Comparison of 68Ga-DOTATATE PET/CT for Assessment of Response to Peptide Receptor Radionuclide Therapy after 2 and 4 Cycles of 177Lu-DOTATATE: Preliminary Single Academic Center Experience

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Introduction: Peptide receptor radionuclide therapy (PRRT) usually leads to stable rather than decreased lesion size in neuroendocrine tumors (NETs), therefore RECIST criteria are not used to assess early response to treatment.

Aim(s): Here we report a comparison of 68Ga-DOTATATE PET/CT done after 2 and 4 cycles of PRRT to understand early NET response to PRRT, which may allow physicians to make appropriate treatment adjustments.

Materials and methods: 42 patients (37-80 year-old, mean ± SD: 60.5 ± 10.9) with progressive metastatic NET received at least one cycle of 177Lu-DOTATATE between May 2018 and May 2019 at our institution. 30 patients completed all 4 cycles of PRRT. 19 patients had 68Ga-DOTATATE PET/CT before the first infusion (pretherapy PET #1), after the second infusion (interim PET #2) and after the fourth infusion (posttherapy PET #3). Response to PRRT was compared between interim PET and posttherapy PET.

Conference: 17th Annual ENETSConcerence (2020)

Presenting Author:

Authors: Song H, Kunz P, Fisher G, Franc B, Moradi F,

Keywords: PRRT, 68Ga-DOTATATE PET/CT, Neuroendocrine tumor,