PURPOSE To introduce the concept of energy minimization-based inverse optimization for external beam radiotherapy. MATERIALS AND METHODS Mathematical formulation of energy minimization-based inverse optimization is presented. This mathematical representation is compared to the most commonly used dose-volume based formulation used in inverse optimization. A simple example on digitally created ...

Abstract Introduction: Thanks to modern IGRT procedures, it is possible track changes in the patient's anatomy and thus calculate dose distribution for current anatomical conditions of patient. This allows scheduled be compared with delivered dose. In case large discrepancies, improve treatment plan. Radiotherapy, during which plan modified, resulting from anatomy, referred as adaptive radiothe...

Background: Presence of artifacts, caused by dental filling high-Z materials (DFM), on intensity-modulated radiation therapy (IMRT) treatment plan CT images may lead to uncertainty in head and neck calculated dose distributions. Hence, the purpose of this study was to investigate the effects of DFM on the IMRT calculated dose distribution and consequent radiobiological derived outcomes for naso...

*Correspondence: Jeffrey Cassidy, Edward S. Rogers Sr., Department of Electrical and Computer Engineering, University of Toronto, 10 King’s College Road, Toronto, ON M5S 3G4, Canada e-mail: jeffrey.cassidy@ mail.utoronto.ca Monte Carlo (MC) simulation is recognized as the “gold standard” for biophotonic simulation, capturing all relevant physics and material properties at the perceived cost of ...

Introduction: Hypothyroidism is one of the frequent side effects of radiotherapy of head and neck cancers, breast cancer, and Hodgkin's lymphoma. It is recommended to estimate the normal tissue complication probability of thyroid gland using radiobiological modeling during treatment planning. Moreover, the use of artificial neural network is also proposed as a new method for t...

Introduction: The purpose of this study was to develop a statistical model for prediction of radiation induced sensorineural hearing loss (SNHL) induced by radiotherapy in patients with brain tumors.   Materials and Methods: CT scan of 18 patients (10 males and 8 females) with brain tumor who were referred to Radiation Center of Milad Hospital in Isfahan in 2...

background: to determine which radiotherapy parameters are associated with the tumor response of locally advanced non-small cell lung cancer (nsclc) patients undergoing concurrent chemoradiotherapy. materials and methods: thirty one patients with iiia/iiib nsclc underwent chemoradiotherapy with a median dose of 63 gy. on our actual treatments, we made radiotherapy planning to cover the planning...

INTRODUCTION The gamma analysis used for quality assurance of a complex radiotherapy plan examines the dosimetric equivalence between planned and measured dose distributions within some tolerance. This study explores whether the dosimetric difference is correlated with any radiobiological difference between delivered and planned dose. METHODS VMAT or IMRT plans optimized for 14 cancer patient...

Objective To describe the quantitative image quality and histogram-based evaluation of an iterative reconstruction (IR) algorithm in chest computed tomography (CT) scans at low-to-ultralow CT radiation dose levels. Materials and Methods In an adult anthropomorphic phantom, chest CT scans were performed with 128-section dual-source CT at 70, 80, 100, 120, and 140 kVp, and the reference (3.4 mG...