The influence of basic plan parameters on calculated small field output factors - A multicenter study.

Purpose: The influence of basic plan parameters such as slice thickness, grid resolution, algorithm type and field size on calculated small field output factors (OFs) was evaluated in a multicentric study.

Methods And Materials: Three computational homogeneous water phantoms with slice thicknesses (ST) 1, 2 and 3 mm were shared among twenty-one centers to calculate OFs for 1x1, 2x2 and 3x3 cm field sizes (FSs) (normalized to 10x10 cm FS), with their own treatment planning system (TPS) and the energy clinically used for stereotactic body radiation therapy delivery. OFs were calculated for each combination of grid resolution (GR) (1, 2 and 3 mm) and ST and finally compared with the OFs measured for the TPS commissioning.

IOERT versus external beam electrons for boost radiotherapy in stage I/II breast cancer: 10-year results of a phase III randomized study.

Background: Intraoperative radiotherapy with electrons (IOERT) boost could be not inferior to external beam radiotherapy (EBRT) boost in terms of local control and tissue tolerance. The aim of the study is to present the long-term follow-up results on local control, esthetic evaluation, and toxicity of a prospective study on early-stage breast cancer patients treated with breast-conserving surgery with an IOERT boost of 10 Gy (experimental group) versus 5 × 2 Gy EBRT boost (standard arm). Both arms received whole-breast irradiation (WBI) with 50 Gy (2 Gy single dose).

Dose calculation accuracy in proximity of a pacemaker: A multicenter study with threecommercial treatment planning systems.

This study compares Treatment Planning System (TPS) out of field dose calculation on a pacemaker (PMK) during external beam radiotherapy treatment. We consider four TPSs (Elekta-Monaco, Oncentra- Masterplan and two Philips-Pinnacle3) commissioned for two linacs (Elekta Sinergy and Varian Clinac) delivering two test beams (a highly modulated one and a square field) and two clinical breast plans. To calculate and measure dose to a PMK we built a Real Water3 phantom with a PMK embedded in it.

Lung stereotactic ablative body radiotherapy: A large scale multi-institutional planning comparison for interpreting results of multi-institutional studies.

Purpose: A large-scale multi-institutional planning comparison on lung cancer SABR is presented with the aim of investigating possible criticism in carrying out retrospective multicentre data analysis from a dosimetric perspective.

Methods: Five CT series were sent to the participants. The dose prescription to PTV was 54Gy in 3 fractions of 18Gy.

A feasibility dosimetric study on prostate cancer : are we ready for a multicenter clinical trial on SBRT?

Purpose: The Italian Association of Medical Physics (AIFM) started a working group dedicated to stereotactic body radiotherapy (SBRT) treatment. In this work, we performed a multicenter planning study on patients who were candidates for SBRT in the treatment of prostate cancer with the aim of evaluating the dosimetric consistency among the different hospitals.

Methods And Materials: Fourteen centers were provided the contours of 5 patients.

In vivo dosimetry with MOSFETs: dosimetric characterization and first clinical results in intraoperative radiotherapy.

Purpose: To investigate the use of metal oxide silicon field effect transistors (MOSFETs) as in vivo dosimetry detectors during electron beams at high dose-per-pulse intraoperative radiotherapy.

Methods And Materials: The MOSFET system response in terms of reproducibility, energy, dose rate and temperature dependence, dose-linearity from 1 to 25 Gy, angular response, and dose perturbation was analyzed in the 6-9-MeV electron beam energy range produced by an intraoperative radiotherapy-dedicated mobile accelerator. We compared these with the 6- and 9-MeV electron beams produced by a conventional accelerator.