Correlation between early response and lesion dosimetry in patients with advanced neuroendocrine tumor (NET) treated with radioligand therapy (RLT)

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Introduction: The identification of predictive parameters of response to radioligand therapy (RLT) in NET patients is essential in order to avoid futile therapy toxicities. The relation between the tumor absorbed dose and therapy response has so far not been established.

Aim(s): The aim of this study was to assess the tumor dose-response correlation for NET patients treated with RLT.

Materials and methods: We conducted an analysis of patients with advanced NET enrolled in a phase II clinical study. The trial consisted in the administration of tandem Y90/177Lu-DOTATOC therapy. Dosimetry calculation of absorbed dose relied on 4 sequential SPECT/CT on the first course of therapy at 1 hour, 24 hours, 40 hours and 70 hours. Lesions were manually segmented on 24-h SPECT/CT then the contours were duplicated and translated on the other SPECT/CT images. Therapy response was assessed 3 months after RLT using RECIST criteria.

Conference:

Presenting Author: Durmo R

Authors: Durmo R, Fioroni F, Grassi E, Coruzzi C, Giulia B,

Keywords: RLT, Dosimetry,