Incidental Pulmonary Nodules - What Do We Know in 2022

Abstract

Lung cancer (LC) is the leading cause of cancer-related mortality worldwide, and early LC diagnosis can significantly improve outcomes and survival rates in affected patients. Implementation of LC screening programs using low-dose computed tomography CT in high-risk subjects aims to detect LC as early as possible, but so far, adoption of screening programs into routine clinical care has been very slow. In recent years, the use of CT has significantly increased the rate of incidentally detected pulmonary nodules. Although most of those incidental pulmonary nodules (IPNs) are benign, some of them represent early-stage LC. Given the large number of IPNs detected in the range of several millions each year, this represents an additional, maybe even larger, opportunity to drive stage shift in LC diagnosis, next to LC screening programs. Comprehensive evaluation and targeted work-up of IPNs are mandatory to identify the malignant nodules from the crowd, and several guidelines provide radiologists and physicians' guidance on IPN assessment and management. However, IPNs still seem to be inadequately processed due to various reasons including insufficient reporting in the radiological report, missing communication between stakeholders, absence of patient tracking systems, and uncertainty regarding responsibilities for the IPN management. In recent years, several approaches such as lung nodule programs, patient tracking software, artificial intelligence, and communication software were introduced into clinical practice to address those shortcomings. This review evaluates the current situation of IPN management and highlights recent developments in process improvement to achieve first steps toward stage shift in LC diagnosis.

Keywords: Early-stage diagnosis; Incidental pulmonary nodules; Low-dose computed tomography; Lung cancer screening; Lung nodule management; Stage shift.

Fig. 1

Nodule classification by radio-morphology according to Fleischner Society guidelines. Shown are examples of solid, pure ground-glass, and part-solid nodules (blue arrows) detected on CT images in different patients.

Fig. 2

Exemplary patient journey including pitfalls in assessment of IPNs and in their follow-up management [25, 33, 77, 78, 79, 82].