Purpose: To develop a beam-angle optimization method for non-coplanar VMAT (NC-VMAT) with table-angle and gantry-angle range determined by iterative beam elimination based on 4-π fluence map optimization (FMO).
Methods: FMO is carried out for beam directions covering the 4-π space around the PTV every 10° gantry-angle and 10° table-angle. A gantry-table contribution map is generated from...
Purpose: According to Article 36 of the Radiological Protection Ordinance, medical physicists must be involved in fluoroscopy in the medium- and high-dose range (i.e. examinations resulting in effective doses for the patients > 1 mSv). While the involvement has become well established in hospitals and radiological institutes, the situation in medical practices operating a fluoroscopy...
Purpose
Imaging procedures are indispensable for diagnostics and patient treatment, but they also involve health risks due to the use of ionising radiation. Therefore, the FOPH monitors the radiation exposure of the Swiss population. The frequency of diagnostic examinations performed is recorded and the mean effective dose is estimated. This monitoring helps to recognize emerging changes and...
Purpose:
The aim of this study is to propose Diagnostic Reference Levels (DRLs) values for Mammography in Switzerland.
Methods:
The data was obtained by means of a survey. A total of 31 centres including 5 University hospitals, several cantonal hospitals, and large private clinics, globally covering all linguistic regions of Switzerland participated in the data collection. The data...
Purpose:
Retinoblastoma is a rare eye tumor that develops in children up to 4 years old. Intra-arterial chemotherapy (IAC) is an emerging treatment modality that is gaining recognition worldwide. IAC requires fluoroscopy assistance, which involves multiple irradiations. As consequence, children undergoing IAC can sustain damage to eye lens such as cataracts and radiation induced cancer.
The...
Purpose: Using the photon multileaf collimator (MLC) instead of the electron applicator is a promising solution to improve clinical workflow and enable intensity modulation for electron radiotherapy. Currently, an inefficient manual process is performed to commission beam models for MLC shaped electron beams. The aim of this work is to develop an auto-commissioning procedure for a Monte Carlo...
Purpose: Treatment plans with photon beams typically rely on photon multi-leaf collimators (pMLC) in clinical routine which enable techniques such as volumetric modulated arc therapy (VMAT). Intensity and energy modulated electron beams are facilitated by the usage of pMLCs instead of cut-outs in so-called electron modulated arc therapy (EMAT) and modulated electron radiotherapy (MERT). In...
Aims: Optimally combined proton-photon therapy (CPPT) delivered with a fixed horizontal proton beamline (FHB) and a photon linac showed to be a promising option to increase access to proton therapy for head and neck (HN), breast and lung cancer (Fabiano 2020, Marc 2022, Amstutz 2022). Here, the investigation for HN cancer extends to explore the dependence of CPPT on the flexibility of...
Purpose:
The use of motion mitigation techniques such as breath-hold can reduce the dosimetric uncertainty of lung cancer proton therapy. We studied the feasibility of hypofractionated pencil beam scanning (PBS) proton therapy field delivery within a single breath-hold at PSI’s Gantry 2. Treatment delivery time in PBS proton therapy depends on beam-on time and the dead time between proton...
