Introduction: The present study aimed to generate intensity-modulated beams with Aluminium compensating filters for a conventional telecobalt machine based on the outputs of a treatment planning system (TPS) performing forward planning and cannot simulate directly the compensating filter. Materials and Methods: In order to achieve the beam intensity modulation during treatment planning with th...

BACKGROUND Treatments for cancer spinal metastasis were always palliative. This study was conducted to investigate the safety and effectiveness of IG-IMRT for these patients. METHODS 10 metastatic lesions were treated with conventionally-fractionated IG-IMRT. Daily kilovoltage cone-beam computed tomography (kV-CBCT) scan was applied to ensure accurate positioning. Plans were evaluated by the ...

Introduction: During radiotherapy, high accuracy in the dose delivery is required because there is a strong  relationship between the absorbed dose, local tumor control and particularly the normal tissue damage. In  many institutions, in vivo dosimetry using diodes is performed to check the actual dose delivered. In general,  the uncertainty in the dose delivered should fall within  ± 5% of the...

Helical Tomotherapy (HT) has become increasingly popular over the past few years. However, its clinical efficacy and effectiveness continues to be investigated. Pre-treatment patient repositioning in highly conformal image-guided radiation therapy modalities is a prerequisite for reducing setup uncertainties. A MVCT image set has to be acquired to account for daily changes in the patient's inte...

PROSTATE INTRAFRACTION MOTION ASSESSED BY SIMULTANEOUS KV FLUOROSCOPY AT MV DELIVERY by JUSTUS D. ADAMSON August 2009 Co-Advisor: Dr. Qiuwen Wu Co-Advisor: Dr. Jay Burmeister Major: Medical Physics Degree: Doctor of Philosophy Purpose: To investigate the use of a gantry mounted kV imager for prostate intrafraction motion measurement during simultaneous dose delivery. Materials & Methods: We dev...

OBJECTIVES This study analyzed the long-term hearing loss after treatment of primary nasopharyngeal carcinoma to elucidate its causal factors. METHODS Ninety-two nasopharyngeal carcinoma patients were treated with radiotherapy or chemoradiotherapy. Pure tone audiometry was performed before the therapy and annually up to 9 years after completing treatment. The hearing thresholds were corrected...

Background: In intensity modulated radiation therapy, cone beam computed tomography (CT) has been used to evaluate patients prior to treatment. This study conducted a comparative evaluation of the image reconstruction ability of the clinically used half-fan bowtie filter and the full-fan bowtie filter. Materals and Methods: A CT simulation marker was inserted inside a human phantom, and the pel...

This study demonstrates the degradation in image quality, and subsequent dose evaluation inaccuracies, that are encountered when an optical-CT system reconstructs an image slice of a gel dosimeter containing an opaque implant, and evaluates the feasibility of a simple correction method to improve the accuracy of radiotherapy dose distribution measurements under these circumstances. MATLAB was u...