Investigations
1st investigations to order
chest x-ray
Test
Standard posteroanterior and lateral CXR is an inexpensive and simple initial study to evaluate cough, chest pain, and/or haemoptysis.
Result
central or peripheral mass, hilar lymphadenopathy, superior mediastinal lymphadenopathy, pleural effusion
CT chest, liver, and adrenal glands
Test
A new abnormality on chest x-ray should be further assessed with CT. A chest CT should also be obtained in patients, especially smokers, with concerning symptoms and a normal chest x-ray. Intravenous contrast is helpful to distinguish lymph nodes from vessels, especially in the hilum.
Limited disease: involvement restricted to ipsilateral hemithorax within a single radiation port. Extensive disease: presence of contralateral pulmonary or other distant metastasis.[5][32]
After treatment, chest CT (or chest x-ray) can be obtained to evaluate response to treatment and monitor for disease recurrence.
Result
massive lymphadenopathy and direct mediastinal invasion are common features of SCLC; determines extent of disease
Investigations to consider
bronchoscopy
Test
Bronchoscopy is performed when CT abnormalities (i.e., a mass or adenopathy) are accessible to the bronchoscope. It is also used to assess new and/or unexplained pulmonary symptoms (i.e., haemoptysis, wheezing, cough). Flexible bronchoscopy requires conscious sedation. During the procedure, the tracheobronchial tree is carefully examined. Endobronchial tumours can be biopsied. Washings, brushings, and bronchoalveolar lavage are performed. Suspicious parenchymal lesions and mediastinal lymph nodes that are accessible can also be biopsied.[31]
Endobronchial masses can be biopsied with forceps. Endobronchial brushings, washings, and alveolar lavage increase the diagnostic yield. Trans-bronchial needle aspiration of accessible parenchymal lesions and mediastinal lymph nodes is possible.
Overall, the sensitivity for centrally located lesions is high (about 90%).[31] The sensitivity for peripheral lesions is lower and depends on number of biopsies taken, size of mass, and proximity to the bronchial tree. In general, endobronchial biopsy is more sensitive than brushings or washings.
Detection of small peripheral lesions (<2 cm) is improved by use of endobronchial ultrasound.[37]
Bronchoscopy can be repeated after definitive treatment to assess for recurrent disease.
Result
endobronchial lesions
biopsy
Test
Pathological confirmation of malignancy is the only widely accepted method to diagnose lung cancer. Tissue may be sampled with bronchoscopy if lesions are central, but specimen adequacy for diagnosis is variable. Transbronchial biopsy or endobronchial biopsy, brushings, and lavage are all used to obtain specimens during bronchoscopy. CT-guided needle biopsy, where feasible, allows for core biopsies to obtain sufficient material. If there are suspected metastatic lesions, those are preferred sites for diagnostic biopsy if feasible to confirm metastatic disease. Method of biopsy for metastatic sites depends on the anatomical location and least invasive approach.[32]
Result
malignant cells, high nuclear to cytoplasmic ratio, nuclear fragmentation often present
thoracentesis
Test
Thoracentesis involves placing a needle between the ribs and into the chest to sample fluid that has accumulated in the pleural space. Ultrasound is helpful in directing thoracentesis of small pleural effusions.[5]
Video demonstrating how to perform a pleural aspiration
Result
malignant cells within the pleural fluid
thoracoscopy
Test
May be considered in patients with SCLC and pleural effusion, if thoracentesis is inconclusive, to determine stage.[5]
Result
pleural involvement
MRI or CT of brain
bone scan
Test
May be used to identify metastases if PET/CT is not available.[5]
Result
skeletal metastases
mediastinoscopy
Test
Indicated to determine nodal status in patients with a solitary pulmonary mass without radiographic evidence of lymphadenopathy, as these patients may be candidates for surgery. Can also be used for initial diagnosis.[5]
Result
node involvement
positron emission tomography (PET)
Test
PET is complementary to CT, facilitating accurate assessment of the extent of local, regional, and distant disease.[5][32]
Fluorodeoxyglucose (FDG)-PET/CT scan is superior to PET alone.[5]
PET-CT can also be performed prior to tissue sampling in order to identify possible metastatic lesion(s) that can be biopsied, determining stage and confirming pathological diagnosis in the same procedure.
Result
further evaluates location and extent of primary tumour; evaluates for distant metastases
bone marrow aspirate and biopsy
FBC
Test
Baseline blood counts are necessary before treatment is initiated or invasive procedures are performed.[5][32]
Chemotherapy, and to a lesser degree radiotherapy, can decrease haematopoiesis, necessitating baseline and periodic analysis of blood counts.
Result
usually normal; however, may show anaemia
LFTs
serum sodium
renal function
Use of this content is subject to our disclaimer