Fig. 3.

New pulmonary metastases manifested as ground-glass opacity nodules (part solid) in 78-year-old woman with lung adenocarcinoma in right upper and lower lobes.

A, B. Enhanced weighted-average image obtained from dual-energy CT shows newly developed 10-mm (A) and 12 mm-sized (B) ground-glass opacity nodules in right lung (arrows). Ground-glass opacity nodules are equivocal (not definitely defined) lesions on RECIST 1.1 version. Thus, tumor response was assessed as stable disease. C, D. These nodules shows substantial enhancement (58 HU in C and 89 HU in D) on color coded iodine-enhanced images obtained from dual-energy CT (arrows). Therefore, tumor response was assessed as progressive disease. E, F. Conventional images on further follow-up CT scans (two months after dual energy CT) show marked increase in nodule size with internal new cavitation (arrows), suggestive of cavitary metastases. Tumor response was again confirmed as progressive disease.