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Lung‐RADS® Version 1.1

Assessment Categories Release date: 2019

Category Lung- Risk of Est.
RADS Findings Management Population
Descriptor Malignancy
Score Prevalence
Prior chest CT examination(s) being located Additional lung cancer
Incomplete 0 for comparison screening CT images and/or n/a 1%
Part or all of lungs cannot be evaluated comparison to prior chest CT
examinations is needed
Negative No lung nodules
No nodules and 1 Nodule(s) with specific calcifications:
complete, central, popcorn, concentric
definitely benign
rings and fat containing nodules
nodules
Perifissural nodule(s) (See Footnote 11)
< 10 mm (524 mm3)
Solid nodule(s):
Benign Appearance or < 6 mm (< 113 mm3) Continue annual
Behavior new < 4 mm (< 34 mm3) screening with LDCT in < 1% 90%
Nodules with a very low Part solid nodule(s): 12 months
2 < 6 mm total diameter (< 113 mm3) on
likelihood of becoming a baseline screening
clinically active cancer Non solid nodule(s) (GGN):
due to size or lack of
3
growth <30 mm (<14137 mm ) OR
3
≥ 30 mm (≥ 14137 mm ) and unchanged
or slowly growing
Category 3 or 4 nodules unchanged for ≥ 3
months
Solid nodule(s):
Probably Benign ≥ 6 to < 8 mm (≥ 113 to < 268 mm3) at
baseline OR
Probably benign new 4 mm to < 6 mm (34 to < 113 mm3)
finding(s) ‐ short term Part solid nodule(s)
follow up suggested; 3 ≥ 6 mm total diameter (≥ 113 mm3) with 6 month LDCT 1‐2% 5%
includes nodules with a solid component < 6 mm (< 113 mm3) OR
low likelihood of new < 6 mm total diameter (< 113 mm3)
becoming a clinically Non solid nodule(s)
active cancer (GGN) ≥ 30 mm (≥ 14137 mm3) on
baseline CT or new
Solid nodule(s):
≥ 8 to < 15 mm (≥ 268 to < 1767 mm3) at
baseline OR
Suspicious growing < 8 mm (< 268 mm3) OR
new 6 to < 8 mm (113 to < 268 mm3)
3 month LDCT; PET/CT may be
4A Part solid nodule(s):
Findings for which used when there is a ≥ 8 mm (≥ 5‐15% 2%
≥ 6 mm (≥ 113 mm3) with solid
additional diagnostic 268 mm3) solid component
component ≥ 6 mm to < 8 mm (≥ 113 to
testing is recommended
< 268 mm3) OR
with a new or growing < 4 mm (< 34 mm3)
solid component
Endobronchial nodule
Solid nodule(s) Chest CT with or without
≥ 15 mm (≥ 1767 mm3) OR contrast, PET/CT and/or tissue
new or growing, and ≥ 8 mm (≥ 268 mm3) sampling depending on the
Very Suspicious *probability of malignancy and
4B Part solid nodule(s) with:
comorbidities. PET/CT may be
a solid component ≥ 8 mm (≥ 268 mm3)
Findings for which used when there is a ≥ 8 mm
OR
additional diagnostic (≥ 268 mm3) solid component. > 15% 2%
testing and/or tissue a new or growing ≥ 4 mm (≥ 34 mm3) For new large nodules that
solid component
sampling is develop on an annual repeat
recommended Category 3 or 4 nodules with additional screening CT, a 1 month LDCT
4X may be recommended to
features or imaging findings that
address potentially infectious
increases the suspicion of malignancy
or inflammatory conditions
Other
Clinically Significant or Modifier ‐ may add on to category 0‐4 As appropriate to the specific
Potentially Clinically S n/a 10%
coding finding
Significant Findings
(non lung cancer)

IMPORTANT NOTES FOR USE:

  1. Negative screen: does not mean that an individual does not have lung cancer
  2. Size: To calculate nodule mean diameter, measure both the long and short axis to one decimal point, and report mean nodule diameter to one decimal point
  3. Size Thresholds: apply to nodules at first detection, and that grow and reach a higher size category
  4. Growth: an increase in size of > 1.5 mm (> 2 mm3)
  5. Exam Category: each exam should be coded 0‐4 based on the nodule(s) with the highest degree of suspicion
  6. Exam Modifiers: S modifier may be added to the 0‐4 category
  7. Lung Cancer Diagnosis: Once a patient is diagnosed with lung cancer, further management (including additional imaging such as PET/CT) may be performed for purposes of lung cancer staging; this is no longer screening
  8. Practice audit definitions: a negative screen is defined as categories 1 and 2; a positive screen is defined as categories 3 and 4
  9. Category 4B Management: this is predicated on the probability of malignancy based on patient evaluation, patient preference and risk of malignancy; radiologists are encouraged to use the McWilliams et al assessment tool when making recommendations
  10. Category 4X: nodules with additional imaging findings that increase the suspicion of lung cancer, such as spiculation, GGN that doubles in size in 1 year, enlarged lymph nodes etc
  11. Solid nodules with smooth margins, an oval, lentiform or triangular shape, and maximum diameter less than 10 mm or 524 mm3 (perifissural nodules) should be classified as category 2
  12. Category 3 and 4A nodules that are unchanged on interval CT should be coded as category 2, and individuals returned to screening in 12 months
  13. LDCT: low dose chest CT

*Additional resources available at – https://www.acr.org/Clinical-Resources/Reporting-and-Data-Systems/Lung-Rads *Link to Lung-RADS calculator – https://brocku.ca/lung-cancer-screening-and-risk-prediction/risk-calculators/

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