[¹⁸F]FMISO PET in metastatic neuroendocrine tumours: a pilot study

Area of Science:

• Nuclear Medicine
• Oncology
• Radiochemistry

Background:

• Neuroendocrine neoplasms (NENs) can exhibit unique imaging characteristics.
• Peripheral [⁶⁸Ga]DOTATATE avidity without central avidity (DONUT lesions) is observed in NENs.
• Hypoxia in NENs has potential prognostic and therapeutic implications.

Purpose of the Study:

• To evaluate hypoxia in DONUT lesions using the PET tracer [¹⁸F]FMISO.
• To compare static and dynamic [¹⁸F]FMISO imaging for hypoxia detection in NEN DONUT lesions.

Main Methods:

• Prospective pilot study in patients with metastatic NENs and DONUT lesions.
• Acquisition of [¹⁸F]FDG, [¹⁸F]FMISO, and [⁶⁸Ga]DOTATATE PET/CT scans.
• Dynamic [¹⁸F]FMISO imaging analyzed quantitatively for influx rate constant (Ki); qualitative scoring of delayed scans.

Main Results:

• Ten NEN patients with DONUT lesions were studied.
• Quantitative dynamic [¹⁸F]FMISO imaging showed increased uptake rate (Ki) in 8/10 subjects' DONUT lesions.
• Qualitative delayed [¹⁸F]FMISO imaging identified increased uptake in only 1/10 subjects.

Conclusions:

• Dynamic [¹⁸F]FMISO PET imaging is superior to static imaging for detecting hypoxia in NEN DONUT lesions.
• Hypoxia is present in the central photopenic regions of most DONUT lesions.
• Future research should utilize dynamic [¹⁸F]FMISO imaging in NEN patients.