investigations

Last edited 04/2019 and last reviewed 09/2021

Chest radiography - posteroanterior and lateral films.

Diagnostic and staging investigations

• sputum cytology - only used for investigation in people with suspected lung cancer who have centrally placed nodules or masses and who decline or cannot tolerate bronchoscopy or other invasive test
  
  
• if suspected or known lung cancer then
  • CT > contrast-enhanced chest CT (include the liver, adrenals and lower neck in the scan)
    • when assessing mediastinal and chest wall invasion:
      • CT alone may not be reliable
        • consider other techniques such as ultrasound if there is doubt be aware that surgical assessment may be necessary if there are no contraindications to resection
    • if with lung cancer where could potentially have treatment with curative intent then requires a positron-emission tomography CT (PET-CT) before treatment
    • perform contrast-enhanced CT of the chest, liver adrenals and lower neck before any biopsy procedure
  • MRI - to assess the extent of disease, for people with superior sulcus tumours
    
    
• endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) for biopsy of paratracheal and peri-bronchial intra-parenchymal lung lesions

Peripheral primary tumour

• image-guided biopsy for people with peripheral lung lesions when treatment can be planned on the basis of this test
• biopsy any enlarged intrathoracic nodes (10 mm or larger maximum short axis on CT) or other lesions in preference to the primary lesion if determination of nodal stage affects treatment

Central primary tumour

• flexible bronchoscopy - for people with central lesions on CT if nodal staging does not influence treatment

Intrathoracic lymph node assessment

• PET-CT - the preferred first test after CT with a low probability of nodal malignancy (lymph nodes below 10 mm maximum short axis on CT), for people with lung cancer who could potentially have treatment with curative intent
  
  
• PET-CT should be offered (if not already done), followed by EBUS-TBNA and/or EUS-FNA (endoscopic ultrasoundguided fine-needle aspiration), to people with suspected lung cancer who have enlarged intrathoracic lymph nodes (lymph nodes greater than or equal to 10 mm short axis on CT) and who could potentially have treatment with curative intent
  
  
• surgical mediastinal staging should be considered for people with a negative EBUS-TBNA or EUS-FNA if clinical suspicion of nodal malignancy is high and nodal status would affect their treatment plan
  
  

Further Staging:

• presence of isolated distant metastases/synchronous tumours should be confirmed by biopsy or further imaging (for example, MRI or PET-CT) in people being considered for treatment with curative intent
  
  
• dedicated brain imaging should not be offered to people with clinical stage I NSCLC who have no neurological symptoms and are having treatment with curative intent
  
  
• contrast-enhanced brain CT
  • if clinical stage II NSCLC where planned treatment with curative intent. If CT shows suspected brain metastases, offer contrast-enhanced brain MRI
    
    
• contrast-enhanced brain MRI for people with stage III NSCLC who are having treatment with curative intent
  
  
• if clinical features suggestive of intracranial pathology CT of the head followed by MRI if normal, or MRI as an initial test
  
  
• X-ray as the first test if localised signs or symptoms of bone metastasis. If the results are negative or inconclusive, offer bone scintigraphy or an MRI scan

Blood tests - FBC, U+Es, LFTs, Ca2+:

• may help to indicate disseminated disease
• small cell tumours may secrete substances such as ADH producing hyponatraemia, or ACTH producing Cushing's syndrome
• squamous cell carcinomas may secrete PTH-like substances producing hypercalcaemia

Reference:

• NICE (March 2019). Lung cancer: diagnosis and management