Incidental lung nodules are encountered commonly in normal clinical practice on CT. The risk of developing cancer in very small nodules (<5 mm) is very low. However, clear-cut recommendations are still not in place with high variation in practice amongst reporting radiologists 1. As a result, it is common practice to note these nodules in the report and move on, leaving the ball in the clinician's court to decide whether to follow them up and at what interval.
The Quantitative Imaging Biomarkers Alliance, a group within the Radiological Society of North America, began developing protocols and tools for using CT volumetry of lung nodules as an quantitiative imaging biomarkers of cancer risk 2, but resources available such as their online calculator are still in a prototype phase. Other quantitative imaging biomarkers beyond those related to volumetry, such as biomarkers from texture analysis, are under investigation as well.
- 1. Johnson DB, Powers MA, Wu S et-al. Follow-up recommendations for chest CT scan reports of incidental pulmonary nodules. Chest. 2012;141 (1): 280-1. doi:10.1378/chest.11-2157 - Pubmed citation
- 2. Fernando U. Kay, Orhan K. Oz, Suhny Abbara, Eduardo J. Mortani Barbosa, Jr, Prachi P. Agarwal, Prabhakar Rajiah. Translation of Quantitative Imaging Biomarkers into Clinical Chest CT. (2019) RadioGraphics. 39 (4): 957-976. doi:10.1148/rg.2019180168 - Pubmed