April 9, 2017
Radiation In Healthcare And Its Measurement
By Michael D. Shaw
Broadly speaking, “radiation” is simply energy in motion—usually at the speed of light, but always at a speed much greater than so-called thermal velocities (the velocities of molecules forming a sample of air). Stedman’s Medical Dictionary refines this for the world of healthcare as: The sending forth of light, short radio waves, ultraviolet rays, or x-rays, or any other rays for treatment, diagnosis, or another purpose.
The term “radioactivity” denotes the emission of ionizing radiation or particles caused by the spontaneous disintegration of atomic nuclei.
Ionizing radiation is radiation with sufficient energy to remove electrons from the orbit of an atom, causing the atom to become charged or ionized. Only the high frequency portion of the electromagnetic spectrum which includes X rays, gamma rays, and the higher ultraviolet is ionizing. There is also particle radiation (alpha, beta, and neutron). Except for certain phenomena such as radioluminescence, ionizing radiation cannot be sensed by humans. Thus, specialized instruments are required.
We are exposed to both natural sources of ionizing radiation (such as radon) and manufactured sources on a daily basis. The greatest part of the annual dose of background radiation that we receive is due to naturally occurring terrestrial and cosmic radiation sources. Not far behind, though, is radiation from various standard medical procedures. This does not include radiation therapy for cancer, which for an affected individual would be the key source.
Common uses of radiation in healthcare include X-ray, and the special cases of mammography and computerized tomography (CT) scanning, certain cardiac diagnostics, and the aforementioned radiation cancer therapy. In nuclear medicine, radioactive material is often injected into the patient, as when radioactive iodine is used to treat thyroid conditions.
The discovery of electromagnetic radiation—other than visible light—is credited to astronomer William Herschel, and the discovery of X-rays to Wilhelm Röntgen, who won a Nobel. It was double Nobel laureate Marie Curie who coined the term “radioactivity.” Sadly, her death in 1934 was attributed to excessive radiation exposure. Indeed, some of her personal items are still too radioactive to be handled today.
And, let’s not forget DNA hero Rosalind Franklin, whose death from ovarian cancer at age 37, in 1958, was very likely triggered by radiation exposure from her X-ray crystallography work.
What probably heightened public awareness of the dangers of ionizing radiation was the gruesome 1932 death of wealthy industrialist, athlete, and playboy Eben Byers, who consumed three bottles per day of radium-laced patent medicine Radithor. After consuming 1400 bottles of the stuff, he developed all sorts of symptoms, causing the FDA and the Federal Trade Commission to get involved. His death was featured on the front page of the New York Times.
The familiar Geiger counter has been around since 1928. Other standard instrumentation methods include scintillation detectors and solid state X-ray and gamma-ray detectors. There is also a need for dosimetry, whereby the exposure of a given individual over time can be determined. Many are familiar with the film badge, as introduced during the Manhattan Project of World War II. Upon exposure to radiation, the film emulsion darkens, and the cumulative “dosage” can be determined.
Other dosimeter methods include thermoluminescent elements and aluminum oxide based optically stimulated luminescence detectors. All of these methods require that the badges be collected, and be sent out for processing—introducing a delay in obtaining the results of two or three weeks.
The new dosimeters use Bluetooth Low Energy (BLE) Technology to transmit dose data. As such, the dosimeters can be read in a number of ways, all securely communicating dose data to Mirion’s servers, allowing the user to view dose history, dosimeter assignment details, dose reads, and status.
** Via smart devices incorporating BLE technology with the instadose app installed
** Via a computer with an instaLink™ USB drive connected
** Via instaLink™ Hotspot Stations installed at your facility (can be connected to your network by Ethernet or WiFi)
This dose data becomes part of Mirion’s web-based Account Management Program, allowing the radiation safety officer to manage individual wearers, devices, and locations, and get real-time access to account details, dosimeter assignments, reports, and pertinent account information. Significantly, no badges ever have to be collected and sent away for processing. In fact, any Instadose+ Dosimeter can be interrogated at any time with a suitably outfitted computer or mobile device.
Finally, the Instadose+ Dosimeter is personalized with the wearer’s name, encouraging them to take ownership in their health and safety. One wonders if the great minds of Marie Curie or Rosalind Franklin could have imagined such technology.