Radiology of Lung Cancer and Staging Flashcards
Describe the causes of a localised opacity (coin lesion) on the chest xray.
- Pneumonia.
- Pulmonary embolism: infarction or intrapulmonary hemorrhage.
- Neoplasm: alveolar cell carcinoma, lymphoma (usually diffuse)
- Atelectasis: opacity accompanied by signs of volume loss.
Mediastinum
- Hilar vascular structures should be crisply defined.
- There should be no widening of the mediastinum.
- Trachea should be central
- Left hilum is typically higher than the right hilum. If the hilum is lower than normal, it may indicate a lobar collapse
Left hilum is typically higher than the right hilum. If the hilum is lower than normal
it may indicate a lobar collapse
Investigation-imaging
- Compare upper, mid and lower zones.
- Look between ribs for lung detail.
- Remember to look behind the heart and hila for lesions.
- Behind the diaphragm
- Lung apices
- Always compare with previous imaging.
diagrams of carcinoma, lobar collapse, opacity
look at notes
Investigation of lung cancer
- Clinical history
- Always compare with previous imaging.
- Confirm lesion is intrapulmonary.
- Next step is CT:
what does ct scan evaluate?
o Evaluate size, shape, atelectasis, border, density, solid or non solid, dynamic contrast enhancement >25 HU, growth.
What is a pulmonary nodule/mass?
A pulmonary mass is an opacity in lung >3cm with no mediastinal adenopathy(disease of the lymph nodes) or atelectasis (collapse of lung tissue with loss of volume).
A pulmonary nodule is an opacity in lung up to 3cm with no mediastinal adenopathy or atelectasis.
how to determine the stage of lung cancer?
- Clinical history/examination
- Perfomance status
- Pulmonary function
- TNM- Tumour, Node, Metastases
TNM staging:
- Size and position of the tumour (T)
- Whether cancer cells have spread into the lymph nodes (N)
- Whether the tumour has spread anywhere else in the body i.e. metastases (M)
- Bronchoscopy directly scans ?
lymph nodes.
how to scan TNM?
- T can be scanned using CT, PET-CT, bronchoscopy.
- N can be scanned using PET-CT, mediastinoscopy, CT, EBUS/EUS
- M can be scanned using PET-CT, CT, bone scan
What is FDG PET scan?
- Functional imaging
- Nuclear medicine technique
- Glucose metabolism- using a labelled glucose analogue 18F – FDG
- Expensive
What is a PET-CT scan?
- Really important in T staging
- Assessing chest wall or mediastinal invasion that may be missed in CT scan- more sensitive
- Metabolc test
- 18FDG lung staging : half body time 60 mins
- post injection 370MBq
- Non invasive
What are limitations of PET CT scans?
- False negative and false positive results
- Cost
