Fig. 11

A patient with rectal NET (G2, Ki 67 12%) with progressive disease despite long-acting somatostatin analogues underwent ⁶⁸Ga-DOTATATE PET (A), which showed intense uptake in the mesorectal lymph nodes and bone lesions but sufficient uptake only in one of the hepatic metastases (Krenning score 3–4) on PET/CT (B), while other contrast-enhancing lesions on MRI (arterial phase, C) had uptake similar to background liver (Krenning score 2). Contemporaneous ¹⁸F-FDG PET did not show any avid disease (not shown). Following discussion at the NET multidisciplinary team meeting, the decision was made to proceed with ¹⁷⁷Lu-DOTATATE but only proceed with further cycles if high tracer retention is noted on post-treatment SPECT imaging. Post-treatment ¹⁷⁷Lu-DOTATATE SPECT/CT (D) and SPECT (E) imaging showed high tracer retention (Krenning score 4) in all hepatic lesions, including lesions that showed low ⁶⁸Ga-DOTATATE. The patient proceeded with 4 cycles of ¹⁷⁷Lu-DOTATATE