calculated with the Monte Carlo code EGS4 and with a pencil-beam algorithm are compared for the treatment of a pelvis with an implant. Overestimations of dose values inside the target volume by the pencil-beam algorithm of up to 10% were found, which are attributed to the underestimation of the absorption of photons by the implant. The differences in dose distributions are also expressed by comparing the tumor control probability (TCP) of the Monte Carlo dose calculations with the TCP of the pencil-beam calculations.

The volume effect of detectors in the dosimetry of small fields used in IMRT.

In this study we investigate the effect of detector size in the dosimetry of small fields and steep dose gradients with a particular emphasis on IMRT measurements. Comparisons of calculated and measured cross-profiles and absolute dose values of IMRT treatment plans are presented. As a consequence of the finite size of the detector that was used for the commissioning of the IMRT tool, local discrepancies of more than 10% are found between calculated cross-profiles of intensity modulated beams and intensity modulated profiles measured with film.

Comparison of TG-43 dose calculations to pinpoint ion chamber and diamond detector measurements.

Brachytherapy is an area of radiation therapy where the availability of high-resolution detectors with a low energy-dependence is of great importance. The suitability of two detectors is investigated in this study. Measurements in the proximity of an Ir-192 source were performed with a diamond detector type 60003 and a pinpoint chamber type 31006 (both PTW-Freiburg).