Conformal Therapy Conformal Therapy for Lung Cancerfor Lung Cancer

Conformal Therapy Conformal Therapy for Lung Cancerfor Lung Cancer

B. Schicker, F.J. Schwab*, U. GötzB. Schicker, F.J. Schwab*, U. Götz

Institute of Radiotherapy and Radiation Institute of Radiotherapy and Radiation Oncology St. Vincenz-Krankenhaus Oncology St. Vincenz-Krankenhaus

LimburgLimburg

*Clinic of Radiotherapy*Clinic of Radiotherapy

University of WürzburgUniversity of Würzburg

B. Schicker, F.J. Schwab*, U. GötzB. Schicker, F.J. Schwab*, U. Götz

Institute of Radiotherapy and Radiation Institute of Radiotherapy and Radiation Oncology St. Vincenz-Krankenhaus Oncology St. Vincenz-Krankenhaus

LimburgLimburg

*Clinic of Radiotherapy*Clinic of Radiotherapy

University of WürzburgUniversity of Würzburg

DefinitionDefinition

INTRODUCTION

For lung cancer radiotherapy is an essential treatment mode. The major problem for the treatment planning is the fact that the target volume is surrounded by organs at risk. Acute or late reactions of the lung, the myelon and the heart are dose limiting factors. If curative doses are aspired the old fashioned opposed fields techniques are not applicable because of the high dose load to the organs at risk. Curative doses for lung cancer, however, usually exceed 70 Gy. Therefore conformal treatment techniques have to be developed aiming at the reduction of the normal tissue complication probability and the high tumor control probability.

ADJUVANT TREATMENT

For local advanced tumor stages the postoperative irradiation of the regional lymphatics and of the bronchial stump is indicated. The mediastinum should always be included in the clinical target volume if involved nodes were found but no systematic lymph node dissection was performed. The supraclavicular lymph nodes are not included in the CTV for adjuvant treatment with curative intent. The involvement of these lymph nodes probably improves local control, whereas the improvement of survival remains questionable. The lymph nodes included in the CTV are: the intrapulmonary, the subcarinal, the tracheobronchial, the paratracheal and the preaortic group. For lower lobe primaries the inclusion of the lymph nodes along the ligamentum pulmonale and the paraesophageal nodes should be considered.

RadiotherapyRadiotherapydecades agodecades ago

RadiotherapyRadiotherapydecades agodecades ago

Conventional Opposed Fields Conventional Opposed Fields TechniqueTechnique

based on radiographsbased on radiographs

Conventional Opposed Fields Conventional Opposed Fields TechniqueTechnique

based on radiographsbased on radiographs

Conventional Opposed Fields Conventional Opposed Fields TechniqueTechnique

CChange from Radiograph to Target Volumehange from Radiograph to Target Volume

Conventional Opposed Fields Conventional Opposed Fields TechniqueTechnique

CChange from Radiograph to Target Volumehange from Radiograph to Target Volume

Traditional irradiation portals recommended in textbooks for irradiation of lung cancer patients.

selected clinical target volume based on the oncological prin-ciples (no inclusion of the supraclavicular and contra-lateral hilar lymph nodes in the CTV for curative RT).

Development of Conformal Treatment Development of Conformal Treatment TechniquesTechniques

Development of Conformal Treatment Development of Conformal Treatment TechniquesTechniques

first step: precise definiton of the planning target volume based on oncological criteriafirst step: precise definiton of the planning target volume based on oncological criteria

conformal treatment = precise irradiation of a precisely defined PTVconformal treatment = precise irradiation of a precisely defined PTV

first step: precise definiton of the planning target volume based on oncological criteriafirst step: precise definiton of the planning target volume based on oncological criteria

conformal treatment = precise irradiation of a precisely defined PTVconformal treatment = precise irradiation of a precisely defined PTV

Target Volume Target Volume for adjuvant treatmentfor adjuvant treatmentTarget Volume Target Volume for adjuvant treatmentfor adjuvant treatment

Z +8 Z +3 Z +0

Z -2 Z -4 Z -8

DefinitionDefinition

CONFORMAL RADIOTHRAPY

A high dose to the PTV means a high tumour control probability were as a low dose to the normal tissue or organ at risk means a low normal tissue complication probability

Low side effects = live quality for the Patient

BENEFIT FOR PATIENT

Ideal Treatment vs. RealityIdeal Treatment vs. RealityIdeal Treatment vs. RealityIdeal Treatment vs. Reality

Ideal:

D(PTV) = 100%

D(NT,OAR) = 0%

Real:

D(PTV) ~ 100%

D(NT,OAR) >> 0%

Dose DistributionDose DistributionDose DistributionDose Distribution

Dose Volume HistogramDose Volume HistogramDose Volume HistogramDose Volume Histogram

Dose [%]

Volume [%]

100

100

PTV

Dose [%]

Volume [%]

100

100 Normal Tissue, Organ at Risk

Ideal Treatment vs. RealityIdeal Treatment vs. RealityIdeal Treatment vs. RealityIdeal Treatment vs. Reality

High TCP and low NTCP:High TCP and low NTCP:high dose within the PTV and a good protection of the OARhigh dose within the PTV and a good protection of the OAR

Reduction of the dose to the OAR below critical values (tolerance doses)Reduction of the dose to the OAR below critical values (tolerance doses)

Concentration of the therapeutic dose on the PTV:Concentration of the therapeutic dose on the PTV:Dose homogeneity within the PTVDose homogeneity within the PTV

(ICRU recommendations -5 % ... +7 %)(ICRU recommendations -5 % ... +7 %)

High TCP and low NTCP:High TCP and low NTCP:high dose within the PTV and a good protection of the OARhigh dose within the PTV and a good protection of the OAR

Reduction of the dose to the OAR below critical values (tolerance doses)Reduction of the dose to the OAR below critical values (tolerance doses)

Concentration of the therapeutic dose on the PTV:Concentration of the therapeutic dose on the PTV:Dose homogeneity within the PTVDose homogeneity within the PTV

(ICRU recommendations -5 % ... +7 %)(ICRU recommendations -5 % ... +7 %)

Aim of the OptimizationAim of the Optimization - minimum requirements -- minimum requirements -

Aim of the OptimizationAim of the Optimization - minimum requirements -- minimum requirements -

Development of a Development of a 3-D Conformal 3-D Conformal Standard Technique for Lung CancerStandard Technique for Lung Cancer

Development of a Development of a 3-D Conformal 3-D Conformal Standard Technique for Lung CancerStandard Technique for Lung Cancer

From opposed fields to conformal techniqueFrom opposed fields to conformal technique

=>=>

??????

From opposed fields to conformal techniqueFrom opposed fields to conformal technique

=>=>

??????

DefinitionDefinition

3 Dimensional Conformal- CT based Treatment planning

- Slice distance 1.0 or 0.5 cm

- Definition and delineation of PTV and Organ at risk in every slice

- using other imaging procedures as MR, PET etc.

-Calculation and optimisation of the dose distribution in every CT slice to achieve a homogenous dose distribution

PTV

Lung

Heart

Myelon

Development of a Development of a Standard Technique Standard Technique

for Lung Cancerfor Lung Cancer

Development of a Development of a Standard Technique Standard Technique

for Lung Cancerfor Lung Cancer

PTV

Lung

Heart

Myelon

Development of a Development of a Standard Technique Standard Technique

for Lung Cancerfor Lung Cancer

Development of a Development of a Standard Technique Standard Technique

for Lung Cancerfor Lung Cancer

PTV

Lung

Heart

Myelon

Development of a Development of a Standard Technique Standard Technique

for Lung Cancerfor Lung Cancer

Development of a Development of a Standard Technique Standard Technique

for Lung Cancerfor Lung Cancer

PTV

Lung

Heart

Myelon

Development of a Development of a Standard Technique Standard Technique

for Lung Cancerfor Lung Cancer

Development of a Development of a Standard Technique Standard Technique

for Lung Cancerfor Lung Cancer

PTV

Lung

Heart

Myelon

Development of a Development of a Standard Technique Standard Technique

for Lung Cancerfor Lung Cancer

Development of a Development of a Standard Technique Standard Technique

for Lung Cancerfor Lung Cancer

PTV

Lung

Heart

Myelon

Development of a Development of a Standard Technique Standard Technique

for Lung Cancerfor Lung Cancer

Development of a Development of a Standard Technique Standard Technique

for Lung Cancerfor Lung Cancer

PTV

Lung

Heart

Myelon

Development of a Development of a Standard Technique Standard Technique

for Lung Cancerfor Lung Cancer

Development of a Development of a Standard Technique Standard Technique

for Lung Cancerfor Lung Cancer

Development of aDevelopment of a Standard TechniqueStandard TechniqueStandard Beam Set upStandard Beam Set up

Development of aDevelopment of a Standard TechniqueStandard TechniqueStandard Beam Set upStandard Beam Set up

- Isocenter – placed at the ventral tip of the vertebral body

- easy to find uneder X-Ray controll from 0° and also 90° gantry angle

Development of aDevelopment of a Standard TechniqueStandard TechniqueStandard Beam Set upStandard Beam Set up

Development of aDevelopment of a Standard TechniqueStandard TechniqueStandard Beam Set upStandard Beam Set up

Aim of Field 1 is to spare a maximum volume of both lungs

F10°

Development of aDevelopment of a Standard TechniqueStandard TechniqueStandard Beam Set upStandard Beam Set up

Development of aDevelopment of a Standard TechniqueStandard TechniqueStandard Beam Set upStandard Beam Set up

The gantry angle and blocking of field 2 (135°) was chosen to protect the myelon

F2135°

Development of aDevelopment of a Standard TechniqueStandard TechniqueStandard Beam Set upStandard Beam Set up

Development of aDevelopment of a Standard TechniqueStandard TechniqueStandard Beam Set upStandard Beam Set up

Field 3 (40°) reduce the high dose regions in the left lung and contribute to a better adaptation of the isodoses to the PTV

3 fields: 3 fields: 0° fixed wedge (lung)0° fixed wedge (lung)

~ ~ 140° fixed wedge 140° fixed wedge (myelon)(myelon)

40° ... 80° fixed or arc, 40° ... 80° fixed or arc, wedge wedge ??

(heart, contralateral (heart, contralateral lung, myelon)lung, myelon)

start with dose contribution 1 : 1 : 1start with dose contribution 1 : 1 : 1 field shaping using beams eye viewfield shaping using beams eye view

good protection of the contra-lateral lunggood protection of the contra-lateral lung myelon dose (adjustable from 30% to myelon dose (adjustable from 30% to

70%) below critical values for curative 70%) below critical values for curative total dosestotal doses

3 fields: 3 fields: 0° fixed wedge (lung)0° fixed wedge (lung)

~ ~ 140° fixed wedge 140° fixed wedge (myelon)(myelon)

40° ... 80° fixed or arc, 40° ... 80° fixed or arc, wedge wedge ??

(heart, contralateral (heart, contralateral lung, myelon)lung, myelon)

start with dose contribution 1 : 1 : 1start with dose contribution 1 : 1 : 1 field shaping using beams eye viewfield shaping using beams eye view

good protection of the contra-lateral lunggood protection of the contra-lateral lung myelon dose (adjustable from 30% to myelon dose (adjustable from 30% to

70%) below critical values for curative 70%) below critical values for curative total dosestotal doses

Standard TechniqueStandard Techniqueat the ISRO Limburgat the ISRO LimburgStandard TechniqueStandard Techniqueat the ISRO Limburgat the ISRO Limburg

Clinical Case 1Clinical Case 1Adjuvant TreatmentAdjuvant TreatmentClinical Case 1Clinical Case 1

Adjuvant TreatmentAdjuvant TreatmentThe 72 year old patient with a non small cell left localized lung cancer was operated. The primary lung cancer infiltrated the left pulmonary artery. A questionable R0 resection was performed. An adjuvant radiotherapy was indicated. From 12 examined lymph nodes 5 were found involved. A total dose of 66.6 Gy was applied in this clinical case. For the main series the target volume was treated with a dose of 50.4 Gy and for the boost technique a dose of 16.2 Gy was given. For both series a dose per fraction of 1.8 Gy was chosen.

ZV+4 cm

ZV-1 cm

ZV-3 cm

Clinical Case 1Clinical Case 1Clinical Case 1Clinical Case 1

Clinical Case 1Clinical Case 1Clinical Case 1Clinical Case 1Field 3 (35°) and 4 (100°) reduce the high dose regions in the left lung and contribute a better adaption of the isodoses to the PTV.

Clinical Case 1Clinical Case 1Clinical Case 1Clinical Case 1Full homogeneity over all slices requires two further fields (5 and 6).

Technique for Case 1Technique for Case 1Variation of the Standard TechniqueVariation of the Standard TechniqueTechnique for Case 1Technique for Case 1Variation of the Standard TechniqueVariation of the Standard Technique

Conformal Therapy for Lung CancerFirst International Symposium onTarget VolumeDefinition

F.Schwab

HS+6 cm

95%95%

85%85%

70%70%

50%50%

Clinical Case 1Clinical Case 1

HS+4 cm

95%95%

85%85%

70%70%

50%50%

Clinical Case 1Clinical Case 1

HS0 cm

95%95%

85%85%

70%70%

50%50%

Clinical Case 1Clinical Case 1

HS-1 cm

95%95%

85%85%

70%70%

50%50%

Clinical Case 1Clinical Case 1

HS-3 cm

95%95%

85%85%

70%70%

50%50%

Clinical Case 1Clinical Case 1

HS- 4 cm

95%95%

85%85%

70%70%

50%50%

Clinical Case 1Clinical Case 1

Clinical Case 1Clinical Case 1frontal / sagittal dose frontal / sagittal dose

distributiondistribution

Clinical Case 1Clinical Case 1frontal / sagittal dose frontal / sagittal dose

distributiondistribution100%

95%

90%

85%

80%

70%

50%

30%

10%

frontal sagittal

Clinical Case 1Clinical Case 1DVHDVH

Clinical Case 1Clinical Case 1DVHDVH

PTV

Lung

Myelon

Clinical Case 1Clinical Case 1DVH Box / 3 Field TechniqueDVH Box / 3 Field Technique

Clinical Case 1Clinical Case 1DVH Box / 3 Field TechniqueDVH Box / 3 Field Technique

PTV

Lung

Myelon

Clinical Case 1Clinical Case 1

BoostBoost

Clinical Case 1Clinical Case 1

BoostBoost

Clinical Case 1Clinical Case 1

Boost – Beam SetupBoost – Beam Setup

Clinical Case 1Clinical Case 1

Boost – Beam SetupBoost – Beam Setup

BST-1 cm

95%95%

85%85%

70%70%

50%50%

Clinical Case 2Clinical Case 2Radiotherapy after PneumonectomyRadiotherapy after Pneumonectomy

Clinical Case 2Clinical Case 2Radiotherapy after PneumonectomyRadiotherapy after Pneumonectomy

A 46 year old male patient with a left located non small cell lung cancer of the upper lobe with infiltration of the upper lung vein. Nine involved nodes from 29 examined nodes were described. In many of the examined lymph nodes a capsule disruption was found. The CTV includes the paratracheal area, the upper mediastinum, the aortic pulmonary window, the left hilus and the subcarinal area. The lymph node capsule disruption and the infiltration of the upper pulmonary vein determine the necessity of a high total dose (at least 66 Gy).

Clinical Case 2Clinical Case 2Clinical Case 2Clinical Case 2

100%

95%

90%

85%

80%

70%

50%

30%

10%

+ 8 cmClinical Clinical Case 2Case 2Clinical Clinical Case 2Case 2

100%

95%

90%

85%

80%

70%

50%

30%

10%

+6 cmClinical Clinical Case 2Case 2Clinical Clinical Case 2Case 2

100%

95%

90%

85%

80%

70%

50%

30%

10%

- 2 cmClinical Clinical Case 2Case 2Clinical Clinical Case 2Case 2

Clinical Clinical Case 2Case 2Clinical Clinical Case 2Case 2

PTV

Myelon

Lung

100%

95%

90%

85%

80%

70%

50%

30%

10%

Clinical Case Clinical Case 33Definitive radiotherapyDefinitive radiotherapy

Clinical Case Clinical Case 33Definitive radiotherapyDefinitive radiotherapy

A primary inoperable periphery non-small cell lung cancer of the right upper lobe was diagnosed for the 77 year old female patient. In this case the CTV included only the tumor with small margins as shown in figure 23A and B. A total dose of 68.4 Gy was applied.

Clinical Clinical Case Case 33Clinical Clinical Case Case 33

Clinical Clinical Case Case 33Clinical Clinical Case Case 33

95%95%

85%85%

70%70%

50%50%

Clinical Clinical Case Case 33Clinical Clinical Case Case 33

95%95%

85%85%

70%70%

50%50%

do the isodoses only look nice ordo the isodoses only look nice or

can the patient profit from the conformal techniquecan the patient profit from the conformal technique??

=> analysis of the DVHs=> analysis of the DVHs

Treatment Index TI Treatment Index TI

TI := QI(PTV)/(Dmax(m)*QI(m)+Dmean(l)*QI(l)+Dmean(h)*QI(h))TI := QI(PTV)/(Dmax(m)*QI(m)+Dmean(l)*QI(l)+Dmean(h)*QI(h)) m = mm = myyelonelon

l = lung (left and right)l = lung (left and right)

hh = heart / myocard = heart / myocard

side condition: no violation of critical dosesside condition: no violation of critical doses

do the isodoses only look nice ordo the isodoses only look nice or

can the patient profit from the conformal techniquecan the patient profit from the conformal technique??

=> analysis of the DVHs=> analysis of the DVHs

Treatment Index TI Treatment Index TI

TI := QI(PTV)/(Dmax(m)*QI(m)+Dmean(l)*QI(l)+Dmean(h)*QI(h))TI := QI(PTV)/(Dmax(m)*QI(m)+Dmean(l)*QI(l)+Dmean(h)*QI(h)) m = mm = myyelonelon

l = lung (left and right)l = lung (left and right)

hh = heart / myocard = heart / myocard

side condition: no violation of critical dosesside condition: no violation of critical doses

Evaluation of the Treatment PlansEvaluation of the Treatment PlansEvaluation of the Treatment PlansEvaluation of the Treatment Plans

TI=QI(PTV)/(Dmax(m)*QI(m)+Dmean(l)*QI(l)+Dmean(h)*QI(h))TI=QI(PTV)/(Dmax(m)*QI(m)+Dmean(l)*QI(l)+Dmean(h)*QI(h)) TI=QI(PTV)/(Dmax(m)*QI(m)+Dmean(l)*QI(l)+Dmean(h)*QI(h))TI=QI(PTV)/(Dmax(m)*QI(m)+Dmean(l)*QI(l)+Dmean(h)*QI(h))

Evaluation of the Treatment PlansEvaluation of the Treatment PlansTreatment IndexTreatment Index

Evaluation of the Treatment PlansEvaluation of the Treatment PlansTreatment IndexTreatment Index

Treatment Index TI

1,40 1,561,90

2,653,00 3,09

0,00

0,50

1,00

1,50

2,00

2,50

3,00

3,50

Technique

TI i

n a

.u.

The prerequisite for a conformal therapy The prerequisite for a conformal therapy is a precisely defined target volume in a is a precisely defined target volume in a 3D patient model. The target volume has 3D patient model. The target volume has to be defined on the basis of oncological to be defined on the basis of oncological criteria and the success of the therapy criteria and the success of the therapy has to be checked in clinical studies. The has to be checked in clinical studies. The clinical target volumes presented here for clinical target volumes presented here for the adjuvant and definitive radiotherapy the adjuvant and definitive radiotherapy are different from that nowadays usually are different from that nowadays usually shown in the clinical textbooks. shown in the clinical textbooks.

The prerequisite for a conformal therapy The prerequisite for a conformal therapy is a precisely defined target volume in a is a precisely defined target volume in a 3D patient model. The target volume has 3D patient model. The target volume has to be defined on the basis of oncological to be defined on the basis of oncological criteria and the success of the therapy criteria and the success of the therapy has to be checked in clinical studies. The has to be checked in clinical studies. The clinical target volumes presented here for clinical target volumes presented here for the adjuvant and definitive radiotherapy the adjuvant and definitive radiotherapy are different from that nowadays usually are different from that nowadays usually shown in the clinical textbooks. shown in the clinical textbooks.

Conclusions and DiscussionConclusions and DiscussionConclusions and DiscussionConclusions and Discussion

One of the advantages of conformal treatment planning is the reduction of the dose load to the normal tissue and to the organs at risk compared to an opposite field technique. The dose at the organs at risk is lowered in two ways: First the total dose is reduced on the basis of the conformal treatment and second the dose per fraction is reduced resulting in a lowering of the biological effective dose at the organs at risk. Both effects in combination allow the application of curative doses to the target volume. The conformal techniques, however, also require an improvement in patient positioning. Finally, modern techniques like intensity modulated therapy may in future help to improve the homogeneity of the dose distribution.

One of the advantages of conformal treatment planning is the reduction of the dose load to the normal tissue and to the organs at risk compared to an opposite field technique. The dose at the organs at risk is lowered in two ways: First the total dose is reduced on the basis of the conformal treatment and second the dose per fraction is reduced resulting in a lowering of the biological effective dose at the organs at risk. Both effects in combination allow the application of curative doses to the target volume. The conformal techniques, however, also require an improvement in patient positioning. Finally, modern techniques like intensity modulated therapy may in future help to improve the homogeneity of the dose distribution.

Conclusions and DiscussionConclusions and DiscussionConclusions and DiscussionConclusions and Discussion

conformal therapy conformal therapy => => improvement of the treatment qualityimprovement of the treatment quality

conformal therapy => reduction of the high dose region for the OARs (responsible for side-effects)conformal therapy => reduction of the high dose region for the OARs (responsible for side-effects)

lowering of the daily dose to the OAR additionally reduces the biological effective doselowering of the daily dose to the OAR additionally reduces the biological effective dose

IMRT for enhanced dose homogeneityIMRT for enhanced dose homogeneity

optimized depth doses optimized depth doses (proton facilities)(proton facilities)

conformal therapy conformal therapy => => improvement of the treatment qualityimprovement of the treatment quality

conformal therapy => reduction of the high dose region for the OARs (responsible for side-effects)conformal therapy => reduction of the high dose region for the OARs (responsible for side-effects)

lowering of the daily dose to the OAR additionally reduces the biological effective doselowering of the daily dose to the OAR additionally reduces the biological effective dose

IMRT for enhanced dose homogeneityIMRT for enhanced dose homogeneity

optimized depth doses optimized depth doses (proton facilities)(proton facilities)

Conclusion and FutureConclusion and FutureConclusion and FutureConclusion and Future