Prepared : Igor Leskiv Department of oncology and radiology

1. Prepared: Igor Leskiv Department of oncology and radiology Technology basis radiotherapy. Complex, combine and joining methods radiotherapy of neoplasm. Radial reaction and damages.

2. Radiotherapy • Radiotherapy is a science about use of ionizing radiation (IR) mainly to treat malignant tumors. • The first time of using X-rays was in 1896. • Principles of Radiation Oncology - e a r l ydiagnosis

3. Treatment may be: purely surgical, purely radiation (exposure) (INDEPENDENT RT) purely medicamentous. INDEPENDENT RT COMBINED TREATMENT is a combination of surgery & irradiation Preoperative, postoperative RT. COMPLEX TREATMENT consists of operation, irradiation & chemotherapy, hormonal therapy.

4. The therapeutic use of IRs is based on their b I o l o g I c a l action, that is, their ability to cause changes in cells, tissues, organs, the body as a whole. It depends on the ABSORBED DOSE (AD) – e n e r g y transmitted to irradiated tissues (Gr). Clinicobiologic foundations of RT of Tumors

5. Principles of Radiotherapy 1.Delivery of an o p t i m a l dose to the tumor. 2. M i n i m a l damage to surrounding organs & tissues. 3. Carrying out measures stimulating p r o t e c t i v e forces of the body.

6. Treatment of tumors may be: RADICAL RT– complete cure of the patients –Indications: an early stages (I-II). PALLIATIVE RT - a temporary improvement of patients life, life prolongation. stages (III- IV). SYMPTOMATIC RT - to alleviate the most several manifestations of disease

7. Contraindications for RT grave patient’s state, cachexia, anemia, leukopenia, acute septic states decompensated states of the heart, the liver, the kidneys. Active TB. Extension of tumors to adjacent hollow organs, growth into great blood vessels. An inflammatory process.

8. Cell Radiosensitivity Cell Radiosensitivity (its reaction to irradiation) depends on patient’s age, state, on the state of tissues surrounding the tumors, histologic structure, the presence of hypoxic & anoxic cells, the proliferation level &cell differentiation. Mildly hypoxified cells are radioresistant.

9. Management of radioactive reactions of tumors & normal tissues. Selection of an irradiation regimen: delivery of an optimal total tumor dose (TTD). Radiosensitivity of healthy & tumor cells is practically the same. The r a d i o t h e r a p e u t i c i n t e r v a l is a difference between radiosensitivity of the tumor & that of its surrounding healthy organs & tissues. It should be increased

10. TNM – clinical classification Т - cancer in situ; N- region lymphatic nodules; М - metastases. Cancer stages: StageI- Т1 N0 M0; StageII - Т2 N0 M0; StageIII - Т N1M0; StageIV - Т и NM1. Basic criteria of cancer stages cancer sizes, quantity of focuses, spreading of tumour on adjacent tissues , region lymphatic nodules; metastases

11. The histological structure of the tumor to a great degree determines the effective absorbed tumor dose. A tumor from lymphoid cells requires 40-50 Gr, embryonal & reticular tumors are highly sensitive. Squamous cell carcinoma & adenocarcinoma – 60-80 Gr. Cancer – 80 Gr – average radiosensitivity. Sarcoma - 100-120 Gr – soft-tissue & osteal sarcomas, melanomas – tumors with expected radioresistancy. These doses are given for X-ray & gamma-radiation, fast electrons (energy – 200 Kev). Peculiarities of tumor growth.The tumor size

12. The radiation rhythm or fractioning regimen- the timing of the dose absorption. As a rule the total dose is divided into separate fractions. Small fractioning – 2 Gr 5 times a week – for tumors with high & moderate radiosensitivity. Average fractioning - 3-4 Gr 3-4 times a week for resistant tumors. Large fractioning – 4 Gr & more (10 Gr). It depends on the tactics of treatment. The uninterrupted regimen lasts for days & weeks. One-stage irradiation.

13. Means of r a d I o m o d I f I c a t I o n - for damage of tumor Oxygenous effect: Oxybaroradiotherapy Hypoxiradiotherapy- gaseous hypoxia-protection of N tissues Chemical compounds. R a d i o s e n s i b i l i g e r s . Hyperglycemia & hyperthermia. Polyradiomodification is carried out.

14. Clinico-dosimetric planning of RT The main clinico-dosimetric task is to create the most favourable spatial distribution of absorbed radiation doses in patient’s body. EXTERNAL BEAM THERAPY

15. R a d I a t I o n B e a m s: For X-raysgenerated at a voltage of 100 keV : 100% of the dose remain on the skin, therefore the single skin tolerable dose (STD) = 2 Gr . Rapid & steep drop of the dose. only for treating surface masses.

16. R a d I a t I o n B e a m s Gamma-units charged with Co-60 emiss a photon beam (1.17-1.33 MeV) of great energy! A maximum absorption – at a depth of 0,5 cm under skin. STD of 4 Gr. For treating deep tumors

17. R a d I a t I o n B e a m s Linear accelerators generate brake radiation & election beams. Brake radiation of high energies in 25 MeV – the maximum AD is at a depth of 4-6 cm. . Electron beams of high energies – a maximum AD at a depth of 1-3 cm, a rapid drop of the dose. For tumors which do not lie deep.

18. R a d I a t I o n B e a m s For deep tumors we use beams of h e a v y charged particles (protons, alfa, pions). The adjacent tissues are not factually irradiated. Synchrocyclotron

19. Methods of RT Distancional methods. Contact method. Distancional irradiation: /External Beam Therapy/ E x p o s u r e. A notion “distance-source-skin” (DSS) is used. D i s t a n c i o n a l (Remote irradiation) – the DSS is equal to 30 cm – 1.5-4 m. More often – 50-80 cm. S u p e r f I c I a l therapy – 1.5-25 cm, more often – 1.5-7.5 cm. Superficial X-ray therapy is used only for skin tumors.

20. Devices for Distancional Irradiation The linear accelerator generates high-energy electron or proton beams. Gamma-units for mobile, static, movable & intracavitory therapy. a radiation source – Co 60. The half-decay period is equal to 5.3 years. The superficial X-ray-therapy unit. Synchrocyclotrons for receiving protons &cyclotrons for neutron radiation.

21. Method of patient’s irradiation S t a t i c irradiation can be performed through: single field technique, multiple field technique. M o b i l e irradiation: Rotational

22. The form the working beam we use : compensators (boluses) from tissue equivalent materials wedge screen filters lead & splitting blocks

23. Contact Methods of Irradiation (Brachytherapy) The application method – placement of radiation sources above the superficially located tumors the skin, mucousmembranes) not more than 1-2 cm deep. The i n t r a c a v I t o r y method : insertion of the radioactive source in the organ cavity. Linear or volumetric sources are shaped.

24. Brachytherapy I n t r a t i s s u e method: a radioactive preparation is inserted directly to tumor tissue. A high dose is continuously created. Caesium needles & tubes are used for intratumoral & intracavitary cancer therapy.

25. R a d i o s u r g i c a l method-intraoperative exposure of tumors is carried out in the operation table; or sources with a short half-decay time are implanted into the inoperable tumor

26. Sources of Radiation Closed sources of radiation exclude ingress of radioactive substances into the environment. needles & tubules with Cs 137,Co 60 , radium, irridium etc.

27. Sources of Radiation . Outer sources:I 131, P 32, Sr-89, colloidal solutions of ittrium. The use of outer radioactive preparations for oral administration or administration into the blood is a variety of the contact method

28. Body Reactions to Irradiation: General &local reactions – accompany the therapy & resolve without any special treatment. General: the CNS disorders, a decreased tonus, flaccidity, high irritability, loss of appetite, the CVS disorders, indigestion, hematological shifts . Treatment: vitamins, liquid, antihistamines, hemopoietic stimulators, antibiotics.

29. Local Skin Reaction: Erythema - reddening, dry radiodermatitis pigmentation & thinning of the skin develops. P r e v e n t I o n: indifferent powders, cod-liver oil, sea-buckthorn oil, mednisolone, methyluracylic ointments. Local reactions of mucous membranes: pain, dysphagia, radioepitheliites, colites ect. Prevention:sanitation of the cavities, sparing, disinfectant solutions, oils, novocain.

30. Local Radiation Damage There are subcutaneous scleroses, ulcers, pneumonites, colites, rectosigmoitites, dystrophic changes in bones, indurative edema, myelitis, radiation cancer. Radioinduced sclerosis. A special treatment is required.

31. RT of NON-TUMOUR DISEASES It is carried out only according to strict indications when other methods failed. Single & total doses should be small in the range of 0.1-0.7 Gr every alternate day up to a TTD of 4-7 Gr. The basic method is a direct local irradiation of the focus using the distancional technique, Radiation fields according to the focal size. The X-ray unit or distancional therapy are used in deep foci (more often X-ray therapy ).

32. Inflammatory processes Boils, carbuncles, hydrodenites, panaritia, thrombophlebites, erysipelatous inflammatory anastomositis, osteomyelitis. We cause local plethora, an increased permeability of capillaries, formation of bioactive substances, lymphocytolysis. The principle of treatment – the more the process, the lower the dose. At the initial stage, it is possible to terminate the process, alleviate pain, relieve inflammation. At phase of necrosis and purulation - rapid infiltrate melting & its delimitation. At the phase of regeneration – rapid wound epithelisation.

33. Degenerative dystrophic disorders of the osteoarticular system Periarthritis, deforming arthrosis with the pain syndrome, calcaneal bursitis, osteochondrosis. We lower the pain syndrome – act on immunospecific reactions of articular tissues & nerve receptors. Distancional irradiation. A dose of 0.3-0.5 Gr, a total dose of 3-5 Gr every 48 hours. An effect can be obtained in 4-6 weeks. Neurologic disorders – inflammatory disorders of the CNS – neurites, neuralgias, radiculites. Irradiation of nerve centers, roots of cranial & spinal nerves. The postamputation pain syndrome. We irradiate the stump, reflexogenic areas

34. Organs & Tissues Radiosensitivity - Bony brain, gonads. - Lens of the eye,thyroid, cartilages, fat tissue, lungs, muscles, liver, kidney, spleen, digestive canal. - Skin, bones, extremity. Lymphatic tissue, bony brain, gonads, mucous membranes, skin,cartilages, vascular system,endocrine glands,internal organs,bones, nervous system. age: young & old.