Radiation Exposure Monitoring

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Radiation Exposure Monitoring (REM) is a framework developed by Integrating the Healthcare Enterprise (IHE), for utilizing existing technical standards, such as DICOM, to provide information about the dose delivered to patients in radiology procedures, in an interoperable format.

Contents

Ready access to dose information aids medical staff, including radiographers, radiologists and medical physicists, in the radiation protection goal of reducing doses to a level "as low as reasonably practicable". [1]

Collecting and using dose data

A challenge in automating the reporting of radiation exposure estimations has traditionally been a function of whether the record of dose provided by a manufacturer is persistent (i.e. stored electronically) or transient (i.e. displayed on a read-out). Many current radiology devices provide only transient records, either in the form of human-readable dose screens that require manual intervention (i.e. pencil and paper) to permanently capture the patient exposure, or else in the equally perishable data generated by a modality-performed procedure step (MPPS) created to help manage the scheduling system.[ citation needed ]

MPPS is insufficient, having a limited ability to encode complex data, and no options for long-term storage or queries. Newer scanners are able to create DICOM radiation dose structured reports (RDSRs) alongside the images themselves. REM addresses perishable dose data by creating a persistent record that can be sent to a central repository, and then queried and analyzed by health information systems for either a specific patient's history or for analysis of radiation exposure levels among patient groups, platforms, or clinical operations. [2] RDSRs, and the use of the IHE REM framework are part of the IEC 61910 standard. [3]

Standards and Integrating the Healthcare Enterprise (IHE)

Integrating the Healthcare Enterprise (IHE) is an initiative by healthcare professionals and industry to improve the way computer systems in healthcare share information. IHE "Integration Profiles" are designed make systems easier to implement and integrate, and help care providers use information more effectively. [4] IHE Integration Profiles describe clinical information management use cases and specify how to use existing standards (HL7, DICOM, etc.) to address them. Systems that implement integration profiles solve interoperability problems. For equipment vendors, Integration Profiles are implementation guides. For healthcare providers, Integration Profiles are shorthand for integration requirements in purchasing documents. Integration Statements tell customers the IHE Profiles supported by a specific release of a specific product.

The REM Profile enables imaging modalities to export radiation exposure estimation details in a standard format. Radiation reporting systems can either query for these "dose objects" periodically from an archive, or receive them directly from the modalities. The radiation reporting system is expected to perform relevant dose QA analysis and produce related reports. The analysis methods and report format are not considered topics for standardization and are not covered in the profile. The profile also describes how radiation reporting systems can submit dose estimation reports to centralized registries such as might be run by professional societies or national accreditation groups. In the United States, the American College of Radiology DIR [5] is one such registry. By profiling automated methods, the profile allows dose information to be collected and evaluated without imposing a significant administrative burden on staff otherwise occupied with caring for patients.

In addition to supporting profile quality assurance (QA) of the technical process at the local facility, (e.g. determining if the dose was appropriate for the procedure performed), the profile also supports population analysis performed by national registries. Compliant software products are capable of de-identifying and submitting dose reports to a national dose register securely, making it relatively simple for groups such as ACR to collect and process dose data from across the country once they have recruited participating sites.

Challenges

Fluoroscopy monitoring

Most fluoroscopic x-ray equipment can provide an estimate of the cumulative dose that would have resulted to a point on the skin if the x-ray beam was stationary during the complete procedure. Such an estimate is derived from the fluoroscopic technique factors and the total exposure time, including any image recording, or from built-in dosimetry systems. However, these systems, known as dose area product meters (DAP meters), do not directly provide skin dose information without further knowledge of the sizes of the x-ray beam during the entire procedure. The relationship between cumulative skin dose and peak skin dose is highly variable, as has been demonstrated in a number of publications. [6]

Limitations of dose monitoring

According to IHE, "It is important to understand the technical and practical limitations of dose monitoring and the reasons why the monitored values may not accurately provide the radiation dose administered to the patient": [1]

  1. The values provided by this tool are not "measurements" but only calculated estimates.
  2. For computed tomography, "CTDI" is a dose estimate to a standard plastic phantom. Plastic is not human tissue. Therefore, the dose should not be represented as the dose received by the patient.
  3. For planar or projection imaging, the recorded values may be exposure, skin dose or some other value that may not be patient's body or organ dose.
  4. It is inappropriate and inaccurate to add up dose estimates received by different parts of the body into a single cumulative value.

Despite such limitations, interest in monitoring radiation dose estimates is clearly expressed in such documents as the European directive Euratom 97/43 [7] and the American College of Radiology Dose Whitepaper. [8]

Related Research Articles

<span class="mw-page-title-main">Picture archiving and communication system</span> Medical imaging technology

A picture archiving and communication system (PACS) is a medical imaging technology which provides economical storage and convenient access to images from multiple modalities. Electronic images and reports are transmitted digitally via PACS; this eliminates the need to manually file, retrieve, or transport film jackets, the folders used to store and protect X-ray film. The universal format for PACS image storage and transfer is DICOM. Non-image data, such as scanned documents, may be incorporated using consumer industry standard formats like PDF, once encapsulated in DICOM. A PACS consists of four major components: The imaging modalities such as X-ray plain film (PF), computed tomography (CT) and magnetic resonance imaging (MRI), a secured network for the transmission of patient information, workstations for interpreting and reviewing images, and archives for the storage and retrieval of images and reports. Combined with available and emerging web technology, PACS has the ability to deliver timely and efficient access to images, interpretations, and related data. PACS reduces the physical and time barriers associated with traditional film-based image retrieval, distribution, and display.

Digital Imaging and Communications in Medicine (DICOM) is the standard for the communication and management of medical imaging information and related data. DICOM is most commonly used for storing and transmitting medical images enabling the integration of medical imaging devices such as scanners, servers, workstations, printers, network hardware, and picture archiving and communication systems (PACS) from multiple manufacturers. It has been widely adopted by hospitals and is making inroads into smaller applications such as dentists' and doctors' offices.

<span class="mw-page-title-main">Sievert</span> SI unit of equivalent dose of ionizing radiation

The sievert is a unit in the International System of Units (SI) intended to represent the stochastic health risk of ionizing radiation, which is defined as the probability of causing radiation-induced cancer and genetic damage. The sievert is important in dosimetry and radiation protection. It is named after Rolf Maximilian Sievert, a Swedish medical physicist renowned for work on radiation dose measurement and research into the biological effects of radiation.

Medical physics deals with the application of the concepts and methods of physics to the prevention, diagnosis and treatment of human diseases with a specific goal of improving human health and well-being. Since 2008, medical physics has been included as a health profession according to International Standard Classification of Occupation of the International Labour Organization.

<span class="mw-page-title-main">Medical imaging</span> Technique and process of creating visual representations of the interior of a body

Medical imaging is the technique and process of imaging the interior of a body for clinical analysis and medical intervention, as well as visual representation of the function of some organs or tissues (physiology). Medical imaging seeks to reveal internal structures hidden by the skin and bones, as well as to diagnose and treat disease. Medical imaging also establishes a database of normal anatomy and physiology to make it possible to identify abnormalities. Although imaging of removed organs and tissues can be performed for medical reasons, such procedures are usually considered part of pathology instead of medical imaging.

Radiation dosimetry in the fields of health physics and radiation protection is the measurement, calculation and assessment of the ionizing radiation dose absorbed by an object, usually the human body. This applies both internally, due to ingested or inhaled radioactive substances, or externally due to irradiation by sources of radiation.

<span class="mw-page-title-main">Nuclear medicine</span> Medical specialty

Nuclear medicine or nucleology is a medical specialty involving the application of radioactive substances in the diagnosis and treatment of disease. Nuclear imaging, in a sense, is "radiology done inside out" because it records radiation emitted from within the body rather than radiation that is transmitted through the body from external sources like X-ray generators. In addition, nuclear medicine scans differ from radiology, as the emphasis is not on imaging anatomy, but on the function. For such reason, it is called a physiological imaging modality. Single photon emission computed tomography (SPECT) and positron emission tomography (PET) scans are the two most common imaging modalities in nuclear medicine.

<span class="mw-page-title-main">Fluoroscopy</span> Production of an image when X-rays strike a fluorescent screen

Fluoroscopy is an imaging technique that uses X-rays to obtain real-time moving images of the interior of an object. In its primary application of medical imaging, a fluoroscope allows a surgeon to see the internal structure and function of a patient, so that the pumping action of the heart or the motion of swallowing, for example, can be watched. This is useful for both diagnosis and therapy and occurs in general radiology, interventional radiology, and image-guided surgery.

<span class="mw-page-title-main">Radiation burn</span> Damage to skin or biological tissue from radiation exposure

A radiation burn is a damage to the skin or other biological tissue and organs as an effect of radiation. The radiation types of greatest concern are thermal radiation, radio frequency energy, ultraviolet light and ionizing radiation.

Moist desquamation is a description of the clinical pattern seen as a consequence of radiation exposure where the skin thins and then begins to weep because of loss of integrity of the epithelial barrier and decreased oncotic pressure. Moist desquamation is a rare complication for most forms of radiology, however it is far more common in fluoroscopy where threshold doses lie between 10-15 Gy and increasingly common above 15 Gy. It has been noted that fractionation of fluoroscopic procedures significantly reduces the likelihood of moist desquamation occurring. In animal studies done on pig skin, moist desquamation was found to occur with a 50% of the time after a single dose of 28 Gy, however a 2×18 Gy fractionation scheme was needed to produce the same 50% occurrence.

The American College of Radiology (ACR), founded in 1923, is a professional medical society representing nearly 40,000 diagnostic radiologists, radiation oncologists, interventional radiologists, nuclear medicine physicians and medical physicists.

<span class="mw-page-title-main">Radiographer</span> Healthcare professional

Radiographers, also known as radiologic technologists, diagnostic radiographers and medical radiation technologists are healthcare professionals who specialise in the imaging of human anatomy for the diagnosis and treatment of pathology. Radiographers are infrequently, and almost always erroneously, known as x-ray technicians. In countries that use the title radiologic technologist they are often informally referred to as techs in the clinical environment; this phrase has emerged in popular culture such as television programmes. The term radiographer can also refer to a therapeutic radiographer, also known as a radiation therapist.

Image-guided radiation therapy is the process of frequent imaging, during a course of radiation treatment, used to direct the treatment, position the patient, and compare to the pre-therapy imaging from the treatment plan. Immediately prior to, or during, a treatment fraction, the patient is localized in the treatment room in the same position as planned from the reference imaging dataset. An example of IGRT would include comparison of a cone beam computed tomography (CBCT) dataset, acquired on the treatment machine, with the computed tomography (CT) dataset from planning. IGRT would also include matching planar kilovoltage (kV) radiographs or megavoltage (MV) images with digital reconstructed radiographs (DRRs) from the planning CT.

The collective effective dose, dose quantity S, is calculated as the sum of all individual effective doses over the time period or during the operation being considered due to ionizing radiation. It can be used to estimate the total health effects of a process or accidental release involving ionizing radiation to an exposed population. The total collective dose is the dose to the exposed human population between the time of release until its elimination from the environment, perhaps integrating to time equals infinity. However, doses are generally reported for specific populations and a stated time interval. The International Commission on Radiological Protection (ICRP) states: "To avoid aggregation of low individual doses over extended time periods and wide geographical regions the range in effective dose and the time period should be limited and specified.

<span class="mw-page-title-main">Radiation dose reconstruction</span>

Radiation dose reconstruction refers to the process of estimating radiation doses that were received by individuals or populations in the past as a result of particular exposure situations of concern. The basic principle of radiation dose reconstruction is to characterize the radiation environment to which individuals have been exposed using available information. In cases where radiation exposures can not be fully characterized based on available data, default values based on reasonable scientific assumptions can be used as substitutes. The extent to which the default values are used depends on the purpose of the reconstruction(s) being undertaken.

<span class="mw-page-title-main">Hybrid operating room</span> Type of surgical theatre

A hybrid operating room is a surgical theatre that is equipped with advanced medical imaging devices such as fixed C-Arms, X-ray computed tomography (CT) scanners or magnetic resonance imaging (MRI) scanners. These imaging devices enable minimally-invasive surgery. Minimally-invasive surgery is intended to be less traumatic for the patient and minimize incisions on the patient and perform surgery procedure through one or several small cuts.

The committed dose in radiological protection is a measure of the stochastic health risk due to an intake of radioactive material into the human body. Stochastic in this context is defined as the probability of cancer induction and genetic damage, due to low levels of radiation. The SI unit of measure is the sievert.

A Vendor Neutral Archive (VNA) is a medical imaging technology in which images and documents are stored (archived) in a standard format with a standard interface, such that they can be accessed in a vendor-neutral manner by other systems.

<span class="mw-page-title-main">Medical image sharing</span> Electronic exchange of medical images

Medical image sharing is the electronic exchange of medical images between hospitals, physicians and patients. Rather than using traditional media, such as a CD or DVD, and either shipping it out or having patients carry it with them, technology now allows for the sharing of these images using the cloud. The primary format for images is DICOM. Typically, non-image data such as reports may be attached in standard formats like PDF during the sending process. Additionally, there are standards in the industry, such as IHE Cross Enterprise Document Sharing for Imaging (XDS-I), for managing the sharing of documents between healthcare enterprises. A typical architecture involved in setup is a locally installed server, which sits behind the firewall, allowing secure transmissions with outside facilities. In 2009, the Radiological Society of North America launched the "Image Share" project, with the goal of giving patients control of their imaging histories by allowing them to manage these records as they would online banking or shopping.

<span class="mw-page-title-main">Integrating the Healthcare Enterprise</span> Non-profit organization

Integrating the Healthcare Enterprise (IHE) is a non-profit organization based in the US state of Illinois. It sponsors an initiative by the healthcare industry to improve the way computer systems share information. IHE was established in 1998 by a consortium of radiologists and information technology (IT) experts.

References

  1. 1 2 "Radiation Exposure Monitoring". IHE Wiki. 7 March 2015. Retrieved 1 June 2017.
  2. O’Donnell, Kevin (14 April 2011). "Radiation exposure monitoring: a new IHE profile". Pediatric Radiology. 41 (5): 588–591. doi:10.1007/s00247-010-1903-4. PMID   21491199. S2CID   31939028.
  3. "IEC 61910-1:2014". International Electrotechnical Commission. 24 September 2014. Retrieved 1 June 2017.
  4. "Profiles". IHE. Retrieved 1 June 2017.
  5. American College of Radiology (ACR) Dose Index Registry (DIR)
  6. The Joint Commission FAQ Page
  7. Eurotom 97/43 Archived 2012-10-30 at the Wayback Machine
  8. ACR White Paper on Radiation Dose in Medicine

Further reading