Assessment of DNA Double-Strand Breaks in Blood Lymphocytes after Whole-Body Radiation Exposure in Patients with Neuroendocrine Tumors Undergoing 177Lu-Octreotate Therapy

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Introduction: Peptide receptor radionuclide therapy using somatostatin receptor-binding peptides, such as 177Lu-Octreotate (LuTate), has been clinically proven to be effective in treating patients with inoperable neuroendocrine tumors. Despite the rather high radiation exposure, only few side effects have been reported. However, blood cells are very sensitive to radiation. Therefore, it is important to determine how much radiation they received. Recently, the detection by immunofluorescence of the phosphorylation of the histone variant H2AX (γ‐H2AX) has been established as a reliable and sensitive technique to monitor DNA double-strand breaks (DSBs) in blood lymphocytes.

Aim(s): To investigate the kinetics of DSBs in blood lymphocytes in patients with neuroendocrine tumors undergoing up to four LuTate treatments.

Materials and methods: Ten patients received between 6‐11 GBq of LuTate with an administered activity adapted to the burden of a somatostatin receptor-expressing tumor and renal function. We measured γ‐H2AX foci up to 72 hrs post‐treatment, and correlated these numbers with 177Lu radioactivity clearance data in serum.

Conference: 10th Annual ENETSConcerence (2013)

Presenting Author: Denoyer D

Authors: Denoyer D, Martin O, Jackson P, Johnston V, Hicks R,

Keywords: 177Lu-Octreotate, γ‐H2AX, DNA damage,