The increased use of imaging tests in modern medicine, which are essential for screening and diagnosing various diseases and for accurately monitoring treatments, has made many patients fearful of exposure to radiation. The fear is understandable, especially when we consider that, for most people, radiation is associated with catastrophic events, such as the explosion of the atomic bombs that destroyed Hiroshima and Nagasaki, the disaster at the Chernobyl plant and – much closer to us – exposure to Cesium-137 from an abandoned radiotherapy device, a fact that, almost 40 years ago, marked the country.
In , however, imaging exams and radiation-guided treatments are part of the routine. The SUS annually performs more than 100 million imaging exams that use ionizing radiation, an amount that, added to the total number of exams performed in the private network, reaches 168 million per year, according to mapping by the Atlas of Radiology in Brazil. What not everyone knows is the degree of technological evolution in the area: today, much more modern equipment can produce more precise images with much lower doses of radiation than those used in the past.
At the end of the 19th century and beginning of the 20th century, when radiology was in its infancy, there were real risks, as, without knowing the effects of ionizing radiation, scientists and health professionals exposed themselves to high doses without any type of protection, suffering serious consequences, such as burns, amputations and even deaths from cancer. Since then, things have changed radically, both in terms of protecting patients and professionals and in the evolution of the equipment itself, including the use of .
Computed tomography is the exam that most exposes the patient to radiation, but, for several decades, the equipment, in addition to being much more efficient in capturing images, has greatly reduced the time of exposure to radiation. Today we have devices equipped with algorithms that adjust the radiation dose based on the patient’s anatomy.
In addition to technological innovation, protection protocols have also evolved. Today, no radiation exam can be carried out without there being a consistent medical justification, which proves that the benefit of the diagnosis outweighs the risk of exposure, however minimal it may be. The ALARA (As Low As Reasonably Achievable) principle applies, that is, the dose must be “as low as rationally feasible”.
Thus, the radiation dose is calculated according to the patient’s weight and height, being drastically reduced in the case of examinations in children, whose cells multiply faster and are more sensitive, and may suffer more severe damage. Health workers (technicians and doctors) are also protected, with a ceiling on accumulated radiation allowed per year being guaranteed.
Patients can and should question doctors when they are asked for tests. It is important to know whether the exam is really necessary at that moment, what benefits it can bring to the treatment, what type of protection will be used and, finally, if there are options without radiation. It is worth remembering that ultrasound does not use radiation, offering no risk. In the case of pregnant women, if it is really necessary to have a CT scan in the abdominal region or pelvis, the doctor must adopt maximum protection protocols.
It is important to keep in mind that exams are absolutely necessary tools to guide treatments and should never be neglected due to any type of fear. Today protocols and equipment offer safety to all patients.
*Text written by radiologist Giovanni Cerri (CRM 28697), from the Imaging Diagnostic Service at Hospital Sírio-Libanês and head of Radiology at Brazil Health
