From the Guidelines
For a patient who cannot afford a CT scan for evaluation of a pulmonary nodule, a standard two-view chest X-ray (posteroanterior and lateral views) is the best alternative. This approach provides basic visualization of the nodule from two different angles, helping to better localize the lesion and assess its characteristics. While chest X-rays are significantly less sensitive than CT scans for detecting and characterizing pulmonary nodules, they can still provide valuable information for initial or follow-up assessment, as noted in the ACR Appropriateness Criteria for incidentally detected indeterminate pulmonary nodules 1. For optimal results, the X-rays should be high-quality and compared with any previous imaging if available. The radiologist should be informed about the specific concern for a pulmonary nodule to ensure careful evaluation of the relevant area. It's also important to consider the limitations of chest X-rays, including lower sensitivity for small nodules (less than 1 cm), poor characterization of nodule features, and limited ability to detect calcification patterns. If the nodule appears suspicious on X-ray or if there are high-risk clinical features, efforts should be made to eventually obtain a CT scan through patient assistance programs, charity care, or payment plans, as CT remains the gold standard for pulmonary nodule evaluation, recommended by guidelines such as those from the ACCP and supported by studies like the evaluation of pulmonary nodules: clinical practice consensus guidelines for Asia 1. Key considerations for the use of chest X-rays in this context include:
- High-quality imaging to maximize the detection of relevant features
- Comparison with previous imaging to assess stability or change
- Radiologist awareness of the specific concern for a pulmonary nodule
- Limitations of chest X-rays in detecting small nodules and characterizing nodule features
- The need for eventual CT scan evaluation if the nodule is suspicious or if there are high-risk clinical features.
From the Research
Evaluation of Pulmonary Nodules
When a patient cannot afford a CT scan of the chest for the evaluation of a pulmonary nodule, chest X-ray becomes a crucial alternative. The following points highlight the best approach using chest X-ray:
- Nodule Size and Malignancy Risk: The probability of malignancy is less than 1% for all nodules smaller than 6 mm and 1% to 2% for nodules 6 mm to 8 mm 2.
- Chest X-ray Limitations: While chest X-ray can detect larger nodules, it may not be as sensitive as CT scans for smaller nodules or those in certain locations.
- Diagnostic Approach: For patients with a low risk of cancer and a nodule that appears benign on chest X-ray, a watchful waiting approach with repeat chest X-ray in 6 to 12 months may be considered 2.
- Combining Diagnostic Tools: Combining bronchoscopy and positron emission tomography (PET) scanning can be useful in the diagnosis of noncalcified chest radiologic lesions ≤ 3 cm in size 3.
- Cost-Effectiveness: Navigation bronchoscopy (NB) and computed tomography-guided fine-needle aspiration (CT-FNA) are more cost-effective than FDG-PET or video-assisted thoracoscopic surgery (VATS) for diagnosing lung cancer in moderate- to high-risk nodules 4.
Key Considerations
- Patient Risk Factors: The presence of patient comorbidities, such as chronic obstructive pulmonary disease and coronary artery disease, should be considered when evaluating pulmonary nodules 2.
- Imaging Characteristics: The appearance of the nodule on chest X-ray or CT scan can suggest a benign or malignant etiology 5.
- Clinical Judgment: Clinical judgment about the probability of malignancy and patient preferences should guide the management of pulmonary nodules 2.