|Year : 2019 | Volume
| Issue : 2 | Page : 139-141
Clinical three-dimensional dosimetry in modern radiation therapy
Department of Radiation Oncology, Manipal Hospitals Dwarka, New Delhi, India
|Date of Web Publication||11-Jun-2019|
Dr. Tharmarnadar Ganesh
Basement 3rd Floor, Manipal Hospitals Dwarka, Secor-6, Dwarka, New Delhi - 110 075
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Ganesh T. Clinical three-dimensional dosimetry in modern radiation therapy. J Med Phys 2019;44:139-41
Editor: Prof. Ben Mijnheer
Title: Clinical 3D Dosimetry in Modern Radiation Therapy
Series: Imaging in Medical Diagnosis and Therapy
Series Editors: Andrew Karellas and Bruce R. Thomadsen
Published: CRC Press, Taylor and Francis Group, London and New York
Pages: Hardback, 673 pages, 46 Color and 100 black/white illustrations
Price: US $260
ISBN No: 13: 978-1-4822-5221-7
CRC Press, Taylor and Francis Group, has brought out another great book in its series on Imaging in Medical Diagnosis and Therapy. The book has been edited by Prof. Ben Mijnheer of Netherlands Cancer Institute, Amsterdam, The Netherlands, a name that is familiar to everyone in the radiation oncology field for decades.
As mentioned by the Founding Series Editor Prof. William R. Hendee, the responsibilities for the medical physicists in the clinical arenas of medical imaging and radiotherapy (RT) are growing continuously. Toward this end, this particular series has been consistently providing support to all of us in the profession in the form of several useful titles. The current book turns out to be an exceptionally good one.
The rapid growth in new RT techniques and their clinical applications has expanded the practice of dosimetry with the focus on precision and accuracy. The series of three-dimensional (3D) measurements that we make, the instruments that we use, and their applications in clinics that we come across are vast and wide. This book addresses the needs of all medical physicists not only those who are working in clinics but also those who are engaged in teaching and research by providing one comprehensive reference resource on the subject, and I am sure no one referring to this book will go disappointed in not finding the information what he/she wanted.
The book has been thoughtfully arranged into five sections, Introduction, Instrumentation, Measurements, Applications, and Emerging Trends, making it easy for the reader to zero in on the subject of interest.
The Introduction section starts with a clear description on what each section covers and what the reader can look for in each chapter. Predictably, Chapter 2 covers the need for accuracy in RT and what can realistically be achieved in a clinical environment along with an extensive coverage on the clinical uncertainties associated with modern dose-delivery technologies. The next chapter is on detectors for reference dosimetry – a short one, yet a useful one. Readers will find it helpful in clearing several practical doubts related to absolute dose measurements under reference conditions, including those for flattening filter-free beams. The following chapter discusses about the requirements of ideal detector, and the detectors used in RT, specific requirements forin vivo dosimetry, and a multitude ofin vivo measurements. The fast emerging polymer gel dosimetry is covered extensively in Chapter 5. From dosimetry principles of gel dosimeters, to different options for imaging, clinical applications, and its uncertainties – everything is elaborately covered. Readers interested in gel dosimetry would find this chapter extremely useful with multiple color palettes that make it easy to comprehend. It concludes with useful guidelines for setting up a 3D gel dosimetric measurement. The next chapter is on another true 3D detector – radiochromic 3D detectors. It covers other methods of 3D dosimetry, including Fricke gel, radiochromic plastics, and their clinical applications. Chapters 7 and 8 cover electronic portal image device, and a variety of 2D and semi 3D dosimetry systems that are used by every clinical physicist in day-to-day practice such as film, different types of arrays (ion chamber and solid state), and novel dosimetry systems. There is a nice discussion on quality assurance (QA) check on these systems and the treatment planning considerations in using them. Physicists engaged in patient-specific QA programs would find these chapters handy.
The third section of the book deals with chapters on measurement and computation. It starts with a chapter on small field dosimetry, presented in a logical manner. It guides the readers through all the intricacies related to small field dosimetry, including step-by-step practical guidelines on how-to-perform small-field dosimetry in a clinic. Many readers would find this chapter practically relevant and useful. Modern-day delivery systems are much more sophisticated, offering several unique ways/features of treatment delivery. Chapter 10 covers all these new delivery systems such as Gamma Knife, CyberKnife, Tomotherapy, intraoperative RT, multiple-image guidance technologies, and motion management in detail. The next chapter deals with 4D dosimetry – the need for it, how is it done, applications, and challenges associated with the technique. There is a chapter on light ion-beam dosimetry that deals with the special requirements of particulate dosimetry and special detectors used for the purpose. Following that, a brief chapter on Monte Carlo (MC) applications in clinical 3D dosimetry explains how MC techniques are currently used in clinics. The last chapter in Section 3 discusses in length about the subject of comparing differences in dose distributions between measured and calculated. This chapter is one among the best in the book, and every clinical physicist would find it handy since it addresses questions and challenges that clinical physicists would face in their daily practice. It deals in length about the qualitative and quantitative ways of comparing the differences, the different indices in practice, how to interpret the results, and understanding the limitations of the methods. As a clinical physicist, I found this chapter valuable.
Section 5 on clinical applications starts with linac acceptance testing, commissioning, and QA, comprehensively covering every aspect of inducting a linac into clinical use. There are several practically important discussions such as setting up of a water phantom and obtaining a “clean family” of depth dose curves enumerated with useful pictures. A similar chapter on treatment planning system (TPS) covers its commissioning procedures, including common sources of errors, beam modeling, and validation of calculated data. Considering the importance of patient-specific QA, the topic is spread over two chapters – the first one deals with the pretreatment dose verification methods and the second one covers thein vivo approaches. Both have been elaborately described, each chapter supported with vivid color figures that add to the clarity. There is a chapter on end-to-end testing that explains the concept and the need for such a testing in the modern practice of RT, followed by an exhaustive presentation on approaches adopted in various countries and their results. This will teach the readers on not only how-to-perform an end-to-end test, but also compare their centers' results against those from international centers. Not to be left behind amidst the extensive coverage on external-beam 3D dosimetry, brachytherapy does find a place in the book and that is an indicator on its comprehensiveness. This thoughtful chapter on brachytherapy dosimetry in three dimensions begins with an in-depth coverage on the data acquisition, followed by data comparison metrics used in brachytherapy, and explanation on where one can find data for brachytherapy dosimetry. Treatment planning in 3D space and 3D measurement techniques are also covered exhaustively. The subsequent chapter is a short one, yet an important one - that is on dose outside treatment volume in external-beam radiation therapy. The authors of the chapters present a review on the characteristics of out-of-field radiation and dose, typical levels seen with different delivery systems, detectors, and methods used in photon and as well as neutron dosimetry. On similar notes, there is a chapter on imaging dose in radiation therapy explaining the readers on how to measure dose in computed tomography (CT), dose in cone-beam CT (CBCT) applications in RT, dose planar imaging using kV, MV, and MV CBCT, different dose calculation methods employed in clinics, on combining RT dose and imaging dose, clinical consequences, and benefits. The comprehensive nature of the book is brought out yet again in the next chapter which is on dose verification in proton and carbon-ion beam treatments. The chapter covers different types of measurements, namely, 3D in vivo treatment QA and neutron dosimetry.
The last section outlines the emerging technological developments that include dosimetry of small animal precision irradiators, dosimetry in synchrotron radiation therapy techniques, and 3D dosimetry in magnetic fields.
The first thing that strikes the reader is the comprehensiveness of the book – there is practically nothing related to 3D dosimetry that has been left out. It discusses everything under the umbrella of 3D dosimetry in complete justification to its title. The presentation style of dividing each chapter into subsections – an apt introduction part, a section outlining the fundamental concepts, followed by sections on applications and limitations of the subject it deals with - is attractive and every reader would like it. It must have taken a lot of efforts on the part of editor to have this organized from all contributors. The next best thing about the book is the fact several chapters discuss in length about the practical issues that a clinical physicist would face in daily professional life. These facts make the book an indispensable item in the bookshelves of clinical physicists for their ready reference. Physicists engaged in research and teaching also would find this book invaluable. The bibliography in each chapter is quite exhaustive which would benefit all researchers by providing them with plenty of cross-references. For those who are teaching medical physics to students, they can find everything that they have to teach and would not have to search through many other books and periodicals. This book would serve them as a one-stop ready reference resource addressing all their needs. The other nice thing about the book lies in its color figures. Several chapters have supporting color figures, and that is one of the biggest plus points about this book. I would have preferred a larger font size for easy reading and publishers could have accommodated it by reducing the lateral margins which appear to be large. Similarly, many figures are small in size.
Overall, the book is a valuable addition to the series. I am an avid reader of this series and personally feel that this book is certainly one of the best among all its titles. I strongly recommend to every clinical physicist, researcher, and medical physics teacher to acquire this book.