Lung Oncology Flashcards
What are the risk factors for lung cancer?
cigarette smoking (10x risk) absbestos radon metals polycyclic aromatic hydrocarbons ionizing radiation
What are the two types of lung cancer?
non small cell (80%)
Small cell carcinoma (20%)
What pathology makes up non small cell lung cancer?
SCC (30%)
Adenocarcinomas (50%)
Large cell carcinomas
Upon clinical presentation what are the four areas that symptoms relate to?
primary lesion
intrathoracic spread
distant metastases
paraneoplastic syndromes
What are the symptoms for a primary lesion?
cough
breathlessness
haemoptysis
chest pain
What are the symptoms for intrathoracic spread?
pleural or percardial effusion
hoarseness of voice
brachial plexus involvement
compression of SVC
What are the symptoms for distant metastases?
pain (bone mets) weakness and weight loss headaches seizures neurological symptoms (cerebral mets)
What are paraneoplastic syndromes?
set of symptoms due to either a immune response to the cancer or by substances secreted by the cancer
(Hyperdalcemia, clubbing, hypertophic pulmonary osteopathy, SIADH- Syndrome of inappropriate antidiuretic hormone secretion)
What are the four steps of diagnostic evaluation of lung cancer?
- confirm the diagnosis of cancer
- determine what type of cancer (pathology, cytology, immunohistochemistry)
NSCLC vs SCC
NSCLC- adeno vs SCC - evaluate staging
- if localised determine if patient is fit for radicl or palliative RT
What are the other considerations in diagnostic evaluation?
symptoms other medical condition (heart disease, chronic lung disease) weightloss exercise tolerance full respiratory function tests (RFTs) (spirometry- FEV1/FVC) (measures of diffusion (DLCO))
What techniques can be used in diagnostic evaluation?
chest x-ray
CT scan (chest, abdomen +/- brain)
Biopsy (e.g. CT-guided fine needle aspiration biopsy, bronchoscopy)
What is the ‘resectability’ of the different stages of lung cancer
early stage (IA, IB, IIA, IIB)- potentially resectable locally advanced (IIIA, IIIB)- usually unresectable metastatic (IV)
What techniques can be used in diagnostic evaluation/ investigation of NSCLC?
NSCLC- positron emission tomography (PET) scan
EBUS- Endobronchial USS
Mediastinoscopy
(both considered where PET +ve mediastinum and want to exclude false +ve)
How would you treat Early stage NSCLC if resectable + acceptable lung & cardiac function + no other co-morbidities that would preclude surgery?
surgery +/- adjuvant chemotherapy (lobectomy, pneumonectomy, wedge resection)
How would you treat Early stage NSCLC if patient refused surgery or they had co-morbidities that precluded surgery + acceptable lung function?
Radical Radiotherapy
(50Gy/ 20# OR 60Gy/ 30#)
SBRT
How would you treat Early stage NSCLC if poor lung function - CI to high dose RT?
Observe or Palliative RT (depending on whether symptomatic)
SBRT
For treatment of early stage NSCLC would adjuvant treatment after surgery be used?
Chemo: improved survival (4%) in ≥iB disease, platinum based doublet
Radiotherpy: not indicated unless +ve margins. Evidence suggests worse survival when RT affed after complete resection for early disease
What does treatment of locally advance (Stage III) (usually unresectable) NSCLC depend on?
volume of disease
lung function
co-morbidities (fitness for chemo)
symptoms
What are the limitation for RT in lung cancer?
lung cancer is aggressive
normal lung radiosensitive (lungs are vital)
uninvolved lung often doesn’t work wll due to pre-existing smoking related lung disease (chronic obstructive pulmonary disease)
What is the typically treatment for locally advance NSCLC if:
volume of disease not too large
acceptable lung function
fit for chemo?
Radical Chemoradiotherapy
(concurrent platinum-based chemotherapy and 60Gy/30# radical RT)
(addition of chemo to RT gives better overall survival than RT alone although increases toxicity
What is the typically treatment for locally advance NSCLC if:
volume of disease not too large
acceptable lung function
unfit for chemo?
Radical Radiotherapy
60Gy/ 30#
What is the typically treatment for locally advance NSCLC if:
volume of disease not too large
acceptable lung function
Symptoms?
Palliative RT +/- chemo
OR
Chemo alone
What is the typically treatment for locally advance NSCLC if:
volume of disease not too large
acceptable lung function
No symptoms?
Observe
or chemo
Has concurrent or sequential chemoradiotherapy resulted in a better survival?
concurrent
What was the result of dose escalation trials for inoperable stage III NSCLC?
compared 60Gy/30# with concurrent chemotherapy with 74Gy/ 37#
worse survival with high dose (more treatment related deaths)
What is the process for the small % of stage III locally advanced disease that can receive surgery?
appropriate only for low volume or unexpected mediastinal node disease
Neoadjuvant chemotherapy to improve resectability for those borderline resectable
Adjuvant chemotherapy indicated
When may post-operative RT (PORT) be used?
rarely indicated
incomplete resection (+ve or very close margins)
involvement of mediastinal nodes (N2) (controversial)
Although controversial, what is the dose fractionation for PORT for N2 disease?
PTV = mediastinum (50Gy/25#) Residual disease (+ve margins) (PTV= area of residual only, 60Gy) Concurrent cisplatin-based chemotherapy
When is neoadjuvant chemoradiotherapy indicated?
rarely indicated
pancoast’s tumour (superior sulcus tumours)
45-60Gy followed by surgery if it becomes resectable
What benefits does PET scan have over CT?
PET: evaluation of primary tumour especially differentiation between tumour tissue and atelectasis (collapsed part of lung)
For an optimal GTV what CTV expansion should be used to account for potential microscopic tumour?
6mm SCC
8mm Adenocarcinoma
Why does GTV/CTV usually only include clinically involved nodes?
irradiation of all high-risk lymph nodes does not increase overall survival or local control and does increase toxicity and dose escalation
What does a lung tumour PTV take into account?
tumour movement during respiration
observed fluoroscopic motion
What to do about respiratory motion?
adequate margins on CTV to PTV (1.5cm)
4DCT (GTV in all stages of respiratory cycle)
breath hold techniques
respiratory gating (radiation only delivered at a predefined phase of the respiratory cycle)
what are the critical structures for lungs?
spinal cord ≤45Gy
lung (radiation pneumonitis, late pulmonary fibrosis)
heart
oesophagus
What is radiation pneumonitis?
lung inflammation usually after 6 weeks post RT
presents with shortness of breath, cough, fever, malaise
treat with prolonged steroids
What does QUANTEC recommend for total lung volume?
total lung = volume of R + L lung - GTV
V20 < 30-35%
What are typical field arrangements for lung treatment?
AP/PA (for late stage NSCLC) – however can only prescribe 40-45Gy due to spinal cord tolerance
3 Field – post obliques
4 Field- ANT, LPO, LT LAT, POST
What are the risk factors for radiation oesophagitis?
oesophageal volume treated by > 50Gy
use of concomitant Chemo
agressive RT fractionation
Which concomitant Chemo therapy can cause oesophagitis?
adriamycin (primary or recall at 20Gy)
Gemcitabine (49% incidence ≥ grade 3)
What are the indications for palliative RT?
Stage I-III if: volume of disease very large poor lung function poor (patient status) PS due to other co-morbidities OR Stage IV disease (metastases)
How many fractions are typically recommended for palliative patients with poor PS?
1 or 2
higher doses may provide survival advantage in patient with relatively localised disease and good PS
What is typically done for palliative patient who are asymptomatic?
observation
no increased survival or symptom delay with RT
What are the possible treatment palliative strategy for locally advanced NSCLC with chest symptoms and poor PS?
16Gy/ 2# OR 10Gy/1#
What are the possible treatment palliative strategy for locally advanced NSCLC with chest symptoms and good PS?
36Gy/ 12#
What are the possible treatment palliative strategy for locally advanced NSCLC with no symptoms?
observe or 16Gy/2# or 10Gy/1 #
What is Stereotactis Ablative Radiotherapy (SABR) and what is it used for?
early stage NSCLC precisely targeted RT to tumour, with steep dose gradient, while minimizing dose to adjacent tissue BED >100Gy usually <5 # (e.g. 54Gy/ 3#) 10-12 beams or large angle arcs non-opposing/ non-coplanar
What is the patient selection for early stage NSCLC SABR?
early stage peripheral disease
<5cm, no nodes
not within 2cm of named bronchial tree, oesophagus, heart, brachial plexus or spine
Increased toxicity in early studies- bronchial stenosis, pneumonia, deaths
What are typical dose fractionations for SABR?
54Gy/ 3# (standard fractionation) if PTV does not abut chest wall or mediastinal structures
55-60Gy/ 5# (conservative) if PTV touches or extends to ribs/ pleura
60Gy/ 8# (very conservative) for tumours where the dose constraints for an OAR cannot be met at 3 or 5 fraction constraints
What is the overall view on SABR vs normal fractionation?
well tolerated
more convenient
good Local control and overall survival compared to surgical series
(becoming standard of care for early NSCLC)
Chemotherapy NSCLC?
- Adjuvant after surgery: improves survival 5% (increased benefit with increasing stage)
e. g. cisplat vinerelbine, carboplatin/ paclitaxel - Concurrent with RT for locally advanced
- Neoadjuvant for borderline resectable
Chemotherapy NSCLC for metastatic disease?
survival benefit for good performance status
similar cytotoxic chemotherapy
dependent on adenocarcinoma vs SCC
Targeted therapies (personalised genotype directed to marked improvements in survival/ long term disease control)
Is Small Cell lung cancer or NSCLC more aggressive?
small cell lung cancer most aggressive form of lung cancer
(rapid growth & early systemic spread
What is the mainstay therapy treatment for small cell lung cancer?
chemotherapy
What are the two different staging of small cell lung cancer?
Limited stage SCLC
Extensive stage SCLC
What is Limited Stage SCLC?
- disease which can be encompassed within a reasonable RT portal
- cancer is in the lung where it started and may have spread to the area between the lungs or supraclavicular LNs
- median survival
What is Extensive Stage SCLC?
cancer has spread beyond the lung or the area between the lungs or the supraclavicular LNs
-median survival
What is the treatment for limited stage SCLC?
chemotherapy is the mainstay of treatment (4x cisplatin/ etoposide)
+ thoracic RT increases local control and small statistically significant improvement in survival
What needs to be considered when using RT with Chemo for limited stage SCLC?
optimal timing of RT in relation to chemo
RT dose and fractionation
optimal treatment volume
What is the optimal timing of RT for limited stage SCLC?
evidence: earlier RT given better survival (but practically not ready to give RT straight away therefore usually start RT with 2nd cycle of chemo
unless very large tumour volume therefore may need to wait for shrinkage if V20 is initially unacceptable
What fractionation is used for limited stage SCLC?
prolonging treatment time can lead to accelerated repopulation of tumour cells (once exposed to IR, begin proliferating at a faster rate)
Therefore want to reduce treatment time to improve outcome (using hyperfractionated RT)
(e.g. instead of 45Gy/25#, giving 45Gy/ 30# 2x daily in 3 weeks)
What is a result of hyperfractionated treatment?
oesophageal toxicity (comparing once daily to twice daily) e.g. toxicity is less for Grade 0 but increased toxicity for Grade 3 no difference Grade 4
What is prophylactic Cranial Irradiation?
Prophylactically (as precaution) give whole brain irradiation because of the high incidence of cerebral metastases in SCLC
Brain mets significantly shorten survival and cause morbidity
(once cerebral mets have been discovered often treatment is unsuccessful because the brain is a sanctuary site (BBB toxins can’t cross))
What techniques are used for Metastatic lung cacer?
- Palliative RT for primary or symptomatic metastatic treatment (e.g. bone, brain)
- Palliative surgery (for bone-prophylactic pinning, brain-excising solitary metastases)
- Palliative chemo (conventional cytotoxic chemotherapy, targeted therapy)
What is a risk of lung cancer in regards to the superior vena cava?
Superior vena cava obstruction due to invasion or external compression by tumour
What are the symptoms of SVCO?
dyspnoea 'fullness in the head'/ headache facial/ upper limb swelling hoarseness of voice cough blockage leads to collateral veins forming
Screening for lung cancer?
CT able to identify disease that is asymptomatic, at a curable stage
good for high risk (e.g. smokers)
however a number of false +ves
