# Computing in Radiotherapy # ## Contact ## - alasdair.rutherford@ggc.scot.nhs.uk - 0141 301 7521 --- # Learning Outcomes # - Understand the role of computing in radiotherapy - Understand the role of the medical physicist in computing - Be able to explain the components that ensure high availability service delivery in the department - Understand the principles of physical and logical networking, with reference to the OSI Model - Describe various data standards (DICOM/HL7) in radiotherapy/healthcare --- # ARIA Environment Architecture (v15.x)  --- # Beatson ARIA Environment (2019) #  --- # Scope of Computing # - Oncology Management/Information Systems - Treatment Planning Systems - RT PACS - Other commercial planning, physics and dosimetry applications - In-house or bespoke applications, included scripted packages - Hardware & software inventory and management - Operating systems = Networks & infrastructure - Some aspects of treatment machines - Databases - Informatics dashboards/presentation software --- # The Role of the Computing Medical Physicist Depending on the specific department, these roles may be performed by different people, some outwith Medical Physics - Procurement and acceptance of systems - Quality assurance and routine monitoring - Troubleshooting - Liaising with Hospital IT/Manufacturers/Suppliers - Inventory management - Antivirus and patching - Knowledgeable on current guidance and regulations - Develop scripts/programs to automate tasks --- # Computing Service Provision (1) # Within RT Physics - Advantages - Total control over network - Increased security due to less users/less interaction with the outside world - Less inertia to overcome when performing upgrades/buying new software - Disadvantages - Requires expertise in many areas - Difficult to recruit – hire physicist or computer scientist? HCPC registration? MPE status? - Difficulty in connecting to other departments/centres --- # Computing Service Provision (2) # Service provided by Hospital IT - Advantages - Deep and wide ranging expertise not as vital - Computing Medical Physicist can focus on development, less routine work - Some cost savings due to buying infrastructure in bulk - Interaction with other centres easier - Disadvantages - Less flexibility - restricted to certain OS/applications - Upgrades tied in with Hospital IT procurement cycles - Less intimate knowledge of system in-house, and hospital IT may lack context of situations – troubleshooting is harder --- # Computing Service Provision (3) # Managed Service from Supplier - Advantages - Responsibility of routine maintenance, hardware support and QA offloaded to supplier - Less specialist IT knowledge is required - Supplier more likely to make small improvement changes if they are more aware of day-to-day running - Disadvantages - Less flexibility - Major/ongoing financial burden - Lose expertise, inside knowledge of systems - Quality of service may be tied to cost (basic package vs gold package) --- # High Availability Service # - Essential for all routine clinical applications - NHS 7-day working coming? - Already often have 6-day treatment weeks + emergencies - Achieved through - Redundancy - Resilience - High speed network - Essential for implementation of paper-lite operation - Important to have a support infrastructure - Staffing - Monitoring - Servicing --- # Redundancy # - Redundancy is the intentional duplication of system components in order to increase a system’s dependability. - Used in many aspects of networking - RAID drives – multiple disks with data redundancy - Multiple power supplies supplied with servers - Multiple network adapters in fault-tolerant, load balancing configurations - Redundant network routes through separate switches and routers --- # Failover # > “A backup operation that automatically switches to a standby database, server or network if the primary system fails or is temporarily shut down for servicing. Failover is an important fault tolerance function of mission-critical systems that rely on constant accessibility. Failover automatically and transparently to the user redirects requests from the failed or down system to the backup system that mimics the operations of the primary system.” - Webopedia --- # Resiliency # - The ability to provide and maintain an acceptable level of service in the face of faults and challenges to normal operation - Most obvious example Uninterruptible Power Supply (UPS) - Simple UPS – single inline battery - Medium complexity – multiple batteries, power distribution units, and intelligence units with redundancy and failover - High end UPS – multiple sources of power (different phases, different generators), internal redundancy and failover with high levels of remote monitoring and control including server shutdown options, with SMS and email alerts --- # Example (1) #  --- # Example (2) #  **Pump 1 fails - monitor detects failure** --- # Example (3) #  **Control box directs flow to pump 2, which takes over** --- # Example (4) # - Redundancy: Multiple pumps available and ready to continue service - Resiliency: Monitoring system detected fault, control system automatically failed over to backup device, monitor remains in faulted state to ensure corrective action is performed. Quality control process ensured backup system would be ready to handle workload --- # Networking # A network is made up of three main components: - Physical infrastructure, e.g. cabling - Logical infrastructure, e.g. IP addressing - Networked applications, e.g. email, web browser etc. --- # Physical Networking # - Covers both wired and wireless connections - All modern computer systems are network ready, and require network access for authentication, updates, access to certain software - Physical networking infrastructure includes: - Cabling, outlets, patch panels, switches, routers, physical firewalls - Connecting servers, workstations (clients), printers - Example wired connection from client to server: - Client has a network interface card (NIC), which connects to a wall outlet via a cable - Wall outlet then connects through the wall/ceiling space to a patch panel in a node room - Patch panel connects to a switch via cable - Then a similar route to a remote server’s NIC - Difference with a wireless connection is the NIC connects to a wireless access point, which then connects via cable to the patch panel --- # Logical Networking # - Defined by TCP/IP - Transmission Control Protocol/Internet Protocol - Large organisations will generally use private network addresses and use network address translation (NAT) to communicate with the outside world - NAT allows multiple private IP addresses to be translated into a single public IP address by use of multiple TCP port numbers - Routers separate network into variable sized domains - Flexible network addressing space is provided by subnetting --- # Networking in Radiotherapy # - Client-Server Networks are fundamental to modern radiotherapy systems - Servers store clinical and machine data in databases - Servers also often host applications, to reduce licencing/install/maintenance requirements - Clients are workstations which access data and images on the servers through networked applications - Metropolitan and Wide Area Networks allow access to data and images on other hospital networks, and access to manufacturer support --- # The OSI Model # The Open System Interconnection (OSI) reference model is a conceptual model used to represent data communication between devices | Layer | Layer Name | Definition | Examples | |-------|--------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------| | 7 | Application | The direct means of communication of a user with data, presentation of data in an understandable format | Web browser, Outlook, Aria, Office | | 6 | Presentation | The non-visible layer of data which is translated between transmissions and application. May be thought of as encryption/decryption, and/or compression/decompression | SSL, SSH, IMAP, FTP, MPEG, JPEG | | 5 | Session | Setup and coordination of a ‘session’ between communicating nodes, which may include details on how long a system should wait on a response, termination of the session following application closure | APIs, Sockets | | 4 | Transport | Coordination of the transfer of data between nodes, how much data to send, transfer rate, addressing etc. Does the packaging of data | TCP, UDP | | 3 | Network | Provides the means of transferring data sequences (packets) from one node to a node in a different network – packet include address and other information alongside the data for transmission | IP (logical) addressing | | 2 | Data link | Node-to-node data transfer, detecting and correcting errors in the physical layer, assists with flow control | MAC addresses | | 1 | Physical | Responsible for transmission and reception of raw unstructured data | Voltage on a copper cable, optical signal on a fibre-optic cable, radio signals | --- # OSI vs TCP/IP  --- # Health Informatics # - Describes the management of data related to healthcare - Can be concerned with data acquisition, transfer, storage and analysis - Requires robust data to give confidence in results - Robust data a result of accurate acquisition, complete transfer between systems, appropriate storage and routine checks - Becoming more effective as the NHS slowly becomes digital and connected --- # Data Standards # What is a standard? International Organisation for Standardisation: > “a document that provides requirements, specifications, guidelines or characteristics that can be used consistently to ensure that materials, products, processes and services are fit for their purpose.” Why use a standard? - Data transmission must be understood by the sender and receiver – easier to communicate if speaking the same language Department of Health and Social Care: ‘Code of conduct for data-driven health and care technology’: > Principle 5: Make use of open standards [1] Scotland’s Digital Health & Care Strategy: Domain E - National Digital Platform > “We will develop at a national level a digital platform that enables the appropriate creation and use of information at source and facilitates the interoperability of existing and new health and care technologies. This will be delivered through the development of a new architecture, the use of secure cloud-based services and the use of common shared international standards” [2] [1]: GOV.UK. (2019). Code of conduct for data-driven health and care technology. [online] Available at: [link](https://www.gov.uk/government/publications/code-of-conduct-for-data-driven-health-and-care-technology/initial-code-of-conduct-for-data-driven-health-and-care-technology) [2]: Scotland's digital health & care strategy. (2018). Scottish Government. Available online at [link](https://www.digihealthcare.scot/wp-content/uploads/2018/04/25-April-2018-SCOTLANDS-DIGITAL-HEALTH-AND-CARE-STRATEGY-published.pdf) --- # Open Standards # Open standards: - Non-proprietary - Available - Maximise end-user choice - Are free to implement with no royalties or fees - Do not discriminate (e.g. Open Document [.odt] do not prioritise implementation for Microsoft Word vs. Open Office) Why use ‘open’ standards? - Allows communication between different manufacturers/suppliers/systems - Increases efficiency (no-need for translation of data) - Increases accuracy/robustness of data communicated - Improved informatics (can query from different or collated systems with confidence) - Development of the standard is faster (many users) - Easier to understand communication - Troubleshooting of faults is easier - Increased flexibility in choosing a supplier/larger market for a supplier --- # Standards vs. Law # - Adherence to standards is voluntary - Standards are the same, regardless of country of implementation - Only one version of the law in effect at one point in time, standards may have multiple active versions at once - Interpretation of the law decided by courts - Interpretation of standard decided by whoever is implementing it --- # DICOM # - Digital Imaging and Communications in Medicine - A standard covering digital images and associated data - CT, MR, PET, NM, DR, US, etc. - Radiotherapy data, spatial registration matrices, patient reports, modality worklist, presentation state - Coordinated by National Electrical Manufacturers Association (NEMA) - Developed by multiple working groups using a consortium approach - Not enforced, only voluntarily adhered to - Current standard is DICOM 3.0 (1993) (though has had many minor updates, current standard: [link](https://www.dicomstandard.org/current/)) --- # DICOM History # - In the early 1980s, it was difficult for anyone other than the manufacturer to read images from medical digital imaging systems. - Therapists and physicists desired to use medical images from disparate systems to help plan radiotherapy treatments. The American College of Radiology (ACR) and the National Electrical Manufacturers Association (NEMA) formed a committee and this led to the development of a standard. - DICOM 3.0 (1991-95) evolved from earlier standards (1985,1988). New versions are still shown as 3.0 with updates suffixed with the year of release. --- # DICOM Scope # ``` 1. Introduction and Overview 2. Conformance ★ 3. Information Object Definitions ★ 4. Service Class Specifications ★ 5. Data Structures and Encoding ★ 6. Data Dictionary ★ 7. Message Exchange ★ 8. Network Communication Support for Message Exchange 9. Media Storage and File Format for Media Interchange ★ 10. Media Storage Application Profiles 11. Media Formats and Physical Media for Media Interchange 12. Grayscale Standard Display Function 13. Security and System Management Profiles 14. Content Mapping Resource 15. Explanatory Information 16. Web Services 17. Application Hosting 18. Imaging Reports using HL7 Clinical Document Architecture 19. Transformations between DICOM and other Representations 20. Real-Time Communication ``` --- # Dicom RT# After the development of DICOM 3.0, there was a strong need to extend the standard into radiotherapy to support the transfer of radiotherapy-related data between devices found within and outside a radiotherapy department, since multivendor installations are common in RT. - Supplements to original standard published in 1997 and 1999. - DICOM-RT comprises five types of object. - RT Image (RI) - RT Structure Set (SS) - RT Dose (RD) - RT Plan (RP) - RT Treatment Record – three types: - RT Beams Treatment Record (BM) - RT Brachy Treatment Record (BR) - RT Treatment Summary Record (SU)