If you have been x-rayed at least once in your life, when a doctor suspected pneumonia, or were checked for a fracture before plastering, or the dentist sent you for a “control” picture before each appointment, or perhaps someone of your relatives or friends underwent radiation therapy, or if you are interested in what actually PET-CT is, which everyone is talking about, then it’s time to learn a little more about radiation safety in medicine.
When carrying out all the above types of medical procedures, for diagnosis or treatment, ionizing radiation is used (that can lead to the excitation of cell molecules and cause rupture of bonds inside them and, as a consequence, their possible destruction). Since it cannot be known exactly how radiation will affect you or your relatives, it is generally accepted that the harmful effects of radiation are possible, starting with minimal exposure levels. In fact, inside a person there are so-called “repair mechanisms”, that is, repair services that are part of the cells themselves. If ionizing radiation acts are continuously with low intensity, such as, for example, the natural radiation background, they manage to eliminate all (or almost all) of the damages. These regulatory processes are quite physiological and allow you to maintain a healthy state of the body. The effects of exposure with more intense radiation to a specific, individual for each person threshold can also be neutralized by the cells themselves, leveling harm to the whole body.
The research danger to determine the effect of radiation on living matter has led to the fact that the rules of the interaction with ionizing radiation were created empirically during the entire period of radiation use by humans. Consequences of nuclear bombing and accidents at nuclear power plants, many registered radiation incidents gave basic knowledge about the negative effects of radiation on the body. All such events have served as proof of the need to develop clear rules and regulations when using ionizing radiation to ensure maximum human security from its negative consequences. The developed regulations and restrictions concern not only the handling of radiation sources, but also the need to use personal protective equipment, as well as special design of the premises in which they are used.
The effect of ionizing radiation is determined by the dose, that is, the amount of energy that was transferred to the substance. The occurrence of certain side effects from radiation, which are called long-term effects, is associated with the dose received by a person for a certain period of time. Generally ionizing radiation has a destructive effect on living organisms, but under certain conditions we can use it for success. Due to its features, radiation allows obtaining unique and very valuable data for making an accurate and timely diagnosis, to perform complex surgical operations with minimal incisions. By radiation therapy, a high-power dose of radiation can destroy cancer cells, which allows people to recover.
The main problems in the use of ionizing radiation in medicine are: a large number of studies that are performed without sufficient justification, the rejection of using the personal protective equipment, duplication of procedures due to the initial incorrect parameters or the lack of access to previous results. The harm could become greater by the improper use of the parameters of the machines and insufficient control of their quality. In addition, it is necessary to take into account the possibility of long-term effects, so-called tissue reactions, during therapeutic procedures and surgical interventions under X-ray control, which should be minimized or avoided altogether as side reactions of such interventions.
There are three main areas of using the ionizing radiation in medicine: diagnostic, therapy and treatment of blood components and organs for transplantation in vitro. In turn, each of these areas uses the radiation that is created by:
- generating devices (diagnostic and therapeutic X-ray machines, linear accelerators, sources of neutrons and protons used in radiation therapy);
- radionuclide sources (open and sealed) used for therapy and diagnostics.
To date, there is the most commonly used is X-rays diagnostics due to its wide range of visualization and ease of use. Over the year, more than 30 million radiological examinations are performed in Ukraine:
The highest dose in the diagnostic segment patients can receive by the use of ionizing radiation for angiographic procedures with minimally invasive (with the help of small incisions) interventions under x-ray control. The reason is in the possible prolonged exposure to x-rays during surgery. Given the increasing use of these procedures, based on their convenience, minimally invasiveness, efficiency and accuracy, much attention needs to be paid to the rules of conducting such interventions (using special techniques to reduce the burden on the patient), and controlling the qualifications of personnel, the state of the apparatus and possible radiation reactions from the skin of patients.
According to Svyatoslav Denisov, an interventional cardiac surgeon, the head of the Center for Interventional Cardioradiology of the Clinical Hospital Feofaniya, during his practice at the Center there was not a single case of delayed skin reactions resulting from the use of radiation during the operation. Doctors keep in touch with the patient to provide advice and, if necessary, help. There is required to talk to patients about the use of x-rays and x-ray contrast agents during surgery, and when planning a long-term intervention, about the possible risks of radiation too. The main methods of minimizing the harmful effects of radiation on patients, as noted by Svetoslav Denisov, are careful planning of the intervention and reduction of radiation time, when it’s possible and appropriate, as well as minimum distance compliance between the x-ray detector and the patient.
Diagnostic procedures also include the visualization of organs and tissues by using radioisotopes that are bound to biological molecules able to target specific organs, tissues or cells within the human body. Radiopharmaceutical are actively involved in the metabolism of organs and tissues necessary for diagnostics, and with the registration of radiation from isotopes, doctors get a picture of the radiotracer accumulation difference from the inside and thus the possible desease. The most common are the technetium isotope radiopharmaceuticals (used in single photon emission computed tomography – SPECT), and fluorine (used in positron emission tomography – PET). Thus, it is possible to obtain data on the pathology of various organs and tissues, the presence and extent of oncological diseases with a small radiation dose for patient. For maximum accuracy PET is usually combined with CT (computed tomography):
By the appointing a procedure, diagnostic exposure should be assessed by the benefit – harm ratio to health. Stuff that are engaged in medical practice related to human exposure (radiation diagnostics and radiation therapy) are responsible for providing radiation protection during medical radiation exposure and during it. In turn, radiation safety specialists should create the necessary informative base for doctors, technologists, radiology engineers, nurses by providing training in safe methods of using ionizing radiation.
The difference between using ionizing radiation for diagnostics and for therapy is the use of radiation with much higher energies, which makes it more penetrating and, if necessary, destructive. Radiation therapy is one of the main methods of treatment of malignant neoplasms, and in more rare cases, benign neoplasms and non-neoplastic diseases.
In X-ray machines, this is achieved by increasing the voltage and current of the X-ray tube, in linear accelerators – by acceleration of charged particles (electrons) inside the machine creates ionizing radiation with high penetrating power, which can destroy malignancy. In therapy using sealed (gamma therapy, brachytherapy) or open isotope sources, the treatment of tumors occurs due to radiation generated by isotopes, depending on the activity and lifetime of these isotopes, what is enough to destroy malignant cells.
On average, about 60,000 people undergo treatment for various types of cancer in Ukraine per year. The types of radiation therapy according to the number of people exposed to radiation has the following form:
Radiation therapy consists of several stages. The most important factor at all stages is the destruction of malignant tumors and the preservation of healthy tissue as much unaffected as possible.
At the first stage, the patient need in radiation therapy is justified by the doctor on the basis of medical indications. Next, the planning of radiation treatment is carried out by a doctor and medical physicist. The dose quantities of medical exposure is determined by the doctor individually for each patient, based on clinical indications and recommended limits for medical exposure. The prescribed dose and all parameters of radiation exposure should be recorded in the individual Patient Card. Before the radiation therapy procedure all patients receive information about the prescribed procedure and the ability to refuse it, being advised on the behavior rules during the procedure and after it, the possible negative effects of ionizing radiation.
Because of serious harm possibility, ionizing radiation therapy is the area of high control and invention of the most advanced medical techniques and engineering solutions to minimize the impact on healthy organs and tissues. As Olga Silaeva, a radiation therapist, an oncologist at the Oberig Medical Center and the Feofania Clinical Hospital, patients who areundergoing radiation therapy, always receive information about the methods and techniques of treatment, and also about possible reactions, long-term effects. After that, the patient signes the informed consent to radiation therapy. “To reduce the reactions of healthy tissues, the IMRT technique (modulated beam intensity irradiation) is now widely used. This technique allows to bring the maximum necessary therapeutic dose of radiation to the focus (target), while protecting the surrounding healthy organs and tissues.”
Due to the high dose that is used to treat cancer, there is a possibility of a skin reaction to radiation (radiation dermatitis). Given this, according to Olga Silayeva, patients undergoing radiation therapy are under the supervision of a radiation therapist during and after treatment. Depending on which area was irradiated, appropriate maintenance therapy is prescribed after the procedure.
Patient rights – whose concern?
Patient rights are regulated by many normative acts: the Constitution of Ukraine, sanitary rules and norms of the Ministry of Health of Ukraine, the requirements of the SNRIU.
The patient undoubtedly has the right for any medical procedure, but at the same time, the patient also has the right to refuse the prescribed procedure for any reason. While undergoing treatment, a person has the right to be free in the doctor choice, medical institution and treatment methods in accordance with the doctor’s recommendations. Any information about the patient is a medical secret. A person has the right to appeal unlawful decisions and actions of employees, institutions and health authorities at all stages of diagnosis or treatment. If, in the case of poor treatment, health was injured, the patient is always entitled to appropriate compensation for the damage.
To appoint a patient with a diagnostic or therapeutic radiation procedure can only be a doctor for reasonable clinical indications. Physicians who prescribe and perform such procedures should know and inform the patient about the possible reactions of the body and the risks of long-term effects.
It is important for both doctors and patients to remember that the radiologist has the right to refuse the patient to provide an X-ray examination, which was appointed by a specialist, if one believes that this appointment was unreasonable due to the lack of appropriate symptoms, the presence of contraindications and other.
The inadmissibility of repeated diagnostic and therapeutic interventions is an important component in the system to protect the patient from unjustified radiation. All research results – the description, disks, pictures, should be transferred together with an individual card of the patient.
For female patient it is necessary to inform about pregnancy possibility in order to take it into account when choosing the type of procedure and the time it will be carried out.
By law, when carrying out X-ray diagnostic examinations, shielding by special personal protective equipment of all parts of the patient’s body, which are not critical to the diagnosis, is required.
For patients who are undergoing examination or treatment, dose limits are not set, and it is recommended that the patient’s medical exposure limits be controlled with the identifying of four categories of exposed individuals.
Ensuring respect of the patient’s rights is carried out by personnel directly involved in the procedures. When deciding whether to “do” or “not to do?”, the patients must compile for themselves a checklist of three questions: Will it do me good? Or are there other options? Will the procedure be carried out qualitatively? Positive answers to all three questions will give confidence in the choice made.
The main issues that need to be given special attention in the field of medical use of ionizing radiation, according to Olga Silayeva, is maintaining an appropriate level of care for cancer patients. For this, it is necessary to constantly improve the qualifications of both the doctor and the medical physicist, a technologist. “International medical publications, ESTRO courses, congresses, online workshops, webinars are the least that is necessary for self-improvement, and government support in that regard will not be superfluous. It all depends on the individual – whether there is a desire to acquire new knowledge, to develop, despite the difficulties, or not. Medicine, especially oncology, does not stand still. And I am very proud that Ukraine has specialists and equipment that are not inferior to the European level” , – summarizes the radiation therapist.
Svyatoslav Denisov believes – the main problem is the depreciation of equipment, which makes it difficult to maintain the provision of services at the highest level: “These are the points that need to be regulated and controlled. But the staff is all well trained, there are no problems with it.”
It should be remembered that the use of the most modern technology, the latest methods of treatment and diagnosis, compliance with all the rules and norms of radiation safety could only minimize the negative impact of ionizing radiation on the human body. Every patient should know his rights, and at the same time, both the doctor and the patient should always remember that the balance of benefits/harms should always, by any medical procedure, be outweighed by the benefits.
Uatom.org Editorial Board