Diagnostic value of 68Ga-DOTA-TATE PET/CT imaging for tumor- induced osteomalacia

Tumor-induced osteomalacia (TIO) is often misdiagnosed as hypophosphatemia that is not valued. The aim of this study was to analyze the diagnostic value of 68Ga-DOTA-TATE PET/CT imaging for TIO.

Clinical data was retrospectively collected for 56 patients with suspected TIO at the Affiliated Hospital of Southwest Medical University between January 2016 and December 2019, where patients were examined by 68Ga-DOTA-TATE PET/CT and 99mTc-HYNIC-TOC SPECT. Based on the results of the patient's surgery, the diagnostic efficacy of the two imaging techniques on TIO were analyzed.

Of the 56 patients, 41 were diagnosed with TIO, with phosphorus levels ranging from 0.25 to 0.75 mmol/L. The remaining 15 patients were non-TIO. Results of 99mTc-HYNIC-TOC SPECT showed 33 cases were positive, with a diagnostic sensitivity, specificity, and accuracy of 58.54%, 86.67%, and 66.07%, respectively. Results of 68Ga-DOTA-TATE PET/CT imaging showed 46 cases were positive, with a diagnostic sensitivity, specificity, and accuracy of 95.13%, 60.00%, 71.43%, respectively. The average tumor size with 68Ga-DOTA-TATE PET/CT imaging was 2.58±1.71 cm. The lesions of 41 patients involved bone and soft tissue, while 18 patients showed osteolytic bone destruction. Distribution was mainly under the skin, followed by intermuscular space, and cortex of bone. Compared with muscle density, the lesions showed uniformly or slightly lower density nodules. Using 99mTc-HYNIC-TOC SPECT, the planar imaging of 30 patients showed that radioactive uptake increased at the early stage, and it can be accurately positioned on the SPECT imaging.

The 68Ga-DOTA-TATE PET/CT imaging demonstrated high accuracy in the diagnosis of TIO and detected small lesions, which could provide more comprehensive information for clinicians, and provide a reference value for the treatment and prognosis of patients.