Design and Shielding of Radiotherapy Treatment Facilities

Description

The aim for this book is to be a single point of reference for all aspects of shielding design and radiation protection advice to the construction and modification of radiotherapy facilities. The book assembles a faculty of national and international experts on all modalities including megavoltage and kilovoltage photons, brachytherapy and high energy particles and on conventional and Monte Carlo shielding calculations. Their consensus and expertise is reflected through the list of chapters, but the editors have also ensured a consistent message throughout the text, by face-to-face discussion and thorough editing. PRELIMS.pdf Preface Acknowledgments Author biography Patrick Horton David Eaton Contributors CH001.pdf Chapter 1 The design and procurement process 1.1 Introduction 1.2 Strategic proposal and business case for a new development 1.3 Design team 1.3.1 General 1.3.2 Minor capital schemes 1.3.3 Major capital schemes 1.3.4 Public private partnership 1.4 Process, tenders and contracts 1.4.1 Minor capital schemes 1.4.2 Major capital schemes 1.4.3 Public private partnership 1.5 Construction 1.6 Acceptance and handover 1.6.1 Buildings and services 1.6.2 Radiotherapy treatment facilities 1.7 Commissioning 1.7.1 Clinical services 1.7.2 Equipment commissioning 1.8 Project evaluation References CH002.pdf Chapter 2 The design of radiotherapy facilities 2.1 General 2.2 Linear accelerators 2.3 Cobalt-60 units 2.4 Kilovoltage units 2.5 Brachytherapy 2.6 Particle therapy References CH003.pdf Chapter 3 Radiation protection requirements 3.1 Introduction 3.2 Quantities and units 3.2.1 Radiation exposure and dose 3.2.2 Operational quantities 3.2.3 Dose rate 3.3 System of radiation protection 3.4 Regulatory framework in the UK 3.5 Basic radiation protection principles in radiotherapy 3.5.1 Justification 3.5.2 Optimisation 3.5.3 Dose limitation 3.6 Controlled areas 3.7 Optimisation in the design process 3.7.1 The radiation protection working year 3.7.2 Occupancy factors 3.7.3 Annual dose constraints 3.7.4 Time averaged dose rate 3.7.5 Instantaneous dose rate 3.7.6 Other dose constraints/time averaging 3.8 Engineering controls 3.9 Prior risk assessment 3.10 Additional regulatory requirements 3.10.1 Investigation level and personal dose monitoring 3.10.2 Critical examination 3.10.3 Warning signs 3.10.4 Quality assurance and maintenance 3.10.5 Incidents 3.10.6 Contingency plans References CH004.pdf Chapter 4 Clinical practice, treatment room and control room design 4.1 Clinical practice 4.1.1 General 4.1.2 Treatment modalities 4.1.3 Information required for shielding calculations 4.2 Treatment room design 4.2.1 Introduction 4.2.2 Internal dimensions 4.2.3 Site access 4.2.4 Lintels, baffles and nibs 4.2.5 Room access arrangement—last person out (search button) 4.2.6 Emergency stops 4.2.7 Lighting arrangements (including alignment lasers) 4.2.8 Services 4.2.9 Gating interfaces 4.2.10 Motion management systems 4.2.11 Storage solutions 4.2.12 Finishes and fittings 4.3 Control room design 4.3.1 Introduction 4.3.2 Control room dimensions 4.3.3 Patient access arrangements 4.3.4 Treatment room door operation 4.3.5 Warning lights/signs 4.3.6 Equipment status notification 4.3.7 Lighting arrangements 4.3.8 Electrical services and IT connectivity References CH005.pdf Chapter 5 Empirical shielding calculations for treatment rooms with linear accelerators 5.1 General principles 5.2 Primary barriers 5.2.1 General 5.2.2 Annual dose 5.2.3 Dose rate measures and verification of shielding 5.2.4 Primary barrier width 5.3 Secondary barriers 5.3.1 General 5.3.2 Annual dose 5.3.3 Dose rate measures and verification of shielding 5.4 Roofs and skyshine 5.5 Groundshine 5.6 Obliquity factor 5.7 X-ray scatter down the maze 5.7.1 Scatter of the primary beam from the bunker walls 5.7.2 Scatter of the primary beam by the patient 5.7.3 Scatter of head leakage radiation by the bunker walls 5.7.4 Transmission of head leakage radiation through the inner maze wall 5.7.5 Total x-ray dose rate and annual dose at the maze entrance 5.8 Neutron scatter down the maze 5.9 Maze doors and lining 5.10 Direct doors 5.11 Laminated walls and roofs 5.12 Spreadsheet approach for primary and secondary shielding References CH006.pdf Chapter 6 Monte Carlo methods 6.1 Introduction 6.2 Available Monte Carlo codes and deciding which one to use 6.3 Using the MCNP code 6.3.1 Specification of the source characteristics 6.3.2 Specification of the room geometry and materials to be simulated 6.3.3 Description of the tally volumes and types 6.3.4 Other input cards 6.3.5 Executing the problem in a reasonable time 6.3.6 Validating the simulations 6.3.7 Results and their interpretation 6.3.8 Enhanced particle track visualisation capabilities 6.4 Using the FLUKA code 6.5 MCNP, induced neutrons and particle therapy 6.6 Calculation of whole-body doses 6.7 Summary References CH007.pdf Chapter 7 Shielding materials and construction details 7.1 Introduction 7.1.1 Poured concrete 7.1.2 High density concrete 7.1.3 Blocks 7.1.4 Steel sheet 7.1.5 Lead 7.1.6 Sandwich construction 7.1.7 Earth 7.2 Materials with unspecified TVLs 7.3 Construction details 7.3.1 Formwork, shuttering, tie bolts and reinforcement for poured concrete 7.3.2 Block construction 7.3.3 Nibs in bunkers 7.3.4 Lintels 7.3.5 Ducts and cableways 7.3.6 Direct doors 7.3.7 Wall fixings 7.3.8 Warning lights References CH008.pdf Chapter 8 Specialist applications: Gamma Knife®, TomoTherapy® and CyberKnife® 8.1 The Gamma Knife® 8.1.1 Introduction 8.1.2 Sources and source loading 8.1.3 Treatment room design considerations 8.1.4 Shielding considerations 8.2 TomoTherapy® 8.2.1 Introduction 8.2.2 Basic operation 8.2.3 Machine calibration 8.2.4 Shielding considerations 8.2.5 Workload 8.2.6 Leakage 8.2.7 Scatter 8.2.8 Primary beam 8.2.9 Summary of practical considerations for shielding 8.2.10 Case study: installation into an existing cobalt-60 bunker Acknowledgements 8.3 CyberKnife® 8.3.1 Introduction 8.3.2 CyberKnife specification 8.3.3 Typical CyberKnife bunker features 8.3.4 Worked example: primary barriers 8.3.5 Worked example: secondary barriers References CH009.pdf Chapter 9 Kilovoltage therapy and electronic brachytherapy 9.1 Superficial and orthovoltage therapy 9.1.1 Introduction 9.1.2 Superficial therapy 9.1.3 Orthovoltage therapy 9.1.4 Example of superficial/orthovoltage room protection 9.2 Electronic brachytherapy and intra operative radiotherapy 9.2.1 Intraoperative (x-ray) radiotherapy 9.2.2 Superficial x-ray brachytherapy 9.2.3 Small animal irradiators 9.2.4 Intraoperative (electron) radiotherapy (IOERT) References CH010.pdf Chapter 10 Brachytherapy 10.1 Treatment modes 10.2 Regulatory considerations 10.2.1 Use of radioactive material 10.2.2 Work with ionising radiation 10.2.3 Patient protection 10.3 Room design 10.3.1 General considerations 10.3.2 Engineering controls 10.3.3 Security 10.4 High dose-rate afterloading 10.4.1 Workload 10.4.2 Room layout 10.4.3 Calculation of shielding thickness 10.4.4 Maze/door calculations 10.4.5 Engineering controls 10.5 Pulsed dose-rate afterloading 10.5.1 Workload 10.5.2 Layout 10.5.3 Shielding calculations 10.5.4 Engineering controls 10.6 Permanent implants: iodine-125 seeds 10.7 Eye plaques References CH011.pdf Chapter 11 Radiation shielding and safety for particle therapy facilities 11.1 Introduction 11.2 Sources of extraneous radiation 11.2.1 Beam interactions within the accelerator during the acceleration process 11.2.2 Beam interactions with the beam extraction system or deflector 11.2.3 Beam interactions with the energy selection system 11.2.4 Beam interactions in the beam transport line 11.2.5 Beam interactions with the treatment nozzle 11.2.6 Beam interactions in the patient 11.3 Design and build process considerations 11.4 Regulatory requirements and design criteria 11.5 Workload, use and occupancy factors 11.5.1 Beam energy 11.5.2 Beam use 11.5.3 Orientation factor 11.5.4 Occupancy factors 11.5.5 Work patterns and staff positioning 11.5.6 Future-proofing 11.5.7 Uncertainties 11.6 Construction materials 11.7 Theory of radiation transport: solving the Boltzmann equation 11.8 Practical shielding calculations 11.9 Monte Carlo calculation methods 11.10 Mazes and ducts 11.10.1 Mazes 11.10.2 Ducts 11.11 Room interlocks and monitoring 11.12 Radiation hazards resulting from activation 11.12.1 Solid material activation 11.12.2 Water and air activation 11.12.3 Risks from activation 11.12.4 Radioactive solid waste 11.13 Measuring and monitoring techniques and instrumentation 11.14 Summary References CH012.pdf Chapter 12 Shielding verification and radiation surveys 12.1 Introduction 12.2 During construction 12.3 Post construction radiation survey—detailed shielding integrity testing 12.4 Preliminary safety assessment 12.5 Critical examination 12.6 Radiation surveys 12.6.1 Radiation monitoring equipment 12.6.2 Linear accelerator bunker checks 12.7 Surveys of kilovoltage equipment 12.8 Surveys of brachytherapy facilities 12.9 Surveys of CT scanners 12.10 Validation of results References Glossary.pdf