2D and 3D Planning in Lung

7/31/2019 2D and 3D Planning in Lung

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Planning Meet

2D and 3D Planning in Lung


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Lung Cancer

Most commonly diagnosed cancer world wide.Also leading cause of cancer related deaths.

Treatment depends upon Type, Stage of the

disease & GC of patient.

50 60% pts. Require RT at least once while45% of pts. receive RT as initial t/t.


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TMH Data (2007) 861 new cases. (5.3%)

M:F = 3.7:1 Median age = 56.9/52.8

Histology : SCC 055/861

Adenoca 336/861

SCC 206/861 NCSLC 099/861

Others 165/861

Only 37% cases are localised. 26% - distant mets. 3- locoregionally advanced.


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ANATOMY OF LUNG

Oblique fissure: extends fromthe lung surface to the hilum

Horizontal fissure: extendsfrom the anterior margin into

oblique fissure.

Rt lung: three lobes

Lt lung: two lobes, middle oneis replaced by lingula


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BRONCHOPULMONARY SEGMENTS

APICAL

ANTERIOR

POSTERIOR

MEDIAL

LATERAL

UL

ML

ANT BASAL

LA T BASAL

POST BASAL

MED BASAL

LL

APICAL

ANTERIOR

SUP SEG

INF SEG

LIN

ANTERO

BA

POSTERIOR

BASAL

LATERAL

BASAL


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LYMPH NODE MAP:Nomenclature*

*American College of Surgeons


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Lymphatic drainage

Right upper lobe

Tracheobronchial LN

Left upper lobe venous angle of same side as w

as opposite side.

Rt and lt lower lobe - subcarinal nodes and to Rt

superior mediastinum and directly into inferior

mediastinum


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STAGING Tx : primary tumour can not be assessed

T0 : no evidence of primary tumour.

T1 : tumour 3cm, involves main bronchus >2cm distal to carina, invades visceral pleura asso atelectasis or obstructive peumonitis not inv entire lung

T3 : invades diaphragm, mediastinal pleura, parietal pericardium, bronchus


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Nx : Regional lymph can not be assessed

N0 : No regional lymph nodal metastasis

N1 : Mets to ipsilateral peribronchial and/or ipsilateral hilar, andintrapulmonary nodes.

N2 : Mets to ipsilateral mediastinal and/or subcarinal nodes

N3 : Mets to contralateral mediastinal, contralateral hilar, ipsilateral orcontralateral scalene, or supreclavicular lymph nodes

M0 : No distal mets.

M1 : Distal mets present


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STAGE GROUPING


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WORK UP

Clinical history, Physical Examination

Performance Status, h/o wt loss

Hematological : CBC, Biochem, Sr. Alk Po4, LDH

Endoscopic findings

Imaging : X ray chest, CECT, PET/PET-CT Pleural fluid cytology if PE

Assessment of Cardiopulmonary function


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PET is now standard component of staging in nan

metastatic NSCLC pts. Considered superior to CT in determining TNM stage

Although CT with its better spatial resolution remains th

standard assessment

WORK UP

Modality Sensitivity Specificity PPV NPV

CT 57% 82% 56% 83%

PET 84% 89% 79% 93%


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HISTOLOGIC TYPES OF LUNG CANCER

2 major types:

Small-cell lung cancer

Nonsmall-cell lung cancer, which is further subdivide

into:

1. squamous cell carcinoma,

2. adenocarcinoma, and

3. large-cell carcinoma.


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Origin and characteristics

Squamous cell lung cancer: commonest type in males,

central origin, manifests early

Adenocarcinoma: commonest type in females, peripherorigin, manifests late

Large cell lung cancer: least common type, peripheral o

Small cell lung cancer: most aggressive type, central or

spreads quickly


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RT PLANNING


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POSITIONING AND IMMOBILIZATION

Pt taken on couch after explaining procedure and taking consent.

Immobilization done in supine position

Arms: Lateral

Above head

Neck: Neutral position and chin to SSN distance should be recorded

Normal breathing

Various immobilization boards can be used for better reproducible positVac lock can be used.


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Beam arrangement

AP/PA parallel opposed

Most commonly used

Lower integral dose to rest of the lung

Simple Comfortable

Easily reproducible

Spinal cord shielding

Post spinal block


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Radiotherapy treatment portals

Central

upper

lobe

periphera

upper

lobe

Ipsilateral supraclav to be included

Inferior margin 5-6 cm below carina


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No need to treat ipsilateral supraclav area

If mediastinal nodes are involved then ipsilateralSCF should be treated


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Phase II

Only primary tumour and

ipsilateral hilum with margin

for organ uncertainties.

To reduce dose to cord

To reduce dose to other critical structures

Field arrangement like ant + post oblique or both

oblique can be used


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Radiation dose

Radical (definitive) RT in stage I/II NSCLCmedically unfit patients for surgery

60 64 Gy / 30 32 #/ 6 7 wks

Phase I : 40 Gy / 20 # / 5 wks across mediastinum

Phase II : 10 Gy / 5 # off cord with 2 cm margin to

tumour

Phase III: 10 Gy / 5 # with 1 cm margin to tumour


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POST OP ADJUVANT RADIOTHERAPY IN EARLY

STAGE NSCLC STAGE I/II

Residual disease after lung resection

Resection with positive margins

Positive lymph node status

DOSE

50-54 Gy/ 25-27 fr/ 5-6 weeks

Phase I: 40 Gy/ 20 fr across the mediastinum

Phase II: 10-14 Gy/ 5-7 fr/2 cm margin (off cord).


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Radical Radiation therapy in stage III/IV NSCLC

Dose and fractionation

60-64 Gy/ 30-32 fr/ 6-7 weeks

Phase I : 40 Gy/ 20 fr/ 5 weeks across the

mediastinum

Phase II : 10 Gy/ 6 fr/ 2 cm margin to tumour (off

cord)

Phase III : 10 Gy/ 6 fr/ 1 cm margin to tumour.


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3D PLANNING


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Conformal techniques / 3DCRT

What is the need ?

Toxicity major problem

Dose escalation

some possibility

Already compromised CARDIOPULMONARY functio

because of Smoking, Cardiac morbidity , COPD,

Atelectasis.


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NORMAL TISSUE TOLERANCE TD 5/5

STRUCTURE 1 / 3 2 / 3 3 / 3SELECETEEND POIN

SPINALCORD 5000 5000 4700 MYLITIES

LUNG 4500 3000 1750

RADIATION

PNEUMON

HEART 6000 4500 4000 PERICARD

ESOPHAGUS 6000 5800 5500 STRICTUR

BRACHIALPLEXUS 6200 6000 6000

NERVEDAMAGE


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NORMAL TISSUE TOLERANCE TD 50

STRUCTURE 1 / 3 2 / 3 3 / 3

SPINAL

CORD 7000 7000 ----

LUNG 6500 4000 2450

HEART 7000 5500 5000

ESOPHAGUS 7200 7000 6000

BRACHIAL

PLEXUS 7700 7600 7500


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DATA ACQUISITION

Positioning and immobilization.

Reference markers placed

CT scan taken in treatment position. Contrast should be used.

Extends from thyroid cartilage to umbililcus

Slice thickness 5mm.

Spiral mode preferred over seq. mode


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STEPS Select proper window

Normal critical structures contoured first

GTV to be drawn

CTV and PTV to be generated

Images and RT structures then transferred to TPS.

Planning done.

Plan evaluation

DRR generated after plan approval.

DRR matched with sim / port film.

EPID taken for verification.


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IMPACT OF CT WINDOW LEVEL


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IMPACT OF PET ON RT PLANNING

PTV increased in 64% (detected nodes)decreased in 36% (exclusion of atelectasis)

(Erdi et al 2002)

Average reduction of PTV by 29%

Average reduction of V20 by 27%(Vanuytsel et al. 2000)

Interobserver variability reduced:

mean ratio of GTV without PET: 2.31

mean ratio of GTV with PET: 1.56

(Caldwell 2001)



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Impact of PET: Atelectasis




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Impact of PET: PTV


C O O


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Impact of PET: PTV

IMPACT OF PET ON RTPLANNING



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Limiting factors of PET

-Resolution 4-8mm (depending on scanner and institution)

-Registration errors (esp. with software based fusion)

-Threshold value (SUV) individually to be determined

Summary:

PET is a promising complementary tool in RT planning of NSCLC. Its

for staging has been established and preliminary reports suggest that

may lead to more consistent definition of GTV in RT planning. Howeve

still not clear, whether this will translate into better survival.


VOLUMES


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VOLUMES

GTV: Primary and Nodal disease as per Clinico

radiological findings

CTV: GTV + margins for subclinical disease

PTV: CTV + Margins for Set up error and Organ

motion ( Internal + External)

CTV t th b li i l i i di


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CTV to encompass the subclinical microscopic diseas

is difficult to define

Rarely mentioned in literature. Depends upon histological type and tumour volume.

Proposed margin : 5 15 mm

TMH: 0.7-1.0 cm margin around GTV

Microscopic extension Adeno Squamos

mean value 2.69mm 1.48mm

5mm margin covers: 80% 91%

margin to cover 95% 8mm 6mm

Phase1: Gross + Subclinical disease + PTV marginPhase2: Gross disease + PTV margin

(Giraud 2000):


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RT-Planning Defining the CTV


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RT-Planning Defining the CTV

Subclinical lymph nodes (ENI)

-high risk of nodal spread in lung cancer

-but value of ENI is not proven

Reasons against ENI:

-less than 20% locally controlled 1y after RT with conventional

dose (Arriagada 1991)

-need for more intense treatment to gross tumour-large volumes prevent dose escalation (normal tissue tolerance)

-small primary tumor and small total tumor volume predictive

(Basaki 2006, RTOG 93-11 2008)

-modern chemotherapy regimens may lead to better control of

microscopic disease

RT Pl i D fi i th PTV


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Created by adding margin to CTV

Based on institutional experience

Factors to be taken into account Set up uncertinties

Internal organ motion Respiration

Cardiac motion

Tumour location in lung

Fixation to adjacent structures

RT-Planning Defining the PTV

RT Pl i D fi i th PTV


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RT-Planning Defining the PTV

Reducing respiration induced errors:

Size of movement dependent on:- tumour location in the lung

- fixation to adjacent structures

- lung capacity and oxygenation

- patient fixation and anxiety

Average movement in normal breathing:- Upper lobe 0 - 0.5cm- Lower lobe 1.5 - 4.0cm- Middle lobe 0.5 - 2.5cm- Hilum 1.0 - 1.5cm

Steppenwoold


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SOME EXAMPLES

UPPER / MIDDLE LOBE TUMOUR AND


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UPPER / MIDDLE LOBE TUMOUR AND

HEART DOSES


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UPPER LOBE TUMOUR

MIDDLE LOBE CENTRAL TUMOUR


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(HEART)

MIDDLE LOBE TUMOUR (CORD


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MIDDLE LOBE TUMOUR (CORD

IMRT : non uniform dose intensity maps


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IMRT : non uniform dose intensity maps

Variabledoseacrossthefield

toachieveaspecificallydesignedintensitypattern

Sumofallfieldsin3Dspacedelivershighdosestoirregularlyshapedvolumes

ReducesV20 Non


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CONCERNS LIMITING USE OF IMRT Increased volume of lung receiving low dose of radiatio

resulting in more chances of radiation pneumonitis anddecrease in DLCO.

Impact of tumour motion.

Tissue inhomogeneity requires high degree of accuracdose calculaiton.

Although dosimetrically superior there is no robustevidence to suggest that it improves the health outcom

RESPIRATORY GATING


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RESPIRATORY GATING Technique to counteract the effect of target volume motion due to resp

Defines a physical window and delivers radiation when tumour passes radiation portal

Good compliance and pul. Functions

Video monitor and analyser characterizes breathing pattern and identifirange of chest wall motion.

Correlation of this data with tumour motion in simulation.

Create treatment that gates the treatment beam on when the tumour faplaned beam aperture.


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4D CT BASED RESPIRATION GATED RT

Treatment beam fixed in spaceand gated to turn ononly when

the target (or surrogate signal) comes into the pre-planned area

TOXICITIES


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TOXICITIES

Oesophagitis

Radiation pnemonitis acute / late

Radiation mylities

Brachial plexus injury

OESOPHAGITIS


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Concurrent chemotherapy and V60 weresignificantly associated with grade III esophagitis

LUNG TOXICITY For grade I RP


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LUNG TOXICITY

Related to both dose

and volume effect

Acute complication radiation pneumonitis

Late complication fibrosis

Severely debilitating

and fatal

For grade I RP

KPS

Tumour location

No previous surgeConcomitant

chemotherapy

gender

For grade II RP

High MLD

V20

, V30

MY SECONDLAST SLIDE


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MY SECONDLAST SLIDE

DONT use dose escalation and highly conformaltechniques such as IMRT for lung cancer until tumourmotion can be taken into account !

In the meantime ...

-Outline GTV as best as possible -Construct CTV based on the literature

-Construct PTV based on measured tumour motion andknown setup uncertainty.


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MONDAY SEMINAR 11/01/09


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MONDAY SEMINAR 11/01/09

Early Stage NSCLC: Stage I, II


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y g g ,

Standard of care = Surgery

Relapse rate 35%-50% in St. I

Relapse rate 40%-60% in St. II

Adjuvant radiotherapy ? Adjuvant chemotherapy ?

Adjuvant Radiotherapy


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Port meta-analysis Trialist Group. Lancet 1998;352:257

9 randomised trials of postoperative RT versus surger

(2128 patients)

21% relative increase in the risk of death with RT

Reduction of OS from 55% to 48% (at 2 years)

Adverse effect was greatest for Stage I,II

St.III (N2): no clear evidence of an adverse effect



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j py

Conclusion

Postoperative RT should not be used outside of

clinical trial in Stage I, II lung cancer, unless surg

margins are positive and repeated resection is nfeasible.

Adjuvant Chemotherapy


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Adjuvant Chemotherapy

Undetectable microscopic metastasis at diagnosis

Individual trials have not shown a significant benefi

Meta-analysis BMJ 1995;311:899:

Alkylating agents had an adverse effect

Cisplatin-based therapy:

13% reduction in risk of death (not significant)

P t ti Ch d R di th


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Postoperative Chemo- and Radiothe

ECOG-Trial: 488 patients with stage II, IIIA RT alone (50.4 Gy) versus

RT + 4x Cisplatin/Etoposid

Median survival 39 vs 38 months (ns) TRM 1.2 vs 1.6% Local recurrence 13 vs 12%

Keller et al. NEJM 2000;343:12

Cisplatin-based Adjuvant Chemotherapy(International Adjuvant Lun Cancer Trial Collaboratvie Gro


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(International Adjuvant Lung Cancer Trial Collaboratvie Gro

Randomised trial of 3-4 cycles of cisplatin-based

CT vs observation in patients with St. II, III LC

CT no CT

5-Y. DFS 39.4% 34.3% p


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Adjuvant Chemotherapy Conclusion:

One should consider the use of adjuvantplatinum-based chemotherapy in patients witstage I,II or IIA NSCLC

Locally advanced NSCLC


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Thoracic irradiation is the mainstay oftreatment for inoperable stage III dise

Its curative potential is extremely poor5-year survival rates 3-5%



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A meta-analysis of 22 randomised studishowed a beneficial effect of CT addedRT 10% reduction in risk of death per year

Small absolute survival benefit:4% after 2 years2% after 5 years

NSCLC Collaborative Group. BMJ 1995;311:

Neoadjuvant Therapy


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Neoadjuvant Therapy Pancoast`s tumor, vertebral invasion

Combined neoadjuvant CT-RT should be considered

Tumors with ipsilateral mediastinal spread (N2 Poor survival with surgery alone

2 small randomised trials showed a benefit of neoadjuvacombined CT-RT

Roth et al. JNCI 1994;86:673

Phase II trials report good results of neoadjuvant CT

SAKK Studies


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SAKK Studies SAKK 16/00

Preoperative CRT vs CT in NSCLC stage IIIA CT: 3 cycles docetaxel and cisplatin (D1,22,43) RT: 3 weeks of RT (44 Gy in 22 fractions)

SAKK 16/01 Preoperative CRT in NSCLC pts with operable

stage IIIB disease The same regimen as 16/00

Metastasis


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M40-50% at diagnosis

70% during follow-up

NSCLC: chemotherapy combinations


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NS L ch moth rapy com nat ons

Regimes

Cisplatin+Paclitaxel

Cisplatin+Gemcitabine

Cisplatin+Docetaxel

Carboplatin+paclitaxel

Results (n=1155 pts.)

Response rate 19%

Median survival 8 mont

1-year survival 33% 2-year survival 11%

Schiller et al. NEJM 2002;34

Conclusion: Combined-Modality Therapy forStage III Disease


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Stage III Disease

Adding CT to radiation therapy improves survival and alterscourse of this disease

Phase III studies suggest improvement in both local contro

survival with concomitant CT-RT

Combined CT-RT should be the standard of care of patient

good PS and minimal weight loss

The absolute gain from combined CT-RT is still modest

The role of surgery following induction CT-RT is for patien

with unresectable Cancer is being explored

Small-cell Lung Cancer (SCLC)


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g ( )

15-20% of all lung cancer

Incidence: 15/100000/year

Men : women = 5 : 1

SCLC


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Rapid local and metastatic spread Mediastinal lymph node metastasis in most

cases

Median Survival in untreated patients 2-3

months Superior vena caval obstruction and

paraneoplastic syndromes (SIADH, Cushin

Association with smoking

SCLC Staging


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g g Limited Disease

Confined to:

One hemithorax Mediastinum

Ipislateral hilarand supraclavicularnodes

Extensive Disease

Malignant pleuraand pericardeffusion

Contralateral hilaand supraclaviculanodes

SCLC Therapy


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py No surgery; SCLC is a systemic disease

Chemotherapy is the standard of care Cisplatin+Etoposid

Limited stage SCLC: Bimodality therapywith chemotherapy and radiotherapy

SCLC Therapy


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py

The addition of thoracic RT significantly improsurvival in patients with LS-SCLC

Meta-analysis. Pignon et al. NEJM 1992;327:1618

14% reduction in the mortality rate

5.4% benefit in terms of OS at 3 years

Early use of RT with CT improves cure rates

SCLC Therapy


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py

The actuarial risk of CNS metastasis develo2 years after CR of SCLC is 35%-60%

Prophylactic cranial Irradiation is recommend

for pts. With LS-SCLC in CR

Meta-analysis: Auperin et al. NEJM;1999:341 PCI: 5.4% greater absolute survival at 3 year

SCLC Results


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Limited Disease:

Remission rate 80-90% CR 50-60%

Median Survival 18-20 months 2-year Survival 40% 5-year Survival 15-25%

SCLC Results


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Extensive Disease:

Remission rate 70-80% CR 20-30%

Median Survival 8-10 months 2-year Survival < 10%

FLUROSCOPY


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Average movement with respiration in each patient should berecorded

Eikberg et al : 200 patients2.4 cm in ML directions3.9 cm in cranioquadal directions

Huang et al :distal hilum 1 1.5 cmarch 0-0.5lower lobe 1.5 4 cmmid lobe 0.5 2.5 cm

TUMOUR EDGE DEFINITION


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Visual interpretation of PET images.

arbitrarily windowing, may lead significantly different appar

tumour volumes

Automatic Image segmentation methods based on SUV eithe

as an absolute SUV.

a SUVmax of 2.5 is often used as a threshold for the distinction betwmalignant and benign lesions.

threshold value (a percentage of SUV max)

40% to 50% of the maximum uptake

15% for moving targets


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Important role in differentiating disease from benigpulmonary nodule and from atelectasis.

As ENI is not routinely delivered, PET CT may helin identification of involved nodal areas.

Despite better tumour volume deliation and reductof interobserver variation there is not enough robuevidence to suggest that it improves the outcome.

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2D and 3D Planning in Lung