Increased Activity Due to Fractures Does Not Significantly Affect the Accuracy of 68Ga-DOTATATE PET/CT in the Detection of Culprit Tumor in the Evaluation of Tumor-Induced Osteomalacia

Abstract

Objective 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. Method 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. Results 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. Conclusions 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.

Detection Rate of Culprit Tumors Causing Osteomalacia Using Somatostatin Receptor PET/CT: Systematic Review and Meta-Analysis

“…No additional records were found screening the references of these articles, whereas six articles were excluded after the analysis of the full text. Therefore, 14 articles were included in the qualitative analysis (systematic review) [16][17][18][19][20][21][22][23][24][25][26][27][28][29]. Three articles were excluded from the meta-analysis for possible patient data overlap [18,25,26].…”

“…Three articles were excluded from the meta-analysis for possible patient data overlap [18,25,26]. Overall, 11 articles (166 patients with TIO) were included in the quantitative analysis (meta-analysis) [16,17,[19][20][21][22][23][24][27][28][29]. The characteristics of the 14 studies included in the systematic review are presented in Tables 1 and 2.…”

“…As shown in Table 3, most of the selected studies showed a good DR of culprit tumors in patients with TIO using SSTR-PET/CT. The culprit lesions were usually small benign tumors located in the bones or soft tissues, presenting a high uptake of radiolabeled somatostatin analogues ( 68 Ga-DOTATATE, 68 Ga-DOTATOC or 68 Ga-DOTANOC) at SSTR-PET/CT [16][17][18][19][20][21][22][23][24][25][26][27][28][29]. The most frequent site of culprit tumors were the lower limbs; other frequent sites were the cranio-facial region and the trunk, whereas the localization of culprit tumors in the upper limbs was less frequent.…”

“…Most of the culprit tumors detected by SSTR-PET/CT were confirmed by histopathology and phosphaturic mesenchymal tumor was the most frequent histological type. Malignant or metastatic tumors detected by SSTR-PET/CT in patients with TIO were rare [16][17][18][19][20][21][22][23][24][25][26][27][28][29]. A very high inter-observer concordance among PET/CT masked readers was reported by one study for the visual detection of culprit tumors by SSTR-PET/CT [20].…”

“…For the majority of patients with TIO included in the selected studies, before performing SSTR-PET/CT, conventional imaging (including CT and MRI) failed to detect the culprit tumors. This has delayed the recognition of TIO and/or led to difficulties in localizing the culprit tumor once TIO was suspected [16][17][18][19][20][21][22][23][24][25][26][27][28][29]. When a culprit tumor was detected by SSTR-PET/CT, anatomical localization studies using additional CT or MRI were performed in some patients, for the localization and characterization of the lesion where the surgeon deemed it necessary for surgical intervention.…”