Thoracic Flashcards
NCCN recommendation for screening
- Annual low dose CT for high risk patients
- “Shared decision making”
Who are eligible pts for screening CT?
- >30 pack year history
- Current or former smoker within 15 years
- age 55-74
- age 50+ with other risk factors (radon, occupational exposures, Fhx of lung cancer, COPD/fibrosis)
In the National Lung Screening Trial, how much did CT screening reduce mortality?
20%
Solid nodules > X or part solid nodules > Y deserve CT at 3 months, PET or biopsy
Solid > 8 mm
Semi-solid > 6
Plan for solid nodules 6-8 mm in size
CT at 6 months
Plan for single ground glass opacitiy
If > 6 mm, CT at 6 months to confirm no growth or development of solid component –> q2y for 5 years
Plan for multiple subsolid nodules
CT in 3-6 months
What history should be asked for thoracic patient
- Pulm symptoms
- Weight loss
- Fevers
- Hemoptysis
- Shoulder pain/dysufunction
- Neuro exam/headaches
- Paraneoplastic questions
What labs and tests should be ordered for a thoracic patient
- CBC
- CMP
- LDH
- PFTs
How best to pathologically diagnosis central lesion
Bronch and EBUS
How best to pathologically diagnose peripheral lesion
CT guided biopsy
Pneumothorax risk with CT-guided bx
20%
How to manage a pleural effusion
Perform thoracentesis with US
Obtain 50 cc of fluid and send for culture and cytology
Diagnostic yield of pleural cytology
50%, increases to 70% if 2 performed
Which patients are exempt from mediastinal sampling?
NCCN says patients with solid lesions <1cm or non-solid <3 cm, especially if PERIPHERAL
How many stations should be sampled on a good mediastinal review
3 stations, including 7
Try to hit all involved stations
Level 2 thoracic
High paratracheal
Level 3 lymph nodes
Retrotracheal or prevascular
Level 4 nodes
Paratracheal
Level 5 nodes
AP window
Level 6 nodes
Para-aortic nodes
Level 7 nodes
Subcarinal
Level 8 nodes
para-esophageal
Level 10 nodes
Hilar
Level 11 nodes
Interlobar
What levels are obtained with cervical mediastinoscopy
- 1 - high mediastinal
- 2 - high paratracheal
- 3 - prevascular
- 4 - low paratracheal
- 7 - subcarinal
- 10 - hilar
What levels are obtained with EBUS
1, 2, 4, 7, 10, 11, 12
What levels obtained with chamberlain procedure
5 - AP window
6 - para-aortic
Principles of lung cancer imaging
- CT chest w contrast - compare with prior
- CT AP - look at adrenals
- PET CT
- MRI brain if stage IB or greater
- MRI spine or brachial plexus if Pancoast
MRI brain should be ordered for which stages
IB or greater
T2b or higher
T1 lung cancer
<3 cm
T1a lung cancer
<1 cm
T1b lung cancer
1-2 cm
T1c lung cancer
2-3 cm
T2 lung cancer
3-5 cm
Involvement of mainstem bronchus or visceral pleura
T2a lung cancer
3-4 cm
T2b lung cancer
4-5 cm
Involvement of mainstem bronchus
Involvement of visceral pleura
T3 lung cancer
5-7 cm OR
Invasion of
- Parietal pleura
- Chest wall
- Phrenic nerve
- Parietal pericardium
- Separate tumor nodules in same lobe as primary
T4 lung cancer
- >7 cm
- Involvement of
- Diaphragm
- Mediastinum
- Heart
- Great Vessels
- Trachea
- Recurrent laryngeal nerve
- Esophagus
- Vertebral body
- Separate nodules in ipsilateral lung but different lobe
Separate nodule in different lobe IPSILATERAL is
T4
Separate nodule in same lobe IPSILATERAL
T3
Separate nodule in diff lobe CONTRALATERAL
M1a
N1 lung cancer
Ipsilateral 10-14
N2 disease
Ipsilateral 1-9
N3 lung cancer
Contralateral mediastinal or hilar nodes
Ipsi or contra SCV nodes
What is sens/spec of PET for nodes
~80%
more false positives with central tumors
How many are surgically upstaged in terms of nodal disease?
10-20%
M1a lung cancer
Separate tumor nodule in contralateral lobe
Tumor with pleural or pericardial nodules
Malignant pleural effusion
M1b lung cancer
single extrathoracic met
T1 N0 lung cancer is stage X
IA
T2N0 lung cancer is stage X
IB or IIA
Criteria for IIIA disease
T1 or T2 N2
T3N1
T4 N0
T4 N1
Criteria for IIIB cancer
T1 or T2 N3
T3 N2
T4 N2
Criteria for stage IIIC lung cancer
T3 N3
T4 N3
OS at 5 years of stage I lung cancer
70-90%
5 year OS of stage II lung cancer
50-60%
OS at 5 years of stage IIIA lung cancer
35-40%
5 year OS of stage IIIB lung cancer
25%
5 year OS of stage IIIC lung cancer
12%
Medically inoperable DLCO
<50%
Medically inoperable FEV1
<50%
Medically inoperable FEV1/FVC
< 75%
If pneumonectomy planned, FEV1 must be
>2L (preoperative)
If lobectomy planned, FEV1 should be
1.2 L (preoperative)
Other medical inoperable characteristics
Severe pulm HTN
DM with severe end organ damage
Severe vascular or cardiac disease
Patient refusal
What is preferred surgical approach
- Lobectomy (periop mortality 3%)
- Pneumonectomy if near proximal bronchus (periop mortality 6%)
When is wedge resection ok
Tumor < 2cm, margin > 2cm
LRR is 18% (vs. 6% for lobectomy)
Paraneoplastic syndrome with squamous
HyperCa
Paraneoplastic syndrome with adenocarcinoma
Hypercoagulable state
Hypertrophic osteoarthropathy
Paraneoplastic syndromes with SCLC
SIADH
Ectopic ACTH
Lambert-Eaton
Cerebellar ataxia
SIADH symptoms
Hypo Na
HA
N/V
Confusion
Seizures
Lambert-Eaton symptoms
Proximal muscles weak
Ptosis
Improves with exercise
Cerebellar ataxia symptoms
Gait instability
Dysphagia
Dysarthria
Diplopia
Retinopathy
What is stage IIB NSCLC
T1N1
T2N1
What is the management for stage I or II NSCLC (resectable)
- Surgery if option
- Risk adapted adjuvant therapy
What are high risk features warranting adjuvant chemo for resected NSCLC?
- Poor diff
- LVI
- Wedge resection
- >4 cm (T2b)
- Visceral pleural involvement
- N2 disease
What are adjuvant chemo options?
- Cis 75 mg/m2 or carbo AUC 5 + pemetrexed 500 mg (ADENO)
- Docetaxel 75 mg (SQUAMOUS)
- q3w
How many cycles of adjuvant chemo should there be?
4 cycles
What is the benefit of adjuvant chemo?
Probably 5-10% OS advantage
When should PORT be considered?
- N1/N2 - ONLY if no chemo planned
- Positive margin - favor re-resection or CRT
- Stage III, R1: PORT –> chemo
- Stage III, R2: CRT
Per LungART, what is the benefit of PORT for N2 disease
Reduces mediastinal relapse 50%
Other outcomes similar
What stages are considered potentially resectable NSCLC
- Stage IIIA (T1-T2bN2 or T3N1)
- Stage IIIB (T3N2)
Treatment options for potentially resectable NSCLC
- Trimodality therapy: CRT –> surgery (if lobectomy)
- Definitive CRT
- Chemo –> surgery –> +/- PORT
- Surgery –> chemo +/- PORT (in either order)
If resection if planned, what should be the CRT strategy
- Platnium doublet chemo (cis/etoposide or carbo/taxol)
- Plan for 45-54 Gy neoadjuvant
*
If contemplating trimodality therapy, what surgery is preferred?
Lobectomy
If pneumonectomy is required, discuss with surgeons and consider definitive CRT given excess mortality risk
What is the benefit of chemotherapy?
5% OS improvement
Same if pre or post operative
Definition of superior sulcus tumors
- Apical tumor with chest wall or rib invasion
- Pancoast syndrome
- Shoulder pain
- Brachial plexopathy
- Horner’s syndrome
- Usually T4N0 or N1
Horner syndrome
Ptosis
Myosis
Anhidrosis
Additional workup required for Pancoast tumor
- MRI brain
- MRI brachial plexus
- Rule out other sources of pain (cardiac)
Strategy to treat superior sulcus tumors
- Neoadjuvant cis-etoposide plus 45 Gy
- Restage with MRI brachial plexus after 45 Gy
- If good response –> surgery
- If poor response –> continue to 60-66 Gy with concurrent chemo
- In either scenario: 2 more cycles of chemo and/or durva
What is the brachial plexus consideration for superior sulcus tomor
Dmax <60 (66 is necessary)
For medically inoperable early stage tumors, local control of SBRT
95% local
90% local/lobar
For medically inoperable early stage tumors, local control of hypofractionation
75% LC
For medically inoperable early stage tumors, local control of conventional fx
50-60%
What are the RT options for medically inoperable stage I/II tumors?
- SBRT (goal BED > 100)
- Moderate hypofractionation (60/15)
- RT alone to 60-66 Gy
Consider post RT chemo for >IA based on risk factors
What tumors are eligible for SBRT
- <5 cm
- >2 cm from central structures
Definition of central tumor for SBRT
tumor in the no fly zone (2 cm expansion of distal 2 cm of carina through mainstem bronchi to lobar bronchi)
Dose of RT for central tumor
10 Gy x 5
Definition of ultracentral tumor for SBRT
- PTV abuts major airway, pulm vein, pulm artery, mediatinum
Dose of SBRT for ultracentral malignancies
7.5 Gy x 8 QOD
Characteristics for unresectable stage III tumors
- Medically inoperable
- T4 (unresectable)
- N3 disease
- High N2 or contralateral N2 disease
- Bulky or multi-station N2
- Pneumonectomy (relative)
Treatment options for inoperable Stage III NSCLC
- Concurrent chemoRT (to 60-66 Gy)
- Sequential chemo –> RT (or hypofractionated RT)
- Sequential RT –> chemo (if very symptomatic or obstructive)
- Consider adjuvant durva following chemoRT
Chemo options for NSCLC definitive CRT
- Cis/etoposide
- Carbo/pemetrexed
- Weekly carbo-taxol
Dose of cis and etoposide for definitive CRT
- Cisplatin 50 mg/m2 days 1,8, 29, 36
- Etoposide 50 mg/m2 days 1-5 and 29-33
Dose of carbo pemetrexed for definitive CRT
- Only for non squamous histologies!
- Carbo AUC 2 day 1
- Pemetrexed 500 mg/m2 day 1 and 21
Dose of weekly carbo taxol
- Carbo AUC 2
- Taxol 50 mg/m2 weekly
Adjuvant immunotherapy option for definitive CRT, NSCLC
durvalumab 10 mg/kg, q2weeks
Start within 2-6 weeks post CRT
Get restaging scan after CRT!
What is the benefit of PCI for NSCLC
Decreased number of mets but no difference in OS or DFS
What is 5 year OS for concurrent vs. sequential CRT for NSCLC (no durva)
- CRT - 16%
- Sequential 10%
What is the benefit of induction chemo for pts planned for definitive CRT
- No benefit to induction chemo –> CRT
- Consider if significant bulk and would be beneficial to shrink fields to meet constraints
Treatment options for oligometastatic disease
- Per Gomez et al - pts with NSCLC with 1-3 mets with lack of progression after 1L systemic therapy randomized to local consolidation therapy (surgery or SBRT) or maintenance treatment , PFS and OS favors local therapy
First line treatments for metastatic NSCLC
- If PDL1 > 50%: Pembro
- If PDL1 < 50%: Pembro + Carbo + Pemetrexed
Second line therapies for stage IV NSCLC
Pembro (if PDL1 >1%)
Nivo
Atezolizumab
Chemo
High risk CT features after RT
- Enlarging opacity (after 12 months)
- Craniocaudal growth
- Sequential enlargement
- Loss of linear margins
- Bulging margins
- Loss of air bronchograms
FOR THESE CONSIDER PET –> BX
Dose and targets for definitive RT of NSCLC
- 60 Gy in 2 Gy fractions
- Treat the primary and affected nodal disease
- >1 cm
- PET+
- Bx+
- No elective nodal irradiation
Simulation setup for lung treatment
- Supine
- Arms raised
- Alpha cradle
- CT sim with IV contrast, small amount of esophageal contrast
- Image from cricoid to below diaphragm
Volumes for definitive lung
- GTV = tumor and involved nodes
- ITV = tumor + nodes with motion accounted per 4DCT
- CTV = ITV + 7 mm (subtract from esophagus, bone)
- PTV = CTV + 5 mm setup
What is a 4DCT
Multiple images in thin section, the images are sorted into each breathing phase and reconstructed into a 4D movie, if the tumor is ever in that location during breathing, it is included in the ITV
Treatment volumes for PORT
- +Margin
- Treatment stump
- For N2, include the high risk or involved nodal stations
- Ipsilateral level 4, 7, hilum
Doses for PORT
- If negative margin: 50.4 Gy in 28 fractions
- If microscopic margin: 54 Gy in 30 fractions
- If R2 margin or ENE: 60 Gy in 30 fractions
What is the coverage objective for lung plans?
- V100% > 95%
- V90% > 99%
What is the benefit of IMRT over 3DCRT for conventional lung plans?
- Reduce pneumonitis risk
What is the V20 goal for conventional lung plans
- Consider lung minus GTV
- V20 < 37%
Strategies to reduce V20
- Switch from 3D to IMRT/IGRT
- Reduce CTV margin
- Induction chemo
- Consider DIBH to reduce ITV
- Replan after 40-45 Gy
V5 goal for conventional lung plans
<65%
Mean lung dose for conventional lung plans
<20 Gy
Spinal cord constraint for conventional lung plans
<50 Gy
Heart constraints for conventional lung plans
- Mean < 35 Gy
- V45 < 60%
- V60 < 30%
Esophagus constraint for conventional lung plans
- Mean < 34 Gy
- MPD < 105%
Brachial plexus constraint
MPD < 66 Gy
SBRT planning considerations
- 7-10 non opposing, non coplanar beams
- Heterogeneity corrections
- 100% IDL covering the PTV
SBRT lung coverage goals
- D95% > 100%
- MPD < 115%
- <105% dose outside of PTV
- Max dose >2 cm from PTV < 50%
- No hot spots in OARs
Acute toxicities of lung RT
- Dermatitis
- Esophagitis
- Cough
- Fatigue
- Cytopenias (weekly CBC if on CRT)
Late toxicities from lung RT
- Brachial plexopathy
- Pericarditis
- Pulmonary fibrosis –> cor pulmonale
- Dyspnea
- Respiratory failure
Time course for RT pneumonitis
subacute, 6w to 6mos
Symptoms of pneumonitis
- Fever
- SOB
- Opacities in treatment field
- Hypoxia
- Tachycardia
Workup for pneumonitis
- Rule out other causes - COVID, PNA
- Cardiac dx
- POD
- GI causes
- Get PFTs to follow (DLCO might be reduced)
Treatment of pneumonitis
- Prednisone 60 mg daily
- Slow taper over 2-3 months
- PPI + Bactrim
- O2 if needed
- Pulm c/s
For SCLC volumes, how to approach if post chemo
- Ok to limit GTV to post induction volumes
- Initially involved nodal regions should be covered (not volumes)
Spinal cord constraint if doing 45 Gy in BID fractions
MPD < 41 Gy
Workup for suspected SCLC
- H&P
- CXR –> CT w contrast (including adrenals)
- Labs
- Bronch or mediastinoscopy
- PET
- MRI brain
- PFTs
- BM bx
- Thoracentesis if effusion
When to do BMBx for SCLC
Evidence of nucleated RBC or cytopenias
Definition of extensive stage SCLC
- “Can’t fit within one radiation portal”
- N3 disease
- Pleural or pericardial effusions
- Distant mets or bone marrow involvement
Treatment strategy for ES SCLC
- Chemoimmunotherapy is standard
- Cis-etoposide x 4-6 cycles with atezolizumab or durvalumab
- Followed by maintenace atezo (q3w) or durva (q2w)
- Consolidation of chest disease if good response to chemoimmuno
Dose for consolidation lung RT for ES-SCLC
- 30 Gy in 10 fx
How to manage brain disease in pts with ES-SCLC
- If symptomatic: WBRT –> chemo
- If asymptomatic: chemo –> WBRT (if persistent)
5 year OS rates for ES-SCLC
<10%
What is the management approach for LS-SCLC
- Can consider surgery for very select early stage pts with N0 disease (T1/T2N0)
- If N+ at time of surgery –> abort and go to CRT
- Definitive CRT is SOC
- Consider PCI
Which patients could you consider surgery for LS-SCLC
- Select T1/T2 N0 by mediastinoscopy
- Recommend lobectomy + MLND + chemo
What is the most preferred CRT regimen for LS-SCLC
- 45 Gy in 30 fractions of 1.5 Gy delivered BID
- Concurrent cis-etoposide x 4 cycles
Dose of chemo for LS-SCLC
- Cisplatin: 60 mg/m2 day 1
- Etoposide: 120 mg/m2 day 1-3
- 4 cycles q3w
Field designs for LS-SCLC
- Primary: post chemo vols (after 1 cycle)
- Nodes - include:
- Ipsi hilum
- Involved levels (pre chemo)
- Use post-chemo vols
- Ipsi SCV if involved
When should RT begin for LS-SCLC
With cycle 1 or 2 of chemo (needs to start within 30d)
Is there an alternative CRT regimen for LS-SCLC
60-70 Gy in daily 2 Gy fractions
concurrent Cis/Etoposide
What is the 5 year OS estimate for LS-SCLC with definitive CRT
25-30%
What is the ancitipated rate of G3 esophagitis from definitive CRT for LS-SCLC
26% (requiring feeding tube or IVF)
Who is a candidate for PCI?
- Restrict to LS-SCLC with CR or good PR
What should be done first if considering PCI?
- Restage with MRI brain
- Restage with CT CAP
Dose of PCI
25 Gy in 10 fractions
When should PCI be given?
4-6 weeks after completion of chemo
What is the DDx for anterior mediastinal mass?
- Thymoma
- Teratoma
- Lymphoma
- Thymic carcinoma
- Thyroid lesions
What are the borders of the anterior mediastinum
Anterior: sternum
Posterrior: heart and great vessels
Laterally: pleural surfaces
What is the workup for an anterior mediastinal mass
- H&P focusing on paraneoplastic symptoms
- CXR
- CT chest w con or MRI chest
- Labs (CBC, CMP, LDH, bHCG, AFP)
- PFTs
- Core/open bx if not resectable
What is the preferred first step for thymic tumor
Median sternotomy and en block thymectomy
What are the histologic subtypes of thymoma
- Type A - benign
- Type AB or B1-3: moderately malignant
- Type C: very malignant (thymic carcinoma)
Symptoms of myesthenia gravis
- fatiguing of voluntary muscles
- bulbar muscle fatigue
What percent of MG patients have thymoma?
10-15%
What percent of thymoma pts have MG?
50%
What paraneoplastic syndromes are present in thymoma?
- MG (40-50%)
- Pure red cell aplasia (10%)
- Hypogammaglob (5%)
- Addison’s or Cushing’s
What happens to MG after treatment of thymoma?
50% will improve
Stage I thymoma
No capsule invasion
Stage IIA thymoma
microscopic transcapsular invasion
Stage IIB thymoma
macroscopic invasion into fatty tissues or mediastinal pleura
Stage III thymoma
invades adjacent organs including pericardium, great vessels or lung
Stage IVA thymoma
pleural or pericardial mets
Stage IVB thymoma
distant mets
Treatment of earlier stage thymoma
- Surgery
- Get multiD involvement, if resectable, do not attempt bx and go for thymectomy
- All patients going for surgery need preop AchE inhibition (neostigmine)
What should be studied on the path report for thymic tumor?
- Path - carcinoma vs. thymoma, WHO subtype
- Invasion of capsule
- Pleural involvement
- Organ invasion
- Margin status
What is the intent of PORT for thymoma
Improves LC and decreases risk of relapse
For thymic tumors, indication of PORT for stage I
- If thymoma, R0 - obs
- If thymic carcinoma, R0 - obs
- If thymoma R1 or R2 - consider PORT
- If thymic cancer R1 or R2 - PORT
For thymic tumors, indication for PORT for stage II
- For thymoma: consider for all, especially if B2-B3 histology
- For thymic carcinoma - consider PORT for all
For stage III or IV thymic tumors, which should get PORT
All, dose determined by margins
Dose of PORT for stage II thymomas
- If R0 with B2/B3- 45 Gy
- If R1 - 50.4 Gy
- If R2 - 60 Gy
- If unresectable - 60 Gy
Dose of PORT for stage III or IV thymoma
- If close margins 50.4 Gy
- If R2 or unresectable: 60 Gy
Does of RT for thymic carcinoma
- If R0 negative margin - no role
- If stage II+ or R1: 60 Gy
What to do if thymic tumor is borderline resectable
- Start with chemo (adriamycin based)
- Then surgery
- Then RT with dose depending on margin status
- Then more chemo
5 year OS for Stage I thymomas
>90%
5 year OS for Stage II thymomas
80%
5 year OS for Stage III thymomas
70%
5 year OS for Stage IV thymomas
50-60%
Treatment option for unresectable thymic tumor
CRT to 60-70 Gy
Concurrent cyclophosphamide, adriamycin, cisplatin
Contouring for thymic tumors
- CTV = tumor bed + gross residual + 1.5 cm margin
- PTV = CTV + 5mm
- No elective nodes (maybe for carcinoma)
Special constraints for thymoma
Consider mean heart dose of 30 Gy since younger pts
What is the most prognostic feature for mesothelioma
Subtype NOT stage
What are the mesothelioma subtypes
Epithelioid (60%)
Sarcomatoid (worst prognosis)
Biphasic/mixed
T1 mesothelioma
Ipsi parietal pleura with extension to visceral, mediadtinal or diaphragm
T2 mesothelioma
Involving pleural surfaces with diaphragm muscle or pulm parenchymal involvement
T3 mesothelioma
Potentially resectable, involved local fascial, mediastinal fat, chest wall, pericardial fat
T4 mesothelioma
Technically unresectable
Imaging workup of meso
- CT CAP
- PET
- MRI C/A (to determine invasion of chest wall and diaphragm)
Tissue diagnosis of mesothelioma
Thoracentesis is diagnostic 25% of times
BUT STILL NEED tissue to do IHC
VATS biopsy is preferred over CNB
Surgical options for mesothelioma
- EPP - extrapleural pneumonectomy (en bloc removal of full pleural and lung, pericrdium and hemi diaphragm
- P/D - pleurectomy and decortication - parietal and visceral pleruectomy: leaves residual tumor but less morbid
Treatment strategy for resectable meso
- Induction chemo (cis/pem) –> restage
- Surgery
- Adjuvant RT
Strategy for adjuvant RT after P/D
- Use IMRT
- Dose of 54 Gy in 27 Fx
- 1.5 cm above the lung apex
- Include CW, latral portion of the vertebral body and sternum
- Include ipsi pericardium
- Include diaphragm insertion T12-L1
- Ensure 8 mm on gross disease
Constraints for adjuvant RT after P/D
- Lung V20 < 20%
- MLD < 10 Gy
Suitable location for 18 x 3 SBRT
- Peripheral tumors
- >1 cm from the chest wall
Suitable location for 12 Gy x 4 SBRT lung
Central or peripheral tumors <5 cm
Especially <1 cm from chest wall
Suitable location for 10 Gy x 5 SBRT
Central tumors (PTV in NFZ)
Location less than 1 cm from chest wall
Spinal cord constraint for 3-5 fx SBRT
- Remember ~6 Gy per fraction
- 3 fx: 18 Gy
- 4 fx: 26 Gy (6.5/fraction)
- 5 fx: 30 Gy
Esophagus constraint for 3-5 fx SBRT
- 3 fx: 27 Gy
- 4 fx: 30 Gy
- 5 fx: 105% of RX
Chest wall constraint for 3-5 fx SBRT
- Try for V30 < 30 cc (2 cm rind of the chest wall)
- If impossible, accept V30 < 50 cc
Brachial plexus constraint for 3-5 fx SBRT
- 3 fx: 27 Gy (9/fraction)
- 4 fx: 32 Gy (8/fraction)
- 5 fx: 35 Gy (7/fraction)
Small bowel MPD for 5 fx SBRT
30 Gy
Heart constraint for 3-5 fx SBRT
- 3 fx - 30 Gy MPD
- 4 fx - 34 Gy MPD
- 5 fx - 105% RX MPD
Lung constraint for 3-5 fx SBRT
Ipsi lung V20 < 25%
V20 of Lungs minus GTV < 12%
How is SBRT contoured?
GTV= gross disease, fuse PET to help
ITV= GTV with motion
PTV = ITV + 5 mm
How is SBRT plan normalized
100% corresponds to PTV at isocenter
What is the goal coverage for SBRT
95% of PTV receives 100% of dose
If not doing 45 Gy BID for SCLC, what is other options
66 Gy / 33 fx
Contouring for locally advanced NSCLC
GTV = gross disease, tumor and involved nodes
Use 4DCT to create ITV
CTV = ITV + 7 mm
PTV = CTV + 5 mm
What is a 4DCT
During 4DCT acquisition, images are acquired in all phases of the respiratory cycle while simultaneously recording respiration, followed by a retrospective sorting process that correlates CT images with the phase of respiration.
The respiratory cycle is derived using chest height as a surrogate, which is determined using an RPM marker on the patient’s upper abdomen. An infrared camera notes the height of the box
What is benefit of PCI for LS-SCLC
5% benefit in 3 year OS
How does PCI change risk of BM for SCLC
roughly half
60% to 30%
How to approach borderline resectable thymomas?
Try neoadjuvant chemo
Adriamycin-based chemo (Adria/ cyclophos/ cis) then surgery or RT
Then more chemo
What is the GTV to CTV margin for thymoma
0.5 cm
What is the contouring strategy for thymoma
CTV = GTV + 0.5
Form ITV
PTV = ITV + 0.5 cm
Regimen for ES-SCLC
carbo, etoposide, atezo
Contouring approach for SBRT
GTV –> ITV
PTV of 5 mm