Radiation medicine today
The term radiation medicine (radiation medicine) summarizes a number of methods and applications that deal diagnostically and / or therapeutically with ionizing radiation. These include radiology, radiotherapy and nuclear medicine (areas in which doctors can train to become a specialist), in a broader sense - also in the field of research - the radiation biology, which deals with the biological effects of all forms of radiation.
In nuclear medicine, radioactive substances and nuclear physics procedures for functional and localization diagnostics of organs, tissues and systems are used. In the treatment short-lived open radionuclides are used, ie radioactive nuclei, which decay under radiation of α-, ß- or γ- radiation.
One of the most frequently used nuclear medical procedures in practice is scintigraphy, which is used to examine organ functions - particularly frequently in the thyroid, kidneys, bones, lungs and heart muscle. Further methods of nuclear medicine are positron emission tomography PET, the medical assessment of radioactivity that has entered the body during radiation accidents and, as a form of radiotherapy, radioiodine therapy and radionuclide treatment.
In radiology, disorders are detected and treated by means of ionizing radiation, nuclear physics and sonography. In addition to classical x-ray, the procedures include computed tomography, magnetic resonance imaging and spectroscopy as well as the various ultrasound examinations (sonography).
In order to better visualize organs or to distinguish them from the surrounding tissue, contrast agents such as insoluble barium salts, iodine compounds, air or carbon dioxide are added. Especially in examinations of the stomach and intestines or in the depiction of vessels, contrast agents are used. X-ray examinations without contrast medium are mainly known from images of the lungs (thorax), the abdomen (abdomen), the skeleton and the bones, or even breast cancer screening in mammography.
Diagnostic Radiology and Interventional Radiology
A distinction is made between diagnostic radiology and interventional radiology, ie, low-invasive therapeutic measures that are carried out using imaging techniques. These include, for example, the dilation of vasoconstrictions or the insertion of a catheter under fluoroscopic control (angiography), the treatment of acute bleeding or puncturing with a cannula to recover tissue or fluid.
Diagnostic and interventional measures often flow into each other fluently - during an ultrasound examination a change in the tissue can be detected, simultaneously removed and treated.
The treatment of diseased tissue, especially malignant tumors, with ionizing radiation is called radiotherapy. In addition to surgery, chemo and hormone therapy, it is one of the main therapeutic methods of cancer. The basis of radiotherapy is the recognition that tumor tissue is much more radiosensitive than healthy tissue. The genetic structure of the tumor cells is damaged by the high-energy forms of electromagnetic radiation or particle radiation, thus destroying the tumor.
Unlike chemotherapy, where the drug is distributed throughout the body, most forms of radiotherapy have a local effect. However, there are also radioactive drugs (radiopharmaceuticals) that spread through the bloodstream in the body and contain substances that accumulate due to special properties in the tumor. For example, radioactive iodine is used in the treatment of thyroid cancer, and in the treatment of bone metastases, strontium-89 is chemically similar to bone minerals.
In some cases, the radiation effect may be assisted by drugs or other methods that make the tumor tissue more radiation sensitive.