Based on a study featured in Radiology, the Lung-RADS v2022 classification system has the potential to facilitate the detection of lung malignancies linked to cystic airspaces up to 75% earlier.
Researchers in Italy and Germany analyzed data from three landmark lung cancer screening trials involving 1,258 participants. The findings suggest the updated framework can reduce missed or delayed diagnoses for this specific radiological phenotype.
Low-dose computed tomography (LDCT) screenings miss or delay diagnoses in roughly 22.7% of cases involving lung cancers associated with cystic airspaces. In this radiological-morphologic phenotype, a primary lung cancer arises within, abuts, or forms the wall of a discrete air-filled space.
To address this clinical gap, Lung-RADS v2022 introduced the atypical pulmonary cyst category. Lead author Mario Mascalchi, MD, PhD, and colleagues evaluated whether these criteria would successfully translate to earlier clinical recognition.
The research team reviewed data from the National Lung Screening Trial (2002–2007; NLST), the Italian Lung Cancer Screening Trial (2004–2010; ITALUNG), and the German Lung Cancer Screening Intervention trial (2007–2016; LUSI). Two radiologists jointly identified cystic airspace-associated cancers and applied the Lung-RADS v2022 criteria retrospectively.
Application of the criteria to serial LDCT examinations could have led to potential diagnostic anticipation in 80% of unilocular cysts with associated nodules. The tool also showed potential in 53% of thick-walled unilocular cysts and 88% of multilocular cysts.
The retrospective analysis revealed that 73 lung cancers were associated with cystic airspaces, comprising 6.1% of screening-detected cases and 5.4% of non-screening-detected cases. When comparing cystic airspace cancers to noncystic non-small cell lung cancers, the five-year lung cancer-specific survival rates were 51.4% and 53.2%, respectively.
Participants with lung cancers associated with cystic airspaces had 5-year cancer-specific survival similar to those with noncystic non–small cell lung cancers, and retrospective simulations suggested that management recommendations based on low-dose CT Lung Imaging Reporting and Data System 2022 enabled earlier diagnosis,
the study authors wrote.
The investigators concluded that prospective validation studies incorporating dedicated segmentation tools are necessary to improve the characterization of these complex lesions. Radiologist education remains a critical component of successful implementation.
In an accompanying editorial, Suzanne Byrne, MD, and Mark Hammer, MD, emphasized the broader clinical reach of the criteria. The current study reinforces the need for radiologist education and integration of cyst-specific assessment into nodule management guidelines, not only in the context of lung cancer screening but also in incidental detection,
Byrne and Hammer wrote.
Patients undergoing serial LDCT monitoring for atypical pulmonary cysts or lung nodules can be evaluated using Lung-RADS categories.
- Mascalchi, M., et al. Radiology.
- N Engl J Med.
- Radiology.
