Fig 1.
Flow diagram showing the patient selection process with inclusion and exclusion criteria.
Fig 2.
Representative examples of the four-point scaling likelihood scores for a (a) very low level of suspicion (including those without pulmonary nodules); (b) low level of suspicion; (c) indeterminate level of suspicion; and (d) definite metastasis.
(a) Score 1. Axial staging chest-CT scan of a 53-year-old female with pathologic stage I breast cancer showing a 4-mm sized polygonal shaped nodule with a thin tag extending to the pleura in the right lower lobe, which probably represents an intrapulmonary lymph node. (b) Score 2. Axial staging chest-CT scan of a 72-year-old female with pathologic stage II breast cancer showing a 3-mm sized solid nodule in the right upper lobe. The likelihood score for presence of metastasis was score 2. (c) Score 3. Axial staging chest-CT scan of a 59-year-old female with pathologic stage I breast cancer showing a 6-mm sized solid nodule in the right lower lobe, which was classified as score 3. (d) Score 4. Axial staging chest-CT scan of a 39-year-old female with pathologic stage II breast cancer showing a 22-mm-sized lobulating nodule in the right lower lobe with ground-glass opacities. This nodule subsequently disappeared on follow-up chest-CT and was finally diagnosed as a benign inflammatory nodule.
Table 1.
Clinical characteristics of study population.
Fig 3.
Patient flow diagram stratified according to pathologic stage and presence of metastatic lung nodule.
Fig 4.
Axial CT images of true lung metastases in a 78-year-old female with pathologic stage III breast cancer.
(a and b) Staging chest CT images show two small nodules (arrow) in the right middle lobe and left lower lobe (indeterminate). (c and d) Follow-up chest CT images show growth of two nodules (arrow), which are thought to be pulmonary metastasis.
Fig 5.
CT and fluorine 18 fluorodeoxygluocose (FDG) positron emission tomography (PET)/CT images of a true lung metastasis of a 71-year-old female with pathologic stage III breast cancer.
(a) Staging chest-CT image shows an enhancing indeterminate nodule (arrow) in left upper lobe lingular segment. In addition, descending thoracic aortic aneurysm was incidentally detected. (b) A follow-up chest-CT image shows an interval growth of nodule (arrow). (c and d) Axial and coronal FDG PET/CT scans show FDG uptake in a growing nodule in the left upper lobe lingular segment (SUVmax, 7.7) and multiple axial bony thorax (SUVmax, 12.1). The bony lesion of the left ilium (not shown) was pathologically confirmed as metastasis after CT-guided biopsy. The nodule in the left upper lobe lingular segment was subsequently regarded as pulmonary metastasis.
Table 2.
Comparison of patients with pulmonary metastasis versus without pulmonary metastasis.
Table 3.
Significant ancillary findings on chest CT.