Hendee's Radiation Therapy Physics (eBook)

Todd Pawlicki, PhD, FAAPM Professor and Vice-Chair of Medical Physics Department of Radiation Medicine and Applied Sciences University of California, San Diego, CA, USA Daniel J. Scanderbeg PhD Associate Professor Department of Radiation Medicine and Applied Sciences University of California, San Diego, CA, USA George Starkschall PhD, FACMP, FAAPM, FACR Research Professor, Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA

Hendee's Radiation Therapy Physics 3
Contents 7
Preface to the Fourth Edition 8
Preface to the Third Edition 9
Preface to the Second Edition 10
Preface to the First Edition 11
1 Atomic structure and radioactive decay 13
Introduction 13
Atomic and nuclear structure 13
Atomic units 14
Mass defect and binding energy 14
Electron energy levels 15
Nuclear stability 17
Radioactive decay 18
Types of radioactive decay 19
Alpha decay 20
Beta decay 21
Gamma emission and internal conversion 23
Radioactive equilibrium 23
Natural radioactivity and decay series 25
Artificial production of radionuclides 25
Summary 26
Problems 26
References 27
2 Interactions of x rays and gamma rays 28
Introduction 28
Attenuation of x rays and gamma rays 29
X-ray and gamma-ray interactions 33
Coherent scattering 33
Photoelectric interactions 33
Compton interactions 34
Pair production 38
Photodisintegration 38
Likelihood of interactions 39
Summary 39
Problems 39
References 40
3 Interactions of particulate radiation with matter 41
Introduction 41
Differences between charged particles and photons 41
Classification of particles 42
Collisional interactions 42
Radiative interactions 44
Summary 45
Problems 46
References 46
4 Machines for producing radiation 47
History of xrays 48
Conventional x-ray tubes 48
Electron source 48
X-ray tube voltage 49
X-ray spectra 50
Low-energy therapy x-ray units 52
Grenz–ray units 52
Contact therapy units 53
Superficial therapy units 53
Orthovoltage therapy units 53
Supervoltage therapy units 53
Megavoltage x-ray units 53
Isotope teletherapy units 54
Cobalt units 54
Source capsule 54
Source exposure mechanism 54
Collimators 54
Beam edge unsharpness 54
Isocentric units 55
137Cs teletherapy units 55
Linear accelerators 56
Historical development 56
Major components of medical electron accelerators 58
Modulator and pulse-forming network 58
Magnetrons 59
Klystrons 60
Microwave power-handling equipment 60
Vacuum pump 61
Bending magnet 61
X-ray target 63
Flattening filter and scattering foil 63
Monitor ionization chamber 64
Collimator 64
Treatment couch 64
Other medical accelerators 66
Cyclotrons 66
Microtrons 67
Summary 67
Problems 67
References 68
5 Measurement of ionizing radiation 69
Introduction 69
Radiation intensity 70
Radiation exposure 70
Energy and photon fluence per unit exposure 71
Measurement of radiation exposure 72
Free-air ionization chamber 72
Thimble chambers 74
Condenser (“ionization”) chambers 75
Correction factors 76
Extrapolation and parallel-plate chambers 77
Radiation dose 77
Measurement of radiation dose 79
Calorimetric dosimetry 79
Radiographic film dosimetry 79
Radiochromic film dosimetry 80
Chemical dosimetry 80
Scintillation and semiconductor dosimetry 81
Luminescent dosimetry 81
Absorbed dose measurements with an ionization chamber 82
Bragg–Gray cavity theory 82
Dose equivalent 83
Radiation quality 84
Spectral distributions 84
Summary 86
Problems 86
References 87
6 Calibration of megavoltage beams of x rays and electrons 89
Introduction 89
Calibration standards and laboratories 90
Calibration coefficient as a function of energy 91
Estimation of dose to a medium from a calibration in air 91
Work function 91
Dose to air 91
Dose to another medium 92
Measurement in a phantom 94
Calibration of low-energy x-ray beams 95
Beam quality 95
Ionization chamber 95
In-air calibrations 96
In-phantom calibrations 97
Calibration of megavoltage beams: The AAPM protocol 97
Calibration of photon beams versus electron beams 98
Calibration with an ionization chamber in a medium 98
Dose to water from a measurement of ionization 98
Dose to water calibration coefficient (ND,w) 99
Effective point of measurement 101
Beam quality specification 102
Calibration of photon beams 103
Calibration of electron beams 104
The IAEA calibration protocol 104
Summary 106
Problems 106
References 106
7 Central-axis point dose calculations 108
Introduction 108
Dose calculation model 109
Machine calibration 109
Corrections for field size 110
Inverse square correction 110
Corrections for beam modifiers 111
Corrections for patient attenuation 111
Percent depth dose 111
Influence of depth and radiation quality 112
Effect of field size and shape 113
Effect of distance from source to surface 114
Effect of depth of underlying tissue 115
Tables of percent depth dose 115
Tissue-air ratio 116
Computing tissue-air ratio from percent depth dose 116
Influence of field size and source–axis distance on tissue-air ratio 117
Influence of radiation energy and depth 117
Backscatter 118
Scatter-air ratio 118
Tissue-phantom ratio 119
Monitor unit calculations for electrons 119
Summary 120
Problems 120
References 121
8 External beam dose calculations 122
Introduction 122
Dose calculation challenges 123
Treatment fields 123
Lateral disequilibrium in high-energy beams 123
Interface effects 123
Aspects of clinical photon beams 123
Beam data 125
Patient data 125
Photon beam computational algorithms 126
Analytical methods 126
Matrix techniques 126
Semi-empirical methods 127
Clarkson method 127
Differential scatter-air ratio calculation 128
Three-dimensional integration methods 129
Monte Carlo methods 130
Electron-beam computational algorithms 131
Summary 132
Problems 132
References 133
9 External beam treatment planning and delivery 135
Introduction 135
Virtual simulation techniques 137
Immobilization and localization 139
Segmentation of the CT image data set 139
Selection of ideal treatment plan 140
Dose–volume histograms 141
Biological modeling 145
Forward planning 145
Inverse planning 146
Intensity modulated radiation therapy 147
Treatment planning techniques 147
Setting the objective function 149
Optimization 149
Conversion to deliverable treatment 150
Dynamic delivery techniques 151
Tomotherapy 151
Serial tomotherapy 151
Helical tomotherapy 151
Robotic treatments 152
Summary 153
Problems 154
References 155
10 The basics of medical imaging 158
Introduction 158
Characteristics of imaging systems 159
Image contrast 159
Digital imaging concepts 160
Dynamic range 160
Gray-scale binning 161
Spatial resolution 163
Image enhancement 164
Summary 165
Problems 165
References 165
11 Diagnostic imaging and applications to radiation therapy 166
Introduction 166
Radiography 167
Digital radiography 167
Digital x-ray detectors 168
Computed tomography 169
History 169
Principles of computed tomography 169
Reconstruction algorithms 171
Ultrasonography 172
Nuclear medicine 173
Properties of radioactive pharmaceuticals 174
Nuclear medicine imaging 174
Emission computed tomography 175
Single-photon emission computed tomography 176
Positron emission tomography 176
Magnetic resonance imaging 177
Functional magnetic resonance imaging 179
Summary 180
Problems 180
References 180
12 Tumor targeting: Image-guided and adaptive radiation therapy 182
Introduction 182
Intrafractional motion 183
Imaging of effects of respiratory motion 183
Planning with respiratory motion 185
Motion mitigation 186
Positioning uncertainties 186
Two-dimensional versus three-dimensional alignment 187
Two-dimensional alignment 188
Three-dimensional alignment 188
Non-radiographic image-guided radiation therapy 190
Surface-based image-guided radiation therapy 190
Ultrasound systems 190
Electromagnetic transponder 191
MR-based image-guided radiation therapy 191
Data requirements for image-guided radiation therapy 192
Summary 192
Problems 192
References 192
13 Computer systems 194
Introduction 194
Terminology and data representation 195
Number systems 195
Conversion from one system to another 196
Bits, bytes, and words 196
Representation of data 196
Indication of states 196
Numeric data 197
Alphanumeric data 197
Analog-to-digital and digital-to-analog conversion 197
Representation of graphic data 198
Computer architecture 199
Memory 200
Central processing unit 200
Graphics processing unit 201
Inputoutput devices 201
Mass storage devices 201
Computer software 202
Programming languages 202
Computer languages 202
Low-level languages 202
High-level languages 203
Networking† 203
Network components and structure 205
Interfaces 206
Transmission media 206
Data compression 206
Display stations and standards 206
Computer requirements for treatment planning 207
Summary 207
Problems 208
References 208
14 Radiation oncology informatics 209
Introduction 209
Ontologies 210
Information standards 210
Information flow in radiation oncology 211
Informatics for treatment planning 213
Future trends in radiation oncology informatics 214
Summary 214
Problems 214
References* 215
15 Physics of proton radiation therapy 216
Introduction 216
Production of proton beams 217
Characteristics of clinical proton beams 218
Generating a clinically useful beam 219
Passive scattering 219
Scanning beams 219
Proton treatment planning 220
Planning with passive scattering 220
Planning with spot scanning 222
Planning quality assurance 222
Uncertainties in proton radiation therapy 222
Quality assurance for proton radiation therapy 224
Patient-plan-specific quality assurance 224
Machine-specific quality assurance 224
Summary 225
Problems 225
References 225
16 Sources for implant therapy and dose calculation 227
Introduction 227
Radium sources 228
Construction of radium sources 229
Types of radium sources 229
Radium substitutes 229
Cesium-137 232
Cobalt-60 233
Tantalum-182 233
Iridium-192 233
Gold-198, Iodine-125, Palladium-103, and Cesium-131 234
Americium-241 234
Ophthalmic irradiators 234
Implantable neutron sources 235
Radiation safety of brachytherapy sources 236
Storage 236
Test for uniform distribution of activity 236
Evaluating the safety of brachytherapy sources 236
Specification of brachytherapy sources 236
Radiation dose from brachytherapy sources 237
Sievert integral 238
Isodose distributions from individual sealed sources 239
Summary 240
Problems 240
References 240
17 Brachytherapy treatment planning 243
Introduction 243
Design of implants 243
Intracavitary implant applicators 243
Interstitial implant applicators 246
Distribution rules for interstitial implants 246
The Quimby system 246
The Manchester system 246
The Paris system 246
Remote afterloading 248
Computer calculations 249
Air-kerma strength calculation 249
Dose over treatment duration 250
Plaques 251
Radiographic localization of implants 252
Three-dimensional image-based implants 252
Prostate seed implants 252
Prostate HDR 253
LDRHDR gynecologic interstitial implant 255
Breast brachytherapy 255
Therapy with radiopharmaceuticals 255
Intravascular brachytherapy 256
Summary 256
Problems 257
References 257
18 Radiation protection 260
Introduction 260
Effects of radiation exposure 262
Stochastic radiation effects 262
Nonstochastic effects 262
History of radiation protection standards 263
Current limits on radiation exposure 264
Protective barriers for radiation sources 266
Protection from small sealed gamma-ray sources 267
Design of structural shielding 268
Primary radiation barriers 268
Secondary barriers for scattered radiation 269
Secondary barriers for leakage radiation 271
Door shielding 272
Neutron shielding 273
Protection for sealed radioactive sources 274
Radiation surveys 275
Ionization chambers 275
Geiger–Müller counters 275
Neutron detectors 275
Personnel monitoring 276
Summary 276
Problems 276
References 277
19 Quality assurance 279
Introduction 280
Recommended quality assurance procedures 280
Physics instrumentation 280
Ionization chambers and electrometers 281
Beam scanning systems 282
Ancillary equipment 282
Relative dose measuring equipment 283
Survey meters 283
Conventional linear accelerators 283
Safety procedures 283
Mechanical alignment 283
Beam alignment tests 286
Multileaf collimator quality assurance 287
Beam calibration 288
Photon beam characterization 288
Electron beam characterization 290
In-room image-guidance quality assurance 290
Safety procedures 290
X-ray beam performance 290
Quality assurance procedures for conventional simulators 291
CT simulator quality assurance 291
Lasers 291
CT couch 292
Image orientation 292
Image quality 292
Computed tomography to density table 292
Treatment planning computers 293
Quality assurance for intensity-modulated radiation therapy 296
Radiation safety 296
Treatment planning 296
Machine characteristics 296
Patient-specific dose verification 297
Stereotactic radiosurgery and radiotherapy 297
Brachytherapy quality assurance procedures 298
Applicators 298
Radioactive sources 298
Remote afterloading equipment 299
Safety procedures 299
Source-change quality assurance 299
Daily quality assurance 301
Monthly quality assurance procedures 301
Patient-specific brachytherapy treatment plan quality assurance 301
Summary 303
Problems 303
References 304
20 Patient safety and quality improvement 306
Introduction 306
Human factors 307
Understanding accidents 307
Mitigating errors 308
Hazard analysis 311
Prospective analysis 311
Retrospective analysis 312
Incident learning 314
Incident learning systems 314
Organizational culture 314
Quality improvement 315
Plan–do–study–act 315
Six-sigma and lean 316
Process control 316
Quality and process variation 316
Use and interpretation of control charts 317
Summary 319
Problems 319
References 319
Appendix: Answers to selected problems 322
Index 329
Supplemental Images 340
EULA 348

"The book is well structured and gives an excellent overview on all practical aspects of modern radiotherapy and the physics involved. The many examples and problems allow for immediate check of the understanding of the text and make it fun to read. The new editors certainly did a very good job in carrying on the tradition of the original book" Physica Medica, Feb 2017. Full review available here

"The newly published fourth edition of Hendee's Radiation Therapy Physics (Authors: Todd Pawlicki, Daniel J. Scanderbeg, George Starkschall) provides an updated overview, analysis and practical guidance of the various aspects of the radiation therapy physics. Published ten years after the publication of the third edition, this book reviews all newly introduced modalities and approaches in
Radiation therapy - intensity-modulated radiation therapy (IMRT), image-guided radiation therapy (IGRT), digital imaging, CT simulation, proton therapy, radiation therapy informatics. An important part of the book is the focus on the professional approaches in radiation protection, patient safety, quality assurance, quality improvement and even training for residents. The book is written by experts in the field - all three authors are well known professionals working in the field of Radiation Physics and Radiation Medicine. Throughout this book the reader finds scientific, educational and practical information from the very basics of radiation physics to the latest achievements in the field of Radiation Therapy. Each chapter is well structured, giving a good balance between the theoretical and practical aspects. The appendix is dedicated to solving practical problems and provides professional advice, as well as self-tests......This book is both an excellent reference which will be useful in all medical physics departments and at the same time a perfect guidance material for professionals in related specialties. It continues very well the line set by Prof. William Hendee (past IOMP ExCom member). The Content and Structure of the book are excellent. These are really necessary for a book with such coverage and volume. Thefourth edition of Hendee's Radiation Therapy Physics is yet another fundamental book that will be very useful reference for various specialists for many years
ahead" - Medical Physics World 2016