SUV (standardized uptake value) is a semiquantitative measure of metabolic activity on PET (positron emission tomography). For pulmonary nodules, SUV max of 2.5 has traditionally been used as a rough cutoff to differentiate between benign and malignant nodules, but this is not cut and dry, as there can be overlap as well as confounding factors (e.g., image noise, low image resolution, and variable user-biased region of interest (ROI) selection, as well as patient sugar/glucose levels). Although nodules measuring greater than 1 cm with spiculated margins are suspicious, the interval decrease in size and SUV max measuring less than 2.5 are reassuring, suggesting that this was infectious rather than neoplastic.
Hello and welcome to the forum. This has certainly been a scary time for you and your husband and we are glad you've worked closely with his doctors. Hopefully they can give you the final reassurance that will let you both rest easy after this. Lung nodules are surprisingly common and certain factors trigger more concern than others when evaluating them. Infection is a very common culprit resulting in lung nodules. https://www.medicalnewstoday.com/articles/317531.php That your husband's has reduced in size is most definitely reassuring and as Chin states above, suggestive of infection rather than malignancy. Please do confirm this with your doctor. Please let us know!