Over the weekend, the long-awaited update of Lung-RADS was published with changes that aim to reduce lung cancer screening false positives by downgrading many category 3 findings to category 2.
Lung-RADS (lung imaging reporting and data system) is a quality assurance tool to aid with findings in low-dose CT screenings for lung cancer. First introduced in 2014 by the American College of Radiology, Lung-RADS aims to standardize recommendations, reduce confusion in screening interpretations, and facilitate outcome monitoring.
Here are the key revisions in Version 1.1:
- Lung-RADS 2, Non Solid nodule(s) (GGN): These are now classified as < 30 mm OR ≥ 30 mm and unchanged or slowly glowing [was previously <20 mm].
- Lung-RADS 3, Non Solid nodule(s) (GGN): ≥ 30 mm on baseline CT or new [was previously ≥20 mm].
- *Lung-RADS 4A: Category Descriptor is now “Suspicious” for which “additional diagnostic testing is recommended”. While Version 1.0 diagnostic testing recommendations included tissue sampling as a consideration for 4A, 4B, and 4X nodules, Version 1.1 removes tissue sampling as a 4A recommendation.
- *Lung-RADS 4B, 4X: Category descriptor is now “Very Suspicious – Findings for which additional diagnostic testing and/or tissue sampling is recommended.” Management includes an additional notation that “For new large nodules that develop on an annual repeat screening CT, a 1 month LDCT may be recommended to address potentially infectious or inflammatory conditions.”
- Volumetric measurements are included.
- Exam modifier “C” noting prior lung cancer in version 1.0 has been eliminated in version 1.1.
- Footnote 2 “Size” now specifies: “To calculate nodule mean diameter, measure bot the long and short axis to one decimal point, and report mean nodule diameter to one decimal point.” [Previously recommended rounding to nearest whole number.]
- Note 11 is new: “Solid nodules with smooth margins, an oval, lentiform or triangular shape, and maximum diameter less than 10 mm (perifissural nodules) should be classified as category 2.”
*Please note the revised language for Lung-RADS 4A and 4B/4X category descriptors, as we are tracking ACR’s on-going revisions between the May and June 2019 1.1 version. For the current version, please click the ACR Lung-RADS 1.1 link above.