Utility of Multimodality Approach Including Systemic FGF23 Venous Sampling in Localizing Phosphaturic Mesenchymal Tumors

Hajime Kato; Minae Koga; Yuka Kinoshita; Naoko Hidaka; Yoshitomo Hoshino; Yuichi Takashi; Makoto Arai; Hiroshi Kobayashi; Masaki Katsura; Yuji Nakamoto; Naohiro Makise; Tetsuo Ushiku; Kazuto Hoshi; Masaomi Nangaku; Noriko Makita; Seiji Fukumoto; Nobuaki Ito

doi:10.1210/jendso/bvac181

Utility of Multimodality Approach Including Systemic FGF23 Venous Sampling in Localizing Phosphaturic Mesenchymal Tumors

J Endocr Soc. 2022 Nov 24;7(2):bvac181. doi: 10.1210/jendso/bvac181. eCollection 2022 Dec 15.

Authors

Hajime Kato^{1

2}, Minae Koga^{1

2}, Yuka Kinoshita^{1

2}, Naoko Hidaka^{1

2}, Yoshitomo Hoshino^{1

2}, Yuichi Takashi³, Makoto Arai⁴, Hiroshi Kobayashi⁵, Masaki Katsura⁶, Yuji Nakamoto⁷, Naohiro Makise^{8

9}, Tetsuo Ushiku⁸, Kazuto Hoshi¹⁰, Masaomi Nangaku¹, Noriko Makita^{1

2}, Seiji Fukumoto¹¹, Nobuaki Ito^{1

2}

Affiliations

¹ Division of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo, 113-8655, Japan.
² Osteoporosis Center, The University of Tokyo Hospital, Tokyo, 113-8655, Japan.
³ Department of Endocrinology and Diabetes Mellitus, Fukuoka University School of Medicine, Fukuoka, 814-0180, Japan.
⁴ Division of Molecular Physiology and Metabolism, Faculty of Medicine, Tohoku University, Miyagi, 980-8575, Japan.
⁵ Department of Orthopedic Surgery, The University of Tokyo Hospital, Tokyo, 113-8655, Japan.
⁶ Department of Radiology, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-8655, Japan.
⁷ Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine Kyoto University, Kyoto, 606-8507, Japan.
⁸ Department of Pathology, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-8655, Japan.
⁹ Division of Surgical Pathology, Chiba Cancer Center, Chiba, 260-8717, Japan.
¹⁰ Department of Oral-maxillofacial Surgery, Dentistry and Orthodontics, and Division of Tissue Engineering, The University of Tokyo Hospital, Tokyo, 113-8655, Japan.
¹¹ Fujii Memorial Institute of Medical Sciences, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, 770-8503, Japan.

Abstract

Context: Tumor-induced osteomalacia (TIO) is one of the most common forms of acquired fibroblast growth factor 23 (FGF23)-related hypophosphatemia and is usually caused by phosphaturic mesenchymal tumors (PMTs). Although the complete resection of PMTs can cure TIO, preoperative localization of tumors by standard imaging modalities is often challenging. In addition to ¹⁸F-fluoro-2-deoxy-D-glucose positron emission tomography-computed tomography (FDG-PET) and ¹¹¹In-pentetreotide scintigraphy (SRS), systemic FGF23 venous sampling (FGF23VS) has been used to help localize PMTs in specialized institutions.

Objective: This study aimed to evaluate the diagnostic performance of each imaging test and their combinations in localizing PMTs.

Methods: In an observational retrospective study of patients with adult-onset FGF23-related osteomalacia who underwent all 3 imaging studies (FDG-PET, SRS, and FGF23VS), the rate of successful preoperative localization of the tumors was evaluated only in the patients with pathological diagnoses of PMTs, considering the possibility that pathogenesis of patients without identified tumors might be due to other causes such as late-onset hereditary FGF23-related hypophosphatemia.

Results: A total of 30 Japanese patients with TIO (median age, 60 years [range, 28-87 years]; 10 women [33.3%]) were included in the study. The success rate of preoperative localization for each test and combinations of 2 or 3 tests among 18 patients with PMTs was as follows: 72% (FDG-PET), 72% (SRS), 94% (FGF23VS), 89% (FDG-PET, SRS), 100% (FDG-PET, FGF23VS), 94% (SRS, FGF23VS), and 100% (FDG-PET, SRS, and FGF23VS).

Conclusion: We observed the highest localization rate of PMTs in patients with identified PMTs with the combination of FDG-PET and FGF23VS.

Keywords: 111In-pentetreotide scintigraphy; 18F-FDG PET/CT; fibroblast growth factor 23; phosphaturic mesenchymal tumor; tumor-induced osteomalacia; venous sampling.