This is a pilot study to assess the value of whole-body Al18F-NOTA-LM3 PET/CT in patients with tumor-induced osteomalacia.

Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome. The main cure for TIO is surgical removal of the responsible tumor. Somatostatin receptors (SSTR) targeted PET imaging with radiolabeled somatostatin analogs can help locate these tumors. It can detect culprit tumors in TIO patients, even small ones that CT or MRI might miss. 68Ga-DOTATATE is the most commonly used SSTR PET tracer for TIO, recommended as the first-line imaging tool to find the causative tumor.

Compared to 68Ga-based tracers, 18F-labelled radiotracers offer several advantages, including higher cyclotron production, lower positron energy, and longer half-life. These features may improve image quality. Al18F-NOTA-LM3 is an SSTR2 specific antagonist used as a PET tracer. This pilot study is designed to compare Al18F-NOTA-LM3 with 68Ga-DOTATATE in the same group of TIO patients.

Inclusion Criteria:

• Patients aged 18 to 80 years.
• Suspected or confirmed TIO patients.

Exclusion Criteria:

• Combined with other types of tumors.
• Severe liver or renal dysfunction (ALT/AST≥5 ULN, GFR<30ml/min).
• Pregnant or breast-feeding women.
• Inability to perform PET/CT scans.