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.”

For more details regarding the ACR Lung-RADS 1.1, please click here.  Questions about lung cancer screening? Reach out to screening@go2foundation.org.

*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.