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Is 4mm to 8mm in a year not a significant change?

My dad, 67, lifelong smoker, quit over a year ago, got his lung scan back today. His previous one was last year. Looks like within a year he went from RADS 2 to RADS 3. 

Questionable solid nodule went from 4mm to 8mm in a year. Which they describe as “not significantly changed”. ….

How worried should we be here? Is 4mm to 8mm in a year not a significant change?

A follow up is recommended for 6 months to confirm stability.

But if it grew from 4 to 8mm in a year. Wouldn’t that mean it's unstable?

Or if it was cancerous, would it be growing at a much faster rate?

Why not biopsy now to see if its cancer and get it before it gets larger?

It looks like he's on the bring on becoming RADS 4a. If it was 9mm it would be 4a?

I'm assuming we're doing the right thing here by getting my dad lung scans so we can do whatever treatment early, before it spreads.

Can these nodules theoretically grow quick in 6 months and put him at like a stage 2 of lung cancer?

Or no?


I think you are on to something and encourage you to advocate for your dad! I looked up the recommendations for Lung-RADS assessment on Up to Date ( and see that by definition, 8mm (if solid) or growing would be classified as 4A and have recommended CT follow up in 3 months, not 6. ≥8 mm and growing would be considered 4B and have a recommended PET/CT scan. I would print out that page and bring it to the doctor & pulmonologist to have them walk you through why they think it is RADS3. Hope this helps!

Best Wishes,
Jason Sager, MD