18F-FMISO PET in metastatic neuroendocrine neoplasms – A pilot study

#3680

Introduction: The phenomenon of peripheral 68Ga-DOTATATE avidity without central avidity (a so-called “donut") has been observed in neuroendocrine neoplasm (NEN) lesions. There has been speculation as to whether this region of non-avidity reflects hypoxia, de-differentiated disease or other causes. The presence of hypoxia has significant prognostic and therapeutic implications, and was evaluated in these lesions using 18F-FMISO PET/CT.

Aim(s): To determine the frequency of 18F-FMISO uptake in NEN lesions with "donut" avidity.

Materials and methods: Prospective pilot study in n=10 patients with metastatic NENs. “Donut” lesions with >1cm peripheral avidity and >1cm central non-avidity were identified by experienced nuclear medicine specialists. 18F-FDG and 18F-FMISO scans were completed within 60 days of the 68Ga-DOTATATE PET/CT and were co-registered for review. Subjects were administered 2-8 MBq/kg of 18F-FMISO. Uptake within the identified ‘donut hole’ was scored by a team of two experienced nuclear medicine physicians as 0 (no uptake), 1 (uptake less than normal liver), 2 (uptake equal to normal liver), or 3 (uptake greater than normal liver).

Conference:

Presenting Author: Chan D

Authors: Chan D, Conner A, Pavlakis N, Bailey E, Aslani A,

Keywords: hypoxia, 18F-FMISO, 68Ga-DOTATATE, PET/CT, biomarker,