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13 Sep 2023
Ionizing Radiation, Medical Physics, Radiation Safety, Radioactive Material Versant Physics 0 comment

The Units to Measure Radiation: Explained

The history of radiation units ties closely to the development of our understanding about radiation and its effects. The discovery of x-rays and radioactivity in the late 19th century by scientists like Wilhelm Roentgen, Henri Becquerel, and Pierre Curie paved the way for the exploration of radiation measurement.

As our knowledge of radiation’s effects on living organisms grew, the need for standardized units became evident. The roentgen was one of the earliest units to measure ionization, followed by the introduction of the curie to measure radioactivity. Over time, advancements in our understanding of radiation’s biological effects led to the development of units like the rem and the sievert.

Creating Radiation Units

The development of the SI system (International System of Units) established a standardized set of units to provide a coherent and universal way to measure radiation. The gray and the sievert were introduced as the primary units for absorbed dose and equivalent dose, respectively, within the SI system.

Four distinct yet interconnected units quantify radioactivity, exposure, absorbed dose, and dose equivalent. The mnemonic R-E-A-D creates a simple way to recall these units, which consist of a combination of commonly used (British, e.g., Ci) and internationally recognized (metric, e.g., Bq) units.1 Below, we will detail the mnemonic and discuss the history of the radiation units along with their relevant scientists:

Radioactivity defines the release of ionizing radiation from a substance. Whether it emits alpha or beta particles, gamma rays, x-rays, or neutrons, the radioactivity of a material is a measure of how many atoms within it decay over a specific period of time. The curie (Ci) and becquerel (Bq) units quantify radioactivity.1


Antoine Henri Becquerel was a French physicist, engineer, and Nobel laureate who discovered evidence of radioactivity. Becquerel’s earliest works centered on the subject of his doctoral thesis: the plane polarization of light, with the phenomenon of phosphorescence and absorption of light by crystals. Early in his career, Becquerel also studied the Earth’s magnetic fields. In 1896, Becquerel discovered evidence of radioactivity while investigating phosphorescent materials such as some uranium salts. For his work in this field, he shared the 1903 Nobel Prize in Physics with Marie Curie and Pierre Curie. The SI unit for radioactivity, becquerel (Bq), is named after him.2

The curie (Ci) unit was created in 1910 by the International Congress of Radiology to measure radioactivity. Pierre Curie, another French physicist, and his wife Marie Curie, who also sat on the committee that named the unit, were the inspirations for the name through their radioactive studies. The original definition of the curie was “the quantity or mass of radium emanation in equilibrium with one gram of radium (element)”.3 In 1975, the becquerel replaced the curie as the official radiation unit in the International System of Units (SI) where 1 Bq = 1 nuclear decay/second4. The relationship between the two units is 1 Ci = 37 GBq (giga becquerels).

Exposure quantifies the extent of radiation going through the atmosphere that reaches a person’s body or a material. Numerous radiation monitors gauge exposure, utilizing the units of roentgen (R) or coulomb/kilogram (C/kg).1

The roentgen is a legacy unit of measurement for the exposure of X-rays and gamma rays. This unit is defined as the electric charge freed by such radiation in a specified volume of air divided by the mass of that air and has the value 2.58 x 10-4 C/(kg air).5 It was named after Wilhelm Roentgen, a German physicist who discovered X-rays and was awarded the first Nobel Prize in Physics for the discovery.

In 1928, the roentgen became the first international measurement quantity for ionizing radiation defined for radiation protection. This is because it was, at the time, the most easily replicated method of measuring air ionization by using ion chambers.6 However, although this was a major step forward in standardizing radiation measurement, the roentgen had a disadvantage: it was only a measure of air ionization rather than a direct measure of radiation absorption in other materials, such as different forms of human tissue. As a result, it did not take into account the type of radiation or the biological effects of the different types of radiation on biological tissue. Consequently, new radiometric units for radiation protection came to be which took these concerns into account.7

The SI unit for measuring exposure to ionizing radiation is coulomb per kilogram (C/kg). Interestingly, unlike other SI radiation units, this unit does not have a specific name. It officially replaced the previous unit, the roentgen, in 1975, with a transition period of at least ten years.8 The SI unit of electric charge, the coulomb, was named in honor of Charles-Augustin de Coulomb in 1880. Charles-Augustin de Coulomb was a French physicist whose best-known work is his formulation of Coulomb’s law. This law states that the force between two electrical charges is proportional to the product of the charges and inversely proportional to the square of the distance between them. He also made important contributions to the fields of electricity, magnetism, applied mechanics, friction studies, and torsion.9

Absorbed dose refers to the quantity of energy that is absorbed by an object or person where the energy is deposited by ionizing radiation as it passes through materials or the body. The units, radiation absorbed dose (rad) and gray (Gy), measure absorbed dose.1

In 1953, the International Commission on Radiation Units and Measurements (ICRU) adopted the unit rad at the Seventh International Congress of Radiology. This was the unit that replaced the rep, roentgen equivalent physical (detailed later in this blog). Although many believe that the rad is an abbreviation of “radiation absorbed dose”, the ICRU never identified it as such. This suggests that the term “rad” was as a standalone word to be a unit for absorbed dose. There was no documented discussion regarding the use of the rad prior to the Seventh International Congress of Radiology. The closest discussion was during the meeting in 1951 when they determined the need for this type of unit. In 1975, the gray (Gy) replaced the rad as the SI unit of absorbed dose where 1 Gy = 100 rad.10

Louis Harold Gray was a 20th century English physicist who worked mainly on the effects of radiation on biological systems. He was one of the earliest contributors to the field of radiobiology. He worked as a hospital physicist at Mount Vernon Hospital in London and developed the Bragg–Gray equation in collaboration with the father and son team of William Henry Bragg and William Lawrence Bragg. Bragg-Gray theory is the basis for the cavity ionization method of measuring energy absorption by materials exposed to ionizing radiation. Gray’s contributions to radiobiology were numerous. Amongst many other achievements, he developed the concept of RBE (Relative Biological Effectiveness) of doses of neutrons and initiated research into cells in hypoxic tumors and hyperbaric oxygen.11 Gray defined a unit of radiation dosage (absorbed dose) which was later named after him as an SI unit, the gray.

Dose equivalent, also known as effective dose, is a measurement that combines the amount of radiation absorbed and the impact it has on the human body. When it comes to beta and gamma radiation, the dose equivalent is equal to the absorbed dose. However, for alpha and neutron radiation, the dose equivalent surpasses the absorbed dose because these types of radiation have a greater biological impact resulting from their increased ability to damage tissue. To quantify dose equivalent, we use the units of roentgen equivalent man (rem) and sievert (Sv).1

Roentgen equivalent man, or “rem”, was first proposed for use in 1945, but under a different abbreviation. The roentgen was the only unit capable of expressing a radiation exposure at the time. However, it fell short being specifically measurable for photons. Workers came into contact with many other forms of radiation such as alpha particles, beta particles, and neutrons, so Herbert Parker, British-American physicist, created units that would be able to gauge exposures to many types of radiation. These were the roentgen equivalent physical (rep) and the roentgen equivalent biological (reb). Due to similarity in pronunciation between rep and reb, reb was eventually renamed to roentgen equivalent man or mammal (rem) to avoid confusion.

The first appearances of the rem unit in scientific literature were not until 1950.10 The rem related to the rad by multiplying the latter by a quality factor (QF) used to account for the varying biological effects of the different types of radiation. The rad in turn may be obtained from the roentgen by multiplying a dose conversion factor. In air, the dose conversion factor relationship between rad and roentgen is 1 R = 0.88 rad. The absorbed dose to a material is in turn found by multiplying 0.88 by the ratio of the mass energy absorption of the material to that of air.12

Rolf Maximilian Sievert was a Swedish medical physicist. He is best known for his work on the biological effects of ionizing radiation and his pioneering role in the measurement of doses of radiation, especially in its use in the diagnosis and treatment of cancer.13 Sievert contributed significantly to medical physics, earning him the title of “Father of Radiation Protection”. The sievert (Sv), the SI unit representing the stochastic health risk of ionizing radiation, is named after him. The sievert officially replaced the rem as the international SI unit in 1979 with 1 Sv = 100 rem.14

Conclusion

In summary, the history of radiation units is a journey that reflects the progress in our understanding of radiation’s properties and its impact on living organisms. The development of these units has enabled safer and more accurate measurement and assessment of radiation exposure and its effects on human health. By understanding the intricate relationship between radiation and our bodies, we can now take proactive measures to mitigate its harmful effects and promote a safer environment for all.

Sources

  1. NRC: Measuring Radiation. Nrc.gov. Published 2017. https://www.nrc.gov/about-nrc/radiation/health-effects/measuring-radiation.html
  2. The Nobel Prize. The Nobel Prize in Physics 1903. NobelPrize.org. Published 2019. https://www.nobelprize.org/prizes/physics/1903/becquerel/biographical/
  3. Curie – Unit of Radioactivity | nuclear-power.com. Nuclear Power. https://www.nuclear-power.com/nuclear-engineering/radiation-protection/units-of-radioactivity/curie-unit-of-radioactivity/
  4. ‌ Bell DJ. Becquerel (SI unit) | Radiology Reference Article | Radiopaedia.org. Radiopaedia. https://radiopaedia.org/articles/becquerel-si-unit
  5. ‌ Bashir U. Roentgen (unit) | Radiology Reference Article | Radiopaedia.org. Radiopaedia. Accessed August 29, 2023. https://radiopaedia.org/articles/roentgen-unit?lang=us
  6. ‌ Roentgen – Unit of Exposure | nuclear-power.com. Nuclear Power. Accessed August 29, 2023. https://www.nuclear-power.com/nuclear-engineering/radiation-protection/radiation-exposure/roentgen-unit-of-exposure/
  7. ‌ Roentgen (unit) explained. everything.explained.today. Accessed August 29, 2023. http://everything.explained.today/Roentgen_(unit)/
  8. ‌ Bell DJ. Coulomb per kilogram | Radiology Reference Article | Radiopaedia.org. Radiopaedia. Accessed August 29, 2023. https://radiopaedia.org/articles/coulomb-per-kilogram
  9. ‌ Laboratory NHMF. Charles-Augustin de Coulomb – Magnet Academy. nationalmaglab.org. https://nationalmaglab.org/magnet-academy/history-of-electricity-magnetism/pioneers/charles-augustin-de-coulomb/
  10. ‌ Why Did They Call It That? The Origin of Selected Radiological and Nuclear Terms. Museum of Radiation and Radioactivity. Accessed August 29, 2023. https://orau.org/health-physics-museum/articles/selected-radiological-nuclear-terms.html#rad
  11. ‌ LH Gray Memorial Trust: About L.H. Gray. www.lhgraytrust.org. Accessed August 29, 2023. http://www.lhgraytrust.org/lhgraybiography.html
  12. ‌Dosimetric Quantities and Units. U.S. NRC. Published October 25, 2010. Accessed September 11, 2023. https://www.nrc.gov/docs/ML1122/ML11229A688.pdf
  13. Aip.org. Published 2023. Accessed August 29, 2023. https://pubs.aip.org/physicstoday/Online/8433/Rolf-Sievert
  14. ‌ Bell DJ. Sievert (SI unit) | Radiology Reference Article | Radiopaedia.org. Radiopaedia. https://radiopaedia.org/articles/sievert-si-unit?lang=us
21 Apr 2023
Cancer Treatment, Medical Physics, Nuclear Medicine, Radiation Therapy Versant Physics 0 comment

X-Ray Evolution: An Accident that Revolutionized Healthcare

It is no question that modern diagnostic imaging and radiation therapy machines play large parts in today’s healthcare. But where did x-ray usage begin? Let’s journey through the timeline of when the first x-ray was taken to today and the growth of its technology into some of the most common machines you may see for diagnostic imaging and radiation therapy.

Diagnostic Imaging

1895

Wilhelm Conrad Röntgen, a physicist, became the first person to observe x-rays, and quite accidentally. Röntgen noticed a glow coming from a nearby chemically coated screen while testing whether cathode rays (known today as electron beams) could pass through glass. After examining the rays emanating from the electrons impacting the glass and their unknown nature, Röntgen dubbed them as “X-rays”. He learned that x-rays could penetrate human flesh but less so higher density substances like bone or lead, and that they were photographable.1

Röntgen’s work paved the way for x-rays to become a vital diagnostic tool in medicine. Dentists such as Otto Walkhoff, Frank Harrison, and Walter König helped spark the advancement of dental radiography, publishing their findings on the topic in 1896.2 During the Balkan War in 1897, doctors used the rapidly improving x-ray radiographs to find bullets and broken bones inside patients on the battlefield.1

1900-1950

Fluoroscopy was invented after the discovery of x-rays in 1900. Continuing into the 20th century, x-rays and fluoroscopy became popular on a consumer level without the risk fully understood. There were rising reports of burns or other skin damage after x-ray radiation exposure; Thomas Edison’s assistant, Clarence Dally, even passed away from skin cancer in 1904 after working extensively with x-rays. Regardless, products like shoe-fitting fluoroscopes were popular from the 1930s until the 1950s so customers at shoe stores could see the bones in their feet.1

On a medical level, scientists progressed with inventing the modern x-ray tube, introducing film into radiology, and the first mammography. Reseachers performed further studies to get a better understanding of the genetic effects of x-ray exposure and the damage caused. Using fluoroscopes in shops tapered off starting in the 1950’s, the practice proven more dangerous than beneficial.3

1970s

X-rays began transitioning into digital imaging by the 1970s which helped save time, money, and storage space.4 Godfrey Hounsfield of EMI Laboratories created the first commercially available CT scanner in 1972. He co-invented the technology with physicist Dr. Allan Cormack and both researchers were later on jointly awarded the 1979 Nobel Prize in Physiology and Medicine.

The cross-sectional imaging, or “slices”, from CT scans made diagnosing health issues like heart disease, tumors, internal bleeding, and fractures simpler for doctors while also being easier on the patients. Through the following years, with how effective the CT scanners proved to be improvements on the design were quickly developed.5

1990s

In the early 1990s, developments with x-ray computed tomography came into a new realm of imaging. Newer CT scanners allowed for the X-ray source to scan in a continuous spiral around the body, which gave an image of a whole organ at once instead of individual cross sections.5 This technique is called helical or spiral CT scanning. C-arm machines created by companies such as Philips introduced Rotational Angiography, in which the C-arm takes a series of images around the patient. This generates an almost 3D picture when viewing the images in a loop.6

Diagnostic Imaging of Today

Diagnostic imaging from the 2000s to present day demonstrate enhanced versions of all diagnostic tools from history. Doctors still use general x-rays for determining severity of injury, check disease, and to evaluate treatment. CT scans have continued to develop so that analysis of issues occurring in a patient’s body can be more clearly seen to determine treatment.7 Mammograms have become instrumental in determining early diagnosis of breast cancer; fluoroscopy still helps doctors today determine effect of movement to certain areas of the body–although not to determine if you should buy a pair of shoes.

Within dental care, veterinary work, and even unexpected industries such as manufacturing and mining, diagnostic imaging has proven its worth.

Radiation Therapy

1895 – 1910

The discovery of x-rays also ushered in research on radiation treatment, eventually leading to some of the machines we see in today’s healthcare. Use of x-ray treatments began between 1895 and 1900, generally delivered as singular, large exposures to the necessary areas. Despite the high doses, the treatments proved to be insufficient over the area of exposure for actual treatment of malignancies, appearing to cause extensive damage to normal surrounding tissues instead.8

1911

As damage from radiation to healthy tissues became more widely known as an issue within the medical world, solutions to a more controlled type of treatment came to creation in 1911. Around this time external beam radiotherapy (XRT) and slow, continuous low-dose-rate (LDR) radium treatments were established from the studied principle of fractionation.8 Splitting the total radiation dose into smaller fractions and delivering it over days achieved better management over cancer growth even while reducing adverse effects to non-cancerous areas of the body.

1920 – 1930

The Coolidge tube, initially invented by William D. Coolidge in 1913 as an improvement over the earlier Crookes tube methods to produce x-rays, became the most popular method for x-ray generation during the 1920s. The Crookes tube used a high voltage between an anode and a cathode, depending on the ionization of the gas in the tube for x-ray production. The Coolidge tube introduced a hot cathode that directly produced electrons from its surface allowing for better control of both energy and intensity of the x-rays produced. Coolidge tubes produced x-rays usable for both diagnostic and therapeutic purposes.

1930 – 1950

Development of more refined machinery truly began within the 1930s for radiation therapy. One of the first machines used for superficial therapy was the Grenz Ray machine. Dr. Gustav Bucky (inventor of the first x-ray grid as well in 1913), invented and made this machine in the 1930s for commercial use by German company Siemens Reiniger. The Grenz Ray machine was effective as a treatment for skin cancers (superficial cancers) due to the rays not passing deep into the body.9 Bucky labeled the rays Granz, the German word for border, as their biological effects seemed to be bordering those of UV light and traditional x-rays.

Treatments for delving deeper started seeing further progression by 1937 through development of supervoltage x-ray treatment; this dubbed the time period from 1930 – 1950 as the “Orthovoltage Era”. Supervoltage x-ray tubes had a staggeringly high kilovolt range compared to previous machines (50 kV to 200 kV). These orthovoltage treatment machines provided higher and variable energies to treat deeper tumors.8 Continued advancements in the Orthovoltage Era became the beginning of electron beam therapy.

1950 – 1980

From the rise in supervoltage x-ray treatment and through inspiration from other machines such as the Grenz Ray machine emerged the linear accelerator. Also known as a LINAC, these machines nowadays are large devices that emit high energy x-rays and electron beams. After use of the first linear accelerators to treat cancer patients in 1953–with lower energy and restricted range of movement–English physicist Frank Farmer developed a comparison between them and other popular machines of the time. This included resonant transformer units, van de Graaff units, and gamma ray units like Co-60 radiation machines.10

In 1962, the conclusions Farmer came to were that LINACs were the ideal choice for larger departments due to a higher price point and hefty size. However, its design at the time left something to be desired. His hopes for linear accelerator improvements included a more robust operation, smaller unit size, and better vacuum systems. Through manufacturers’ dedicated work on improvements up into the 1970s, the LINAC began to fully establish itself as Farmer’s vision came to life with more stable, reliable, compact, and fully isocentric machines.10

Radiation Therapy of Today

After the 1970s, significant changes to linear accelerators slowed. There were no further radical changes to basic structures and concepts for the generation of the x-ray and electron beams. Modern machines became more sophisticated through other improvements. These were advances in beam shaping through the development of multi-leaf collimators, on-board imaging (OBI), and more recently Flattening Filter Free (FFF) designs to permit much greater dose rates. These system and functionality enhancements keep the linear accelerator as the radiation therapy unit of choice for healthcare today.10 Delivering radiation doses deep into cancerous tumors of a patient while minimizing damage to healthy tissue via intensity modulated radiation therapy (IMRT) is achieved confidently with these ever-improving LINACs.

Through the x-ray technologies developed over the last century, scientists continue to develop new methods to safely deliver radiation therapy. Crossing the linear accelerator with the diagnostic imaging capabilities of CT scanners created TomoTherapy®, another radiotherapy option still widely used today. TomoTherapy® machines allow for more precise tumor targeting and preservation of healthy tissue, taking images of cancerous tumors before treatment. The machine will then rotate during treatment to deliver the radiation dose slice by slice, in a spiral-like pattern.11

X-ray radiotherapy is only one type among many cancer treatments now. However, the machines have been honed through the years to create reliable products for healthcare and even veterinary practices. What was once a general, indirect target of radiation exposure has become an extremely pin-pointed, safer technique for the benefit of patients today.

Summary and Conclusion

In summary, x-rays have come a long way since their discovery in 1895 by Wilhelm Conrad Röntgen, revolutionizing medicine. Used for both diagnostic and therapeutic purposes, x-rays underwent significant technological advancements over time starting with producing the first x-ray images on photographic plates. In the early 1900s, the use of x-rays for therapy began with the treatment of skin diseases. By the 1920s, the further developments allowed for the production of higher-energy x-rays. Once in the 1930s, the development of megavoltage x-ray machines allowed for deeper penetration into tissues. Linear accelerators were developed in the 1950s to produce high-energy x-rays and electrons. The 1960s brought the development of computed tomography (CT), which allowed for cross-sectional imaging of the body. In the 1970s, digital radiography was introduced, which allowed for faster image acquisition and processing.

The Versant Physics team has experience that covers a range of equipment including dental units, mobile c-arms and Cone-beam CTs, as well as high energy LINACs and even Proton Therapy units and Cyclotrons. To learn more about how our services can help you, contact us to set up a meeting.

References

  1. History.com Editors. German scientist discovers X-rays. HISTORY. Published July 17, 2019. https://www.history.com/this-day-in-history/german-scientist-discovers-x-rays
  2. ‌Pauwels, Ruben. (2020). HISTORY OF DENTAL RADIOGRAPHY: EVOLUTION OF 2D AND 3D IMAGING MODALITIES.
  3. History Of X-Ray Imaging • How Radiology Works. Published March 12, 2021. https://howradiologyworks.com/history-xray-imaging/
  4. ‌X-Ray Technology: The Past, Present, and Future :: PBMC Health. www.pbmchealth.org. Accessed March 24, 2023. https://www.pbmchealth.org/news-events/blog/x-ray-technology-past-present-and-future#:~:text=Quickly%2C%20military%20doctors%20realized%20the%20life-saving%20potential%20X-rays
  5. Martino S, Cae R, Reid J, Teresa G, Odle B. Computed Tomography in the 21st Century Changing Practice for Medical Imaging and Radiation Therapy Professionals. Published 2008. https://www.asrt.org/docs/default-source/research/whitepapers/asrt_ct_consensus.pdf?sfvrsn=2ac0c819_8
  6. How Philips has been advancing patient care with X-ray for more than a century. Philips. https://www.philips.com/a-w/about/news/archive/standard/news/articles/2020/20201106-how-philips-has-been-advancing-patient-care-with-x-ray-for-more-than-a-century.html
  7. Hanson G. 7 Types of Diagnostic Imaging Tests You May Assist with as a Radiologic Technologist | Rasmussen College. www.rasmussen.edu. https://www.rasmussen.edu/degrees/health-sciences/blog/types-of-diagnostic-imaging/
  8. Cuffari B. The Evolution of Radiotherapy. News-Medical. Published November 11, 2021. Retrieved on March 24, 2023. https://www.news-medical.net/health/The-Evolution-of-Radiotherapy.aspx.
  9. Grenz ray machine used for superficial therapy | Science Museum Group Collection. collection.sciencemuseumgroup.org.uk. https://collection.sciencemuseumgroup.org.uk/objects/co134659/grenz-ray-machine-used-for-superficial-therapy-x-ray-machine
  10. Thwaites DI, Tuohy JB. Back to the future: the history and development of the clinical linear accelerator. Physics in Medicine and Biology. 2006;51(13):R343-R362. doi:https://doi.org/10.1088/0031-9155/51/13/r20
  11. National Cancer Institute. External Beam Radiation. National Cancer Institute. Published May 1, 2018. https://www.cancer.gov/about-cancer/treatment/types/radiation-therapy/external-beam
21 Feb 2023
Uncategorized Versant Physics 0 comment

4 Ways to Protect Healthcare Workers from Scatter Radiation

Patient safety is a major focus of radiation treatments and diagnostic imaging procedures. However, radiation workers in the healthcare field are also at risk for exposure to unsafe amounts of radiation—primarily scatter radiation—due to the nature of their work.

Protecting healthcare workers from scatter radiation is an important part of a successful radiation safety program. In today’s blog post, we discuss what scatter radiation is, effects on the human body, and four ways to help limit occupational exposures.

What is scatter radiation?

During typical diagnostic imaging procedures such as fluoroscopy, CT, or mammography exams, healthcare workers are exposed to scatter radiation.

X-ray machine for scatter radiation primary source example

Scatter radiation is a type of secondary radiation.1 It occurs when the primary beam from a source such as a CT Scanner, X-Ray, or Fluoroscopy unit interacts with matter. For scatter radiation, the “matter” that X-ray beams are most often interacting with is the patient in a procedure. As the primary beam intercepts the patient’s body tissues, some X-rays will bounce off those atoms to create secondary, specifically scatter, radiation.

Scatter radiation can be moderated through some machine positioning, like the C-Arm. The primary beam for a C-Arm is sent up through the table into a patient before being read by the other side of the machine. In this case, the back scattered radiation produced by the entrance beam below the table is mostly towards the floor and lower extremities of the radiation worker. Scatter coming out of the exit radiation from the patient is also present but reduced in intensity as compared with the entrance scatter below the table. Not all units are designed in this manner, however, and these scattered rays will be present in the imaging room until the diagnostic x-ray machine is turned off.2

What are the effects of scatter radiation on the human body?

Professionals performing diagnostic imaging procedures, such as radiologic technologists, are those most susceptible to scatter radiation emanating from a patient. Scatter radiation does not have as much energy as a primary X-ray beam does but over time it still can cause harm without technologists taking appropriate protective measures. This is a real risk for radiation workers, as they are potentially exposed to scatter radiation multiple times a day while running patients through their diagnostic imaging.

Without appropriate protection, radiation workers will begin to experience adverse health effects from prolonged scatter radiation exposure. This is because radiation has the potential to damage living tissue and organs.3 Severity of damage scope is dependent upon several factors:

  • the manner and length of time exposed
  • characteristics of the exposed person
  • the type of radiation
  • any involved radioactive isotopes
  • the sensitivity of affected tissue and/or organs

Since scatter radiation exposure is at lower energy and accumulated over longer periods of time (because technologists are performing X-ray procedures as a daily task), the risks of adverse effects are not as severe. However, radiation workers face an increased risk of cancer over a lifetime if protection is not made a priority in the workplace.4

Protection from your occupational exposure

Radiation worker protection should take as much priority as patient protection when it comes to radiation exposure. The ALARA principle is the standard for keeping radiation exposure “As Low As Reasonably Achievable”. As such, following these practices would be our top recommendation for limiting occupational exposure, with a couple additions. Here are the four ways to be best protected from scatter radiation:

Time

Limit the time that you spend near a radiation source while working. The more time that you are exposed to scatter radiation increases the possibility for a higher overall dose. If you must work near a source of radiation, work as quickly as possible and then leave the area to avoid spending more time around the source than necessary.

Distance

The second ALARA principle, distance, encourages distancing yourself from radiation sources. Radiation exposure decreases with distance, following an inverse square law for a point source. Doubling your distance will cause dose rate to go down by a factor of four. A “general rule of thumb” you can calculate is that any scatter radiation one meter from the side of the patient will be 0.1% of the primary x-ray beam intensity.5 This is helpful to keep in mind when considering how much distance you’re able to maintain during patient treatments.

Shielding

Shielding example for scatter radiation

Shielding is the well-known practice of placing a barrier between you and a radiation source for minimizing exposure. The material for these barriers normally depends on radiation source type. For any radiation, though, the shielding should be something that absorbs radiation such as lead, concrete, or water. The practice of shielding can also include personal protective equipment (PPE) directly worn by individuals, such as thyroid shields, radiation protection glasses, and lead vests. For scatter radiation, a combination of moveable shields either suspended from the ceiling or on rollers in addition to fixed table shields are ideal.6 In general, shields are placed close to the source as that allows for a greater solid angle to be covered.

Dosimetry Program

As medicine and medical technology advances, the use of radiation has become more ubiquitous; there is now a greater risk of ionizing radiation exposure for occupational workers. The need for effective radiation monitoring has become more crucial to account for these modern practices.

Radiation dosimeters worn on the body are able to provide a record of absorbed dose from ionizing radiation. Although the measurement of exposure so obtained is not direct protection, being able to track your absorbed dose is essential to the practice of radiation safety. Through regular dose readings, you can know if you’ve reached or are close to reaching the annual NRC occupational dose limits. In the long run, this is a great method for protection against scatter radiation; should you exceed dose limit, you can adjust your work for the rest of the year to avoid further exposure. Thanks to dosimetry programs, radiation workers can stay informed and avoid potential risks better than ever.

The Take-Away

Scatter radiation, even if not as potent as a primary radiation dose, can still have adverse effects over time. To avoid potential increases to your risk of cancer down the road, it’s essential to maintain protective habits when performing diagnostic imaging procedures. Following the ALARA principles and remembering the long-term value of a dosimetry program can keep exposure to scatter radiation and its negative health effects to a minimum.

Versant Physics’ dosimetry management services are available to help your company take that step further in scatter radiation protection. Learn more about our knowledgeable support team and the Instadose family of dosimeters today. For more information regarding shielding, scatter radiation, and applicable policies for a medical radiation safety officer, try our online MRSO or Medical X-Ray courses.

References

  1. What is primary radiation and secondary radiation? Reimagining Education. Published August 26, 2022. Accessed February 20, 2023. https://reimaginingeducation.org/what-is-primary-radiation-and-secondary-radiation/
  2. Lambert K. hps.org. Health Physics Society. Accessed February 20, 2023. https://hps.org/publicinformation/ate/q11396.html
  3. Radiation and health. Who.int. Accessed February 20, 2023. https://www.who.int/news-room/questions-and-answers/item/radiation-and-health
  4. Morgan WF, Sowa MB. Non-targeted effects induced by ionizing radiation: mechanisms and potential impact on radiation induced health effects. Cancer Lett. 2015;356(1):17-21. doi:10.1016/j.canlet.2013.09.009
  5. Lovins K. hps.org. Health Physics Society. Accessed February 20, 2023. https://hps.org/publicinformation/ate/q11780.html
  6. Klein LW. Proper Shielding Technique in Protecting Against Scatter Radiation. Vascular Disease Management. Published June 2021. Accessed February 20, 2023. https://www.hmpgloballearningnetwork.com/site/vdm/commentary/proper-shielding-technique-protecting-against-scatter-radiation

05 Jan 2023
Medical Physics, Odyssey Software, Personnel Dosimetry, Radiation Safety, Radiation Therapy, Uncategorized Versant Physics 0 comment

A Year in Review & New Resolutions

Coming full circle to another new year invigorates millions. It is a time to reflect and develop goals for a better self, career, or quality of life. Versant Medical Physics & Radiation Safety also looks eagerly into 2023 and new opportunities of growth. We strive to provide our services to continuously benefit existing or future clients—even while appreciating our building-block actions of 2022. Even as our teams replace calendars in the office and spread poor puns about not seeing each other since last year, we shape our goals to provide exceptional support for healthcare providers to ensure safe workplaces and practices:

Remaining at the Forefront of Medical Physics and Radiation Safety

Sometimes the best resolution is to maintain healthy habits achieved from the year before. Versant Physics will continue its focus on sustaining its status as a trusted, knowledgeable business. Our consulting services demonstrate excellence within medical physics and radiation safety and will continue to in 2023. This involves keeping up with new discoveries in science, seeking value-add opportunities, and ensuring our provided support is top quality. It is with this idea that we strive to keep our competitive edge in all aspects.

Maintaining an edge means aligning ourselves with strong sources when the chances arise. In the past year, Versant acquired Radiological Physics Services, Inc (RPS) and completed a business merger with Grove Physics, Inc. We were excited to welcome Joseph Mahoney from Grove Physics as the new Vice President of Diagnostic Physics. Additionally, Versant brought in the talents of Ray Carlson and his team within RPS. The overall consolidation of these companies’ resources with Versant’s has increased services towards our clients. We are enthusiastic about efficiently using these combined assets to their full potential in 2023.

Another constituent to higher performance levels becoming achievable in the new year is that Versant Medical Physics achieved their ISO/IEC 27001:2013 certification in 2022. This certification demonstrates our dedication to being a trusted source. Not only can we be sought for our expertise in the field, but now to maintain personal information and customer data through even better safeguards in 2023. Being certified for strict security and compliance standards allows for peace of mind to clients using our Odyssey software; the protection of which is performed by our own security management team.

Versant Medical Physics and Radiation Safety ISO/IEC 27001:2013 Certification

As a web-based, modern management system, Odyssey’s enhanced security is not its only feature that is being refined. Odyssey is kept as a radiation software suite that our clients can trust for the central administration of radiation safety programs. This is accomplished by our development team’s dedication to the software’s continuous improvement based off internal and external feedback. Radiation safety programs can quickly become complex and difficult to manage for healthcare companies, large or small. In addition to Versant’s experienced personnel, Odyssey provides clients an all-in-one platform to manage their program more easily and effectively. Within 2023, Versant’s development team will be focusing on projects to publish customizable reports. They will also revamp the centralized audit logging in Odyssey as part of software enhancement requests received through the feedback system.  

Radiation Safety Implementation and Maintenance

Radiation safety has an extensive list of requirements and regulations set through organizations such as the NRC. The necessity of radiation safety programs is unquestionable when working with radioactive substances or ionizing radiation generating equipment. However, the issue remains that implementation and maintenance of these programs can become complicated fast. In 2023, Versant Medical Physics will assist healthcare providers simplify program compliance, protecting their employees and overall business.

Versant provides a variety of services, from dosimetry management to the support of our physicists, Radiation Safety Officers, and specialists. These professionals’ collective years of experience range over key modalities of radiation safety:

  • Any company—regardless of size—can run their badge program through our dosimetry monitoring services. Doing so assures access to our competent technical support team that can accommodate any company’s needs. Dosimetry badge management is top priority for this team to make your program easier to handle. The support team provides technical and customer service to your employees, so they understand best practices for the dosimeters they wear and to simplify compliance. This lets your employees quickly get back to what they do best: providing healthcare to those who need it.
  • Versant Medical Physics has board-certified physicists that cover regulatory and diagnostic services across the board. Versant’s physicists are driven to provide top-tier assistance so that our clients meet regulatory guidelines and ALARA fundamentals easily to protect people: employees, patients, and the general population. We will continue to achieve this in 2023 through provision of full-service support for your company’s radiation safety program’s crucial areas. These services can include but are not limited to equipment testing, radiation shielding and design, and comprehensive audits.

Medical Physics and Radiation Safety Certification and Training Support

Another component of medical physics and radiation safety is requirement (depending on role) of being certified for one’s work. Certifications in this field surround topics such as radioactive material handling in a continually evolving medical field. Our online continuing education training courses are available at any time to earn certifications approved by CAMPEP, AAHP, and ASRT. Many professionals within the medical physics and radiation safety fields need continuing education credits; this can be for compliance purposes or to take on new responsibilities within their company. In addition to providing support for our clients, Versant provides certified courses such as

  • Medical Radiation Safety Officer (MRSO) Training – Compliance knowledge and lectures provided to learn day-to-day requirements for a new Medical RSO. This course has been complimented for its clarity and precision of material.
  • Medical X-Ray Radiation Safety Training – Designed for anyone managing a radiation safety program or working with radiative machines in a medical environment. This course is practical and informative to prepare for any inspection.
  • Fluoroscopy Courses – Safety training that details optimization of fluoroscopy techniques while maintaining ALARA practices. This course has been recognized by previous customers for being comprehensive with employable practices.
  • Department of Transportation (DOT) Training – A combination of safety training for radioactive material transport and general handling. Usable for anyone within the shipping process such as technologists.

Our board-certified physicists are available through online communication to assist with questions or understanding of the content. This ensures that students feel supported through the process. By the end, each student can walk away with an accredited certification for the betterment of their career. Versant Medical Physics will ensure this content reaches as many people as possible to deepen their knowledge base in 2023.

Connecting and Sharing Ideas

Over the last decades, social media became an increasingly significant channel of communication for businesses. As a platform to promote their services and generate brand, companies connect in fashions more popular with the public. Although Versant has seen increases in our reach through social media followings and to the visitors of our website, there are still opportunities to further connect with our fellow companies, clients, and acquaintances within the medical physics and radiation safety fields.

In 2023, Versant Physics will bring a stronger focus into revitalizing our most popular channels for engaging content: our blog and podcast. Versant’s blog is a space for informational posts about radiation in the world and its various practices/safe handling in healthcare, as well as general tutorials on our Odyssey software. With the VersantCast Podcast, hosted by our very own medical physicist, Dr. Eric Ramsay, we take our listeners through various topics surrounding radiation, physics, and healthcare with the expansive knowledge of special guests. We are excited to work back into periodic postings and create subject matter that informs, inspires, and educates both readers and listeners alike.

Versant will also strive to further our network through our most popular social media platforms, being LinkedIn, Facebook, and Twitter. Even as a small company in a niche field, social media gives us the opportunity to connect with other people and businesses within the medical physics and radiation safety industry. Creating spaces to share ideas and new discoveries in science are beneficial to us as well as our followers to further our security in the knowledge surrounding the many fields that handle radiation. To join Versant in our goal to be more connected within the industry, you can follow us on LinkedIn, Facebook, and Twitter.

A Leadership Team that Inspires

Our devoted leadership team’s optimistic goals have shaped the future of Versant Medical Physics since 2016 to bring today’s success. Closing out our list of resolutions, our members of leadership provided what they strive to see to fruition in 2023:

Marcie Ramsay – President, CEO

“As president, I hope to continue providing a positive and supportive workplace environment for our professionals. The new year will also bring the opportunity for me to encourage our team to explore new areas of personal interest and work-life balance through Versant Physics’ recent subscription to the online education platform, MasterClass. On a personal note, I intend to devote more time to daily meditation and reflection.”  

Eric Ramsay – Vice President, Commissioning

“Techniques for treatment in Radiation Therapy get more complex each year. Keeping up one’s knowledge base and gaining expertise in new modalities is challenging with a busy schedule. So, a suitable (and frankly, essential) resolution for the new year will be to focus on continuing education and professional development. This involves staying up to date with the latest research and techniques in the field, attending conferences and workshops, as well as seeking out opportunities for collaboration and networking with other professionals including the staff physicists at Versant. This resolution also includes taking steps to maintain a healthy work-life balance as burn out doesn’t help anyone.”

Ben Ramsay – Vice President, Technology & Finance

“Continue to develop a security mindset. With the increase in cyberattacks globally, and the risks internal and external to Versant, establishing a security-focused mindset is one of our goals in line with our ISO 27001 certification. I will also be focusing on improvement of Odyssey usability for existing clients and ways to bundle the software into our services with non-Odyssey customers that will provide enhanced value. Lastly, Versant will benefit from focuses on cross training staff in 2023 so that we are more flexible and capable of maintaining the highest levels of service possible.”

Joseph Mahoney – Vice President, Diagnostic Physics

“In 2023, I will be aiming for improved frequency and clarity of our client communication. Staying up to date and responsive towards the ever-changing regulatory environment will also allow for a strong start into the new year. Aligning with Versant’s desire for our teams to maintain work-life balances, there will be a strong focus in optimization of physical presence for our staff of physicists in geographic regions only where they are most needed so that they all can get back home more often.”  

Cheers to a productive and exciting 2023!

24 Aug 2022
dosimetry wearers
Dosimetry, Instadose+, Personnel Dosimetry, Radiation Safety, Radiation Safety Officer Versant Physics 0 comment

The 3 Best Personnel Dosimeters: Which Should You Choose?

Continual advances in medicine and medical technology have introduced a greater risk of exposure to ionizing radiation for occupational workers. This has increased the need for effective radiation monitoring services which are a key component of a compliant, well-run radiation safety program.

The problem for most new radiation safety officers is the sheer number of dosimeter types to choose from. How do you know which is the best personnel dosimeter for your radiation safety program? When should you consider phasing out your program’s existing dosimeters for something new?

To help you make your decision, we’ve put together this expert guide on the 3 best personnel dosimeters, their applications, and general specifications.

Instadose+ Wireless Dosimeter

The Instadose+ dosimeter badge is one of the best ways to effectively track cumulative dose for high-risk employees.

Instadose+ Dosimeter

These revolutionary electronic dosimeters utilize Bluetooth technology, Direct Ion Storage (DIS), and SmartMonitoring to wirelessly and remotely transmit on-demand dose data. Mobile devices, such as a smartphone or tablets, as well as PCs or hotspot stations, are used to transmit and record the readings to the wearer’s private account.

The Instadose+ is the best personnel dosimeter for occupational workers like:  

  • Healthcare workers
  • Nuclear medicine professionals
  • Chiropractors
  • Veterinarians
  • Power plant employees
  • Military personnel
  • Flight attendants
  • Lab assistants

Instadose+ badges have a useful dose range of 1 mrem – 500 rem (0.01 mSv – 5 Sv) and a minimum reportable dose of 3 mrem (0.03 mSv).

Energy response:

  • Photon 5 keV – 6 keV

Instadose+ badges are ideal for occupational workers who want access to their own data at the drop of a hat.  The digital read-outs are recorded on a regular basis in accordance with the needs of the radiation safety program. This means no off-site processing.

TLD/OSL Dosimeters

The Genesis Ultra TLD-BP is a lightweight, eco-friendly, thermoluminescent dosimeter. It consists of two parts: a sealed blister pack, which protects the TLD’s internal components, and a separate holder with a clip for attaching to the collar or waist. The TLD also comes with a unique serial number that makes reassigning and tracking an individual’s occupational dose easier.

This personal dosimeter is useful for occupational workers with potential exposure to gamma, beta, neutron, or X-ray radiation. It can be used in a wide range of applications, including:

  • Nuclear medicine facilities
  • Medical imaging centers
  • Diagnostic research facilities
  • Hospitals
  • Universities
  • Nuclear power plants
  • Industrial facilities

The Genesis Ultra TLD-BP has a minimum reportable dose of 1 mrem (0.01 mSv) and a useful dose range of 1 mrem – 1000 rad (0.01 mSv – 10 Gy).

Energy response:

  • Photon 5 keV – 6MeV
  • Beta 0.251 MeV – 5 MeV
  • Neutron (TLD): Thermal – 6 MeV

Unlike with the Instadose+ dosimeter, TLDs require off-site processing to obtain the dose information. This process requires an in-house staff person to collect the dosimeters from wearers, send them out for processing, and re-assign new badges on a regular basis.

Ring Dosimeters

Mirion’s durable extremity dosimeters, commonly referred to as ring dosimeters, are the best personnel dosimeter choice for individuals who perform interventional radiographic procedures or who regularly handle radioisotopes.

There are several different options to choose from, including:

These are ideal for measuring low or high energy beta, gamma, or X-ray radiation to the hands and fingers. These dosimeters pair well with the Instadose+, which measures radiation exposure to the whole body, particularly in research and surgical environments.

Depending on the ring badge, the wear period can last from one week up to six months. They also are comfortable to wear under surgical gloves.

So, Which Is the Right Dosimeter for Your Radiation Safety Program?

When choosing a dosimeter for your radiation safety program, we recommend considering the following:  

  • Functionality and scope of use. How will it be worn and by whom?

  • The information you need the dosimeter to record. Do you need to track full body dose, or the dose received to the extremities, like the hands and fingers?
  • Quality. A higher quality better made dosimeter might cost more up front, but it will withstand continual use and record accurate radiation dose.  
  • Processing Requirements. Do you have the administrative support to collect badges from employees, send them out for processing, and redistribute new badges on a regular basis? If not, you may require a digital dosimeter like the Instadose+ that does not require processing.

If you’re still unsure, you can reach out to our physicists for a personal consultation about the best personnel dosimeter for your program.

Personnel Dosimetry Management with Versant Physics

Here at Versant Physics, we are passionate about radiation safety, adhering to ALARA principles, and helping radiation workers feel confident their dose measurements are accurate.

Our team of experienced physicists and technical support specialists will work with you one-on-one to ensure every aspect of your badge program runs smoothly and efficiently. 

With Versant managing your badge program, you can expect:  

  • Unparalleled customer service and technical support. We take care of everything from the initialization of badges for new wearers to badge troubleshooting.

  • Quality badge administration. Our team manages high-dose reports, adding and removing wearers from the program, and communicates consistently with your RSO.

  • Effective compliance administration. Our effective badge management processes are proven to improve compliance, from read day reminders to comprehensive monthly reports.

Schedule a consultation with our dosimetry program management specialists to get started!

17 Aug 2022
Odyssey software on a laptop
Odyssey Software, Radiation Safety, Radiation Safety Officer Versant Physics 0 comment

Odyssey Software: How to Buy in 6 Easy Steps

If you’re struggling to effectively manage the complex, ever-shifting responsibilities of a radiation safety program, we have a solution. Odyssey is a proprietary SaaS product designed by radiation safety experts for radiation safety professionals. It has transformed the way RSOs, EHS specialists, medical physicists, and healthcare professionals manage their programs, with an emphasis on streamlined workflows and minimal costs.

But what is the buying process for software like Odyssey? Refer to this guide to help you understand the ins and outs of purchasing Odyssey and get a feel for what the buying process will be like.

What is Software as a Service (SaaS)?

Before diving into what the Odyssey buying process entails, it may be helpful to understand what exactly we mean when we say that Odyssey is a software as a service (or SaaS) product.

It sounds fancy, but all this means is that the software is accessible through the internet, with your individual account made available through a secure, private login. SaaS products like Odyssey are often referred to as web-based software or on-demand software. Whether you’re at your home office, traveling, or doing an on-site inspection, you have access to the software and your data whenever you need it.

The Benefits of SaaS

There are numerous benefits to using a SaaS product like Odyssey for your radiation safety management needs.

For starters, SaaS products are purchased on a subscription basis. The type of subscription can vary depending on the product and company pricing model. Odyssey, for example, is available for purchase on a monthly or annual basis, with discounts provided for yearly subscriptions. These subscriptions are based on what the end user needs rather than offering everything in a lump sum and forcing you to pay for aspects of the software you have no use for.

SaaS products like Odyssey also allow end users to avoid the hefty up-front cost of purchasing a physical software product. There is no hardware management or expensive software upgrades to contend with. Thanks to the software’s base infrastructure, which is common to all users, any updates are completed behind the scenes and integrated automatically into your account.

Because of this SaaS products are easy to customize to accommodate the individual needs of a client or group.

In summary, the major benefits of SaaS software include:

  • No software installation
  • No license management on your end
  • No equipment updates
  • Cloud-based storage
  • On-demand access

The Odyssey Buying Process

If you’ve never purchased a SaaS product like Odyssey before, the buying process may seem a little overwhelming. However, it is a simple process that can be broken down into six steps.

Step 1: Schedule a Demo

One of the benefits of using a SaaS product over traditional software is that you get to see how it works first. You can schedule an Odyssey demo with our team whenever works best for your schedule.

Once you’re on the calendar, our Sales and Software teams will reach out to introduce themselves and confirm your appointment. They may ask a few questions to narrow down your role, which Odyssey modules you’re interested in, and the size of your dosimetry or radiation safety program. These questions help our team prepare a demo that meets your specific program needs.

We will also send you a Microsoft Teams meeting link for the day of.

Step 2: Receive a Demo

On the appointed day and time, you will meet with our Director of Sales and our Odyssey Implementation Analyst for a virtual demo. The initial demo will last around 45-60 minutes.

During the demo, our team will walk you through what Odyssey is and its basic functionality. We will cover the aspects of Odyssey that you expressed interest in as well. This is an opportunity for you to see the software in action and ask any questions you may have about access, usability, or pricing.

Additional 60-minute follow-up demos can be scheduled as needed.  

Step 3: Review Your Quote

After your demo, our team will send you a custom quote for your Odyssey subscription. The quote will include the license type or modules you discussed during your demonstration, a one-time software implementation fee, and the breakdown of optional training costs.

Step 4: Sign an Agreement

Once you approve your quote, you will receive an End User License Agreement (EULA) for signature. Take your time reviewing this agreement before signing and send any clarifying questions you have directly to our Sales team.

SaaS Odyssey Software

Step 5: Implementation

Once we receive a signed agreement, the Implementation process begins immediately. During this phase, our team works with you 1-on-1 to set up accounts for all Odyssey users and upload your program data. This can include everything from your list of dosimetry wearers to the x-ray machines at your facility. This phase normally takes 2-3 weeks to complete.

Step 6: Additional Training

Odyssey is a user-friendly but comprehensive radiation safety management software. Because of its depth and the number of actions that can be performed throughout the 12 modules, we provide additional training for RSOs and other account holders. Our team of Odyssey experts will train you on each module you’ll use and go over specific workflows to get you started out on the right foot. This step is optional but highly recommended.

Odyssey Customer Support

Another perk of using Odyssey is the continual support you have access to. We don’t just train you and leave you to your own devices (unless that’s what you want!) As you work in the software, questions may arise. You can contact our team directly to submit a ticket to our Support Desk 24/7.  

The Takeaway

Odyssey is changing the way radiation safety officers, EHS specialists, and healthcare professionals manage their programs. It streamlines common administrative processes for more organized and efficient workflows, in addition to providing major cost savings.

If you’re considering making a move to a more efficient radiation safety management software, find out what Odyssey can offer by scheduling a demo today.

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