The Winner and still champion: Nodule volume doubling times

There have been enormous advances in the approach to assessing malignancy status of indeterminate pulmonary nodules including risk models, image based biomarkers and numerous types of biologic and molecular markers. All of these have the advantage of guiding further workup once the nodule is identified. The traditional method, especially for smaller nodules relies primarily on assessing whether a nodule changes in size over time and is a feature in virtually every management protocol for both screen detected as well as incidentally detected nodules. Here, the potential downside is that during the waiting period for obtaining a second scan to assess for growth prognosis changes. However, there must be enough of a time delay to overcome potential measurement error. These two features must be balanced for optimal use of this approach. The alternative approaches do not have this inherent delay, however, their usefulness is a balance between the improvement in prognosis by not having any delays versus their potential to produce false positive and false negative results. Currently nodule volumetric approaches, especially for small nodules remains the method of choice for evaluation.