BACKGROUND Fluoroscopy is widely used in spine surgery to assist with graft and hardware placement. Previous studies have not measured radiation exposure to a surgeon during minimally invasive lateral lumbar spine surgery for single-level discectomy and interbody cage insertion. This study was performed to model and measure radiation exposure to a surgeon during spine surgery using the direct l...

In order to achive best results in radiotherapeutic treatment of tumor tissue, one needs to precisely reconstruct the setup defined in therapy planning before the treatment can start. Inaccuracies in either defining the treatment parameters or transferring positioning markers to the patient’s body, errors in treatment device setup or patient motion during the treatment result in a displacement ...

PURPOSE In this work, a novel stochastic framework for patient positioning based on linac-mounted CB projections is introduced. Based on this formulation, the most probable shifts and rotations of the patient are estimated, incorporating interfractional deformations of patient anatomy and other uncertainties associated with patient setup. METHODS The target position is assumed to be defined b...

The aim of the present study was to investigate the role of CTVision in interfractional setup errors during intensity-modulated radiation therapy (IMRT) in 12 nasopharyngeal carcinoma (NPC) patients. The trend of setup errors as a function of time during a fractionated radiotherapy course was investigated, and the influence of reconstructive thickness on image reconstruction for setup errors wa...

The purpose of this study was to evaluate electronic portal imaging (EPI) as a means of identifying and correcting field displacement in patients with problematic external beam radiotherapy setups. Fourteen patients with problematic setups were identified for pretreatment daily EPI beam monitoring as part of a physician-directed therapist intervention protocol. Pretreatment EPIs were used to re...

Background: Epidemiological studies show that computed tomography (CT) is one of the main sources of ionizing radiations. Shielding of radiosensitive organs is one of the dose reduction methods. This study aimed to assess the eye lens dose reduction and image quality resulting from the use of radio-protective bismuth shield in brain CT imaging. Methods: Bismut...