Nuclear Medicine Radiation Dosimetry

Complexities of the requirements for accurate radiation dosimetry evaluation in both diagnostic and therapeutic nuclear medicine (including PET) have grown over the past decade. This is due primarily to four factors: Growing consideration of accurate patient-specific treatment planning for radionuclide therapy as a means of improving the therapeutic benefit, development of more realistic anthropomorphic phantoms and their use in estimating radiation transport and dosimetry in patients, Design and use of advanced Monte Carlo algorithms in calculating the above-mentioned radiation transport and dosimetry which require the user to have a thorough understanding of the theoretical principles used in such algorithms, their appropriateness and their limitations, increasing regulatory scrutiny of the radiation dose burden borne by nuclear medicine patients in the clinic and in the development of new radiopharmaceuticals, thus requiring more accurate and robust dosimetry evaluations. An element common to all four factors is the need for precise radiation dosimetry in nuclear medicine, which is fundamental to the therapeutic success of a patient undergoing radionuclide therapy and to the safety of the patients undergoing diagnostic nuclear medicine and PET procedures. As the complexity of internal radiation dosimetry applied to diagnostic and therapeutic nuclear medicine increases, this book will provide the theoretical foundations for: enabling the practising nuclear medicine physicist to understand the dosimetry calculations being used and their limitations, allowing the research nuclear medicine physicist to critically examine the internal radiation dosimetry algorithms available and under development; and providing the developers of Monte Carlo codes for the transport of radiation resulting from internal radioactive sources with the only comprehensive and definitive.

Accurate radiation dosimetry is a requirement of radiation oncology, diagnostic radiology and nuclear medicine. It is necessary so as to satisfy the needs of patient safety, therapeutic and diagnostic optimisation, and retrospective epidemiological studies of the biological effects resulting from low absorbed doses of ionising radiation. The radiation absorbed dose received by the patient is the ultimate consequence of the transfer of kinetic energy through collisions between energetic charged particles and atoms of the tissue being traversed. Thus, the ability of the medical physicist to both measure and calculate accurately patient dosimetry demands a deep understanding of the physics of charged particle interactions with matter. Interestingly, the physics of charged particle energy loss has an almost exclusively theoretical basis, thus necessitating an advanced theoretical understanding of the subject in order to apply it appropriately to the clinical regime. ​ Each year, about one-third of the world's population is exposed to ionising radiation as a consequence of diagnostic or therapeutic medical practice. The optimisation of the resulting radiation absorbed dose received by the patient and the clinical outcome sought, whether diagnostic or therapeutic, demands accuracy in the evaluation of the radiation absorbed doses resulting from such exposures. This requirement arrises primarily from two broadly-encompassing factors: The requirement in radiation oncology for a 5% or less uncertainty in the calculation and measurement of absorbed dose so as to optimise the therapeutic ratio of the probabilities of tumour control and normal tissue complications; and The establishment and further refinement of dose reference levels used in diagnostic radiology and nuclear medicine to minimise the amount of absorbed dose for a required degree of diagnostic benefit. The radiation absorbed dose is the outcome of energetic charged particles decelerating and transferring their kinetic energy to tissue. The calculation of this energy deposition, characterised by the stopping power, is unique in that it is derived entirely from theoretical principles. This dominant role of the associated theory makes its understanding of fundamental to the calculation of the radiation absorbed dose to the patient. The theoretical development of charged particle energy loss recognised in medical physics textbooks is in general limited to basic derivations based upon classical theory, generally a simplified form of the Bohr theory. More advanced descriptions of, for example, the Bethe-Bloch quantum result usually do not go beyond the simple presentation of the result without full explanation of the theoretical development of the theory and consideration of its limitations, its dependencies upon the Born perturbation theory and the various correction factors needed to correct for the failures of that Born theory at higher orders. This is not appropriate for a full understanding of the theory that its importance deserves. The medical radiation physicist should be aware of the details of the theoretical derivations of charged particle energy loss in order to appreciate the levels of accuracy in tabular data provided in reports and the calculation methodologies used in modern Monte Carlo calculations of radiation dosimetry.

Written by one of the world's leading experts in the field of nuclear medicine dosimetry, this text describes in detail the use of internal dose calculations in the practice of nuclear medicine. While radiation therapy with external sources of radiation always employs calculations of dose to optimize therapy for each patient, this is not routinely conducted in nuclear medicine therapy. As the trend towards an increasing role of dosimetry in therapy planning increases, this book reviews the available methods and technologies available to make this a more common practice. The book begins by covering the mathematical fundamentals of internal dose calculations, and uses sample calculations to demonstrate key principles. The book then moves forward to describe anthropomorphic models, dosimetric models, and types and uses of diagnostic and therapeutic radiopharmaceuticals. The depth of coverage makes it useful reference and guide for researchers performing dose calculations and for physicians considering incorporating dose calculations into the treatment of their cancer patients.

Written by a leading international authority in the field, this book is ideal for physicians and residents in nuclear medicine who want to improve their knowledge in internal dosimetry. The text is a practical introduction that guides the reader through fundamental concepts in the calculation of radiation dose, including discussions of standardized models, methods of calculations, and available software applications. This comprehensive guide discusses too the biological effects of radiation on living systems. The book also includes an overview of regulatory aspects related to the radiation dosimetry of new radiopharmaceuticals.

Radiation dosimetry has made great progress in the last decade, mainly because radiation therapy is much more widely used. Since the first edition, many new developments have been made in the basic methods for dosimetry, i.e. ionization chambers, TLD, chemical dosimeters, and photographic films. Radiation Dosimetry: Instrumentation and Methods, Second Edition brings to the reader these latest developments. Written at a high level for medical physicists, engineers, and advanced dosimetrists, it concentrates only on evolvement during the last decade, relying on the first edition to provide the basics.

Over the past few decades, the radiological science community has developed and applied numerous models of the human body for radiation protection, diagnostic imaging, and nuclear medicine therapy. The Handbook of Anatomical Models for Radiation Dosimetry provides a comprehensive review of the development and application of these computational models, known as "phantoms." An ambitious and unparalleled project, this pioneering work is the result of several years of planning and preparation involving 64 authors from across the world. It brings together recommendations and information sanctioned by the International Commission on Radiological Protection (ICRP) and documents 40 years of history and the progress of those involved with cutting-edge work with Monte Carlo Codes and radiation protection dosimetry. This volume was in part spurred on by the ICRP’s key decision to adopt voxelized computational phantoms as standards for radiation protection purposes. It is an invaluable reference for those working in that area as well as those employing or developing anatomical models for a a number of clinical applications. Assembling the work of nearly all major phantom developers around the world, this volume examines: The history of the research and development in computational phantoms Detailed accounts for each of the well-known phantoms, including the MIRD-5, GSF Voxel Family Phantoms, NCAT, UF Hybrid Pediatric Phantoms, VIP-Man, and the latest ICRP Reference Phantoms Physical phantoms for experimental radiation dosimetry The smallest voxel size (0.2 mm), phantoms developed from the Chinese Visible Human Project Applications for radiation protection dosimetry involving environmental, nuclear power plant, and internal contamination exposures Medical applications, including nuclear medicine therapy, CT examinations, x-ray radiological image optimization, nuclear medicine imaging, external photon and proton treatments, and management of respiration in modern image-guided radiation treatment Patient-specific phantoms used for radiation treatment planning involving two Monte Carlo code systems: GEANT4 and EGS Future needs for research and development Related data sets are available for download on the authors’ website. The breadth and depth of this work enables readers to obtain a unique sense of the complete scientific process in computational phantom development, from the conception of an idea, to the identification of original anatomical data, to solutions of various computing problems, and finally, to the ownership and sharing of results in this groundbreaking field that holds so much promise.

A straightforward presentation of the broad concepts underlying radiological physics and radiation dosimetry for the graduate-level student. Covers photon and neutron attenuation, radiation and charged particle equilibrium, interactions of photons and charged particles with matter, radiotherapy dosimetry, as well as photographic, calorimetric, chemical, and thermoluminescence dosimetry. Includes many new derivations, such as Kramers X-ray spectrum, as well as topics that have not been thoroughly analyzed in other texts, such as broad-beam attenuation and geometrics, and the reciprocity theorem. Subjects are layed out in a logical sequence, making the topics easier for students to follow. Supplemented with numerous diagrams and tables.

Written by one of the world's leading experts in the field of nuclear medicine dosimetry, this text describes in detail the use of internal dose calculations in the practice of nuclear medicine. While radiation therapy with external sources of radiation always employs calculations of dose to optimize therapy for each patient, this is not routinely conducted in nuclear medicine therapy. As the trend towards an increasing role of dosimetry in therapy planning increases, this book reviews the available methods and technologies available to make this a more common practice. The book begins by covering the mathematical fundamentals of internal dose calculations, and uses sample calculations to demonstrate key principles. The book then moves forward to describe anthropomorphic models, dosimetric models, and types and uses of diagnostic and therapeutic radiopharmaceuticals. The depth of coverage makes it useful reference and guide for researchers performing dose calculations and for physicians considering incorporating dose calculations into the treatment of their cancer patients.