Three Three-Dimensional Conformal Dimensional Conformal - - PowerPoint PPT Presentation

Three Three-Dimensional Conformal Dimensional Conformal Radiotherapy (3DCRT) Radiotherapy (3DCRT)

Treatment planning for external beam Treatment planning for external beam

• Prof. Dr. Golam Abu Zakaria
• Prof. Dr. Golam Abu Zakaria

Gummersbach Hospital Gummersbach Hospital Academic Teaching Hospital of the University of Cologne Academic Teaching Hospital of the University of Cologne Department of Medical Radiation Physics Department of Medical Radiation Physics 51643 Gummersbach, Germany 51643 Gummersbach, Germany E-Mail: GolamAbu.Zakaria@Klinikum Mail: GolamAbu.Zakaria@Klinikum-Oberberg.de Oberberg.de

Professionals involved in the treatment planning Professionals involved in the treatment planning process process (IAEA) (IAEA)

The radiotherapy chain The radiotherapy chain

• A characteristic feature of modern radiotherapy is a

A characteristic feature of modern radiotherapy is a multi multi-

• disciplinary

disciplinary approach approach, consisting of and usage of many complex devices and procedures. , consisting of and usage of many complex devices and procedures.

Dosimetric verification and checks Clinical examination Therapeutic decision Treatment planning: Simulation and dose calculation Radiotherapy 3D Imaging Treatment planning: Evaluation and assessment Localization of target volume and organs at risk Patient- positioning Aftercare, evaluation

Computertomograph Linear accelerator Image data

The Radiotherapy Chain The Radiotherapy Chain example: example:

Treatment planning system Therapy simulator Simulated and marked radiation fields Planned radiation fields

Radiotherapy treatment goal Radiotherapy treatment goal

• The objective of radiotherapy is the destruction of local tumour

The objective of radiotherapy is the destruction of local tumour without severe side effects without severe side effects

• Removal of the tumour

Removal of the tumour

– (Local tumour control / Regional tumour control) (Local tumour control / Regional tumour control) – (Local tumour control / Regional tumour control) (Local tumour control / Regional tumour control)

• Avoidance of treatment effects

Avoidance of treatment effects

– disfigurement disfigurement – loss of function loss of function – restriction of quality of life restriction of quality of life

• Therapy optimization: maximum effect with minimal burden

Therapy optimization: maximum effect with minimal burden

Organ Organ Volume part Volume part TD TD 5/5

5/5 1/3 1/3

TD TD 5/5

5/5 2/3 2/3

TD TD 5/5

5/5 3/3 3/3

TD TD 50/5

50/5 1/3 1/3

TD TD 50/5

50/5 2/3 2/3

TD TD 50/5

50/5 3/3 3/3

Radiation consequense Radiation consequense Arm nerve plexus Arm nerve plexus 62 62 61 61 60 60 77 77 76 76 75 75 Manifeste Plexopathie Manifeste Plexopathie Lens Lens 10 10 18 18 Katarakt Katarakt Bladder Bladder 80 80 65 65 85 85 80 80 Symptomatische Schrumpfblase Symptomatische Schrumpfblase Cauda equina Cauda equina no Volume effect no Volume effect 60 60 no Volume effect no Volume effect 75 75 Manifeste Neuropathie Manifeste Neuropathie Chiasma opticum Chiasma opticum no Volume effect no Volume effect 50 50 no Volume effect no Volume effect 65 65 Blindness Blindness Small intestine Small intestine 50 50

• 40

40a 60 60

• 55

55 Stenose, Perforation, Fistel Stenose, Perforation, Fistel Femurkopf (I+II) Femurkopf (I+II)

• 52

52

• 65

65 Bone necrosis Bone necrosis Skin Skin 10 cm 10 cm2

2: 50

: 50 30 cm 30 cm2: 60 : 60 100 cm 100 cm2: : 55 55 10 cm 10 cm2: : -

• 30 cm

30 cm2: : -

• 100 cm

100 cm2: : 70 70 Nekrose, Ulzeration Nekrose, Ulzeration Heart Heart 60 60 45 45 40 40 70 70 55 55 50 50 Perikarditis Perikarditis Brain Brain 60 60 50 50 45 45 75 75 65 65 60 60 Nekrose, Infarkt Nekrose, Infarkt Brainstem Brainstem 60 60 53 53 50 50

• 65

65 Nekrose, Infarkt Nekrose, Infarkt

Tolerance doses in Gy Tolerance doses in Gy (Emami et al). (Emami et al).

TMJ TMJ 65 65 60 60 60 60 77 77 72 72 72 72 Trismus Trismus Colon Colon 55 55 45 45 60 60 55 55 Stenose, Perforation, Fistel, Ulkus Stenose, Perforation, Fistel, Ulkus Larynx Larynx 79 79a

a

70 70a 70 70a 90 90a 80 80a 80 80a Knorpelnekrose Knorpelnekrose Larynx Larynx

• 45

45 45 45a

• 80

80a Larynxödem Larynxödem Liver Liver 50 50 35 35 30 30 55 55 45 45 40 40 Liver failure Liver failure Lung Lung 45 45 30 30 17,5 17,5 65 65 40 40 24,5 24,5 Pneumonitis Pneumonitis Stomach Stomach 60 60 55 55 50 50 70 70 67 67 65 65 Ileus, Perforation Ileus, Perforation Middle Ear/Externa Ear Middle Ear/Externa Ear 30 30 30 30 30 30a 40 40 40 40 40 40a Akute seröse Otitis Akute seröse Otitis Middle Ear/Externa Ear Middle Ear/Externa Ear 55 55 55 55 55 55a 65 65 65 65 65 65a Chronische seröse Otitis Chronische seröse Otitis Kindney (one) Kindney (one) 50 50 30 30 23 23 40 40a 28 28 Klinisch manifeste Nephritis Klinisch manifeste Nephritis

• sophagus
• sophagus

60 60 58 58 55 55 72 72 70 70 68 68 Striktur, Perforation Striktur, Perforation Parotiden Parotiden 32 32a 32 32a 46 46a 46 46a Xerostomie Xerostomie Rectum Rectum Volume: 100 cm Volume: 100 cm3 60 60 Volume: 100 cm Volume: 100 cm3 80 80 Proktitis, Stenose, Nekrose, Fistel Proktitis, Stenose, Nekrose, Fistel Retina (I+II) Retina (I+II) no Volume effect no Volume effect 45 45 no Volume effect no Volume effect 65 65 Blindness Blindness Rippen Rippen 50 50 65 65 Pathologische Fraktur Pathologische Fraktur Spinal Chord Spinal Chord 5 cm: 50 5 cm: 50 10 cm: 50 10 cm: 50 20 cm:47 20 cm:47 5 cm: 70 5 cm: 70 10 cm:70 10 cm:70 20 cm: 20 cm: -

• Myelopathie, Nekrose

Myelopathie, Nekrose Optic Nerve, Retinae (I+II) Optic Nerve, Retinae (I+II) no Volume effect no Volume effect 50 50 no Volume effect no Volume effect 65 65 Blindness Blindness

Tolerance doses ( Tolerance doses (Organ types) Organ types)

• Serial organs

Serial organs - example example spinal cord spinal cord

• Parallel organ

Parallel organ - example example lung lung

High dose High dose region region High dose High dose region region

What difference in What difference in response would you response would you expect? expect?

Parallel Parallel

• rgan
• rgan

Serial Serial

• rgan
• rgan

In practice not always that In practice not always that clear cut clear cut

Fixation aids and markers on the skin Fixation aids and markers on the skin permit reproducibility of the settings by permit reproducibility of the settings by means of a stationary laser means of a stationary laser- coordinate coordinate system system

Fixing of the treatment position Fixing of the treatment position (positioning, immobilization) (positioning, immobilization)

3-D D-Treatment planning process ( Treatment planning process (positioning) positioning)

Example: HNO Example: HNO-Area Area A technician A technician places the mask on the patient. places the mask on the patient.

3-D D-Treatment planning process ( Treatment planning process (positioning) positioning)

Various tools for the Various tools for the positioning and positioning and immobilization: immobilization: Areas: Skull, chest, Areas: Skull, chest, Areas: Skull, chest, Areas: Skull, chest, abdomen, pelvis, upper abdomen, pelvis, upper and lower extremities. and lower extremities.

3-D D-Treatment planning process Treatment planning process (3-D Imaging) D Imaging)

Example: HNO Example: HNO-Area Area planning CT planning CT

Fixing of the treatment position Fixing of the treatment position (positioning, immobilization (positioning, immobilization)

CT

The patient is positioned according to skin markers or anatomical reference The patient is positioned according to skin markers or anatomical reference points by using mechanical or optical viewing aids, but actually stationary laser. points by using mechanical or optical viewing aids, but actually stationary laser.

Fixing of the treatment position Fixing of the treatment position (positioning, immobilization) (positioning, immobilization)

MRT CT PET SPECT Fusion

3-D D-Treatment planning process ( Treatment planning process (3D Imaging 3D Imaging - Fusion) Fusion)

3-D CT data or optional PET D CT data or optional PET /MR images will be acquired. /MR images will be acquired. Image fusion serves for a better Image fusion serves for a better recognition of the target recognition of the target

MRI CT SPECT

Fixing of the treatment position Fixing of the treatment position (positioning, immobilization) (positioning, immobilization)

MRT CT PET SPECT Fusion

Aquisition unit

3-D D-Treatment planning process ( Treatment planning process (Contouring) Contouring)

For the treatment planning, the For the treatment planning, the images must be exported from images must be exported from the acquisition unit and the acquisition unit and imported to the TPS unit. imported to the TPS unit.

Contouring

TPS unit

Contouring: Contouring:

• On each slice of the CT

On each slice of the CT (e.g.: Larynx Ca.) is (e.g.: Larynx Ca.) is drawn ... drawn ...

• an

an outer contour

• uter contour which

which limits the body ( limits the body (brown brown)

• a

a target volume target volume that that

Larynx Ca.

3-D D-Treatment planning process Treatment planning process (Contouring) Contouring)

encloses the planning encloses the planning target volume target volume PTV PTV (red red)

• rgans at risk
• rgans at risk (here the

(here the spinal cord) ( spinal cord) (blue blue)

• The radiation oncologist

The radiation oncologist is responsible for defining is responsible for defining and contouring the target and contouring the target volume. volume. Depending on tumour location, other organs at Depending on tumour location, other organs at risk are taken into consideration during the risk are taken into consideration during the irradiation irradiation

3-D D-Treatment planning process Treatment planning process (Contouring) Contouring) Strategy Strategy

– tumour mass (X tumour mass (X-Ray, CT, MRT) Ray, CT, MRT) – tumour localization (X tumour localization (X-Ray, CT, MRT) Ray, CT, MRT) – tumour localization (X tumour localization (X-Ray, CT, MRT) Ray, CT, MRT) – tumour character (MR tumour character (MR-Spectrom, SPECT, PET) Spectrom, SPECT, PET)

=> => Target 1 (Tumour detected) → higher dose Target 1 (Tumour detected) → higher dose Target 2 (Tumour suspected) → lower dose Target 2 (Tumour suspected) → lower dose

ICRU: Changes Over Time ICRU: Changes Over Time

3-D D-Treatment planning process Treatment planning process (Contouring) Contouring)

• Single slice (or few)

Single slice (or few)

• External contour

External contour

• Coplanar beams

Coplanar beams

• Simple calculations

Simple calculations

ICRU 29, 1978 ICRU 29, 1978

• Simple calculations

Simple calculations

• Dose prescription to “ICRU

Dose prescription to “ICRU reference point” reference point”

3-D D-Treatment planning process Treatment planning process (Contouring) Contouring)

1993

• Gross Tumour Volume (GTV)

Gross Tumour Volume (GTV) = = clinically demonstrated tumour clinically demonstrated tumour

Target volume definition Target volume definition (ICRU 50) (ICRU 50)

• Clinical Target Volume (CTV)

Clinical Target Volume (CTV) = = GTV GTV + area at risk ( + area at risk (e.g. e.g. potentially involved lymph potentially involved lymph nodes) nodes)

• Planning Target Volume (PTV)

Planning Target Volume (PTV) = = volume planned to be treated = volume planned to be treated = CTV CTV + + margin for set margin for set-up up uncertainties and potential of uncertainties and potential of

• rgan movement
• rgan movement

3-D D-Treatment planning process Treatment planning process (Contouring) Contouring)

1999 1999

Target volume definition Target volume definition (ICRU 62) (ICRU 62)

PRV: Includes margin around the OAR to PRV: Includes margin around the OAR to compensate for changes in shape and compensate for changes in shape and internal motion and for set internal motion and for set-up variation. up variation.

• Irradiation techniques have advanced

Irradiation techniques have advanced

=> =>

• More accurately formulate definitions &

More accurately formulate definitions & concepts concepts

– – Reference points and coordinate systems Reference points and coordinate systems – – Introduction of Introduction of

• Internal Margin (IM)

Internal Margin (IM)

• Setup Margin (SM)

Setup Margin (SM)

• Internal Target Volume (ITV)

Internal Target Volume (ITV)

• Planning organ at Risk Volume (PRV)

Planning organ at Risk Volume (PRV)

• Conformity Index (CI)

Conformity Index (CI)

3-D D-Treatment planning process Treatment planning process (Contouring) Contouring)

Planning Target Volume Planning Target Volume (ICRU 62) (ICRU 62)

3-D D-Treatment planning process Treatment planning process (Contouring Contouring- example) example)

Fixing of the treatment position Fixing of the treatment position (positioning, immobilization) (positioning, immobilization)

MRT CT PET SPECT Fusion Fusion

3-D D-Treatment planning process (Beam Treatment planning process (Beam Modelling) Modelling)

Contouring Contouring

Setting of the radiation fields

virtual simulation Optimization of the dose distribution Evaluation 3-D-Treatment plan

3-D D-Treatment planning process (Beam Treatment planning process (Beam Modelling) Modelling)

Optimization criterion Optimization criterion - field form field form

Multileaf Collimator (MLC) Multileaf Collimator (MLC) Satellites blocks Satellites blocks

Adjustment of the Adjustment of the fielf form to PTV fielf form to PTV

Siemens factory Photo Beam eye view

Optimization criterion Optimization criterion - field form field form

3-D D-Treatment planning process (Beam Treatment planning process (Beam Modelling) Modelling)

Field formation in the AP and lateral fields with a pelvic irradiation (4- field box) based on the Beam Eye View (BEV)

3-D D-Treatment planning process (Beam Treatment planning process (Beam Modelling) Modelling)

Optimization criterion Optimization criterion - radiation type and energy radiation type and energy examples examples

3-D D-Treatment planning process (Beam Treatment planning process (Beam Modelling) Modelling)

target beam patient target beam

Choice of best Choice of best beam angle beam angle Optimization approaches Optimization approaches-Entry point Entry point

patient target patient target wedge

Use of a beam Use of a beam modifier, compensator, … modifier, compensator, …

3-D D-Treatment planning process (Beam Treatment planning process (Beam Modelling) Modelling)

patient target beam

100%

patient Beam 1 50%

50%

Beam 2

Beam number Beam number and weighting and weighting Optimization approaches: Beam number and weighting Optimization approaches: Beam number and weighting

patient target patient

30% 40% 10% 20%

patient Beam 2

3-D D-Treatment planning process (Beam Treatment planning process (Beam Modelling) Modelling)

Wedged pair Wedged pair Three field techniques Three field techniques

Isodose lines Isodose lines Optimization approaches Optimization approaches- use of wedges use of wedges patient patient patient patient Typical isodose lines Typical isodose lines

3-D D-Treatment planning process (Beam Treatment planning process (Beam Modelling) Modelling)

Optimization criterion Optimization criterion - Radiation type Radiation type

Combination of photons and electrons Combination of photons and electrons

BEV (DRR) photon field

Head -Neck

BEV (DRR) electron field

3-D D-Treatment planning process (Beam Treatment planning process (Beam Modelling) Modelling)

Optimization criterion Optimization criterion - Radiation type Radiation type

Combination of photons and electrons Combination of photons and electrons

Breast

3-D D-Treatment planning process (Beam Treatment planning process (Beam Modelling) Modelling)

Optimization criterion Optimization criterion - field number field number

2 opposite fields 2 wedged fields

3-D D-Treatment planning process (Beam Treatment planning process (Beam Modelling) Modelling)

Optimization criterion Optimization criterion - field number field number

3 fields Rotational irradiation

5 Felder non 5 Felder non-coplanar coplanar

3-D D-Treatment planning process (Beam Treatment planning process (Beam Modelling) Modelling)

transversal sagital

3-D D-Treatment planning process (Dose Treatment planning process (Dose Distribution criteria) Distribution criteria)

Criteria of a uniform dose distribution within the target Criteria of a uniform dose distribution within the target

• Recommendations regarding dose uniformity, prescribing,

Recommendations regarding dose uniformity, prescribing, recording, and reporting photon beam therapy are set forth by recording, and reporting photon beam therapy are set forth by the International Commission on Radiation Units and the International Commission on Radiation Units and Radiotherapy Radiotherapy - Spatial dose distribution Spatial dose distribution the International Commission on Radiation Units and the International Commission on Radiation Units and Measurements (ICRU). Measurements (ICRU).

• The ICRU report 50 recommends a target dose uniformity within

The ICRU report 50 recommends a target dose uniformity within +7% and +7% and –5% relative to the dose delivered to a well defined 5% relative to the dose delivered to a well defined prescription point within the target. prescription point within the target.

• The limits of the tolerance doses for the organs at risks are

The limits of the tolerance doses for the organs at risks are given in the next slide. given in the next slide.

Organ Organ Volume part Volume part TD TD 5/5

5/5 1/3 1/3

TD TD 5/5

5/5 2/3 2/3

TD TD 5/5

5/5 3/3 3/3

TD TD 50/5

50/5 1/3 1/3

TD TD 50/5

50/5 2/3 2/3

TD TD 50/5

50/5 3/3 3/3

Radiation consequense Radiation consequense Arm nerve plexus Arm nerve plexus 62 62 61 61 60 60 77 77 76 76 75 75 Manifeste Plexopathie Manifeste Plexopathie Lens Lens 10 10 18 18 Katarakt Katarakt Bladder Bladder 80 80 65 65 85 85 80 80 Symptomatische Schrumpfblase Symptomatische Schrumpfblase Cauda equina Cauda equina no Volume effect no Volume effect 60 60 no Volume effect no Volume effect 75 75 Manifeste Neuropathie Manifeste Neuropathie Chiasma opticum Chiasma opticum no Volume effect no Volume effect 50 50 no Volume effect no Volume effect 65 65 Blindness Blindness Small intestine Small intestine 50 50

• 40

40a 60 60

• 55

55 Stenose, Perforation, Fistel Stenose, Perforation, Fistel Femurkopf (I+II) Femurkopf (I+II)

• 52

52

• 65

65 Bone necrosis Bone necrosis Skin Skin 10 cm 10 cm2: 50 : 50 30 cm 30 cm2: 60 : 60 100 cm 100 cm2: : 55 55 10 cm 10 cm2: : -

• 30 cm

30 cm2: : -

• 100 cm

100 cm2: : 70 70 Nekrose, Ulzeration Nekrose, Ulzeration Heart Heart 60 60 45 45 40 40 70 70 55 55 50 50 Perikarditis Perikarditis Brain Brain 60 60 50 50 45 45 75 75 65 65 60 60 Nekrose, Infarkt Nekrose, Infarkt Brainstem Brainstem 60 60 53 53 50 50

• 65

65 Nekrose, Infarkt Nekrose, Infarkt

Tolerance doses in Gy (Emami et al). Tolerance doses in Gy (Emami et al).

Brainstem Brainstem 60 60 53 53 50 50

• 65

65 Nekrose, Infarkt Nekrose, Infarkt TMJ TMJ 65 65 60 60 60 60 77 77 72 72 72 72 Trismus Trismus Colon Colon 55 55 45 45 60 60 55 55 Stenose, Perforation, Fistel, Ulkus Stenose, Perforation, Fistel, Ulkus Larynx Larynx 79 79a

a

70 70a 70 70a 90 90a 80 80a 80 80a Knorpelnekrose Knorpelnekrose Larynx Larynx

• 45

45 45 45a

• 80

80a Larynxödem Larynxödem Liver Liver 50 50 35 35 30 30 55 55 45 45 40 40 Liver failure Liver failure Lung Lung 45 45 30 30 17,5 17,5 65 65 40 40 24,5 24,5 Pneumonitis Pneumonitis Stomach Stomach 60 60 55 55 50 50 70 70 67 67 65 65 Ileus, Perforation Ileus, Perforation Middle Ear/Externa Ear Middle Ear/Externa Ear 30 30 30 30 30 30a 40 40 40 40 40 40a Akute seröse Otitis Akute seröse Otitis Middle Ear/Externa Ear Middle Ear/Externa Ear 55 55 55 55 55 55a 65 65 65 65 65 65a Chronische seröse Otitis Chronische seröse Otitis Kindney (one) Kindney (one) 50 50 30 30 23 23 40 40a 28 28 Klinisch manifeste Nephritis Klinisch manifeste Nephritis

• sophagus
• sophagus

60 60 58 58 55 55 72 72 70 70 68 68 Striktur, Perforation Striktur, Perforation Parotiden Parotiden 32 32a 32 32a 46 46a 46 46a Xerostomie Xerostomie Rectum Rectum Volume: 100 cm Volume: 100 cm3 60 60 Volume: 100 cm Volume: 100 cm3 80 80 Proktitis, Stenose, Nekrose, Fistel Proktitis, Stenose, Nekrose, Fistel Retina (I+II) Retina (I+II) no Volume effect no Volume effect 45 45 no Volume effect no Volume effect 65 65 Blindness Blindness Rippen Rippen 50 50 65 65 Pathologische Fraktur Pathologische Fraktur Spinal Chord Spinal Chord 5 cm: 50 5 cm: 50 10 cm: 50 10 cm: 50 20 cm:47 20 cm:47 5 cm: 70 5 cm: 70 10 cm:70 10 cm:70 20 cm: 20 cm: -

• Myelopathie, Nekrose

Myelopathie, Nekrose Optic Nerve, Retinae (I+II) Optic Nerve, Retinae (I+II) no Volume effect no Volume effect 50 50 no Volume effect no Volume effect 65 65 Blindness Blindness

Fixing of the treatment position Fixing of the treatment position (positioning, immobilization (positioning, immobilization)

MRT CT PET SPECT Fusion

3-D D-Treatment planning process (Optimized Treatment planning process (Optimized dose Distribution) dose Distribution)

Example: Optimized dose distribution in Example: Optimized dose distribution in larynx Ca. larynx Ca.

Contouring

Setting of the radiation fields

virtual simulation Optimization of the dose distribution Evaluation 3-D-Treatment plan

Fixing of the treatment position Fixing of the treatment position (positioning, immobilization) (positioning, immobilization)

MRT CT PET SPECT Fusion Fusion

3 3-D D-Treatment planning process (Dose Volume Treatment planning process (Dose Volume Histogram) Histogram)

Example: Evaluation (DVH) in Larynx Ca Example: Evaluation (DVH) in Larynx Ca

Contouring Contouring

Setting of the radiation fields

virtual simulation Optimization of the dose distribution Evaluation 3-D-Treatment plan

3 3-D D-Treatment planning process (Dose Volume Treatment planning process (Dose Volume Histogram) Histogram)

• Tumour:

Tumour:

– High dose to all High dose to all – Homogenous dose Homogenous dose

• Critical organ

Critical organ

– Low dose to most of the Low dose to most of the structure structure

volume volume

The ideal DVH The ideal DVH

100% dose 100% dose volume volume

60 80 100 120 lume (%)

Comparison of Comparison of three different three different treatment treatment techniques (red, techniques (red, blue and green) blue and green) in terms of dose in terms of dose to the target and to the target and

3 3-D D-Treatment planning process (Dose Volume Treatment planning process (Dose Volume Histogram) Histogram)

20 40 60 20 40 60 80

Dose (Gy)

Volum

to the target and to the target and a critical a critical structure structure

Target dose Target dose Critical Critical

• rgan
• rgan

3-D D-Treatment planning process (Dose Treatment planning process (Dose Distribution examples) Distribution examples)

Examples: Examples: Malignant tumors such as: Mamma ca., Bronchial ca., Prostate ca., Malignant tumors such as: Mamma ca., Bronchial ca., Prostate ca., Rectum ca., Larynx ca., Metastasis, Sarcomas, lymphomas, ... Rectum ca., Larynx ca., Metastasis, Sarcomas, lymphomas, ...

3-D D-Treatment planning process (DRRs) Treatment planning process (DRRs)

• Computer generated virtual

Computer generated virtual images images

• Requires patient CT dataset

Requires patient CT dataset

• Choice of image quality

Choice of image quality -

Digitally reconstructed radiographs (DRRs) Digitally reconstructed radiographs (DRRs)

• Choice of image quality

Choice of image quality - diagnostic or therapy type image diagnostic or therapy type image

• Depends significantly on the

Depends significantly on the number of CT slices available number of CT slices available

• Important to compare with the

Important to compare with the verification verification

3-D D-Treatment planning process (DRRs) Treatment planning process (DRRs)

• Divergent beams

Divergent beams

• 3D

3D

• Dose images

Dose images DRRs can mimic any geometry DRRs can mimic any geometry Here : Here :Case Prostate Case Prostate

Fixing of the treatment position Fixing of the treatment position (positioning, immobilization) (positioning, immobilization)

MRT CT PET SPECT Fusion

Simulation

3-D D-Treatment planning process (Simulation) Treatment planning process (Simulation)

Example: DRR of 0° in Larynx Ca.

Contouring

Setting of the radiation fields

virtual simulation Optimization of the dose distribution Evaluation 3-D-Treatment plan

3-D D-Treatment planning process (Verification Treatment planning process (Verification System) System)

Fixing of the treatment position Fixing of the treatment position (positioning, immobilization) (positioning, immobilization)

MRT CT PET SPECT Fusion

Simulation

Radiotherapy information system

Contouring

Setting of the radiation fields

virtual simulation Optimization of the dose distribution Evaluation 3-D-Treatment plan

3-D D-Treatment planning process (Positionning Treatment planning process (Positionning

• n LINAC table)
• n LINAC table)

Fixing of the treatment position Fixing of the treatment position (positioning, immobilization) (positioning, immobilization)

MRT CT PET SPECT Fusion

Simulation

Radiotherapy information system Reproducibility of positioning

Contouring

Reproducibility of positioning and settings on the linear accelerator from fraction to fraction

Setting of the radiation fields

virtual simulation Optimization of the dose distribution Evaluation 3-D-Treatment plan

3-D D-Treatment planning process (Positionning Treatment planning process (Positionning

• n LINAC table)
• n LINAC table)
• The patient is usually positioned

The patient is usually positioned

• n skin markers or on
• n skin markers or on

anatomical reference points. anatomical reference points.

• With stationary lasers, the

With stationary lasers, the positioning of the head and positioning of the head and neck is easier and more often neck is easier and more often reproducible than in the pelvic reproducible than in the pelvic

• A stable and reproducible

patient positioning is necessarily required.

– Use of thermoplastic masks or

• ther positioning aids.

reproducible than in the pelvic reproducible than in the pelvic area or by obese patients. area or by obese patients.

3-D D-Treatment planning process (Image Field Treatment planning process (Image Field Control) Control)

Fixing of the treatment position Fixing of the treatment position (positioning, immobilization) (positioning, immobilization)

MRT CT PET SPECT Fusion

Simulation

Radiotherapy information system Reproducibility of positioning

Setting of the radiation fields

virtual simulation Optimization of the dose distribution Evaluation 3-D-Treatment plan

Contouring

Reproducibility of positioning and settings on the Linear accelerator from fraction to fraction

Image field control

3-D D-Treatment planning process (Image Field Treatment planning process (Image Field Control) Control)

• The positioning uncertainty

The positioning uncertainty can be checked by can be checked by comparing simulation / DRR comparing simulation / DRR images from the CT images from the CT simulation with direct simulation with direct simulation with direct simulation with direct multiple acquisition of the multiple acquisition of the field in use. field in use.

• computer

computer-based video based video systems are available with systems are available with versatile software support. versatile software support.

3-D D-Treatment planning process (DRRs) Treatment planning process (DRRs) DRR Simulation Verification

Radiotherapy example Breast Radiotherapy example Breast-Ca. Ca.

Breast Breast-

• Ca. on the left o.a. pT1c pN1biii (7/15) G2 L1 V0
• Ca. on the left o.a. pT1c pN1biii (7/15) G2 L1 V0

(335°) Photons (335°) Photons (335°) Photons

3-D D-Treatment planning process (Image Field Treatment planning process (Image Field Control) Control)

Fixing of the treatment position Fixing of the treatment position (positioning, immobilization) (positioning, immobilization)

MRT CT PET SPECT Fusion

Simulation Radiotherapy information system

Reproducibility of positioning

Contouring

Reproducibility of positioning and settings on the linear accelerator from fraction to fraction

Radiotherapy Image field control

Setting of the radiation fields

virtual simulation Optimization of the dose distribution Evaluation 3-D-Treatment plan

3-D D-Treatment planning process ( Treatment planning process (uncertainties uncertainties)

• Random uncertainties

Random uncertainties

• Small variations in the

Small variations in the positioning of the patient positioning of the patient from day to day from day to day

• Systematic uncertainties

Systematic uncertainties

• Delineation of target volumes

Delineation of target volumes

• A snapshot of the shape and

A snapshot of the shape and position of the organs in the position of the organs in the treatment planning CT treatment planning CT

from day to day from day to day

– Setting of the iso Setting of the iso-centre centre – Breathing Breathing – Intestinal peristalsis Intestinal peristalsis – Different bladder, bowel and Different bladder, bowel and stomach fillings lead to stomach fillings lead to internal organ motion and internal organ motion and

• rgan deformation
• rgan deformation

treatment planning CT treatment planning CT

– – Changes in position of adjacent Changes in position of adjacent structures with a dotting of structures with a dotting of pleural effusion or seroma pleural effusion or seroma – – Bladder and bowel movements Bladder and bowel movements lead to breathing or fillings lead to breathing or fillings position and deformation of position and deformation of

• rgans
• rgans
• Deviations in the transmission

Deviations in the transmission

• f geometrical data to the
• f geometrical data to the

therapy simulator or directly to therapy simulator or directly to the irradiation device the irradiation device

3-D D-Treatment planning process Treatment planning process (Documentation/Archive) (Documentation/Archive)

• All documents relating to the implementation of radiotherapy

All documents relating to the implementation of radiotherapy must be kept for 30 years. must be kept for 30 years.

• The radiation treatment and the decisions must be transparent.

The radiation treatment and the decisions must be transparent.

• Recordings include the duration and timing of radiotherapy, the

Recordings include the duration and timing of radiotherapy, the dose to the target volume, localization and delineation of the dose to the target volume, localization and delineation of the dose to the target volume, localization and delineation of the dose to the target volume, localization and delineation of the radiation fields, setting parameters, setting of protection against radiation fields, setting parameters, setting of protection against scattered radiation. scattered radiation.

Electronic Documents into PACS CD / DVD Disks Printings on Papers in archives room

Documents

References References

• Bamberg, M.; Molls, M.; Sack, H.; (Hrsg):

Bamberg, M.; Molls, M.; Sack, H.; (Hrsg): Radioonkologie , Band 1 Grundlagen Radioonkologie , Band 1 Grundlagen

• W. Zuckschwerdt Verlag München Wien New York 2003
• W. Zuckschwerdt Verlag München Wien New York 2003
• Schlegel, W.; Mahr, A.; (Hrsg):

Schlegel, W.; Mahr, A.; (Hrsg): 3D Conformal Radiation Therapy 3D Conformal Radiation Therapy Springer Springer-Verlag Heidelberg. Verlag Heidelberg. Springer Springer-Verlag Heidelberg. Verlag Heidelberg.

• Van Dyk, Jacob, Van_Dyk_

Van Dyk, Jacob, Van_Dyk_- _Definition_of_Target_Volume_&_Organs_at_Risk[1].pdf, 22.02.2011, _Definition_of_Target_Volume_&_Organs_at_Risk[1].pdf, 22.02.2011, IAEA. IAEA.

• Thema_Bestrahlungsplannung.pdf, Universität Leipzig; Klinik für

Thema_Bestrahlungsplannung.pdf, Universität Leipzig; Klinik für Strahlentherapie; http://radioonkologie.uniklinikum Strahlentherapie; http://radioonkologie.uniklinikum- leipzig.de/radioonko.site,postext,veranstaltungen leipzig.de/radioonko.site,postext,veranstaltungen-lehre,a_id,506.html lehre,a_id,506.html

• Zakaria

Zakaria-SFO_Dhaka14 SFO_Dhaka14-15 15-2012_ REVISED.ppt. 2012_ REVISED.ppt.

• RT10_EBT3a_GoodPractice_Planning_WEB.ppt, IAEA.

RT10_EBT3a_GoodPractice_Planning_WEB.ppt, IAEA.

• RT10_EBT3b_GoodPractice_Planning_WEB.ppt, IAEA.

RT10_EBT3b_GoodPractice_Planning_WEB.ppt, IAEA.

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