Radiotherapy, that is treatment with ionizing radiation, is believed for second in effectiveness method of treatment of malignant tumours. It is rarely used as independent radical method. Radiotherapy is performed generally in combination with surgical treatment and chemotherapy, and its aim is to supplement or intensify the effect of other therapeutic methods. Similarly as operational methods, radiotherapy may serve for radical as well as for palliative treatment.

Action of radiotherapy

Ionizing radiation acts on cells involved by tumour and healthy cells, but the last ones possess bigger chances of regeneration.

The direct reaction of neoplastic cell on radiotherapy is when genetic material of cells is radiated - quant of radiation strikes directly into DNA and destructs it. The indirect reaction occurs in moment, when in neoplastic cells radiolysis of water occurs. In effect free radicals are formed – molecules of big energy, which destruct important for cell’s life elements. It worth to underline, that action of ionizing radiation is not felt by patient during the procedure - radiotherapy is painless.

Used in the past roentgen therapy, with roent­gen apparatus as a source of therapeutic radiation, was substituted with the megavolt therapy (so called cobalt bomb). Megavolt therapy, that uses radiation of bigger energy and penetrating power of radiation is safer and gives less complications than roent­gen therapy. Cobalt bomb is a spherical device, with strong source of cobalt 6OC0 radiation located in the housing. With its help the radiation beam can be directed under various angles and in different planes, thanks to what the radiation became more precise. Rarer in radiotherapy “caesium bomb", that is a device emitting caesium 137Cs radiation is used.

Presently to the radiotherapeutical treatment also line accelerator (conformal therapy 3D) is used. Thanks to its use even bigger precision of performed procedures can be obtained.

Types of radiotherapy

Types of radiotherapy differ in location of radiation source:

Brachytherapy – this method depends on locating radiation source in the body’s cavities, directly in tumour or in its surrounding (oral cavity, uterus and sexual track, penis).

Teleradiotherapy - method with external use of radiation beam. It is usually used to radiate superficial changes (breast cancer, soft tissues cancer) and deeper located tumours (lung cancer, renal cancer, bladder cancer).

Isotope radiotherapy - method on intravenous radiation isotopes administration. It is the most frequently used in treatment of follicular cancer of thyroid gland and polycythemia vera.

Treatment

Preparation for radiotherapy consists the most commonly of few phases. The first step is initial discussion with doctor, who explains aim and method of treatment. Than doctor radiotherapist, together with technician, plan radiotherapy on simulator. Sometimes a few visits in simulator are needed to lay patient in position, which will provide a precise realisation of radiation during the therapy. In modelling room devices which must provide proper immobilisation patient during radiations are prepared; sometimes technicians prepare also special masks and cover to protect healthy issues against radiation.

Plan of treatment is prepared by doctors on basis of data obtained during computed tomography. Presently the plan jest is made using computer programme (3D planning), thanks to what healthy tissues get a smaller amount of harmful radiation than tissues involved by tumour.

Choice of therapeutic apparatus (i.e.: line annihilator, cobalt apparatus) depends mainly from the disease location and aim of treatment.

Radiotherapy is not a singular procedure, consists of particular fractions and lasts the most frequently for few weeks, during which patient is radiated from Monday to Friday. One radiation session lasts about 10 minutes. Correctness of treatment is checked on basis of recordings in radiation card and x-ray pictures. On average once a week patient comes for follow-ups, during which i.a. is checked if postradiation reaction occurred. During radiotherapy, as well as after it is finished, patient is not a source of radiation. He should not be worried, that he poses threaten for his relatives.

Possible side effects of radiotherapy

Effects of radiotherapy are always some changes in these regions of body, which has been radiated. It is impossible to precisely determine possible side effects of therapy - other early reactions (that is reversible changes in healthy cells) will give radiation of laryngeal regions, completely different radiation of tumour located in head or mediastinum. Intensification of reaction depends also on individual, difficult to foreseen patient’s sensitivity - i.e. people of dark complexion usually bear radiotherapy better than those of light complexity.

Skin exposed to radiation is getting darker, dried, susceptible for irritations. Patient should use proper ointments to improve its appearance and condition and prevent formation of more serious changes. Patient should not also sunbath this fragment of skin.

Place exposed to radiation looses hair (they grow back with time) and mucous membranes become dried, frequently so called aseptic inflammation occurs. The rare complication is post-radiation pneumonia, stomach or intestines. Some of complications may appear just after some time after the end of radiotherapy – it is then secondary reaction.

Only sensitive to radiation tumours are qualified to the radiotherapy. Decision to use radiotherapy is not made, if sterilization of tumour without permanent destruction of important adjacent organs is impossible. In other words - theoretically every accessible neoplastic tumour can be destroyed with radiotherapy, however radiation dose cannot be so strong, to destroy organs adjacent to tumour permanently, because it could lead to patient’s death.

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