68Ga-DOTATATE PET/CT is currently the most common imaging modality in localizing culprit tumors, which can result in tumor-induced osteomalacia (TIO). Fracture, which is one of the most common consequences of the TIO, can also lead to increased 68Ga-DOTATATE activity and potentially affect the accuracy of 68Ga-DOTATATE PET/CT imaging. The aim of this investigation is to evaluate whether the increased 68Ga-DOTATATE activity at the sites of the fracture will cause interpretation difficulty in the localizing the culprit tumor causing TIO.
The images of 68Ga-DOTATATE PET/CT scan from a total of 54 patients who had multiple foci of increased 68Ga-DOTATATE PET/CT on PET/CT were retrospectively analyzed. Not only was the intensity of the activity on PET but also the appearance of the activity on CT taken into consideration when the interpretation of the images occurred. The results from imaging analysis were compared with the clinical chart record. All patients had tentative clinical diagnosis of TIO.
The causative tumors in 53 patients were eventually identified. In 1 patient, the causative tumor was not identified. Among the 53 patients with confirmed TIO, 52 tumors were accurately localized.
Mild activity at the sites of fracture is not a major challenging factor in the interpretation of 68Ga-DOTATATE PET/CT in the evaluation of TIO when both intensity on PET and morphology on CT were assessed.
From the *Department of Nuclear Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College;
†Beijing Key Laboratory of Molecular Targeted Diagnosis and Therapy in Nuclear Medicine;
‡Department of Nuclear Medicine, Beijing Shijitan Hospital; and
§Department of Nuclear Medicine, China-Japan Friendship Hospital, Beijing, China.
Received for publication August 15, 2018; revision accepted August 17, 2018.
Conflicts of interest and sources of funding: This work was sponsored in part by the National Natural Science Foundation of China (grant 81571713), Beijing Municipal Science & Technology Commission (grant Z151100003915133), CAMS Innovation Fund for Medical Sciences (grants 2016- I2M-4-003, 2017-I2M-3-001), China Scholarship Council (grant 201708110098), and Capital's Funds for Health Improvement and Research (grant 2016-2-40115). None declared to all authors.
Correspondence to: Li Huo, MD, PhD, Department of Nuclear Medicine, Peking Union Medical College Hospital, 1# Shuaifuyuan, Dongcheng District, Beijing, China 100730. E-mail: Huoli@pumch.cn.