Head-to-head Comparison of 18F-AIF-NOTA-Octreotide and 68Ga-DOTA-TATE PET/CT in Patients with Neuroendocrine Neoplasms - Endo Annual 2022 The 50th Annual Meeting of The Israel Endocrine Society

Simona Grozinsky-Glasberg ^2,5 Simona Ben-Haim ^1,2,6 Alexandre Chicheportiche ¹ Marina Orevi ^1,2 Galith Abourbeh ^3,4 Ofer Shamni ² Ofir Press ^3,4 Yodphat Krausz ^1,2 Kira Oleinikov ^2,5 David J. Gross ^2,5 Eyal Mishani ^2,4

¹Department of Nuclear Medicine & Biophysics, Hadassah Medical Organization
²Faculty of Medicine, Hebrew University of Jerusalem
³S.R.Y Medical Serviced Ltd, Hadassah Medical Organization
⁴Cyclotron/Radiochemistry Unit, Hadassah Medical Organization
⁵Neuroendocrine Tumor Unit, ENETS Center of Excellence, Endocrinology and Metabolism Department, Hadassah Medical Organization
⁶University College London, London

Purpose:
18F-AIF-NOTA-octreotide (F-Oc) is a radiolabeled somatostatin analog and a potential alternative for 68Ga-DOTA-TATE (Ga-DT). We have compared physiological and pathological findings in F-Oc and Ga-DT PET/CT studies in patients with NEN.

Methods:
Normal biodistribution and pathological findings were compared using maximum standard uptake value (SUVmax). Tumor-to-liver ratio was calculated by dividing the SUVmax of tumor lesions by liver SUVmax. Data are expressed as mean ± SD. Differences were assessed using Wilcoxon signed-rank test.

Results:
The results of F-Oc and Ga-DT PET/CT studies of six patients with biopsy proven NEN (F=4, mean age: 61.7 years), performed within 14-228 days (mean 65 days) were analyzed. Ga-DT showed higher physiological uptake in the spleen, salivary glands, pituitary and liver and lower blood pool activity compared to F- Oc. Of 27 abnormal foci (19 liver, 2 pancreatic, 6 mesenteric) F-Oc identified 24 (88.9%), compared to 23 (85.2%) for Ga-DT. Four subcentimeter foci (one mesenteric, three liver) were not visualized with Ga-DT, whereas three subcentimeter foci (two liver, one pancreas) were not seen on F-Oc. SUVmax of 20 lesions detected in both studies was 12.8±7.9 and 16.1±12.2 for F-Oc and Ga-DT, respectively (p= 0.1) and tumor-to-liver ratio was 2.9±2.0 and 2.3±1.8 for F-Oc and Ga-DT, respectively (p=0.007).

Conclusion:
These preliminary data show good agreement between F-Oc and Ga-DT in patients with NEN with a significantly higher tumor-to-liver ratio obtained with F-Oc. The potential added clinical value of these findings needs to be further evaluated and will be assessed in the entire patient cohort.