Tumor metastasis to the skeleton affects over 70% cancer patients, more than any other site of metastasis Skeletal related events (SREs) included spinal cord compression, fracture, bone radiation or surgery, and tumor-related hypercalcemia are severe complications of bone metastases, which impair patients life quality and require particular treatments The gold standard for the definitive diagnosis is still pathological examination, which needs pre-biopsy imaging review to improve the diagnosis efficacy Classic imaging review method for being CT (Computed Tomography) and 18F-FDG PET/CT Research has shown that 18F-FDG PET/CT is superior to CT in detecting bone metastasis, however, it is not validated by a prospective study Besides, as SUVmax is a metabolic parameter in oncology imaging, we can serve as a reliable semiquantitative indicator to differentiate bone lesions We conducted a prospective clinical trial at Shanghai Sixth People’s Hospital Inclusion criteria were as follows: referred for diagnostic biopsy on a suspicion of metastatic disease Exclusion criteria included contraindications for biopsy 205 patients participated in the cohort study, then were randomized into PET/CT and CT group They underwent 18F-FDG PET/CT and CT separately to confirm accurate location, then both received CT-guided bone biopsy to confirm The sensitivity, specificity and accuracy were calculated In PET/CT group, malignant bone metastases were found in 83/137 patients and biopsies proved 80 were actual metastases In CT group, 48 malignant bone metastases were spotted and 47 were truly decisive The sensitivity, specificity and accuracy of 18F-FDG PET/CT and CT are 99% vs 87%, 95% vs 93%, and 97% vs 88% A chi-square test was utilized to analyze The sensitivity of 18F-FDG PET/CT is better than CT (P=0 0065), but the specificity and accuracy had no differences, indicating 18F-FDG PET/CT could detect more bone metastatic lesions potentially than CT We also found metastasis malignant lesions had higher bone SUVmax than benign (median 9 3 vs 4 25, p <0 001) ROC curves were asked to evaluate the differential efficacy of SUVmax In all 137 patients, the SUVmax 6 3 showed an AUC of 0 874 to predict malignant metastases Our research shows that [18F]FDG PET/CT has greater sensitivity in detecting malignant bone metastases than CT, and SUVmax can be different criteria for determining the malignancy of bone lesions

Citation Format: Hui Zhao, Yujie Chang, Zhiyuan Jiang, Zhiyu Wang, Shunyi Ruan. 18F-FDG PET/CT detects potentially malignant bone metastases in patients with suspected lesions: A prospective clinical trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT543.