Pulmonary metastasis from renal cell carcinoma: characterization using contrast-enhanced CT attenuation value measurements.
OBJECTIVE
To retrospectively assess the usefulness of contrast-enhanced computed tomographic (CT) attenuation measurements for differentiating renal cell carcinoma pulmonary metastasis from primary lung cancer.


METHODS
The authors retrospectively evaluated 39 pulmonary nodules in 36 patients with pulmonary metastasis from renal cell carcinoma (RCC; 29 men and 7 women; mean age +/- SD, 56.9 +/-10.0 years; range, 38-76 years) and 30 pulmonary nodules in 42 patients with primary lung cancer (33 men and 9 women; mean age +/- SD, 62.9 +/- 9.8 years; range, 38-81 years). Contrast-enhanced scans were obtained 35 seconds after injecting contrast medium intravenously. Pulmonary nodules were retrospectively analyzed by determining nodule attenuation values in contrast-enhanced CT scans. The Mann-Whitney U test was used to compare pulmonary nodule mean attenuation values in these 2 patient groups.


RESULTS
The mean attenuation value of metastatic pulmonary nodules from RCC (mean +/- SD, 73.6 +/- 40.6 Hounsfield units) was greater than that of primary lung cancer nodules (mean +/- SD, 47.8 +/-17.9 Hounsfield units) (P < 0.001).


CONCLUSIONS
Pulmonary nodule attenuation measurements obtained by contrast-enhanced CT are useful for differentiating pulmonary metastasis from RCC and primary lung cancer.
Jung
Dae Chul
DC
Research Institute and Hospital, National Cancer Center, Goyang, Gyeonggi, Korea.
Choi
Hyuck Jae
HJ
Kim
Hyae Young
HY
Lee
Kang Hyun
KH
D000328:Adult; D000368:Aged; D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging* / Q000556:secondary*; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007472:Iohexol / Q000031:analogs & derivatives*; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging*; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging / Q000556:secondary; D014057:Tomography, X-Ray Computed / Q000379:methods*
D003287:Contrast Media; D007472:Iohexol; C038192:iopromide