(A and B) Two coronal and transaxial sections of 18F-FDG PET/CT scan of 73-y-old woman with stage IV NSCLC (adenocarcinoma; free circulating tumor DNA [cfDNA] level, 462 hTERT copy numbers; 3 CTCs/3 mL). (A) Primary lesion that highly concentrated 18F-FDG in left lung (maximum diameter [dmax], 49 mm; SUVmax, 7.2; MTV, 82.4 mL). (B) Small bone lesion in left scapula (dmax, 10 mm; SUVmax, 5.7; MTV, 5 mL). (C and D) 18F-FDG PET/CT scan of 70-y-old man with stage IV NSCLC (adenocarcinoma; cfDNA level, 113 hTERT copy numbers; 3 CTCs/3 mL). (C) Primary lesion that moderately concentrated 18F-FDG in right lung (dmax, 83 mm; SUVmax, 4.9; MTV, 193.2 mL). (D) Multiple mediastinal and cervical lymph nodes (dmax of largest lymph node, 30 mm; SUVmax, 3.2; MTV, 65 mL). Patient shown in A and B had lower tumor burden (as expressed by MTV) but higher SUVmax and cfDNA levels than patient shown in C and D.
Silvia Morbelli, et al., San Martino Hospital, University of Genoa, Italy.