Chandekar Kunal Ramesh, Satapathy Swayamjeet, Singh Harmandeep, Kumar Rajender, Kumar Santosh, Kakkar Nandita, Mittal Bhagwant Rai, Singh Shrawan Kumar
Department of Nuclear Medicine, .
Department of Nuclear Medicine, All India Institute of Medical Sciences, New Delhi and .
Nucl Med Commun. 2024 Oct 1;45(10):883-891. doi: 10.1097/MNM.0000000000001874. Epub 2024 Jun 27.
This study aimed to explore and compare the utility of baseline 18 F-PSMA-1007 and 68 Ga-PSMA-11 PET/computed tomography (CT) derived volumetric parameters in initial risk stratification and prediction of prostate cancer (PCa) metastasis.
Forty treatment-naïve, biopsy-proven intermediate-/high-risk PCa patients were prospectively recruited. Each patient underwent PET/CT with 68 Ga-PSMA-11 and 18 F-PSMA-1007 (within 2 weeks). The maximum and mean standardized uptake values (SUVmax and SUVmean) of primary tumor, prostate PSMA-tumor volume (PSMA-TVp), and prostate total lesion PSMA (TL-PSMAp) were measured.
PSMA-TVp and TL-PSMAp (with both radiotracers) mostly exhibited moderate-to-strong correlation with Gleason score, serum prostate-specific antigen level and clinical tumor stage (Spearman ρ = 0.361-0.783, P -values ≤0.022). Primary tumor SUVmax values were similar across initial risk categories. PSMA-TVp and TL-PSMAp, however, were significantly higher in high-risk PCa compared to intermediate-risk PCa ( P -values ≤0.001). Receiver operating characteristic (ROC) curve analysis revealed that F-PSMA-TVp, Ga-PSMA-TVp, F-TL-PSMAp, and Ga-TL-PSMAp (optimal cutoff values of 20.9, 23.4, 142.5, and 144.8, respectively) could effectively differentiate high-risk from intermediate-risk PCa [area under the ROC curve (AUCs) 0.859-0.898, P -values <0.001] with high sensitivity (68.8-75%) and excellent specificity (100%). PSMA-TVp and TL-PSMAp (with both radiotracers) could predict presence of regional and extraregional nodal metastasis (AUCs 0.703-0.801, P -values ≤0.03) with moderate sensitivity (47.8-70.6%) and excellent specificity (~82.6-94.1%).
Our results suggest that baseline PSMA-PET primary tumor volumetric parameters provide a noninvasive, objective, and accurate index for initial risk stratification and can predict presence of regional and extraregional nodal metastasis in PCa patients. Larger studies are warranted to evaluate their incremental role over conventional parameters.
本研究旨在探索并比较基线18F-PSMA-1007和68Ga-PSMA-11正电子发射断层扫描/计算机断层扫描（PET/CT）得出的体积参数在前列腺癌（PCa）初始风险分层及转移预测中的效用。
前瞻性招募40例未经治疗、活检证实为中/高危PCa的患者。每位患者均接受了68Ga-PSMA-11和18F-PSMA-1007的PET/CT检查（在2周内）。测量原发肿瘤的最大和平均标准化摄取值（SUVmax和SUVmean）、前列腺PSMA肿瘤体积（PSMA-TVp）以及前列腺总病变PSMA（TL-PSMAp）。
PSMA-TVp和TL-PSMAp（两种示踪剂）大多与Gleason评分、血清前列腺特异性抗原水平及临床肿瘤分期呈中度至强相关性（Spearman ρ = 0.361 - 0.783，P值≤0.022）。不同初始风险类别中原发肿瘤的SUVmax值相似。然而，高危PCa的PSMA-TVp和TL-PSMAp显著高于中危PCa（P值≤0.001）。受试者工作特征（ROC）曲线分析显示，F-PSMA-TVp、Ga-PSMA-TVp、F-TL-PSMAp和Ga-TL-PSMAp（最佳截断值分别为20.9、23.4、142.5和144.8）能够有效区分高危和中危PCa [ROC曲线下面积（AUCs）为0.859 - 0.898，P值<0.001]，敏感性高（约68.8 - 75%）且特异性极佳（100%）。PSMA-TVp和TL-PSMAp（两种示踪剂）能够预测区域和区域外淋巴结转移的存在（AUCs为0.703 - 0.801，P值≤0.03），敏感性中等（约47.8 - 70.6%）且特异性极佳（约82.6 - 94.1%）。
我们的结果表明，基线PSMA-PET原发肿瘤体积参数可为初始风险分层提供一种无创、客观且准确的指标，并能预测PCa患者区域和区域外淋巴结转移的存在。有必要开展更大规模的研究来评估它们相对于传统参数的增量作用。
