gallium-ga-68-dotatate and Osteomalacia

Tumor-induced osteomalacia (TIO) is a paraneoplastic disorder, usually caused by benign mesenchymal tumors that produce high levels of fibroblast growth factor 23. The only curative therapy is resection of the causative tumors.. This research was conducted to evaluate the efficacy of 18F-AlF-NOTA-octreotide (18F-OC) positron emission tomography/computed tomography (PET/CT) in detecting TIO and its impact on patient management.. Retrospective analysis was conducted of 17 patients with hypophosphatemic osteomalacia suspected to be TIO. A  18F-OC PET/CT study was performed in all 17 patients to localize the tumor and 68Ga-DOTATATE PET/CT was performed in 4 out of 17 patients; both studies were performed within 1 week of each other. Both studies were interpreted blindly without the knowledge of other imaging findings. The image findings were compared with the results of histopathological examinations and clinical follow-ups.. The 18F-OC PET/CT scans were positive in 14 patients. Furthermore, 4 of 14 patients were scanned with both 18F-OC and 68Ga-DOTATATE PET/CT. Both studies were able to localize the tumor in all 4 patients. In total, 14 patients had surgery to remove the lesions. Postsurgical pathological examination confirmed causative tumors in these patients, whose symptoms diminished promptly. Serum phosphate levels normalized, confirming the diagnosis of TIO. 18F-OC PET/CT sensitivity, specificity, and accuracy were 87.5%, 100%, and 88.2% respectively. 18F-OC PET/CT findings affected patient management in 88.2% of cases.. 18F-OC PET/CT scan is useful in the detection of tumors causing TIO. Further studies with larger patient populations are needed to validate the result.

Topics: Adult; Aged; Bone Diseases, Metabolic; Female; Fluorine Radioisotopes; Humans; Hypophosphatemia; Male; Middle Aged; Octreotide; Organometallic Compounds; Osteomalacia; Paraneoplastic Syndromes; Positron Emission Tomography Computed Tomography; Radiopharmaceuticals; Retrospective Studies; Sensitivity and Specificity

Giant cell tumor of tendon sheath (GCTTS) is benign mesenchymal neoplasm, and it rarely induces hypophosphatemia. We report a 49-year-old woman with suspicious tumor-induced osteomalacia underwent Ga-DOTA-TATE PET/CT to identify potential causative tumor, which showed a hypermetabolic soft tissue nodule in the right foot. Pathology confirmed it as GCTTS following surgical resection. The patient's symptoms improved rapidly, and the serum phosphate normalized after surgery, which supports the diagnosis of tumor-induced osteomalacia. Our case showed GCTTS can be rich of somatostatin receptor and cause osteomalacia.

Topics: Female; Giant Cell Tumor of Tendon Sheath; Humans; Middle Aged; Neoplasms, Connective Tissue; Organometallic Compounds; Osteomalacia; Paraneoplastic Syndromes; Positron Emission Tomography Computed Tomography; Radiopharmaceuticals

Phosphaturic mesenchymal tumors are benign tumors causing majority of tumor-induced osteomalacia. These tumors are most commonly located in the lower extremities followed by craniofacial regions. However, intracranial lesion is very rare. Here we describe Ga-DOTATATE PET/CT findings of a recurrent intracranial phosphaturic mesenchymal tumor in a 68 year old woman.

Topics: Aged; Brain Neoplasms; Female; Humans; Neoplasms, Complex and Mixed; Organometallic Compounds; Osteomalacia; Positron Emission Tomography Computed Tomography; Radiopharmaceuticals

Ga-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 Ga-DOTATATE activity and potentially affect the accuracy of Ga-DOTATATE PET/CT imaging. The aim of this investigation is to evaluate whether the increased Ga-DOTATATE activity at the sites of the fracture will cause interpretation difficulty in the localizing the culprit tumor causing TIO.. The images of Ga-DOTATATE PET/CT scan from a total of 54 patients who had multiple foci of increased Ga-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 Ga-DOTATATE PET/CT in the evaluation of TIO when both intensity on PET and morphology on CT were assessed.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Female; Fractures, Bone; Humans; Male; Middle Aged; Neoplasms, Connective Tissue; Neuroendocrine Tumors; Organometallic Compounds; Osteomalacia; Paraneoplastic Syndromes; Positron Emission Tomography Computed Tomography; Radiopharmaceuticals; Reproducibility of Results

Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome, usually caused by small benign mesenchymal tumors. The localization of these tumors is challenging, however, essential for the management. We compared the utility of F-FDG PET/CT and Ga DOTATATE PET/CT to detect the site of primary tumor in patients with suspicion of TIO.. Retrospective analysis of 6 patients with hypophosphatemic osteomalacia and suspicion of TIO was performed. Ga DOTATATE PET/CT study was performed in all 6 patients to localize the tumor. F-FDG PET/CT was performed in 4 of 6 patients. F-FDG and Ga DOTATATE PET/CT studies were performed within 1 week of each other. Both studies were interpreted blindly without the knowledge of other imaging findings.. All patients had symptoms of osteomalacia and hypophosphatemia. All except 1 patient had increased level of fibroblast growth factor 23. The lag time (symptoms to PET diagnosis) ranged from 1.5 to 22 years. In 4 patients, where both studies were performed, F-FDG and Ga DOTATATE PET/CT were able to localize the tumor in 2 and 3 patients. Ga DOTATATE PET/CT detected tumor in 5 (83.3%) of 6 patients.. Ga DOTATATE PET/CT performed better than F-FDG PET/CT and is useful in the detection of tumors causing oncogenic osteomalacia. Therefore, in clinically suspected cases of hypophosphatemic osteomalacia, Ga DOTATATE PET/CT may be performed as first-line imaging investigation to avoid delay in the treatment of this devastating but curable disease. However, further studies with large patient population are warranted to validate our data.

Topics: Adult; Female; Fluorodeoxyglucose F18; Humans; Male; Middle Aged; Multimodal Imaging; Neoplasms, Connective Tissue; Organometallic Compounds; Osteomalacia; Paraneoplastic Syndromes; Positron-Emission Tomography; Radiopharmaceuticals; Tomography, X-Ray Computed

Tumor-induced osteomalacia (TIO) is generally caused by small benign mesenchymal tumors producing fibroblast growth factor-23 (FGF-23). The only curative therapy of the disease is resection of the causative tumors. However, these tumors are extremely difficult to detect using conventional imaging modalities. This research was undertaken to evaluate efficacy of (68)Ga DOTATATE PET/CT in this clinical setting.. Images of (68)Ga DOTATATE PET/CT and clinical charts from 54 patients with clinically suspected TIO were retrospectively reviewed. The image findings were compared with the results of histopathological examinations and clinical follow-ups.. (68)Ga DOTATATE PET/CT scans were positive in 44 patients, among which, 33 had surgery to remove the lesions. Postsurgical pathological examination confirmed causative tumors in 32 patients whose symptoms diminished promptly, and the serum phosphate levels became normal, which confirmed the diagnoses of TIO. Eleven patients with positive (68)Ga DOTATATE PET/CT did not have surgery. These 11 patients continued to have symptoms and hypophosphatemia but were not included in the final analysis because of lack of evidence to confirm or exclude TIO. Ten patients had negative (68)Ga DOTATATE PET/CT scans. All of these10 patients responded to conservative therapy and had normal serum phosphate levels in the follow-up, which excluded TIO. Therefore, the (68)Ga DOTATATE PET/CT imaging had a sensitivity of 100% (32/32) and a specificity of 90.9% (10/11). The overall accuracy of (68)Ga DOTATATE PET/CT scan in the detection of tumors responsible for osteomalacia is 97.7% (42/43).. (68)Ga DOTATATE PET/CT scan is an accurate imaging modality in the detection of tumors causing TIO.

Topics: Adult; Aged; Female; Fibroblast Growth Factor-23; Humans; Male; Middle Aged; Multimodal Imaging; Neoplasms, Connective Tissue; Organometallic Compounds; Osteomalacia; Paraneoplastic Syndromes; Positron-Emission Tomography; Radiopharmaceuticals; Tomography, X-Ray Computed