Introduction to Megavoltage X-Ray Dose Computation Algorithms

Read an exclusive interview with Dr. Jerry Battista here. A critical element of radiation treatment planning for cancer is the accurate prediction and delivery of a tailored radiation dose distribution inside the patient. Megavoltage x-ray beams are aimed at the tumour, while collateral damage to nearby healthy tissue and organs is minimized. The key to optimal treatment therefore lies in adopting a trustworthy three-dimensional (3D) dose computation algorithm, which simulates the passage of both primary and secondary radiation throughout the exposed tissue. Edited by an award-winning university educator and pioneer in the field of voxel-based radiation dose computation, this book explores the physics and mathematics that underlie algorithms encountered in contemporary radiation oncology. It is an invaluable reference for clinical physicists who commission, develop, or test treatment planning software. This book also covers a core topic in the syllabus for educating graduate students and residents entering the field of clinical physics. This book starts with a historical perspective gradually building up to the three most important algorithms used for today's clinical applications. These algorithms can solve the same general radiation transport problem from three vantages: firstly, applying convolution-superposition principles (i.e. Green's method); secondly, the stochastic simulation of radiation particle interactions with tissue atoms (i.e. the Monte Carlo method); and thirdly, the deterministic solution of the fundamental equations for radiation fields of x-rays and their secondary particles (i.e. the Boltzmann method). It contains clear, original illustrations of key concepts and quantities thoughout, supplemented by metaphors and analogies to facilitate comprehension and retention of knowledge. Features: Edited by an authority in the field, enhanced with chapter contributions from physicists with clinical experience in the fields of computational dosimetry and dose optimization Contains examples of test phantom results and clinical cases, illustrating pitfalls to avoid in clinical applications to radiation oncology Introduces four-dimensional (4D) dose computation, on-line dose reconstruction, and dose accumulation that accounts for tissue displacements and motion throughout a course of radiation therapy

Review: "This book introduces fundamental physics of x-ray interaction with human tissue and dose deposition and then delves into comprehensive description of the three generations of dose computation algorithms through the evolution of computational hardware power...This is designed as a handbook and teaching resource to fill in the details of the physics and mathematical infrastructure that are not covered in the published literature or vendor software manuals. The author and contributors tried to make each chapter as complete and self-contained as possible, minimizing the need for cross referencing. The book dives into details of the underlying theory, providing definitions and necessary information for readers to gain a deeper understanding of complex algorithms, including their limitations and practical considerations. The author has succeeded in putting together a comprehensive description of megavoltage dose calculations in a book that both medical physics students and experienced clinical medical physicists will find useful...The book is intended primarily for graduate students and residents in clinical medical physics who seek a solid understanding of megavoltage dose calculation algorithms. It also can be used for a graduate course in radiological physics and as a reference for clinical physicists who need to fill in details not in the published literature. The well-organized chapters cover basic concepts in clinical radiation dosimetry and review fundamental high-energy photon interactions and energy deposition. The chapter that provides a conceptual overview of dose calculation algorithms has a logical and well-thought-out layout that makes it a must read for all medical physics students. Each chapter on the different classes of dose calculation algorithms starts with the necessary mathematical framework and physical concepts that students will find helpful. From there, it systematically covers and builds up thorough descriptions of the algorithm and concludes with concise summaries of each method. There are multiple clinical examples and references to commercial software that readers can relate to. This book brings together and explains in detail modern megavoltage dose calculation algorithms that are scattered across multiple publications and briefly described in vendor manuals. There is no other comparable book that covers these topics in such a self-contained manner. I highly recommend this book to all graduate students in radiological physics as well as clinical medical physicists who seek a better understanding of the dose calculation algorithms used commercially. Overall score: 4 Stars!" - Boon-Keng Kevin Teo, PhD, University of Pennsylvania School of Medicine in Doody's Book Review, September 2019

Author Biography: Dr. Jerry Battista completed his Ph.D. degree at the University of Toronto in 1977 (Compton Tomography). As a post-doctoral resident in medical physics he then gained clinical physics experience at the Princess Margaret Hospital, under the guidance of Dr."Jack" Cunningham - a pioneer in computerized dose calculations. Jerry moved to the Cross Cancer Institute and University of Alberta in 1979. His team developed one of the first "3D" treatment planning systems and introduced a new breed of `convolution/superposition' algorithms used for planning radiotherapy of cancer patients. Current research interests include 3D dose measurements in gels using optical CT scans, and adaptive dose re-optimization for image-guided radiotherapy. He has published over 120 peer-reviewed articles. Jerry is a Fellow of the Canadian College of Physicists in Medicine (FCCPM), Canadian Organization of Medical Physics (FCOMP) and American Association of Physicists in Medicine (FAAPM). Since 1988, Dr. Battista has been driving Physics Research at the London Regional Cancer Program, in London, Ontario, Canada. He is Professor of Medical Biophysics at Western University, with cross-appointments to the Departments of Oncology, Physics, Diagnostic Imaging and Nuclear Medicine, and the Biomedical Engineering Program. Jerry is an award-winning teacher and he is nationally known for his clear presentations. His enthusiastic style and vivid analogies bring physics concepts to a wide range of audiences with diverse backgrounds, including clinicians, students, and the general public. He has received the university's top honour for teaching excellence. Dr. Battista has mentored many graduate students, who collectively have received over 20 awards from Canadian, and international, organizations, for excellence in publications or presentations. Jerry was the recipient of the 2017 Gold Medal Award from the Canadian Organization of Medical Physicists (COMP).

Chapter 1: Introduction to 3D Megavoltage X-Ray Dose Computations Chapter 2: X-ray Interactions and Energy Deposition Chapter 3: Conceptual Overview of Algorithms Chapter 4: Convolution and Superposition Methods Chapter 5: Stochastic Radiation Transport Method Chapter 6: Deterministic Radiation Transport Methods Chapter 7: En Route to 4D Dose Computations