New guidelines from the British Thoracic Society on the management of pulmonary nodules suggest a change in terminology and define which nodules do not require follow-up.

Pulmonary nodules are a frequent finding on CT, and their management continues to occupy many hours of debate, noted the guideline authors led by Professor David Baldwin, from Nottingham University Hospitals in the UK.

One-third of the 359 references cited in the guidelines was from 2012 onwards, reflecting the considerable progress in the evidence base, which has resulted in significant changes in the recommendations, they said. 

Published online first in Thorax the guidelines suggest pulmonary nodules are classified using the terms solid and sub-solid nodule (SSN), and further dividing the sub-solid category into part-solid nodule (PSN) and pure ground glass nodules (pGGN).

“The terms non-solid, semisolid and pure ground glass opacity are more ambiguous, and should be avoided,” the authors advised. 

A large body of evidence from screening trials showed that nodules measuring <5 mm in diameter or those with a volume of <80 mm³ do not require further follow-up.

These nodules had a very low chance of being malignant, and according to one large trial, the risk of developing cancer was no greater than in subjects with no nodule detected, the guidelines said.

Surveillance recommendations had also changed, and semiautomated volumetry was now the preferred method of assessment of nodule size and volume doubling time (VDT).

“It is hoped that implementation of the recommendations will lead to a more evidence-based and cost-effective approach to this, often debated, area of respiratory medicine,” the guidelines concluded.

For a copy of the full guidelines and a risk calculator click here.