Selected aspects of side effects in the radiotherapy of head and neck cancer

Currently, except for the control of the malignant process, the range of accompanying complications (intensity and amount) is an exceptionally important criterion in the evaluation of the usefulness of a treatment method. The result of more often applied combined treatment is that each method brings its characteristic side effects. Therefore, the evaluation of side effects in combined treatment should take into account its partial dimensions. It is especially challenging for oncologists to create a common platform for the evaluation of undesirable effects, which is an essential condition for the comparison of the results of treatment taking into account particular methods and oncological centers. Radiotherapy (RT) applied in patients with head and neck cancer results in side effects in each case, however, their clinical representation can differ fundamentally. The most serious complication in the RT of head and neck cancer is spinal cord necrosis. This complication brings tragic effects, however, it is rarely observed in practice. Another complication giving rise to much controversy is the damage of optic nerves and/or retina. Similarly, the risk of its occurrence is not high but it increases in the case of RT of advanced tumors of nasopharynx, paranasal sinuses and the skull base.
On the other pole of the frequency of complications in RT there is dryness of the mouth and pharynx. The clinical aspects of this side effect are the subject of the paper. In practice, this complication can be noticed in each patient. Because of its common occurrence and the fact that it is the main cause of the worsening quality of patient’s life, the attempts to decrease the intensity of this complaint are subject to intensive research. A similar situation appears in mucositis. The application of intensive methods of radiation (intensification of dose, concomitant radiochemotherapy) is the reason why the escalation of the complication is often the factor limiting the planned therapy. The new methods of planning and treatment of RT included into clinical practice such as the 3-dimensional conformal radiotherapy (3D CRT) and the intensive modulated radiotherapy (IMRT) allow for a certain decrease of complications.
In summary, although there has been a significant progress in RT for the last decades, still the side effects connected with this treatment belong to one of the main interests of oncologists, and currently also the interest of geneticists and biologists, which gives hope for a significant progress in prevention and treatment.