radio therapy

8/2/2019 Radio Therapy

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Radio TherapyHigh Energi to shrink ;to kill cancercell

X rays,gamma rays, charged particles

External beam radiation therapy;internalradiation therapy (brachy therapy) ;Systemicradiation therapy


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How radiation Therapy

kill cancer cellKill cancer cells by damaging DNA

Damage DNA directly

Create charged particles (free radicals) can turndamage the DNA

Cancer cell whose DNA damaged ,stop

dividing or die,when damaged cellsdie,,,,,,,broken down and eliminated by naturalprocess


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Does radiation therapy

kill only cancer cellNo,also damage normal cells leading to side

effects

When planning a course radiationtherapy,potential damage to normal cells intoaccount

Amount of radiation that normal tissue can

safely receive is known for all parts of thebody


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Why patients receive

radiation therapyCure a cancer by :

Eliminating a tumor

e,gPreventing cancer recurrence

Combination with surgery,chemotherapy

Palliative treatment,to relieve symptoms and

reduce suffring caused by cancer.e.gBrain,,to shrink metastases cancer spread

Spine ..to shrink tumor on the spine

Oesophagus,to shrink tumor near theoesophagus


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How radiation therapy

plannedSimulation

Detailed imaging scans,show the location of

tumorScans by :

Computed Tomography (TM)

Magnetic Resonansce Imaging (MRI)

Positron Emission Tomography (PET )

If its necessary patient in exactly sameposition to the machine delivering radiation


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continue or imaging

Bodymolds

Head masker

Other device ,may constructed for individualpatient

Skin marks


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After SimulationExact area wil be treated

Total radiation dose will be delivered

How much dose allowed to the normal tissuearound the tumor

Safest angles (paths) for radiation delivery


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How R.T given to the

patientExternal beam R.T ( radiation come from a

machine outside the body

Internal R.T (radioactive material placed inthe body ,near cancer cells ) commonly calledbrachytherapy

Systemic R.T(a radioactive sustance,given by

mouth,or into a vein,that travels in the bloodto tissues throughout the body


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Type of R.T prescribed

depends:Type of cancer

Site of cancer

Cancer location in the body

How close the cancer is to normal tissues,that are sensitive to radiation

How far the radiation need to travel

General health the patients

Other factor:age ,other medical condition

Will have other type s of cancer treatment


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External-Beam R.TIs delivered (most often) in the form photon

beamsEither x-rays or gamma rays

Using a machine a linear accelerator(LINAC)LINAC by electricity to form astream of fast moving subatomicparticles,creates high energy radiation to treatcancer


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External-Beam RT

(continues)Receive in daily treatment sessions over

several weeks

Number of treatment sessions depends ofmany factors incl;total radiation dose that willbe given


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Common type of

External beam RT3 dimensional conformal R.T ( 3D-CRT )

Uses very sophisticated computerAdvanced treatment machine

Intensity-modulated RT

Devices,called collimatorsCollimators can be stationary or move

Intensity of radiation canchange duringtreatment,allows different area of a tumor and

nearby tissues to receive different dose of


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Type of external beam

RT (continues)Image-guided RT (IGRT) in IGRT repeated

imaging scans (CT,MRI,PET) are performedduring tretment,to identify changes in tumors

size and location due to treatment.Repeatedimaging can increase the accuracy radiation

Tomotherapy (satu jenis dari IMRT),is the

hybrid CT imaging scanner and an ExternalBeam RT machine.The part of Tomotherapymachine that deliver radiation for bothimaging and treatment,can rotate completelyaround the patient


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Type of External

RT(continues)Stereotatic Radiosurgery (SRS),can deliver

one or more high doses radiation to a smalltumor.Extremely accurate image-guided

tumor targeting,so high dose of radiation canbe given without exess damage to normaltissue.most commonly ,to treat braintumors,spinal tumors,brain metastases from

other cancer types.


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Type of external beam

RT (continues)Stereotatic body Radio Therapy .

(SBRT);deliver smaller radiation filleds,higherdoses than 3 D-CRT.ussually given to treat

only small ,isolated tumors,,,incl ;lung ,livertumors..brands name :Cyberknife

Proton Therapy External Beam RT can deliverproton beams as well as photon beams.Photon beam deposit energy along their paththrough living tissue,Proton deposit much oftheir energy at the end of their path (Braggpeak)


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External-beam RT

(continues)Other Charged particles

Electrons Beams,irradiated superficial tumors

,such skin cancer,they cannot treat tumors deepwithin the body.


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Internal Radio Therapy

Several brachytherapy techniques are used incancer therapy :

Interstitial brachytherapy e,g :prostat tumorsIntracavitary brachyteraphy,sources placed

within surgical cavity,or a body cavity

Episclera brachytherapy,treat melanoma inside

the eye.


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Internal Radiation

Therapy (continues) Brachy therapy can be given as

Low dose treatment,cancer cell receive

conntinuous low-dose radiation from the sourceover aperiode several days

High dose treatment,robotic machine placedtubes inside the body ,guides one or moreradioactive source into or near the cancer.andthen removes the source at the end of eachtreatment sessions.


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Internal Radiation

Therapy (continuous)The placement of brachytherapy can be

Permanent brachytherapy,after all the radiation

has been given off,the remaining material doesnot cause ; harm or discomfort,is a type of low dose rate brachyteraphy

Temporary brachyteraphy. Tube,or catheters orother carriers used to deliver radiationsources,,removed after treatment. Can be eitherlow-dose rete tretment or high dose treatment.


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Systemic Radiation

TherapyPatient swallow or receive an injection of a

radioactive substance

For a systemic radiation some other types ofcancer,a monoclonal antibody helps target theradio active sustance to the right place

The antibody joined to te radoactive travels

through the blood,locating and killing tumors


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Systemic Radiation

TherapyIbritumomab tiuxetan (Zevalin) approved by

FDA treatment certain type B-cell non HodgkinLymphoma (NHL).the part antibody of this

drug,recognizes and binds to a protein on thesurface of B lymphocytes

Tositumomab and iodine I 131 tositumomab(Bexxar) app for the treatment of certain typeof NHL


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Why some type of RTgiven in many smalldoses ?Patient recieves types of External RT usually

recieves one dose (a single fraction) of thetotal planned dose of radiatioan ,is given each

daily

There are two main reasons for one dailytreatment

Minimize the damage the normal tissueIncrease cancer cell at the points,in the cell

cycle ,exposed to radiation,vulnerable ,to DNAdamage


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When,will a patient get

RTPatients may recieves RT alone

Patients may recieves RT before,during ,after

surgeryPatients may recieves RT and Chemotherapy

at the same timeThe timing of RT depends on:type and the

goal of treatment (cure of palliation)


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continuous

Neoajuvant radiation,RT given before surgery

Intraoperative Radiation Therapy (IORT),given

during surgeryPost operative RT or adjuvant,given after

surgery

Chemoradiation,chemotherapy andradiation,given at the same time.


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Does RT make a patient

RadioactiveTemporary brachytherapy :while radioactive

material is inside of the body ,the patientradioactive,the material removed ,the patient

no longer radioactive(p stay in special room inhospital)

Permanent brachytherapy,the patientradioactive,but the amount reach the surfaceis very low

Systemic RT ,temporarily make a patientsbody fluid emit a low level radiation


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Potential Side Effect Of

RTAccute side effect RT,occur during treatment

Chronic side effect RT,months or even years

after treatment endsCommon side effect : fatigue,nausea,vomit

Late side effects of RT:fibrosis,damage tobowel,memory loss,infertility,rarely secondcancer by radiation exposure


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Side Effect ( continuous)

Develop depend on

Area of the body being treated

Dose given per day

Total dose given

Other treatment given at the same time


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Research being done to

improve RTHow to use RT to treat cancer more safely

and more effectively

Researchers are working to improve image-guided radiation

Researchers are studying Radiosensitizers

Researchers are studying Radioprotectors


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radio therapy

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