Planning of radiation
Before starting treatment, it is necessary to compile a detailed and technically complex treatment plan. The purpose of this plan is to optimize the distribution of the radiation dose to all affected tissues and, at the same time, to ensure minimal negative effects on healthy tissues.
When performing radiotherapy in the head and neck area, the patient is first made an individual plastic mask. This auxiliary means serves to ensure the exact position of the patient's body during irradiation.
For treatment, we need to determine the location and shape of your tumor in order to accurately calculate the dose and direction of radiation.
Therefore, you will have a computerized tomography (CT) with a high resolution, which is necessary only for drawing up a radiation plan. In the course of this research, the position of your body will be the same as later during the sessions of radiotherapy; the duration of the study is only a few minutes. In this case, a cross section is created every 3-5 mm of your body. In the course of study, we get accurate information about the individual anatomical features of each patient, as well as the prevalence and localization of the tumor that we will treat. The planning physician then precisely indicates the area to be irradiated (“target area”), as well as adjacent organs (organs at risk) that need special protection (e.g., the lungs, spinal cord, and kidneys).
After CT completion, a special labeling is applied to the skin, which during the course of treatment for several weeks will allow us determining accurately the place of irradiation, the size of which is often only a few millimeters. During the irradiation, this labelling, if necessary, will be updated by a medical technical assistant in radiology using special markers. The patient can take a shower with caution or wash himself, but should refrain from bathing in the bath, swimming pool and sauna.
Then the results of CT planning are transferred to the computing device where the radiation plan is being generated, and an expert in medical physics, together with a specialist in the field of radiation therapy, develop the best treatment plan. The purpose of this treatment plan is to apply the highest possible dose of tumor radiation and, at the same time, to ensure that adjacent healthy tissues are minimally spared to minimize possible side effects. The preparation of an irradiation plan usually takes several days. In special situations (with radiotherapeutic emergency situations, for example, with venous stasis in the blood vessels in the head due to difficulty in outflow of blood), the plan can be made within a few hours.
In close cooperation of physician and an expert in medical physics, it will be decided which radiation technique will be used for you, and how the optimal sparing effect on your healthy organs will be ensured.