A 45 year old male non-smoker with no family history of lung cancer has an incidental 7x5mm nodule detected in the right lower lobe during CT of the abdomen and pelvis for left renal colic.
What is the most appropriate course of action?
Chest radiograph in 6 weeks | |
Follow up CT at 12 months | |
Follow up CT at 3 months and then 1 year. | |
Initial follow up CT at 6 months | |
No further investigation |
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 7mm. Therefore guidance states w should repeat CT at 3 months and calculate a VDT. Under old guidance (Fleischner society guidelines) the average size of this nodule would be calculated (6mm in this case), which for a low risk patient would mean a 12 month follow up CT.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...