It’s time for a lesson in Physics to explain why radiofrequency energy (RF) is not ionizing radiation.
First of all, what is Radiation?
Radiation is the transmission of energy from a source that travels through space in the form of waves or particles. The warmth that we feel under the sun on a freezing winter day is energy radiated in the form of heat. Radiation exists across an electromagnetic spectrum from very low-energy (low-frequency) to very high-energy (high-frequency). Depending on the energy of the radiated particles, radiation can be categorized as ionizing (high-energy, high-frequency) and non-ionizing (low-energy, low-frequency).
All types of radiation have specific wavelengths and frequencies correlated in an inverse relationship. Wavelengths are the measurement from one peak of the wave to the next peak—think ocean waves. The more waves we see during a period of time, the higher the frequency, the shorter the wavelength, the higher the energy. The inverse relationship is depicted in this equation:
is a type of non-ionizing radiation like microwaves, infrared light, and visible light. It creates thermal energy via an electromagnetic current that oscillates at varying frequencies between 200 and 1200 kilohertz.
RF waves are longer and hence, lower frequency (slower) and lower energy than waves of ionizing radiation, like x-rays and gamma rays. Because of its low-frequency state, it does not carry enough energy to ionize atoms and cause direct damage to cells in organic matter. Hence, according to FDA and the National Cancer Institute, “there is currently no consistent evidence that non-ionizing radiation increases cancer risks in humans. The only consistently recognized biological effect of radiofrequency radiation in humans is heating.” Ionizing radiation, on the other hand, carries a billion times more energy, allowing it to break chemical bonds and knock electrons out of atoms (ionizing atoms), increasing the risks of cancer from causing direct damage to the DNA in cells.
So there it is—RF energy is a form of non-ionizing radiation that is generally perceived as harmless to humans because of its low-energy state1. Thyroid RFA uses RF energy to produce heat, destroying (ablating) abnormal tissue. Because it is slow-moving, non-ionizing radiation, the energy dissipates before reaching nearby normal tissue and that is the genius of thyroid RFA. By inserting the RFA probe directly into the lump, doctors can carefully control the heat energy delivered to the nodule, preserving the surrounding healthy thyroid tissue.