Purpose [18F]Sodium fluoride (NaF) positron emission tomography (PET)/computed tomography (CT) is a promising radiotracer for quantitative assessment of bone metastases. This study assesses changes in early NaF PET/CT response measures in metastatic prostate cancer for correlation to clinical outcomes. Patients and Methods Fifty-six patients with metastatic castration-resistant prostate cancer (mCRPC) with osseous metastases had NaF PET/CT scans performed at baseline and after three cycles of chemotherapy (n = 16) or androgen receptor pathway inhibitors (n = 40). A novel technology, Quantitative Total Bone Imaging, was used for analysis. Global imaging metrics, including maximum standardized uptake value (SUVmax) and total functional burden (SUVtotal), were extracted from composite lesion-level statistics for each patient and tracked throughout treatment. Progression-free survival (PFS) was calculated as a composite end point of progressive events using conventional imaging and/or physician discretion of clinical benefit; NaF imaging was not used for clinical evaluation. Cox proportional hazards regression analyses were conducted between imaging metrics and PFS. Results Functional burden (SUVtotal) assessed midtreatment was the strongest univariable PFS predictor (hazard ratio, 1.97; 95% CI, 1.44 to 2.71; P < .001). Classification of patients based on changes in functional burden showed stronger correlation to PFS than did the change in number of lesions. Various global imaging metrics outperformed baseline clinical markers in predicting outcome, including SUVtotal and SUVmean. No differences in imaging response or PFS correlates were found for different treatment cohorts. Conclusion Quantitative total bone imaging enables comprehensive disease quantification on NaF PET/CT imaging, showing strong correlation to clinical outcomes. Total functional burden assessed after three cycles of hormonal therapy or chemotherapy was predictive of PFS for men with mCRPC. This supports ongoing development of NaF PET/CT-based imaging biomarkers in mCRPC to bone.

中文翻译：

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早期 [18F] 氟化钠正电子发射断层扫描/计算机断层扫描对骨转移性前列腺癌患者治疗反应的定量评估

目的 [18F] 氟化钠 (NaF) 正电子发射断层扫描 (PET)/计算机断层扫描 (CT) 是一种很有前途的放射性示踪剂，可用于骨转移的定量评估。本研究评估了转移性前列腺癌早期 NaF PET/CT 反应测量的变化，以与临床结果的相关性。患者和方法 56 名患有骨转移的转移性去势抵抗性前列腺癌 (mCRPC) 患者在基线和三个周期的化疗 (n = 16) 或雄激素受体通路抑制剂 (n = 40) 后进行了 NaF PET/CT 扫描. 一种新技术，定量全骨成像，被用于分析。全球成像指标，包括最大标准化摄取值 (SUVmax) 和总功能负担 (SUVtotal)，从每位患者的复合病变水平统计数据中提取，并在整个治疗过程中进行跟踪。无进展生存期 (PFS) 被计算为使用常规成像和/或医生判断临床获益的进展事件的复合终点；NaF 成像未用于临床评估。在成像指标和 PFS 之间进行 Cox 比例风险回归分析。结果 治疗中期评估的功能负担 (SUVtotal) 是最强的单变量 PFS 预测因子（风险比，1.97；95% CI，1.44 至 2.71；P < .001）。基于功能负担变化的患者分类显示出与 PFS 的相关性强于病变数量的变化。各种全球成像指标在预测结果方面优于基线临床标志物，包括 SUVtotal 和 SUVmean。不同治疗组的影像学反应或 PFS 相关性没有差异。结论 定量总骨成像能够对 NaF PET/CT 成像进行全面的疾病量化，显示出与临床结果的强相关性。在三个周期的激素治疗或化疗后评估的总功能负担可预测 mCRPC 男性的 PFS。这支持在 mCRPC 到骨骼中持续开发基于 NaF PET/CT 的成像生物标志物。