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.
Munden
Reginald F
RF
Division of Diagnostic Imaging, Department of Diagnostic Radiology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA. rmunden@mdanderson.org
Erasmus
Jeremy J
JJ
Wahba
Hisham
H
Fineberg
Naomi S
NS
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*