FIGURE 5.

Images of 76-y-old man undergoing ¹⁸F-DCFPyL PET/CT for staging of metastatic PCa (prostate-specific antigen level on date of scan, 0.63; prior prostatectomy). (A) Whole-body maximum-intensity projection shows radiotracer uptake in right hilar and subcarinal LNs (arrows), lung lesion (arrowhead), and right iliac bone (doubled arrow). (B–D) Axial CT (B), axial ¹⁸F-DCFPyL PET (C), and axial ¹⁸F-DCFPyL PET/CT (D) show mild to moderate radiotracer uptake in subcarinal LN (arrows). IR called this finding PSMA-RADS-4, whereas ER classified it PSMA-RADS-2 (i.e., likely benign because of low-level uptake in soft-tissue site atypical of metastatic PCa). Hilar and subcarinal LNs remained unchanged on follow-up imaging, suggesting that these are benign. All 4 readers classified overall scan impression as PSMA-RADS-5. (E–G) Axial CT (E), axial ¹⁸F-DCFPyL PET (F), and axial ¹⁸F-DCFPyL PET/CT (G) show intense radiotracer uptake in right iliac bone (doubled arrows). Apart from that, lung lesion (¹⁸F-DCFPyL whole-body maximum intensity projection in A, red arrowhead) was classified as PSMA-RADS-2 by IR. (H–J) Axial CT (H), axial ¹⁸F-DCFPyL PET (I), and axial ¹⁸F-DCFPyL PET/CT (J) of this lesion further confirm suspicion of benign lesion (arrowheads, most likely peripheral interstitial thickening). Follow-up imaging also corroborated this impression.