From the Guidelines
The changing appearance of the nodule on computed tomography (CT) scans over a 3-year period is concerning and warrants immediate follow-up with a specialist for further evaluation, possibly including additional imaging or biopsy, as it may indicate active pathology requiring intervention. The nodule's appearance and visibility have changed significantly over the three-year period, with an initial foggy appearance, followed by a period of near invisibility, and finally becoming more visible and defined. This pattern suggests potential growth or changes in the nodule's composition between years 2 and 3, which is concerning. According to the Fleischner Society guidelines 1, solitary solid noncalcified nodules larger than 8 mm in diameter require a 3-month follow-up, work-up with combined positron emission tomography (PET) and CT (PET/CT), tissue sampling, or a combination thereof. The guidelines also recommend that the dominant nodule should be used as a guide to management, and additional nodules should also be monitored on follow-up images. The NCCN guidelines 1 also recommend a short-term follow-up LDCT scan in 3 months to assess for malignancy for solid or part-solid nodules measuring 6 mm or larger.
- Key factors to consider in the management of incidental pulmonary nodules include:
- Nodule size and composition
- Patient risk factors and preferences
- Imaging parameters and quality
- Follow-up interval and modality
- The Fleischner Society guidelines provide a framework for the management of incidental pulmonary nodules, including recommendations for follow-up intervals and modalities based on nodule size and composition.
- The NCCN guidelines also provide recommendations for the management of lung nodules detected on low-dose computed tomography (LDCT) scans, including the use of the Lung Imaging Reporting and Data System (Lung-RADS) to standardize reporting and management.
- Immediate follow-up with a specialist is recommended to determine the best course of action for the patient, taking into account the changing appearance of the nodule and the patient's individual risk factors and preferences.
From the Research
Significance of Changing Appearance of Nodules on CT Scans
- The changing appearance of nodules on computed tomography (CT) scans over a 3-year period can be significant in determining the clinical outcome of patients with pulmonary nodules 2.
- A study found that CT examinations performed after 3 months often showed some changes, mainly with respect to nodules disappearing, and that a 3-year CT follow-up is justified due to the slow growth rate of these lesions 2.
- The comparison between the first and the last positive CT scan showed that ground glass nodules (GGNs) and/or mixed pulmonary nodules (MPNs) remained unchanged for a median period of 18 months, disappeared after a median of 3.5 months, or increased in diameter after a median period of 17 months 2.
- In particular, two patients with increasing diameter of the nodules had malignant lesions, highlighting the importance of long-term follow-up 2.
Comparison with Other Imaging Modalities
- Other imaging modalities such as positron emission tomography (PET)/CT, magnetic resonance imaging (MRI), and ultrasound have been used to evaluate pulmonary nodules and thyroid lesions 3, 4, 5, 6.
- However, the provided evidence does not directly compare the significance of changing appearance of nodules on CT scans with other imaging modalities in the context of a 3-year follow-up period.
- The evidence suggests that CT scans remain a crucial imaging modality for the diagnosis and staging of pulmonary nodules and other lesions, with advancements in technology improving detection and diagnosis rates 5, 6.