Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, Georgia.
Department of Radiology, Loyola University Medical Center, Maywood, Illinois.
J Nucl Med. 2019 Nov;60(11):1531-1536. doi: 10.2967/jnumed.119.227033. Epub 2019 Apr 6.
We evaluated F-fluciclovine uptake parameters that correlate with true positivity for local recurrence in non-prostatectomy-treated patients. Twenty-one patients (prostate-specific antigen level, 7.4 ± 6.8 ng/mL) with biochemical recurrence after nonprostatectomy local therapy (radiotherapy and cryotherapy) underwent dual-time-point F-fluciclovine (364.1 ± 37.7 MBq) PET/CT from pelvis to diaphragm. Prostatic uptake over background was delineated and coregistered to a prostate-biopsy-planning ultrasound. Transrectal biopsies of F-fluciclovine-defined targets were completed using a 3-dimensional visualization and navigation platform. Histologic analyses of lesions were completed. Lesion characteristics including SUV, target-to-background ratio (TBR), uptake pattern, and subjective reader's suspicion level were compared between true-positive (malignant) and false-positive (benign) lesions. Univariate analysis was used to determine the association between PET and histologic findings. Receiver-operating-characteristic curves were plotted to determine discriminatory cutoffs for TBR. Statistical significance was set at a value of less than 0.05. Fifty lesions were identified in 21 patients on PET. Seventeen of 50 (34.0%) targeted lesions in 10 of 21 patients were positive for malignancy. True-positive lesions had a significantly higher SUV (6.62 ± 1.70 vs. 4.92 ± 1.27), marrow TBR (2.57 ± 0.81 vs. 1.69 ± 0.51), and blood-pool TBR (4.10 ± 1.17 vs. 2.99 ± 1.01) than false-positive lesions at the early time point ( < 0.01) and remained significant at the delayed time point, except for blood-pool TBR. Focal uptake (odds ratio, 12.07; 95% confidence interval, 2.98-48.80; < 0.01) and subjective highest suspicion level (odds ratio, 10.91; 95% confidence interval, 1.19-99.69; = 0.03) correlated with true positivity. Using the receiver-operating-characteristic curve, optimal cutoffs for marrow TBR were 1.9 (area under the curve, 0.82) and 1.8 (area under the curve, 0.85) at early and delayed imaging, respectively. With these cutoffs, 15 of 17 malignant lesions were identified at both time points; however, fewer false-positive lesions were detected at the delayed time point (5/33) than at the early time point (11/33). True positivity of F-fluciclovine-targeted prostate biopsy in non-prostatectomy-treated patients correlates with focal uptake, TBR (blood pool and marrow), and subjective highest suspicion level. A marrow TBR of 1.9 at the early time point and 1.8 at the delayed time point had optimal discriminating capabilities. Despite the relatively low intraprostate positive predictive value (34.0%) with F-fluciclovine, application of these parameters to interpretative criteria may improve true positivity in the treated prostate.
我们评估了与非前列腺切除术治疗患者局部复发的真正阳性相关的 F-氟代赖氨酸摄取参数。21 名（前列腺特异性抗原水平，7.4±6.8ng/mL）在非前列腺切除术局部治疗（放疗和冷冻治疗）后生化复发的患者接受了来自骨盆到膈肌的双时相 F-氟代赖氨酸（364.1±37.7MBq）PET/CT。前列腺摄取超过背景被描绘出来，并与前列腺活检计划超声进行配准。使用三维可视化和导航平台完成了 F-氟代赖氨酸定义目标的经直肠活检。完成了对病变的组织学分析。比较了真正阳性（恶性）和假阳性（良性）病变之间的病变特征，包括 SUV、目标与背景比（TBR）、摄取模式和主观读者的怀疑程度。使用单变量分析来确定 PET 和组织学发现之间的关联。绘制受试者工作特征曲线以确定 TBR 的鉴别截止值。 统计显著性设定为 值小于 0.05。在 21 名患者的 PET 上发现了 50 个病变。在 21 名患者中的 10 名患者的 50 个靶向病变中的 17 个（34.0%）为恶性病变。真正的阳性病变在早期（ < 0.01）和延迟时间点（除了血池 TBR）均具有更高的 SUV（6.62±1.70比 4.92±1.27）、骨髓 TBR（2.57±0.81比 1.69±0.51）和血池 TBR（4.10±1.17比 2.99±1.01），而假阳性病变则具有更高的 SUV（6.62±1.70 比 4.92±1.27）、骨髓 TBR（2.57±0.81 比 1.69±0.51）和血池 TBR（4.10±1.17 比 2.99±1.01）。局灶性摄取（比值比，12.07；95%置信区间，2.98-48.80； < 0.01）和主观最高怀疑程度（比值比，10.91；95%置信区间，1.19-99.69； = 0.03）与真正的阳性相关。使用受试者工作特征曲线，骨髓 TBR 的最佳截止值分别为早期（曲线下面积，0.82）和延迟（曲线下面积，0.85）时的 1.9（曲线下面积，0.82）和 1.8（曲线下面积，0.85）。使用这些截止值，17 个恶性病变中的 15 个在两个时间点均被识别；然而，与早期时间点（11/33）相比，延迟时间点（5/33）检测到的假阳性病变更少。非前列腺切除术治疗患者的 F-氟代赖氨酸靶向前列腺活检的真正阳性与局灶性摄取、TBR（血池和骨髓）和主观最高怀疑程度相关。早期和延迟时间点的骨髓 TBR 为 1.9 和 1.8 时具有最佳的鉴别能力。尽管 F-氟代赖氨酸的前列腺内阳性预测值（34.0%）相对较低，但将这些参数应用于解释标准可能会提高治疗前列腺中的真正阳性率。
