Impact of systematic MLC positional uncertainties on the quality of single-isocenter multi-target VMAT-SRS treatment plans.

Purpose: To study the impact of systematic MLC leaf positional uncertainties (stemming from mechanical inaccuracies or sub-optimal MLC modeling) on the quality of intracranial single-isocenter multi-target VMAT-SRS treatment plans. An estimation of appropriate tolerance levels is attempted.

Methods: Five patients, with three to four metastases and at least one target lying in close proximity to organs-at-risk (OARs) were included in this study.

Evaluation of organ and effective doses during paediatric barium meal examinations using PCXMC 2.0 Monte Carlo code.

Radiation protection and estimation of the radiological risk in paediatric radiology is essential due to children's significant radiosensitivity and their greater overall health risk. The purpose of this study was to estimate the organ and effective doses of paediatric patients undergoing barium meal (BM) examinations and also to evaluate the assessment of radiation Risk of Exposure Induced cancer Death (REID) to paediatric patients undergoing BM examinations. During the BM studies, fluoroscopy and multiple radiographs are involved.

Using four-dimensional computed tomography images to optimize the internal target volume when using volume-modulated arc therapy to treat moving targets.

In this work we used 4D dose calculations, which include the effects of shape deformations, to investigate an alternative approach to creating the ITV. We hypothesized that instead of needing images from all the breathing phases in the 4D CT dataset to create the outer envelope used for treatment planning, it is possible to exclude images from the phases closest to the inhale phase. We used 4D CT images from 10 patients with lung cancer.

Dosimetry using Gafchromic XR-RV2 radiochromic films in interventional radiology.

Patient dose measurements of local entrance dose to the skin have been carried out using radiochromic film (Gafchromic XR-RV2) in a sample of interventional procedures. The major aim of the work was to measure patient entrance dose from such examinations using Gafchromic XR-RV2. Forty-five various interventional procedures (including nefrostomies and urinary stenting, biliary stenting and percutaneous transhepatic biliary drainage (PTBD) and aorta stent grafting) were evaluated.

Estimation of children's radiation dose from cardiac catheterisations, performed for the diagnosis or the treatment of a congenital heart disease using TLD dosimetry and Monte Carlo simulation.

Entrance surface radiation doses were measured with thermoluminescent dosimeters for 98 children who were referred to a cardiology department for the diagnosis or the treatment of a congenital heart disease. Additionally, all the radiographic parameters were recorded and Monte Carlo simulations were performed for the estimation of entrance surface dose to effective dose conversion factors, in order to further calculate the effective dose for each child. For diagnostic catheterisations the values ranged from 0.