Slide deals with introduction to medical oncology

1. Understanding RadiationUnderstanding Radiation
TherapyTherapy
King Faisal Cancer Centre
Riyadh

2. Introduction to Radiation OncologyIntroduction to Radiation Oncology
 Radiation has been anRadiation has been an
effective tool for treatingeffective tool for treating
cancer for more than 100cancer for more than 100
years.years.
 Radiation oncologists areRadiation oncologists are
doctors trained to usedoctors trained to use
radiation to eradicateradiation to eradicate
cancer.cancer.
 About two-thirds of allAbout two-thirds of all
cancer patients willcancer patients will
receive radiation therapyreceive radiation therapy
as part of theiras part of their
treatment.treatment.

3. What Is Radiation Therapy?What Is Radiation Therapy?
 Radiation therapy works by damagingRadiation therapy works by damaging
the DNA within cancer cells andthe DNA within cancer cells and
destroying their ability to reproduce.destroying their ability to reproduce.
 When the damaged cancer cells areWhen the damaged cancer cells are
destroyed by radiation, the bodydestroyed by radiation, the body
naturally eliminates them.naturally eliminates them.
 Normal cells can be affected byNormal cells can be affected by
radiation, but they are able to repairradiation, but they are able to repair
themselves.themselves.
 Sometimes radiation therapy is theSometimes radiation therapy is the
only treatment a patient needs.only treatment a patient needs.
 Other times, it is combined with otherOther times, it is combined with other
treatments, like surgery andtreatments, like surgery and
chemotherapy.chemotherapy.

4. Brief History of Radiation TherapyBrief History of Radiation Therapy
 The first patient was treated withThe first patient was treated with
radiation in 1896, two months after theradiation in 1896, two months after the
discovery of the X-ray.discovery of the X-ray.
 Back then, both doctors and non-Back then, both doctors and non-
physicians treated cancer patients withphysicians treated cancer patients with
radiation.radiation.
 Rapid technology advances began in theRapid technology advances began in the
early 1950s with cobalt units followed byearly 1950s with cobalt units followed by
linear accelerators a few years later.linear accelerators a few years later.
 Recent technology advances have madeRecent technology advances have made
radiation more effective and precise.radiation more effective and precise.

5. Methods of Delivering Radiation TherapyMethods of Delivering Radiation Therapy
Early 1950s Today

6. How Is Radiation Therapy Used?How Is Radiation Therapy Used?
Radiation therapy is usedRadiation therapy is used
two different ways.two different ways.
 To cure cancer:To cure cancer:
• Destroy tumors that have notDestroy tumors that have not
spread to other body parts.spread to other body parts.
• Reduce the risk that cancer willReduce the risk that cancer will
return after surgery orreturn after surgery or
chemotherapy.chemotherapy.
 To reduce symptoms:To reduce symptoms:
• Shrink tumors affecting quality ofShrink tumors affecting quality of
life, like a lung tumor that islife, like a lung tumor that is
causing shortness of breath.causing shortness of breath.
• Alleviate pain by reducing theAlleviate pain by reducing the
size of a tumor.size of a tumor.

7. Meet the Radiation Oncology TeamMeet the Radiation Oncology Team
 Radiation OncologistRadiation Oncologist
• The doctor who oversees the radiationThe doctor who oversees the radiation
therapy treatments.therapy treatments.
 Medical Radiation PhysicistMedical Radiation Physicist
• Ensures that complex treatment plansEnsures that complex treatment plans
are properly tailored for each patient.are properly tailored for each patient.
 DosimetristDosimetrist
• Works with the radiation oncologistWorks with the radiation oncologist
and medical physicist to calculate theand medical physicist to calculate the
proper dose of radiation given to theproper dose of radiation given to the
tumor.tumor.
 Radiation TherapistRadiation Therapist
• Administers the daily radiation underAdministers the daily radiation under
the doctor’s prescription andthe doctor’s prescription and
supervision.supervision.
 Radiation Oncology NurseRadiation Oncology Nurse
• Cares for the patient and family byCares for the patient and family by
providing education, emotional supportproviding education, emotional support
and tips for managing side effects.and tips for managing side effects.

8. Types of Radiation TherapyTypes of Radiation Therapy
 Radiation therapy can beRadiation therapy can be
delivered two ways –delivered two ways –
externally and internally.externally and internally.
• External beam radiation therapyExternal beam radiation therapy
delivers radiation using a lineardelivers radiation using a linear
accelerator.accelerator.
• Internal radiation therapy, calledInternal radiation therapy, called
brachytherapy or seed implants,brachytherapy or seed implants,
involves placing radioactiveinvolves placing radioactive
sources inside the patient.sources inside the patient.
 The type of treatment usedThe type of treatment used
will depend on the location,will depend on the location,
size and type of cancer.size and type of cancer.

9. Planning Radiation Therapy - SimulationPlanning Radiation Therapy - Simulation
 Each treatment isEach treatment is
mapped out in detailmapped out in detail
using treatmentusing treatment
planning software.planning software.
 Radiation therapyRadiation therapy
must be aimed at themust be aimed at the
same target everysame target every
time. Doctors usetime. Doctors use
several devices to doseveral devices to do
this:this:
• Skin markings orSkin markings or
tattoos.tattoos.
• Immobilization devicesImmobilization devices
– casts, molds,– casts, molds,
headrests.headrests.

10. External Radiation TherapyExternal Radiation Therapy
 Specialized types of externalSpecialized types of external
beam radiation therapybeam radiation therapy
• Three-dimensional conformalThree-dimensional conformal
radiation therapy (3D-CRT)radiation therapy (3D-CRT)
 Uses CT or MRI scans to create aUses CT or MRI scans to create a
3-D picture of the tumor.3-D picture of the tumor.
 Beams are precisely directed to avoidBeams are precisely directed to avoid
radiating normal tissue.radiating normal tissue.
• Intensity modulated radiationIntensity modulated radiation
therapy (IMRT)therapy (IMRT)
 A specialized form of 3D-CRT.A specialized form of 3D-CRT.
 Radiation is broken into manyRadiation is broken into many
“beamlets” and the intensity of each“beamlets” and the intensity of each
can be adjusted individually.can be adjusted individually.

11. External Radiation TherapyExternal Radiation Therapy
• Proton Beam TherapyProton Beam Therapy
 Uses protons rather than X-rays to treatUses protons rather than X-rays to treat
certain types of cancer.certain types of cancer.
 Allows doctors to better focus the dose onAllows doctors to better focus the dose on
the tumor with the potential to reduce thethe tumor with the potential to reduce the
dose to nearby healthy tissue.dose to nearby healthy tissue.
• Neutron Beam TherapyNeutron Beam Therapy
 A specialized form of radiation therapy thatA specialized form of radiation therapy that
can be used to treat certain tumors that arecan be used to treat certain tumors that are
very difficult to kill using conventionalvery difficult to kill using conventional
radiation therapy.radiation therapy.
• Stereotactic RadiotherapyStereotactic Radiotherapy
 Sometimes called stereotactic radiosurgery,Sometimes called stereotactic radiosurgery,
this technique allows the radiation oncologistthis technique allows the radiation oncologist
to precisely focus beams of radiation toto precisely focus beams of radiation to
destroy certain tumors, sometimes in onlydestroy certain tumors, sometimes in only
one treatment.one treatment.

12. Internal Radiation TherapyInternal Radiation Therapy
 Places radioactive material intoPlaces radioactive material into
tumor or surrounding tissue.tumor or surrounding tissue.
• Also called brachytherapy –Also called brachytherapy –
brachy Greek for “short distance.”brachy Greek for “short distance.”
• Radiation sources placed close toRadiation sources placed close to
the tumor so large doses can hitthe tumor so large doses can hit
the cancer cells.the cancer cells.
• Allows minimal radiation exposureAllows minimal radiation exposure
to normal tissue.to normal tissue.
• Radioactive sources used are thinRadioactive sources used are thin
wires, ribbons, capsules or seeds.wires, ribbons, capsules or seeds.
• These can be either permanentlyThese can be either permanently
or temporarily placed in the body.or temporarily placed in the body.

13. Side Effects of Radiation TherapySide Effects of Radiation Therapy
 Side effects, like skinSide effects, like skin
tenderness, are generallytenderness, are generally
limited to the arealimited to the area
receiving radiation.receiving radiation.
 Unlike chemotherapy,Unlike chemotherapy,
radiation usually doesn’tradiation usually doesn’t
cause hair loss orcause hair loss or
nausea.nausea.
 Most side effects beginMost side effects begin
during the second orduring the second or
third week of treatment.third week of treatment.
 Side effects may last forSide effects may last for
several weeks after theseveral weeks after the
final treatment.final treatment.

14. Is Radiation Therapy Safe?Is Radiation Therapy Safe?
 Many advances have beenMany advances have been
made in the field to ensure itmade in the field to ensure it
remains safe and effective.remains safe and effective.
 Multiple healthcareMultiple healthcare
professionals develop andprofessionals develop and
review the treatment plan toreview the treatment plan to
ensure that the target area isensure that the target area is
receiving the dose of radiationreceiving the dose of radiation
needed.needed.
 The treatment plan andThe treatment plan and
equipment are constantlyequipment are constantly
checked to ensure properchecked to ensure proper
treatment is being given.treatment is being given.

15.  The American Society for TherapeuticThe American Society for Therapeutic
Radiology and Oncology (ASTRO) canRadiology and Oncology (ASTRO) can
also provide more information onalso provide more information on
radiation therapy.radiation therapy.
 VisitVisit www.astro.org/patientwww.astro.org/patient for freefor free
brochures on how radiation therapybrochures on how radiation therapy
works to treat various cancers.works to treat various cancers.
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