SlideShare a Scribd company logo
Introduction to Medical Technology: Radiotherapy
Contents Why radiotherapy? Some basic principles Approaches to radiotherapy external beam: x-rays, electrons, p, n, heavy ions brachytherapy Stages in the radiotherapy process QA, imaging, planning, simulation, treatment, verification, modelling outcome
Why Radiotherapy? Radiotherapy used to treat cancers In conjunction with surgery and chemotherapy Proven benefit Cells display strong dose-effect relationship Physics, engineering, imaging, technology based
Benefits of Radiotherapy Breast Cancer Mastectomy Compare surgery and chemotherapy (CMF) with and without radiotherapy 10 year survival improvement at 10 years
Contents Why radiotherapy? Some basic principles Approaches to radiotherapy external beam: x-rays, electrons, p, n, heavy ions brachytherapy Stages in the radiotherapy process QA, imaging, planning, simulation, treatment, verification, modelling outcome
Radiobiology: Linear-quadratic model Effects of radiation on cell survival described by: linear-quadratic model Linear single hit sufficient  Quadratic multiple events
Radiobiology: Tumour and normal tissue Different responses to radiation  /   different Deliver one large dose effects similar Deliver many smaller doses effects very different Fractionation e.g. 60 Gy in 2 Gy fractions
Radiobiology:  Tumour and normal tissue Radiation effect vs. dose sigmoid behaviour stochastic process Tumour control lower dose than normal tissue damage Makes radiotherapy possible! Radiotherapy goals and research separate two curves
Some Nomenclature Dose response curve plot of radiation effect vs. dose Radical treatment treatment with curative intent (cf. palliation) RBE (relative biological effect)=quality factor Tumour staging: Tumour, Nodal, Metastasis Necrosis and hypoxia regions of tumour dead or dormant due to low oxygen level
Contents Why radiotherapy? Some basic principles Approaches to radiotherapy external beam: x-rays, electrons, p, n, heavy ions brachytherapy Stages in the radiotherapy process QA, imaging, planning, simulation, treatment, verification, modelling outcome
Approaches to Radiotherapy External beam Fire radiation beam into patient Usually several beams from various directions Cross-fire effect Brachytherapy Place set of sealed radioactive sources or seeds into patient Often contained in applicator tube
External Beam Treatment Most commonly Cobalt 60    rays (1.25 MeV), x-rays, electrons Co 60 radioactive source x-rays and e - , electron linac Sometimes orthovoltage (up to 300 kV) Superficial tumours More rarely hadrons (many MeV) protons, neutrons, heavy ions
Electron Linac for X-ray and Electron Radiotherapy X-rays (4-50 MV), electrons (4-50 MeV) X-rays polychromatic Bremsstrahlung Electrons scatter in air Need for collimation Cross-fire effect Several beams aimed at tumour/target High dose to tumour/small dose to surrounding tissue
Radiotherapy Linacs
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
X-Ray Beam Characteristics
 
 
 
 
 
 
Beam Shaping Devices Main Rectangular Collimators Wedge Multileaf Collimator Field edge shaping Block Compensator Multileaf Collimator IMRT (intensity modulated radiotherapy)
 
 
 
 
 
Lead Compensator Sheets of lead 0.5 mm thick Used in conjunction with wedge Shapes to breast and shields lung
Granulate Compensator Stainless steel granulate Used in conjunction with wedge Shapes to breast and shields lung
Intensity Modulated Radiotherapy Most common delivery method MLC (multileaf collimator) Dynamic Scan MLC leaves across field with radiation on Multiple segment Delivery set of irradiations at same position with different field shapes Compensators
 
Patient Image Cumulative Intensity Field 1 Field 4 Field 3 Field 2
 
Electron Beam Characteristics
 
 
 
 
 
 
Brachytherapy Sources placed in patient using metal tubes or applicators e.g. Ir 192 Afterloading High dose rate (HDR) and low dose rate (LDR), pulsed dose rate (PDR) Fractionated Prescription schemes for location of sources
 
 
 
 
 
 
 
 
 
 
Hadron Radiotherapy Large accelerators High energies needed Large magnetic rigidity Protons most common Over 20 in the world Neutrons Heavy ions
 
 
 

More Related Content

What's hot

New Techniques in Radiotherapy
New Techniques in RadiotherapyNew Techniques in Radiotherapy
New Techniques in Radiotherapy
Santam Chakraborty
 
Radioisotopes and dose rates used for brachytherapy
Radioisotopes and dose rates used for brachytherapyRadioisotopes and dose rates used for brachytherapy
Radioisotopes and dose rates used for brachytherapy
Subhash Thakur
 
Electron beam therapy
Electron beam therapyElectron beam therapy
Electron beam therapy
Kiran Ramakrishna
 
Measurement of absorbed dose
Measurement of absorbed doseMeasurement of absorbed dose
Measurement of absorbed dose
Purvi Rathod
 
Beam modification devices
Beam modification devicesBeam modification devices
Beam modification devices
Vibhay Pareek
 
Treatment plannings i kiran
Treatment plannings i   kiranTreatment plannings i   kiran
Treatment plannings i kiran
Kiran Ramakrishna
 
planning systems in radiotherapy
 planning systems in radiotherapy planning systems in radiotherapy
planning systems in radiotherapy
fondas vakalis
 
Epid
EpidEpid
Isodose lines
Isodose linesIsodose lines
Isodose lines
Tata Memorial Centre
 
Radiotherapy machines upto cobalt 60
Radiotherapy machines upto cobalt 60Radiotherapy machines upto cobalt 60
Radiotherapy machines upto cobalt 60
Dhiman Das
 
Principles of beam direction and use of simulators
Principles of beam direction and use of simulators Principles of beam direction and use of simulators
Principles of beam direction and use of simulators
Anil Gupta
 
Quality assurance of linear accelerator DHX
Quality assurance of linear accelerator DHXQuality assurance of linear accelerator DHX
Quality assurance of linear accelerator DHX
Sohail Qureshi
 
beam modifying devises
beam modifying devisesbeam modifying devises
beam modifying devises
saikishore15
 
Brachytherapy
BrachytherapyBrachytherapy
Brachytherapy
Joann Vargas
 
ELECTRON BEAM THERAPY
ELECTRON BEAM THERAPYELECTRON BEAM THERAPY
ELECTRON BEAM THERAPY
Sathish Kumar
 
Teletherapy Cobalt-60 Machines
Teletherapy Cobalt-60 MachinesTeletherapy Cobalt-60 Machines
Teletherapy Cobalt-60 Machines
Amin Amin
 
GAMMA KNIFE , X-KNIFE AND CYBERKNIFE
GAMMA KNIFE , X-KNIFE AND CYBERKNIFE GAMMA KNIFE , X-KNIFE AND CYBERKNIFE
GAMMA KNIFE , X-KNIFE AND CYBERKNIFE
Pooja Gupta
 
Total body irradiation
Total body irradiationTotal body irradiation
Total body irradiation
basilpaulsunny
 
Gamma Knife
Gamma KnifeGamma Knife
Gamma Knife
kathrnrt
 
Patient Positioning and Immobilization Devices In Radiotherapy Planning
Patient Positioning and Immobilization Devices In Radiotherapy PlanningPatient Positioning and Immobilization Devices In Radiotherapy Planning
Patient Positioning and Immobilization Devices In Radiotherapy Planning
Subhash Thakur
 

What's hot (20)

New Techniques in Radiotherapy
New Techniques in RadiotherapyNew Techniques in Radiotherapy
New Techniques in Radiotherapy
 
Radioisotopes and dose rates used for brachytherapy
Radioisotopes and dose rates used for brachytherapyRadioisotopes and dose rates used for brachytherapy
Radioisotopes and dose rates used for brachytherapy
 
Electron beam therapy
Electron beam therapyElectron beam therapy
Electron beam therapy
 
Measurement of absorbed dose
Measurement of absorbed doseMeasurement of absorbed dose
Measurement of absorbed dose
 
Beam modification devices
Beam modification devicesBeam modification devices
Beam modification devices
 
Treatment plannings i kiran
Treatment plannings i   kiranTreatment plannings i   kiran
Treatment plannings i kiran
 
planning systems in radiotherapy
 planning systems in radiotherapy planning systems in radiotherapy
planning systems in radiotherapy
 
Epid
EpidEpid
Epid
 
Isodose lines
Isodose linesIsodose lines
Isodose lines
 
Radiotherapy machines upto cobalt 60
Radiotherapy machines upto cobalt 60Radiotherapy machines upto cobalt 60
Radiotherapy machines upto cobalt 60
 
Principles of beam direction and use of simulators
Principles of beam direction and use of simulators Principles of beam direction and use of simulators
Principles of beam direction and use of simulators
 
Quality assurance of linear accelerator DHX
Quality assurance of linear accelerator DHXQuality assurance of linear accelerator DHX
Quality assurance of linear accelerator DHX
 
beam modifying devises
beam modifying devisesbeam modifying devises
beam modifying devises
 
Brachytherapy
BrachytherapyBrachytherapy
Brachytherapy
 
ELECTRON BEAM THERAPY
ELECTRON BEAM THERAPYELECTRON BEAM THERAPY
ELECTRON BEAM THERAPY
 
Teletherapy Cobalt-60 Machines
Teletherapy Cobalt-60 MachinesTeletherapy Cobalt-60 Machines
Teletherapy Cobalt-60 Machines
 
GAMMA KNIFE , X-KNIFE AND CYBERKNIFE
GAMMA KNIFE , X-KNIFE AND CYBERKNIFE GAMMA KNIFE , X-KNIFE AND CYBERKNIFE
GAMMA KNIFE , X-KNIFE AND CYBERKNIFE
 
Total body irradiation
Total body irradiationTotal body irradiation
Total body irradiation
 
Gamma Knife
Gamma KnifeGamma Knife
Gamma Knife
 
Patient Positioning and Immobilization Devices In Radiotherapy Planning
Patient Positioning and Immobilization Devices In Radiotherapy PlanningPatient Positioning and Immobilization Devices In Radiotherapy Planning
Patient Positioning and Immobilization Devices In Radiotherapy Planning
 

Viewers also liked

targeted therapy
targeted therapytargeted therapy
targeted therapy
FREE EDUCATION FOR ALL
 
Prostate video 2
Prostate video 2Prostate video 2
Prostate video 2
Robert J Miller MD
 
Bone mets video
Bone mets videoBone mets video
Bone mets video
Robert J Miller MD
 
Radiotherapy for Prostate Cancer
Radiotherapy for Prostate CancerRadiotherapy for Prostate Cancer
Radiotherapy for Prostate Cancer
Robert J Miller MD
 
Prostate video 1
Prostate video 1Prostate video 1
Prostate video 1
Robert J Miller MD
 
Breast cancer video 1
Breast cancer video 1Breast cancer video 1
Breast cancer video 1
Robert J Miller MD
 
Surgeon powerpoint
Surgeon powerpointSurgeon powerpoint
Surgeon powerpoint
muelller
 
Breast cancer video 2
Breast cancer video 2Breast cancer video 2
Breast cancer video 2
Robert J Miller MD
 
Immunotherapy Web Presentation
Immunotherapy   Web PresentationImmunotherapy   Web Presentation
Immunotherapy Web Presentation
anthonymaida
 
Brain mets video
Brain mets videoBrain mets video
Brain mets video
Robert J Miller MD
 
cancer immunotherapy
cancer immunotherapycancer immunotherapy
cancer immunotherapy
Arun Geetha Viswanathan
 
Cancer immunotherapy
Cancer immunotherapyCancer immunotherapy
Cancer immunotherapy
Neha Patel
 
Targeted Therapy in Cancer
Targeted Therapy in Cancer Targeted Therapy in Cancer
Targeted Therapy in Cancer
Rafael Trujillo Vílchez
 
Principles of chemotherapy ppt
Principles of chemotherapy pptPrinciples of chemotherapy ppt
Principles of chemotherapy ppt
madurai
 
Radiation therapy
Radiation therapyRadiation therapy
Radiation therapy
Rad Tech
 

Viewers also liked (15)

targeted therapy
targeted therapytargeted therapy
targeted therapy
 
Prostate video 2
Prostate video 2Prostate video 2
Prostate video 2
 
Bone mets video
Bone mets videoBone mets video
Bone mets video
 
Radiotherapy for Prostate Cancer
Radiotherapy for Prostate CancerRadiotherapy for Prostate Cancer
Radiotherapy for Prostate Cancer
 
Prostate video 1
Prostate video 1Prostate video 1
Prostate video 1
 
Breast cancer video 1
Breast cancer video 1Breast cancer video 1
Breast cancer video 1
 
Surgeon powerpoint
Surgeon powerpointSurgeon powerpoint
Surgeon powerpoint
 
Breast cancer video 2
Breast cancer video 2Breast cancer video 2
Breast cancer video 2
 
Immunotherapy Web Presentation
Immunotherapy   Web PresentationImmunotherapy   Web Presentation
Immunotherapy Web Presentation
 
Brain mets video
Brain mets videoBrain mets video
Brain mets video
 
cancer immunotherapy
cancer immunotherapycancer immunotherapy
cancer immunotherapy
 
Cancer immunotherapy
Cancer immunotherapyCancer immunotherapy
Cancer immunotherapy
 
Targeted Therapy in Cancer
Targeted Therapy in Cancer Targeted Therapy in Cancer
Targeted Therapy in Cancer
 
Principles of chemotherapy ppt
Principles of chemotherapy pptPrinciples of chemotherapy ppt
Principles of chemotherapy ppt
 
Radiation therapy
Radiation therapyRadiation therapy
Radiation therapy
 

Similar to Introduction to radiation therapy

Radiotherapy and radiosensitizers in head and neck cancers.pptx
Radiotherapy and radiosensitizers in head and neck cancers.pptxRadiotherapy and radiosensitizers in head and neck cancers.pptx
Radiotherapy and radiosensitizers in head and neck cancers.pptx
Sudin Kayastha
 
Radiation therapy in head and neck cancer
Radiation therapy in head and neck cancerRadiation therapy in head and neck cancer
Radiation therapy in head and neck cancer
SREENIVAS KAMATH
 
Role of Conformal Radiotherapy in HNC
Role of Conformal Radiotherapy in HNCRole of Conformal Radiotherapy in HNC
Role of Conformal Radiotherapy in HNC
Sasikumar Sambasivam
 
Radiotherapy
RadiotherapyRadiotherapy
Radiotherapy
dr.nikil נαιη
 
Novel rt in sarc2017
Novel rt in sarc2017Novel rt in sarc2017
Novel rt in sarc2017
Mohammad Gouran savadkoohi
 
Radiotherapy and chemotherapy in Oral cancer management
Radiotherapy and chemotherapy in Oral cancer managementRadiotherapy and chemotherapy in Oral cancer management
Radiotherapy and chemotherapy in Oral cancer management
Tejaswini Pss
 
Radiation therapy.ppt and learning how the following statements
Radiation therapy.ppt and learning how the following statementsRadiation therapy.ppt and learning how the following statements
Radiation therapy.ppt and learning how the following statements
neestom1998
 
How is Radiation Therapy Used to Help Lung Cancer Patients?
How is Radiation Therapy Used to Help Lung Cancer Patients?How is Radiation Therapy Used to Help Lung Cancer Patients?
How is Radiation Therapy Used to Help Lung Cancer Patients?
Dana-Farber Cancer Institute
 
Principles of radiotherapy
Principles of radiotherapyPrinciples of radiotherapy
Principles of radiotherapy
AswiniSivan
 
EBRT and brachytherapy radiology go3.ppt
EBRT and brachytherapy radiology go3.pptEBRT and brachytherapy radiology go3.ppt
EBRT and brachytherapy radiology go3.ppt
HahLa2
 
The vmat vs other recent radiotherapy techniques
The vmat vs other recent radiotherapy techniquesThe vmat vs other recent radiotherapy techniques
The vmat vs other recent radiotherapy techniques
M'dee Phechudi
 
Radiation Therapy_2013.ppt
Radiation Therapy_2013.pptRadiation Therapy_2013.ppt
Radiation Therapy_2013.ppt
FrancisKazoba
 
Radiation Therapy of cancer patients _2013.ppt
Radiation Therapy of cancer patients _2013.pptRadiation Therapy of cancer patients _2013.ppt
Radiation Therapy of cancer patients _2013.ppt
Baljeet Kaur
 
Radiation Therapy_2013.ppt etrhw42uuh4w34r
Radiation Therapy_2013.ppt etrhw42uuh4w34rRadiation Therapy_2013.ppt etrhw42uuh4w34r
Radiation Therapy_2013.ppt etrhw42uuh4w34r
ShorenaGedenidze
 
Dr.Shizan Pervez Radiation Therapy_2019.ppt
Dr.Shizan Pervez Radiation Therapy_2019.pptDr.Shizan Pervez Radiation Therapy_2019.ppt
Dr.Shizan Pervez Radiation Therapy_2019.ppt
drshizanpervez786
 
23
2323
Medical Equipment Radiotherapy1
 Medical Equipment Radiotherapy1 Medical Equipment Radiotherapy1
Medical Equipment Radiotherapy1
cairo university
 
AN ANALYSIS OF THE BENEFITS AND ADVANTAGES TO SRT
AN ANALYSIS OF THE BENEFITS AND ADVANTAGES TO SRTAN ANALYSIS OF THE BENEFITS AND ADVANTAGES TO SRT
AN ANALYSIS OF THE BENEFITS AND ADVANTAGES TO SRT
Melissa McClement
 
Control of Scattered Radiation - Saroj.pptx
Control of Scattered Radiation - Saroj.pptxControl of Scattered Radiation - Saroj.pptx
Control of Scattered Radiation - Saroj.pptx
SarojPoudel24
 
Radiation Therapy 1 & 2
Radiation Therapy 1 & 2Radiation Therapy 1 & 2
Radiation Therapy 1 & 2
SCDA
 

Similar to Introduction to radiation therapy (20)

Radiotherapy and radiosensitizers in head and neck cancers.pptx
Radiotherapy and radiosensitizers in head and neck cancers.pptxRadiotherapy and radiosensitizers in head and neck cancers.pptx
Radiotherapy and radiosensitizers in head and neck cancers.pptx
 
Radiation therapy in head and neck cancer
Radiation therapy in head and neck cancerRadiation therapy in head and neck cancer
Radiation therapy in head and neck cancer
 
Role of Conformal Radiotherapy in HNC
Role of Conformal Radiotherapy in HNCRole of Conformal Radiotherapy in HNC
Role of Conformal Radiotherapy in HNC
 
Radiotherapy
RadiotherapyRadiotherapy
Radiotherapy
 
Novel rt in sarc2017
Novel rt in sarc2017Novel rt in sarc2017
Novel rt in sarc2017
 
Radiotherapy and chemotherapy in Oral cancer management
Radiotherapy and chemotherapy in Oral cancer managementRadiotherapy and chemotherapy in Oral cancer management
Radiotherapy and chemotherapy in Oral cancer management
 
Radiation therapy.ppt and learning how the following statements
Radiation therapy.ppt and learning how the following statementsRadiation therapy.ppt and learning how the following statements
Radiation therapy.ppt and learning how the following statements
 
How is Radiation Therapy Used to Help Lung Cancer Patients?
How is Radiation Therapy Used to Help Lung Cancer Patients?How is Radiation Therapy Used to Help Lung Cancer Patients?
How is Radiation Therapy Used to Help Lung Cancer Patients?
 
Principles of radiotherapy
Principles of radiotherapyPrinciples of radiotherapy
Principles of radiotherapy
 
EBRT and brachytherapy radiology go3.ppt
EBRT and brachytherapy radiology go3.pptEBRT and brachytherapy radiology go3.ppt
EBRT and brachytherapy radiology go3.ppt
 
The vmat vs other recent radiotherapy techniques
The vmat vs other recent radiotherapy techniquesThe vmat vs other recent radiotherapy techniques
The vmat vs other recent radiotherapy techniques
 
Radiation Therapy_2013.ppt
Radiation Therapy_2013.pptRadiation Therapy_2013.ppt
Radiation Therapy_2013.ppt
 
Radiation Therapy of cancer patients _2013.ppt
Radiation Therapy of cancer patients _2013.pptRadiation Therapy of cancer patients _2013.ppt
Radiation Therapy of cancer patients _2013.ppt
 
Radiation Therapy_2013.ppt etrhw42uuh4w34r
Radiation Therapy_2013.ppt etrhw42uuh4w34rRadiation Therapy_2013.ppt etrhw42uuh4w34r
Radiation Therapy_2013.ppt etrhw42uuh4w34r
 
Dr.Shizan Pervez Radiation Therapy_2019.ppt
Dr.Shizan Pervez Radiation Therapy_2019.pptDr.Shizan Pervez Radiation Therapy_2019.ppt
Dr.Shizan Pervez Radiation Therapy_2019.ppt
 
23
2323
23
 
Medical Equipment Radiotherapy1
 Medical Equipment Radiotherapy1 Medical Equipment Radiotherapy1
Medical Equipment Radiotherapy1
 
AN ANALYSIS OF THE BENEFITS AND ADVANTAGES TO SRT
AN ANALYSIS OF THE BENEFITS AND ADVANTAGES TO SRTAN ANALYSIS OF THE BENEFITS AND ADVANTAGES TO SRT
AN ANALYSIS OF THE BENEFITS AND ADVANTAGES TO SRT
 
Control of Scattered Radiation - Saroj.pptx
Control of Scattered Radiation - Saroj.pptxControl of Scattered Radiation - Saroj.pptx
Control of Scattered Radiation - Saroj.pptx
 
Radiation Therapy 1 & 2
Radiation Therapy 1 & 2Radiation Therapy 1 & 2
Radiation Therapy 1 & 2
 

More from Rad Tech

Ultrasound 2
Ultrasound 2Ultrasound 2
Ultrasound 2
Rad Tech
 
Ultrasound
UltrasoundUltrasound
Ultrasound
Rad Tech
 
The x ray imaging system
The x ray imaging systemThe x ray imaging system
The x ray imaging system
Rad Tech
 
Rad phy digital radiography
Rad phy digital radiographyRad phy digital radiography
Rad phy digital radiography
Rad Tech
 
Radiographic film
Radiographic filmRadiographic film
Radiographic film
Rad Tech
 
Radiographic exposure and image quality
Radiographic exposure and image qualityRadiographic exposure and image quality
Radiographic exposure and image quality
Rad Tech
 
Radiographic artifacts
Radiographic artifactsRadiographic artifacts
Radiographic artifacts
Rad Tech
 
Radiation protection in nuclear medicine.ppt 2
Radiation protection in nuclear medicine.ppt 2Radiation protection in nuclear medicine.ppt 2
Radiation protection in nuclear medicine.ppt 2
Rad Tech
 
Radiation protection in nuclear medicine
Radiation protection in nuclear medicineRadiation protection in nuclear medicine
Radiation protection in nuclear medicine
Rad Tech
 
Radiation physics 2
Radiation physics 2Radiation physics 2
Radiation physics 2
Rad Tech
 
Radiation physics
Radiation physicsRadiation physics
Radiation physics
Rad Tech
 
Radiation oncology
Radiation oncologyRadiation oncology
Radiation oncology
Rad Tech
 
Procedures i chapter 1 bontrager
Procedures i  chapter 1 bontragerProcedures i  chapter 1 bontrager
Procedures i chapter 1 bontrager
Rad Tech
 
Ultrasound 3
Ultrasound 3Ultrasound 3
Ultrasound 3
Rad Tech
 
Procedures I Chapter 1 Bontrager
Procedures I  Chapter 1 BontragerProcedures I  Chapter 1 Bontrager
Procedures I Chapter 1 Bontrager
Rad Tech
 
Principles of radiation oncology
Principles of radiation oncologyPrinciples of radiation oncology
Principles of radiation oncology
Rad Tech
 
Nuclear medicine 2
Nuclear medicine 2Nuclear medicine 2
Nuclear medicine 2
Rad Tech
 
Nuclear medicine
Nuclear medicineNuclear medicine
Nuclear medicine
Rad Tech
 
Mri 3
Mri 3Mri 3
Mri 3
Rad Tech
 
Mri 2
Mri 2Mri 2
Mri 2
Rad Tech
 

More from Rad Tech (20)

Ultrasound 2
Ultrasound 2Ultrasound 2
Ultrasound 2
 
Ultrasound
UltrasoundUltrasound
Ultrasound
 
The x ray imaging system
The x ray imaging systemThe x ray imaging system
The x ray imaging system
 
Rad phy digital radiography
Rad phy digital radiographyRad phy digital radiography
Rad phy digital radiography
 
Radiographic film
Radiographic filmRadiographic film
Radiographic film
 
Radiographic exposure and image quality
Radiographic exposure and image qualityRadiographic exposure and image quality
Radiographic exposure and image quality
 
Radiographic artifacts
Radiographic artifactsRadiographic artifacts
Radiographic artifacts
 
Radiation protection in nuclear medicine.ppt 2
Radiation protection in nuclear medicine.ppt 2Radiation protection in nuclear medicine.ppt 2
Radiation protection in nuclear medicine.ppt 2
 
Radiation protection in nuclear medicine
Radiation protection in nuclear medicineRadiation protection in nuclear medicine
Radiation protection in nuclear medicine
 
Radiation physics 2
Radiation physics 2Radiation physics 2
Radiation physics 2
 
Radiation physics
Radiation physicsRadiation physics
Radiation physics
 
Radiation oncology
Radiation oncologyRadiation oncology
Radiation oncology
 
Procedures i chapter 1 bontrager
Procedures i  chapter 1 bontragerProcedures i  chapter 1 bontrager
Procedures i chapter 1 bontrager
 
Ultrasound 3
Ultrasound 3Ultrasound 3
Ultrasound 3
 
Procedures I Chapter 1 Bontrager
Procedures I  Chapter 1 BontragerProcedures I  Chapter 1 Bontrager
Procedures I Chapter 1 Bontrager
 
Principles of radiation oncology
Principles of radiation oncologyPrinciples of radiation oncology
Principles of radiation oncology
 
Nuclear medicine 2
Nuclear medicine 2Nuclear medicine 2
Nuclear medicine 2
 
Nuclear medicine
Nuclear medicineNuclear medicine
Nuclear medicine
 
Mri 3
Mri 3Mri 3
Mri 3
 
Mri 2
Mri 2Mri 2
Mri 2
 

Introduction to radiation therapy

  • 1. Introduction to Medical Technology: Radiotherapy
  • 2. Contents Why radiotherapy? Some basic principles Approaches to radiotherapy external beam: x-rays, electrons, p, n, heavy ions brachytherapy Stages in the radiotherapy process QA, imaging, planning, simulation, treatment, verification, modelling outcome
  • 3. Why Radiotherapy? Radiotherapy used to treat cancers In conjunction with surgery and chemotherapy Proven benefit Cells display strong dose-effect relationship Physics, engineering, imaging, technology based
  • 4. Benefits of Radiotherapy Breast Cancer Mastectomy Compare surgery and chemotherapy (CMF) with and without radiotherapy 10 year survival improvement at 10 years
  • 5. Contents Why radiotherapy? Some basic principles Approaches to radiotherapy external beam: x-rays, electrons, p, n, heavy ions brachytherapy Stages in the radiotherapy process QA, imaging, planning, simulation, treatment, verification, modelling outcome
  • 6. Radiobiology: Linear-quadratic model Effects of radiation on cell survival described by: linear-quadratic model Linear single hit sufficient Quadratic multiple events
  • 7. Radiobiology: Tumour and normal tissue Different responses to radiation  /  different Deliver one large dose effects similar Deliver many smaller doses effects very different Fractionation e.g. 60 Gy in 2 Gy fractions
  • 8. Radiobiology: Tumour and normal tissue Radiation effect vs. dose sigmoid behaviour stochastic process Tumour control lower dose than normal tissue damage Makes radiotherapy possible! Radiotherapy goals and research separate two curves
  • 9. Some Nomenclature Dose response curve plot of radiation effect vs. dose Radical treatment treatment with curative intent (cf. palliation) RBE (relative biological effect)=quality factor Tumour staging: Tumour, Nodal, Metastasis Necrosis and hypoxia regions of tumour dead or dormant due to low oxygen level
  • 10. Contents Why radiotherapy? Some basic principles Approaches to radiotherapy external beam: x-rays, electrons, p, n, heavy ions brachytherapy Stages in the radiotherapy process QA, imaging, planning, simulation, treatment, verification, modelling outcome
  • 11. Approaches to Radiotherapy External beam Fire radiation beam into patient Usually several beams from various directions Cross-fire effect Brachytherapy Place set of sealed radioactive sources or seeds into patient Often contained in applicator tube
  • 12. External Beam Treatment Most commonly Cobalt 60  rays (1.25 MeV), x-rays, electrons Co 60 radioactive source x-rays and e - , electron linac Sometimes orthovoltage (up to 300 kV) Superficial tumours More rarely hadrons (many MeV) protons, neutrons, heavy ions
  • 13. Electron Linac for X-ray and Electron Radiotherapy X-rays (4-50 MV), electrons (4-50 MeV) X-rays polychromatic Bremsstrahlung Electrons scatter in air Need for collimation Cross-fire effect Several beams aimed at tumour/target High dose to tumour/small dose to surrounding tissue
  • 15.  
  • 16.  
  • 17.  
  • 18.  
  • 19.  
  • 20.  
  • 21.  
  • 22.  
  • 23.  
  • 24.  
  • 25.  
  • 26.  
  • 27.  
  • 28.  
  • 29.  
  • 30.  
  • 31.  
  • 32.  
  • 34.  
  • 35.  
  • 36.  
  • 37.  
  • 38.  
  • 39.  
  • 40. Beam Shaping Devices Main Rectangular Collimators Wedge Multileaf Collimator Field edge shaping Block Compensator Multileaf Collimator IMRT (intensity modulated radiotherapy)
  • 41.  
  • 42.  
  • 43.  
  • 44.  
  • 45.  
  • 46. Lead Compensator Sheets of lead 0.5 mm thick Used in conjunction with wedge Shapes to breast and shields lung
  • 47. Granulate Compensator Stainless steel granulate Used in conjunction with wedge Shapes to breast and shields lung
  • 48. Intensity Modulated Radiotherapy Most common delivery method MLC (multileaf collimator) Dynamic Scan MLC leaves across field with radiation on Multiple segment Delivery set of irradiations at same position with different field shapes Compensators
  • 49.  
  • 50. Patient Image Cumulative Intensity Field 1 Field 4 Field 3 Field 2
  • 51.  
  • 53.  
  • 54.  
  • 55.  
  • 56.  
  • 57.  
  • 58.  
  • 59. Brachytherapy Sources placed in patient using metal tubes or applicators e.g. Ir 192 Afterloading High dose rate (HDR) and low dose rate (LDR), pulsed dose rate (PDR) Fractionated Prescription schemes for location of sources
  • 60.  
  • 61.  
  • 62.  
  • 63.  
  • 64.  
  • 65.  
  • 66.  
  • 67.  
  • 68.  
  • 69.  
  • 70. Hadron Radiotherapy Large accelerators High energies needed Large magnetic rigidity Protons most common Over 20 in the world Neutrons Heavy ions
  • 71.  
  • 72.  
  • 73.