20. Radiology of Lung Cancer +Staging Flashcards
Majority of patients diagnosed with lung cancer will die within what time period?
Within one year
How many patients present with advanced form of lung cancer? (in fractions)
2/3
What structures to look for in a chest x ray?
- name/marker/rotation/penetration
- lines/metal work
- heart
- mediastinum
- lungs (zones: upper, middle, lower)
- bones
- diaphragm
- soft tissues
Where are tumours/cancer most likely found in the chest?
In the mediastinum
What should hilar vascular structures look like?
should be crisply defined
What should the mediastnium look like on a chest x ray?
no widening of mediastinum
What should the trachea look like on a chest x ray?
should be central
What area in a chest x ray is easily missed and should be looked at in detail?
behind the heart (where tumours like to hide)
Where are lesions in the chest often found? (2)
- behind heart
- behind hila
What are the 4 main review areas?
- hila
- lung apices
- behind the heart
- behind the diaphragm
What diagnostic technique is used after a chest x ray?
CT scan
What does CT scan evaluate?
- size and shape
- ateletasis (collapse)
- border
- density
- solid/non-solid
- dynamic contrast enhancement >25 HU
- growth
What is a pulmonary mass defined as?
An opacity in lung OVER 3cm with no mediastinal adenopathy (enlargement of lymph nodes) or atelectasis (collapse)
What is a pulmonary nodule defined as?
An opacity in lung UP TO 3cm with no mediastinal adenopathy (enlargement of lymph nodes) or atelectasis (collapse)
What are possible causes of solitary (single) pulmonary nodules or pulmonary mass?
- lung cancer
- metastasis (previous history; breast, renal, seminoma, sarcoma)
- benign lung neoplasm (e.g. carcinoid, hemartoma)
- infection; bacterial, TB or fungal
- Vascular haematoma, AVM (arteriovenous malformation)
What patients are only put through treatment/ surgery?
Patients who have high chances of cure/ recovery
What system is used for staging of lung cancer?
TNM system (tumour size and position of primary tumour, lymph node spread, metastasis)
What is taken into account for staging of lung cancer? (3)
- clinical history/examination
- performance status
- pulmonary function
What 3 diagnostic methods are used to identify T staging of lung cancer?
- CT
2 PET-CT - bronchoscopy
What 4 diagnostic methods are used to identify N staging of lung cancer?
- PET-CT
- mediastinoscopy
- CT
- EBUS/ EUS (endobronchial ultrasound, endoscopic ultrasound)
What 3 diagnostic methods are used to identify M staging of lung cancer?
- PET-CT
- CT
- bone scan
What does EBUS/EUS involve?
- sampling nodes from the mediastinum (biopsies taken for testing)
- invasive procedure
What does PET tell us about the tumour?
its activity (of the tumour) and activity of the nodes
What does CT tell us specifically about the tumour?
what vascular structures it’s invading
What analogue is used for a FDG PET (functional imaging) scan which is taken up by the tumour?
labelled glucose analogue 18F- FDG ( fludeoxyglucose) which is a nuclear medicine analogue
Why is FDG PET scan less frequently used than other diagnostic machines?
- expensive
- limited availability in the UK
- only started being used for lung cancer staging in 94
What patients are mainly offered FDG PET scans?
- patients who will directly benefit from it and will be considered for curative treatment (chemotherapy and radiotherapy)
What is the half body time in PET scan?
60 mins post injection (370MBq)
What system is used when we can’t assume what size the tumour is?
TX staging (Tx, T0, Tis)
What does Tx stage mean?
primary tumour cannot be assessed/measured
What does T0 stage mean?
no evidence of primary tumour (cannot be found)
What does Tis stage mean?
carcinoma in situ; CIS (group of abnormal cells forming a neoplasm but not always certain cancer, it varies)
General stages of cancer are used using the combination of the TNM system, what are the 5 less detailed-stages? (which combine aspects of TNM)
- stage 0 (abnormal cells, no spread, CIS, not cancer but may become cancer)
- stage 1
- stage 2
- stage 3
- stage 4 (biggest spread)
What information is ESSENTIAL in determining cancer stage? (6)
- size of tumour
- cancer spread to nearby lymph nodes
- cancer spread to distant body sites
- where tumour is located in the body
- cell type
- tumour grade (how likely to the tumour is to spread further+how they look)
What is T1 tumour?
- tumour <3 cm in greatest dimension
- surrounded by parietal/lung and visceral pleura
- without bronchoscopic evidence of involvement of main bronchus
What does T1a, T1b, T1c refer to?
T1a <= 1cm in greatest dimention
T1b<=2cm
T1c<= 3cm
What is T1a highly likely to be? (what type of tumour)
minimally invasive adenocarcinoma
What is T2 tumour?
- tumour between 3-5cm
-involves main bronchus but not carina
-invades visceral pleura - associated with atelectasis (collapse) or obstructive pneumonitis that extends to the hilar region involving part or all the lung
(T2a is between 3-4cm and T2b is between 4-5cm)
What is a T3 tumour?
- Tumour between 5-7cm
- Tumour which directly invades: chest wall (including superior sulcus tumours), phrenic nerve and parietal pericardium
- Or separate tumour nodule in the same lobe as the primary
What is a T4 tumour?
- tumour >7cm
- tumour invades: diaphragm, mediastinum, heart, great vessels, trachea, recurrent laryngeal nerve, oesophagus, vertebral body and carine
- separate tumour nodule (s) in a different ipsilateral lobe
- extensive involvement in brachial plexus and mediastinal structures
What scan is used to recognise nodes which are involved in tumour growth?
PET scan
What do N0 mean?
No regional lymph node metastasis
What does N1 means?
Ipsilateral peribronchial, hilar or intrapulmonary nodes including by direct extension
What does N2 mean?
Ipsilateral mediastinal, subcarinal
What does N3 mean?
Contralateral mediastinal, contralateral hilar, scalene or supraclavicular
What fraction of patients present with metastasis of lung cancer?
1/3
What are the 4 most common metastasis regions in the body of lung cancer?
- cerebral (brain)
- skeletal
- adrenal
- liver
What does M0 mean?
No distant metastasis
What does M1 mean?
distant metastasis
What does M1a mean?
- separate tumour nodular in a contralateral lobe
- tumour with pleural or pericardial nodules or malignant pleural or pericardial effusion
What does M1b mean?
Single distant metastases
What does M1c mean?
Multiple distant metastases
What are main advantages of PET/CT?
- performs WHOLE body staging in a single study excluding cerebral disease
- discloses metastases and pathology not detected by other means (unexpected mets in 10-20%)
- non-invasive
- excluded mets where structural imaging is abnormal
What are main limitations of PET/CT?
- false negative results
- false positive results
- very expensive cost
What is the T1m N0, M0 approximate survival percentage and what happens to it as more T, N and M are increasing?
~67% and decreasing with rising TNM values
What are the main methods for tissue diagnosis? (2)
- bronchoscopy and EBUS
2. percutaneous image guided biopsy( fluoroscopy/CT/US guide)
What are the less common methods of tissue diagnosis`?
- mediastinoscopy to sample mediastinal nodes
- mediastinotomy for anterior mediastinal nodes
- VATS; video assisted thoracoscopic surgery
- explorative thoracotomy
