In the newly released Lung-RADS 2022 classification system for computed tomography (CT) lung cancer screening, the American College of Radiology (ACR) has noted a variety of updates including new classification criteria for atypical pulmonary cysts and airway nodules, time intervals for nodule growth and a new stepped management approach for Lung-RADS categories 3 and 4A.
The American College of Radiology (ACR) has unveiled Lung-RADS 2022 with a number of key updates and changes in classification criteria and management considerations for lung nodules diagnosed via computed tomography (CT) screening.
Here are seven takeaways from the updated classification system.
1. In regard to atypical pulmonary cysts, the ACR said Lung-RADS category 4B is applicable for growing multilocular cysts, multilocular cysts with increased density or loculation, and growing thick-walled cysts.
2. One may apply the Lung-RADS v1.1 perifissural nodule composition and size criteria to all juxtapleural nodules. For solid juxtapleural nodules that have smooth margins, triangular, ovoid or tentiform in shape, and have a mean diameter less than or equal to 10 mm, radiologists would note these nodules as Lung-RADS category 2, according to the ACR.
3. For airway nodules, the Lung-RADS 2022 classification notes that solid endobronchial or endotracheal nodules that are segmental or more proximal would fall under Lung-RADS category 4A. When a three-month low-dose CT (LDCT) exam reveals persistent 4A endobronchial or endotracheal nodules, the ACR said these nodules should be reclassified as Lung-RADS category 4B. In these cases, the Lung-RADS 2022 classification recommends appropriate diagnostic workup and clinical evaluation for a possible bronchoscopy.
4. For partly solid or solid nodules that increase in size over multiple screening exams but not to the extent of surpassing a 1.5 mm increase during a 12-month period, the ACR said these lesions are suspicious and warrant Lung-RADS 4B classification with diagnostic evaluation recommended.
5. For ground-glass nodules that demonstrate growth over multiple screening exams during a one-year period without exceeding a 1.5 mm size change, the Lung-RADS 2022 document recommends Lung-RADS category 2 classification until subsequent findings, such as a solid nodule component, suggest otherwise.
6. When a six-month follow-up LDCT exam shows stable or decreased size of Lung-RADS 3 nodules, the Lung-RADS 2022 document recommends reclassifying the nodules as Lung-RADS category 2 with a subsequent LDCT exam to be performed one year from the date of the current exam.
7. When a three-month follow-up LDCT exam shows stable or decreased size of Lung-RADS 4A nodules, the Lung-RADS 2022 document recommends reclassifying the nodules as Lung-RADS category 3 with a subsequent LDCT exam to be performed six months from the date of the current exam.
For additional information on Lung-RADS 2022, see https://www.acr.org/-/media/ACR/Files/RADS/Lung-RADS/Lung-RADS-2022.pdf