Principles and methods of Principles and methods of radiation therapyradiation therapy

Radiation therapy Radiation therapy - is one of the sections of medical - is one of the sections of medical radiology, which is examining the use of ionizing radiology, which is examining the use of ionizing radiation for the treatment of various human diseases. radiation for the treatment of various human diseases. International classification of malignant tumors in the International classification of malignant tumors in the system TNM, which is used in oncology reflects the state system TNM, which is used in oncology reflects the state of the primary tumor and its regional and distant of the primary tumor and its regional and distant metastases (T - tumor, N - nodulus, M - metastasis). metastases (T - tumor, N - nodulus, M - metastasis). This allows you to choose the tactics of treatment of This allows you to choose the tactics of treatment of cancer patients. In modern oncology main methods of cancer patients. In modern oncology main methods of treatment of patients with malignant tumors is surgical treatment of patients with malignant tumors is surgical and radiation, and the combination of these methods and radiation, and the combination of these methods greatly improves treatment outcomes. On the greatly improves treatment outcomes. On the effectiveness of radiation therapy in the treatment of effectiveness of radiation therapy in the treatment of inoperable cases ranked first place.inoperable cases ranked first place.

The main goal of radiation therapy The main goal of radiation therapy isis to to determine the optimal dose of radiation to determine the optimal dose of radiation to the pathological focus with minimal the pathological focus with minimal damage to normal tissues located in the damage to normal tissues located in the area of exposurearea of exposure

The main principles of radiotherapy:The main principles of radiotherapy:- Radiotherapy appointed strictly on the - Radiotherapy appointed strictly on the indications;indications;- The absence of contraindications;- The absence of contraindications;- Selection of the optimal dose of radiation;- Selection of the optimal dose of radiation;- Minimal exposure to surrounding normal tissue;- Minimal exposure to surrounding normal tissue;- Course of radiotherapy must be the shortest - Course of radiotherapy must be the shortest and most radical;and most radical;- Radiotherapy should be accompanied by - Radiotherapy should be accompanied by therapeutic measures aimed at improving the therapeutic measures aimed at improving the body's defense power;body's defense power;

Classification methods Classification methods RRT depending on T depending on the placement of the radiation sourcthe placement of the radiation sourcee

METHODS OF RADIOTHERAPYMETHODS OF RADIOTHERAPYEXTERNALEXTERNALFar-distantFar-distant 30cm-2m 30cm-2m

Close distant Close distant 1.5-30cm1.5-30cm

ApplicationalApplicational 0cm0cm

INTERNALINTERNALIntracavitalIntracavitalIntratissularIntratissularWith incorporated elementsWith incorporated elements

External radiation External radiation - - a method in which case the radiation source is placed a method in which case the radiation source is placed outside the body. If the radiation source is placed outside the body. If the radiation source is placed withwithin the body, such a in the body, such a method is called method is called internalinternal..

Contact(brachytherapy)

Distant(teletherapy)

The artificial sources of ionizing radiation used in medicineThe artificial sources of ionizing radiation used in medicine

Radioactive substances Accelerators of the charged particles

Sealed Unsealed Linear Cyclic Roentgen devices

Gamma-therapeutical devices

Radioactive medications

Solutions

Suspensions

CyclotronBetatron

Synchrophasotron

Teletherapy

StaticDynamic

Brachytherapy

Static Dynamic

1. Tubes2. Balls3. Needles4. Darts5. Plastic

masses

UsualColloid

MacroMicro

External exposureExternal exposure is performed using apparatus is performed using apparatus in which the source of ionizing radiation located in which the source of ionizing radiation located at different distances from the surface of the at different distances from the surface of the patient's body.patient's body.

External methods:External methods:- - LongdistanceLongdistance method (from 30 cm to 2 m); method (from 30 cm to 2 m);- - ShortdistanceShortdistance method (from the source to the method (from the source to the skin from 1.5 cm to 30 cm);skin from 1.5 cm to 30 cm);- Application - Application mmethod (from 0 cm to 1.5 cm).ethod (from 0 cm to 1.5 cm).

External exposureExternal exposure

Classification of radiation therapy by the Classification of radiation therapy by the method of use:method of use:

Individual method of treatmentIndividual method of treatmentPrograms: radical, symptomatic, palliativePrograms: radical, symptomatic, palliative

Combination method of treatmentCombination method of treatmentPreoperational radiationPreoperational radiationSuboperational radiationSuboperational radiationPostoperational radiationPostoperational radiation

Complex method of treatmentComplex method of treatment-chemoteraphy +radiotherapy+surgery-chemoteraphy +radiotherapy+surgeryCombined method of treatment Combined method of treatment

-external radiation+brahytherapy (mold)-external radiation+brahytherapy (mold)

Self-radiationSelf-radiation (X-ray, gamma-therapy, therapy by (X-ray, gamma-therapy, therapy by sources of high-energy) has three programs of sources of high-energy) has three programs of usage:usage:1) a 1) a radicalradical program of treatment aimed at the program of treatment aimed at the complete destruction of tumor elements in the complete destruction of tumor elements in the body and complete cure of the patient;body and complete cure of the patient;2) 2) palliativepalliative treatment program is used in treatment program is used in advanced inoperable cases to delay tumor growth, advanced inoperable cases to delay tumor growth, reducing pain and improving the quality of patient reducing pain and improving the quality of patient ‘s life;‘s life;3) 3) symptomaticsymptomatic treatment program aimed at treatment program aimed at removing severe clinical symptoms (bleeding, removing severe clinical symptoms (bleeding, compression, fracturescompression, fractures).).

Combination treatmentCombination treatment - a combination of RT with surgical - a combination of RT with surgical treatment.treatment.

1) preoperative - before the operation to kill tumor cells, 1) preoperative - before the operation to kill tumor cells, prevent metastases, reduce tumor volume.prevent metastases, reduce tumor volume.

2) suboperative irradiation performed during surgery for 2) suboperative irradiation performed during surgery for tumor bed irradiation, prevent metastasis.tumor bed irradiation, prevent metastasis.

3) postoperative irradiation performed in order to increase 3) postoperative irradiation performed in order to increase the efficiency of operations to destroy residual tumor the efficiency of operations to destroy residual tumor elements (within 3 - 4 weeks after surgery).elements (within 3 - 4 weeks after surgery).

  Complex treatment Complex treatment - a combination of RT, chemotherapy - a combination of RT, chemotherapy

and surgery.and surgery.Combined methodCombined method - a combination of remote and contact - a combination of remote and contact

methodsmethods..

Rhythm of radiationRhythm of radiation - the distribution of dose in - the distribution of dose in time.time.

Methods of dose distribution:Methods of dose distribution:- Single- Single irradiation - the planned dose applied to irradiation - the planned dose applied to

the tumor in a single session of irradiation;the tumor in a single session of irradiation;- Fractional- Fractional method - the tumor is irradiated for a method - the tumor is irradiated for a

few days or weeks, total dose divided into few days or weeks, total dose divided into separate factions;separate factions;

- Continuous- Continuous exposure - within hours or days. exposure - within hours or days.

Basic principles of radiation therapy Basic principles of radiation therapy of tumor and non-tumor diseasesof tumor and non-tumor diseases

In the treatment of patients receiving In the treatment of patients receiving radiation therapy are three periods: radiation therapy are three periods: preradiation, preradiation, radiation, radiation, postradiationpostradiation..

  

PreradiationPreradiation period include: period include:-detailed examination of the patient: general clinical, -detailed examination of the patient: general clinical, laboratory and instrumental (ultrasound, CT, MRI, X-ray laboratory and instrumental (ultrasound, CT, MRI, X-ray methods, etc.)methods, etc.);;-verification of diagnosis, cytological and histological -verification of diagnosis, cytological and histological examination of the tumor (needle biopsy)examination of the tumor (needle biopsy);;--determination of indications and contraindications to determination of indications and contraindications to radiation treatment methodradiation treatment method;;-assembly of individual patient treatment plan (plan are-assembly of individual patient treatment plan (plan are made bymade by radia radiationtion physician, surgeon, physician, surgeon, cchemotheraphemotherapistist));;-cho-choosingosing method of radiation treatment, radiation fields, method of radiation treatment, radiation fields, additional therapeutic measuresadditional therapeutic measures;;--preradiationpreradiation preparation of the patient (making topographic preparation of the patient (making topographic anatomical cut at the level of the tumor, depthanatomical cut at the level of the tumor, depth of localization of localization of tumorof tumor, making projections on the skin of the patient, the , making projections on the skin of the patient, the choice of the number and size of radiation fields)choice of the number and size of radiation fields);;

PreradiationPreradiation period period

Radiation therapist should psychologically Radiation therapist should psychologically prepare the patient for the radiation prepare the patient for the radiation treatment, exploretreatment, explore skin skin areas areas that will be that will be irradiatedirradiated. These areas should not be . These areas should not be damaged. damaged. PreradiationPreradiation period may last period may last 3 - 3 - 14 days.14 days.

PreradiationPreradiation period, С period, СT topometryT topometry

PreradiationPreradiation period, С period, СT topometryT topometry

Radiation periodRadiation period

treatment of a patient characterized by certain treatment of a patient characterized by certain planplan. . Duration of exposure ranged from Duration of exposure ranged from 2 to 8 weeks2 to 8 weeks. The . The combined method of treatment (radiotherapy plus combined method of treatment (radiotherapy plus surgery) from surgery) from 1 to 6 days1 to 6 days. During radiation treatment is . During radiation treatment is therapy support. It includes: detoxification measures, therapy support. It includes: detoxification measures, vitaminvitaminss, antioxidants, antioxidants,, prophylaxis prophylaxis of of local inflammatory local inflammatory reactionsreactions

postradiationpostradiation period period

evaluatevaluatinging the effectiveness of treatment the effectiveness of treatment outcomes (degree of tumor regression), outcomes (degree of tumor regression), conductconducting ofing of surveillance of the patient, surveillance of the patient, prevention and treatment of radiation prevention and treatment of radiation reactions. After radiation therapy clinical reactions. After radiation therapy clinical supervision of the patient is held supervision of the patient is held 2 times a 2 times a yearyear. After 10 years of observation, if a . After 10 years of observation, if a person is healthy, it is removed from the person is healthy, it is removed from the cancer registry.cancer registry.

About 80% of cancer patients receiving About 80% of cancer patients receiving x-x-ray therapyray therapy. . It It can also be used to treat can also be used to treat many non malignant diseases that do not many non malignant diseases that do not threaten the life of the patient, but cause threaten the life of the patient, but cause suffering and lead to disability.suffering and lead to disability.

X-ray X-ray therapytherapy - one of the methods of remote - one of the methods of remote radiotherapy. Depending on the distance of the source of radiotherapy. Depending on the distance of the source of radiation to the skin surface is divided into radiotherapy radiation to the skin surface is divided into radiotherapy short-distanceshort-distance and and long-distancelong-distance. The source of . The source of radiation in the X-ray therapeutic apparats is an X-ray radiation in the X-ray therapeutic apparats is an X-ray tube that generates photons with high energy. For low-tube that generates photons with high energy. For low-energy photons used screening filters. For radiotherapy energy photons used screening filters. For radiotherapy applied uniformly high-energy beam of photons.applied uniformly high-energy beam of photons.Tube serves to Tube serves to create create field field of radiation and toof radiation and to capture the capture the desired distance from the source of radiation to the body.desired distance from the source of radiation to the body.    The method of X-ray The method of X-ray therapy therapy used to treat malignant used to treat malignant diseases of the skin, subcutaneous fat, mucous diseases of the skin, subcutaneous fat, mucous membranes, metastatic tumors in lymph nodes.membranes, metastatic tumors in lymph nodes.  X-ray X-ray therapy therapy - the only method that is used in the - the only method that is used in the treatment of non-tumorous diseases.treatment of non-tumorous diseases.

Indications Indications for use of this method of treatment are such groups for use of this method of treatment are such groups are not malignant diseasesare not malignant diseases::1. Inflammatory processes: 1. Inflammatory processes: furunclesfuruncles, carbuncles, , carbuncles, phlegmonsphlegmons, , abscesses, paraproctitis, abscesses, paraproctitis, ostepmyelitisostepmyelitis, puerperal mastitis;, puerperal mastitis;2. Postoperative complications: wounds that heal poorly, voles 2. Postoperative complications: wounds that heal poorly, voles of localisationof localisation;;3. Diseases of the osteoarticular system: heel spurs, 3. Diseases of the osteoarticular system: heel spurs, osteoporosis, bursitis, tendonitis, deforming arthrosis;osteoporosis, bursitis, tendonitis, deforming arthrosis;4. Inflammatory diseases of the peripheral nervous system: 4. Inflammatory diseases of the peripheral nervous system: neuritis, neuralgia, plexitis, sciatica;neuritis, neuralgia, plexitis, sciatica;5. Skin diseases: eczema, atopic dermatitis, fungal nail and 5. Skin diseases: eczema, atopic dermatitis, fungal nail and skin infections.skin infections.The sharper the processThe sharper the process is - the is - the smaller dose smaller dose is is and and it it ranged ranged from 0.15 to 10 Gfrom 0.15 to 10 Grayray..RadiationRadiation is is permorfedpermorfed 1-3 times a week. 1-3 times a week.

The The mechanism of anti-inflammatory mechanism of anti-inflammatory effecteffect of ionizing radiation of ionizing radiation

IIn n case case of non-tumorous diseases of non-tumorous diseases is multi-is multi-faceted. Ionizing faceted. Ionizing radiation has the ability to anesthesia. The changes observed radiation has the ability to anesthesia. The changes observed in pathological focus during ionizing radiation, expressed in in pathological focus during ionizing radiation, expressed in accelerating accelerating of the of the phase phase of of inflammatory infiltrationinflammatory infiltration,, proliferative and reparative processes and analgesic proliferative and reparative processes and analgesic effecteffect. . Due Due to to reducreducing of oedemaing of oedema organ function organ function is is improved, improved, increased circulation, increased phagocytic activity of increased circulation, increased phagocytic activity of leukocytes. After a short extension arterleukocytes. After a short extension arteries are ies are narrownarrowing nowing now, , in consequence of which decreases redness and in consequence of which decreases redness and oedemaoedema. . Thus, under the influence of small doses of radiation Thus, under the influence of small doses of radiation a lot ofa lot of the the mechanisms that are responsible for maintaining the constancy mechanisms that are responsible for maintaining the constancy of the internal environment and aimed at normalization of of the internal environment and aimed at normalization of disturbed functionsdisturbed functions are are simultaneously simultaneously turning onturning on..

  

Short-distanced radiotherapy and Short-distanced radiotherapy and contact methods of radiation contact methods of radiation

therapy.therapy.  Skin cancer.Skin cancer.

When When short-distancedshort-distanced radiotherapy is radiotherapy is using, distance from the source of X-ray using, distance from the source of X-ray radiation to the skin ranged from 1.5 to 25 radiation to the skin ranged from 1.5 to 25 cm. This method is used when placing the cm. This method is used when placing the pathological focus to a depth of 0.5 - 0.7 pathological focus to a depth of 0.5 - 0.7 cm from the skin surface. A type of short-cm from the skin surface. A type of short-distanced radiotherapy which is ultra distanced radiotherapy which is ultra radiotherapy. These rays are used when radiotherapy. These rays are used when surface inflammation, dermatitis, surface inflammation, dermatitis, conjunctivitis. conjunctivitis.

Skin cancerSkin cancerSkin cancer - a malignant tumor that Skin cancer - a malignant tumor that develops from the epidermis and is develops from the epidermis and is characterized by relatively benign course, characterized by relatively benign course, caused by the slow pace of development caused by the slow pace of development and late metastasis. Localized mainly on and late metastasis. Localized mainly on the face.the face.

Skin cancerSkin cancer - a malignant tumor that develops from the epidermis and is characterized by relatively benign course, caused by the slow pace of development and late metastasis. Localized mainly on the face.

There are following treatments methodsThere are following treatments methods: radiation, : radiation, surgery, combined. If the tumor is located on the face, surgery, combined. If the tumor is located on the face, neck - use radiation therapy. When placing skin tumors neck - use radiation therapy. When placing skin tumors on the trunk and limbs, where cosmetic aspect becomes on the trunk and limbs, where cosmetic aspect becomes less important, treatment is coming by using surgical less important, treatment is coming by using surgical method or by cryodestruction (using liquid nitrogen). If method or by cryodestruction (using liquid nitrogen). If skin cancer stage is I or II use short-distanced skin cancer stage is I or II use short-distanced radiotherapy. The total dose of 50-60 gray, single doze - radiotherapy. The total dose of 50-60 gray, single doze - 4-6 gray. Spread of deeper infiltration of surrounding 4-6 gray. Spread of deeper infiltration of surrounding tissues is regarded as stage 3-4 and requires application tissues is regarded as stage 3-4 and requires application of the method of long-distanced radiotherapy. If the of the method of long-distanced radiotherapy. If the tumor is localized on the trunk or limbs at stages I-II - tumor is localized on the trunk or limbs at stages I-II - surgical treatment, III-IV stage - surgical method surgical treatment, III-IV stage - surgical method combined with radiation methods.combined with radiation methods.

Contact methods of radiotherapyContact methods of radiotherapyContact radiation therapy combines intracavitary, Contact radiation therapy combines intracavitary, application, interstitial method and method of tropic application, interstitial method and method of tropic accumulation of radioactive elements. In the case of accumulation of radioactive elements. In the case of using each of these methods, the radiation source is using each of these methods, the radiation source is placed on the skin or mucous membrane, it is injected placed on the skin or mucous membrane, it is injected directly into the tumor or into the exposed cavity. The directly into the tumor or into the exposed cavity. The shape of the radiation source can be: linear (cylinders, shape of the radiation source can be: linear (cylinders, needles), volume (balls, grains, granules), suture needles), volume (balls, grains, granules), suture material, solutions.material, solutions.

Application methodApplication method is a medical procedure is a medical procedure in which radioactive drugs placed on the in which radioactive drugs placed on the skin or mucous membranes using skin or mucous membranes using applicators. If thickness not exceed 1-3 mm applicators. If thickness not exceed 1-3 mm - use beta rays. It is used to treat tumors of - use beta rays. It is used to treat tumors of the cornea, of conjunctiva, eyelid skin the cornea, of conjunctiva, eyelid skin cancer. If the skin depth of the tumor up to cancer. If the skin depth of the tumor up to 2 cm - use gamma therapy. Radiotherapy 2 cm - use gamma therapy. Radiotherapy held in a special chamber equipped with held in a special chamber equipped with protective screens, because the patient is protective screens, because the patient is the source of radiation.the source of radiation.

Intracavitary methodIntracavitary method is used to supply the is used to supply the radiation source as close to the tumor as it radiation source as close to the tumor as it possible. Which is localized in the wall of possible. Which is localized in the wall of any hollow organ. For this method is used any hollow organ. For this method is used as gamma and beta radiation as gamma and beta radiation source. Indications for the use: cancer of source. Indications for the use: cancer of the vagina, cervix and body of the uterus, the vagina, cervix and body of the uterus, rectum, bladder, esophagus, oral cavityrectum, bladder, esophagus, oral cavity

Intracavitary method is used to supply the radiation source as close to the tumor as it possible. Which is localized in the wall of any hollow organ. For this method is used as gamma and beta radiation source. Indications for the use: cancer of the vagina, cervix and body of the uterus, rectum, bladder, esophagus, oral cavity

Intratissular methodIntratissular method-a method of radiation -a method of radiation therapy, in which case the radioactive drug therapy, in which case the radioactive drug is injected directly into the tumor is injected directly into the tumor tissue. For gamma therapy using closed tissue. For gamma therapy using closed radioactive preparations in the form of radioactive preparations in the form of needles, granules, grains, suture needles, granules, grains, suture material. For beta therapy use colloidal material. For beta therapy use colloidal solutions and suspensions of solutions and suspensions of radionuclides Au198, Y90, silicone.radionuclides Au198, Y90, silicone.

Method of tropic accumulation of Method of tropic accumulation of radionuclides - radionuclides - therapy incorporated therapy incorporated elementselements.. This method is based on the ability of certain  This method is based on the ability of certain tissues selectively accumulate radioactive substances.tissues selectively accumulate radioactive substances.Selective accumulation of iodine in thyroid tissue served Selective accumulation of iodine in thyroid tissue served for use J131 radionuclide for therapeutic purposes.for use J131 radionuclide for therapeutic purposes.Radioiodine therapy - treatment of hyperthyroidism that by Radioiodine therapy - treatment of hyperthyroidism that by results can be compared with the operation, but the results can be compared with the operation, but the advantage is that it is carried out without bloodshed, advantage is that it is carried out without bloodshed, without the danger of operating death.without the danger of operating death.P32 selectively accumulates mainly in bone and acts on P32 selectively accumulates mainly in bone and acts on tumor cells with beta radiation. This method is used for tumor cells with beta radiation. This method is used for the treatment of multiple bone metastases in the case of the treatment of multiple bone metastases in the case of breast, prostate, lung.breast, prostate, lung.

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