Shielding Techniques for Radiation Oncology Facilities, 3rd Edition, eBook

Shielding Techniques for Radiation Oncology Facilities, 3rd Edition, eBook

Author:  Melissa Martin and Patton H. McGinley
ISBN:  9781951134013
Published:  July 2020 | 170 pp | eBook

Price:   $ 90.00


Qty:    






Table of Contents


Preface ix

1 History of X-Ray Room Shielding 1

Years of Discovery (1895–1900) 1
Gas Tube Era (1900–1913) 2
Golden Age of X-Ray Generators (1913–1940) 2
Early Betatrons and Linear Accelerators (1941–1960) 5
Modern Radiation Therapy Period (1960–Present) 7

2 Conventional Shielding Design 9

Shielding Design Goals and Occupancy 9
Calculation Methods 12
Example: minimum occupancy 12
Primary Barrier Calculations 14
Example: primary barrier unshielded dose rate 15
Example: primary barrier transmission and shielded dose rate 16
Secondary Barrier Calculations 17
Example: x-ray leakage unshielded dose rate 18
Example: x-ray leakage barrier transmission and shielded dose rate 19
Example: slant thickness 19
Example: patient scatter unshielded dose rate 20
Example: patient scatter shielded dose rate 21
Flattening Filter Free (FFF) Accelerators 22
Workload Examples 23
Primary Barrier Width Calculation 24
Example: recommended primary barrier width 26
Primary Beam Dose Rate vs. Beam Angle 27
Tapered Primary Barrier Ceiling 28
Obliquity Factor 29
Groundshine Calculations 29

3 Conventional Maze Design 31

Patient Scatter 34
Example: maze patient scatter unshielded dose rate 35
Wall Scatter 36
Example: maze wall scatter unshielded dose rate 37
Leakage Scatter 37
Example: maze leakage scatter unshielded dose rate 38
Scatter Shielded Dose Rate 38
Example: total shielded scattered radiation at maze entrance 38
Direct Leakage 39
Wall Scatter (Plane of Rotation Perpendicular to Maze) 40
Inner Maze Wall Side-Scattered Photon Radiation 41
Additional Bends in the Maze 43

4 Photoneutrons 45

Photoneutron Production 45
State Rules and Regulations for Head Leakage 50
Activation of Materials 51
Materials for Neutron Shielding 52

5 Mazes and Doors for High-Energy Rooms 55

Neutron and Capture Gamma Transmission through a Maze 55
Example: maze capture gamma unshielded dose rate 57
Example: maze neutron unshielded dose rate 57
Additional Bends in the Maze 58
Neutron Shielding 60
Example: maze neutron shielded dose rate 60
Capture Gamma Ray Shielding 61
Example: maze capture gamma shielded dose rate 61
Direct-Shielded Doors 62
Example: direct-shielded door with lead and polyethylene core 63
Example: direct-shielded door with high-density concrete core 64
Jamb Shielding at Far Side of Entrance 65
Jamb Shielding at Near Side of Entrance 67
Neutron and Capture Gamma Radiation at Near Side of Entrance 68
Alternatives to Traditional Sliding Direct-Shielded Doors 69
Swinging Direct-Shielded Door 70
Swinging Direct-Shielded Door Surface Mounted to Wall 71
Recesses and Small Penetrations 73
Large Penetration above Maze Entrance 75
Neutron and capture gamma radiation passing through shield interior 77
Scattered radiation passing through shield interior 78
Scattered radiation passing through the material in the shield 78
Duct Penetration in Treatment Room with Direct-Shielded Door 78

6 Metal and Concrete Shields 83

Photoneutron Production in Primary Barriers Containing Metal 83
Capture Gamma Radiation in Primary Barriers Containing Metal 87
Extremely Thin Wall Primary Barriers of Lead and Polyethylene 88
Laminated Ceiling Primary Barriers 89

7 Special Topics 91

X-Ray Skyshine 91
Neutron Skyshine 94
Side Scatter 96
Scatter from Building Ceiling 97
CyberKnife 98
Accuray TomoTherapy and Radixact 100
Varian Halcyon 101
ViewRay 103
Elekta Unity 104
RefleXion 108
Superficial and Orthovoltage 109
Ozone Production 111
Air Activation 112
Atriums 114
High-Density Concrete 116

8 High-Dose-Rate Brachytherapy, Gamma Knife, and

GammaPod Rooms 119
High-Dose-Rate Brachytherapy 119
Elekta Leksell Gamma Knife 121
GammaPod Calculations 123

9 Reports and Room Surveys 127

Shielding Design Development Process 127
The Radiation Shielding Design Evaluation Report 129
Identification Information 130
Therapy Equipment Characteristics 130
Shielding Summary 130
Facility Drawings 131
Shielding Discussion 131
Detailed Calculations 132
Radiation Protection Survey 133
Survey Equipment 133
Survey Measurements 133
Dose Rate Calculations from Survey Measurements 135
Radiation Protection Survey Report 139
Identification Information 139
Therapy Equipment Characteristics 140
Survey Summary 140
Facility Drawings 140
Survey Calculations 140
Survey Discussion 140
Instrumentation Calibration Certificates 141

References 143

APPENDIX A: Parameters Used in Shielding Calculations 149

APPENDIX B: Barrier Materials 157
Normal-Weight Concrete 157
High-Density Concrete 159
Steel 159
Lead 160
Polyethylene 160
Earth and Sand 161

Index 163