From the Guidelines
A CT chest scan should be performed in addition to contrast-enhanced imaging for head and neck cancer diagnosis, particularly in patients with advanced disease or high-risk factors such as heavy smoking history. This recommendation is based on the most recent evidence from the Journal of the American College of Radiology 1. The chest CT helps detect distant metastases or second primary tumors in the lungs, which occur in approximately 10-20% of head and neck cancer patients.
Key Points to Consider
- The use of CT chest with IV contrast can accurately identify pulmonary metastasis and detect thoracic nodal and skeletal metastases to the ribs or vertebrae 1.
- Patients with recurrent head and neck squamous cell carcinoma are significantly more likely to have pulmonary metastatic disease 1.
- Development of lung metastases is also increased in advanced stage disease 1.
- CT chest confers superior spatial localization and contrast resolution compared to radiography, allowing for the improved detection of small pulmonary nodules 1.
Optimal Imaging Approach
For optimal imaging, a contrast-enhanced CT of the chest should be performed using thin slices (1-3 mm) and should extend from the lung apices to the upper abdomen including the liver. This comprehensive imaging approach allows for complete staging of the disease, which is crucial for determining appropriate treatment strategies. The rationale behind this recommendation is that head and neck cancers, especially those associated with smoking and alcohol use, have a propensity to metastasize to the lungs or develop synchronous lung primaries. Early detection of these lesions significantly impacts treatment planning, potentially changing the approach from curative to palliative intent, or necessitating additional treatments for synchronous tumors.
High-Risk Factors
A heavy smoking history may also be a separate indication for CT chest imaging at surveillance because tobacco use is a risk factor not only for non-HPV-related squamous cell carcinoma of the head and neck but also for primary lung cancer 1. This patient population may also qualify for annual chest CT imaging as per the U.S. Preventative Services Task Force guidelines for annual lung cancer screening with low-dose CT in well-defined groups of high-risk smokers 1.
From the Research
CT Chest Scan for Head and Neck Cancer Diagnosis
- The decision to perform a CT chest scan in addition to contrast-enhanced imaging for head and neck cancer diagnosis depends on various factors, including the patient's risk profile and the stage of the disease 2.
- A study published in 2008 found that chest CT scans were abnormal in 29.3% of patients with head and neck squamous cell carcinoma (HNSCC), with a higher rate of abnormal scans in the follow-up case group (44.2%) compared to the new case group (14.2%) 2.
- The predictive factors for development of a malignant neoplasm of the lung in patients with HNSCC include initial N2 or N3 disease, stage IV disease, recurrent disease, and distant metastasis to another site 2.
- Another study published in 2017 suggested that routine extension of PET/CT scans to include the head and abdomen in patients with HNSCC is not indicated, and that for patients without evidence of thoracic metastases, routine PET/CT examinations should include the neck and chest only 3.
- The use of FDG PET/CT for imaging of squamous cell carcinoma of the head and neck has been found to be valuable for identifying unknown primary tumors, assessing therapy response, and detecting recurrences and metastases during follow-up 4, 5, 6.
Key Findings
- Chest CT scans are recommended for high-risk patients with HNSCC, especially during the follow-up period 2.
- FDG PET/CT is a valuable imaging tool for the management of patients with head and neck squamous cell cancer, but its use should be tailored to the individual patient's needs and risk profile 4, 5, 6.
- Routine inclusion of the head and abdomen in PET/CT scans for patients with HNSCC is not necessary, unless there is evidence of thoracic metastases 3.