Follow-up of small (4 mm or less) incidentally detected nodules by computed tomography in oncology patients: a retrospective review.
BACKGROUND
It is often not possible to determine whether small nodules detected on computed tomography (CT) in oncology patients are metastatic. We evaluated a group of oncology patients to determine the outcome of small pulmonary nodules and whether they can be ignored in the therapeutic decision process.


METHODS
Radiology reports of thoracic CTs from a 2-year period were searched for keywords indicating a small pulmonary nodule. All CT images were evaluated by two thoracic radiologists for nodules 4 mm or less. There were 102 cases that met criteria for inclusion.


RESULTS
Forty-seven had follow-up CT of less than 365 days, and 55 had follow-up CT for more than 365 days. For those with less than 365 days, the observed nodule was increased (17, 36%), increased and new nodules (9, 19%); stable (19, 40%); stable but new nodules developed (1); and decreased (1). For those with greater than 365 days follow-up, the observed nodule was increased (3, 5%); stable (51, 93%); and stable but new nodule developed (1). Combined, 28% of patient';s nodules increased (90% were within 365 days; 25% within 203 days; and 14% within 14 days).


CONCLUSIONS
In oncologic patients, 28% of small pulmonary nodules detected at initial CT will increase in size, suggesting metastasis. This increase in size tends to occur early, and follow-up CT in 3 months and 6 months would be appropriate in further evaluation. Small nodules that are stable in size for more than 365 days are unlikely to be pulmonary metastasis.
Division of Diagnostic Imaging, Department of Diagnostic Radiology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA. rmunden@mdanderson.org
Reginald F
RF
Munden
Jeremy J
JJ
Erasmus
Hisham
H
Wahba
Naomi S
NS
Fineberg
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D012189:Retrospective Studies; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging* / Q000473:pathology; D014057:Tomography, X-Ray Computed / Q000379:methods*