A 51 year old male smoker has an incidental 5x5mm nodule detected in the right upper lobe during a CT pulmonary angiogram performed for pleuritic chest pain. Follow up of this nodule is advised by the reporting radiologist.
What is the most appropriate course of action?
Calculate risk of malignancy using British Thoracic Society Risk Calculator | |
Follow up CT at 12 months, if unchanged volumetrically no further follow up | |
Initial follow up CT at 6 months | |
Initial follow up CT at 3 months | |
Staging CT of the chest and abdomen |
There are new guidelines from the British Thoracic Society for the investigation and management of pulmonary nodules (2015). They have produced a lengthy document, but the first few pages provide a summary of the recommendations, with flow-charts to help guide management. The guidelines overall aim to help reduce imaging follow-up. There is also a focus on using volumetric analysis of nodules, and calculating the risk of a nodule being malignant using a risk calculator (link provided in the references). They want to standardise the diagnostic approach for nodules detected incidentally and those that are found during screening.
Nodules with a maximum diameter of <5mm do not get followed up (instead of 4mm with the old Fleischner Guidelines). Nodules with a maximum diameter between 5 - 6mm get a CT at 1 year. Those between 6 - 8mm get a CT at 3 months. When these follow-up CTs are performed, ideally volumetrics should be calculated, and further follow-up guided by the volume doubling time (VDT). Those with a maximum diameter of >8mm get their risk calculated using the Brock Model Risk calculator (provided on the BTS website). The flow charts then determine follow-up based on the risk of malignancy calculated. If it has a malignant risk of <10%, then a CT in 3 months is advised. If it has a risk >10%, then a PET may be appropriate.
This particular nodule has a maximum diameter of 5mm. Therefore we should repeat CT at 1 year. If the size is stable using volumetry, then the patient can be discharged. If it is measured using only the 2D diameter and shown to be stable, then a further follow-up CT in another 12 months is recommended. This demonstrates the emphasis of the new guidelines on volumetric measurements. Under old guidance (Fleischner society guidelines) the average size of this nodule would be calculated (5mm in this case), which for a high risk patient such as this would mean follow up CTs at 6-12 & 18-24 months.ReferencesBritish Thoracic Society Guidelines
https://www.brit-thoracic.org.uk/document-library/clinical-information/p...
British Thoracic Society Risk Calculator
https://www.brit-thoracic.org.uk/guidelines-and-quality-standards/pulmon...