Exploration of Ga-68 DOTA PET radiomics to predict the absorbed dose of Lu-177 DOTATATE® therapy of midgut neuroendocrine tumors

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Introduction: Lu-177 DOTATATE® is a proficient systemic irradiation with heterogeneous individual consequences due to tumor burden, uptake and elimination. Current dosimetry protocols seem not accurate enough to predict efficacy or toxicity.

Aim(s): To correlate radiomic parameters of Ga-68-DOTATOC exam with the absorbed dose of Lu-177 DOTATATE in order to assess the feasibility of a possible dosimetric methodology with an easy to apply routine application.

Materials and methods: We tested our method in two subjects (n=10 lesions>2cm diameter) undergoing both pretherapeutic Ga-68 DOTA PET acquisition (75 min post injection, 85 MBq Ga-68 DOTATOC) and LuPRRT (7.4 GBq tumor dosimetry with serial whole body scans at 4h, 1, 2, 4 and 6 days post PRRT). We measured SUVmax, SUVmean (threshold 40%) and SUVpeak using PETVCAR software performed on AWServer. Automatic contouring with different thresholds (10%, 25% and 40%) was performed for PET and SPECT with PlanetDose software®.

Conference: 18th Annual ENETS Concerence (2021)

Presenting Author: Courbon F

Authors: Brahmi S, Vallot D, Vija L, Dierickx L, Courbon F,

Keywords: midgut NET, Ga DOTA PET CT, LuPRRT, PET metrics, SUV, tumor absorbed dose,