Diagnostic efficiency of 68Ga-DOTANOC PET/CT in patients with suspected tumour-induced osteomalacia.

Abstract

OBJECTIVES:

Currently, the main challenge in tumour-induced osteomalacia (TIO) is the difficulty in locating culprit tumours for definitive diagnosis and surgical therapy. Herein, we retrospectively evaluate the efficiency of 68Ga-DOTANOC PET/CT in the localisation and diagnosis of TIO, and compared with 18F-FDG.

METHODS:

Twenty-four consecutive patients with hypophosphataemic osteomalacia (HO) and suspicion of TIO who were referred to our centre for 68Ga-DOTANOC PET/CT scanning were retrospectively reviewed. The images were evaluated qualitatively as well as semi-quantitatively, and imaging results were compared with the final diagnoses.

RESULTS:

Among the total of 21 patients who were included in the final analyses, 17 were diagnosed with TIO, while four were proven to have other causes of HO. 68Ga-DOTANOC PET/CT produced positive results in 16 of the 17 patients with TIO, representing a sensitivity of 94.1%. Moreover, the 68Ga-DOTANOC PET/CT results were negative in 3 of the 4 patients without TIO, representing a specificity of 75.0%. The overall accuracy of 68Ga-DOTANOC PET/CT in locating the tumours responsible for TIO is 90.5%. In particular, 68Ga-DOTANOC PET/CT detected the culprit tumours in 4 out of 10 patients with negative results on previous 18F-FDG PET/CT and showed a significantly higher T/M ratio of tumours than 18F-FDG PET/CT in the same patients (n = 10; 4.76 ± 3.08 vs 1.95 ± 1.33, p < 0.05).

CONCLUSIONS:

68Ga-DOTANOC PET/CT is an accurate imaging modality in the localisation of tumours for TIO. It is superior to 18F-FDG PET/CT and may be useful in the differential diagnosis of HO.

KEY POINTS:

• TIO should be considered a possible cause for patients diagnosed with HO, which usually needs to be differentiated from other aetiologies. • 68Ga-DOTANOC PET/CT is an accurate imaging modality in locating culprit tumours for TIO, superior to 18F-FDG PET/CT.

• Authors: Qiao He, Bing Zhang, Linqi Zhang, Zhifeng Chen, Xinchong Shi, Chang Yi, Xiaoyan Wang, Xiangsong Zhang
• Journal: European radiology (Eur Radiol) Vol. 31 Issue 4 Pg. 2414-2421 (Apr 2021) ISSN: 1432-1084 [Electronic] Germany
• PMID: 33021702 (Publication Type: Journal Article)

Chemical References

• Gallium Radioisotopes
• Organometallic Compounds

Topics

• Gallium Radioisotopes
• Humans
• Multimodal Imaging
• Organometallic Compounds
• Osteomalacia
• Paraneoplastic Syndromes
• Positron Emission Tomography Computed Tomography
• Positron-Emission Tomography
• Retrospective Studies