68Ga-DOTA-TATE PET-CT comparison with 99mTc-HYNIC-TOC SPECT-CT in the assessment of the extent of the disease in patients with malignant endocrine tumors: our experience (preliminary results)

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Introduction: In neuroendocrine tumors (NETs), the workup is often difficult not only to visualize but also to co-localize the lesions anatomically. Liver and bones are one of the most frequent sites of metastases in patients with endocrine tumors. The Tyr3-octreotate (TATE) somatostatin analogue differs from TOC in that the terminal threonine replaces threoninol. The terminal threonine results in a higher receptor binding (mainly subtype 2) and better internalisation, with the consequence that tumor uptake of the tracer is intense.

Aim(s): To evaluate the diagnostic value of 68Ga-DOTA-TATE PET-CT comparison with 99mTc-HYNIC-TOC SPECT-CT in the assessment of disease extent in patients with malignant neuroendocrine tumors in our institution.

Materials and methods: 68Ga-DOTA-TATE PET-CT and 99mTc-HYNIC-TOC SPECT/CT studies were performed in nine patients. The interval time between of these two studies was 2 – 28 weeks. Conventional scintigraphy was acquired on the hybrid gamma camera SPECT/CT in 2-4 h after intravenous injection of 99mTc-HYNIC-TOC. The injected activity was 550-740 MBq (15-20mCi). The following views were gathered: planar AP, PA and SPECT/CT of the chest and abdomen. PET-CT scans were acquired 45 – 60 min postinjection of 120 – 200 MBq (3.5 – 5.5 mCi) of 68Ga-DOTA-TATE. Data acquisition was performed with a 15-cm axial field of view (FOV) and 55-cm transaxial FOV PET-CT scanner. Patients were imaged in 3-dimensional mode with the duration of acquisition 3 - 5 min per bed position in emission mode.

Conference: 7th Annual ENETSConcerence (2010)

Presenting Author: Szalus N

Authors: Szalus N, Pawlak D, Dziuk M, Koza M, Kaminski G,

Keywords: neuroendocrine tumors, SPECT/CT, PET/CT,