Purpose

Prostate-specific membrane antigen (PSMA)-targeted PET is increasingly used for staging prostate cancer (PCa) with high accuracy to detect significant PCa (sigPCa). [⁶⁸ Ga]PSMA-11 PET/MRI-guided biopsy showed promising results but also persisting limitation of sampling error, due to impaired image fusion. We aimed to assess the possibility of intraoperative quantification of [¹⁸F]PSMA-1007 PET/CT uptake in core biopsies as an instant confirmation for accurate lesion sampling.

Methods

In this IRB-approved, prospective, proof-of-concept study, we included five consecutive patients with suspected PCa. All underwent [¹⁸F]PSMA-1007 PET/CT scans followed by immediate PET/CT-guided and saturation template biopsy (3.1 ± 0.3 h after PET). The activity in biopsy cores was measured as counts per minute (cpm) in a gamma spectrometer. Pearson’s test was used to correlate counts with histopathology (WHO/ISUP), tumor length, and membranous PSMA expression on immunohistochemistry (IHC).

Results

In 43 of 113 needles, PCa was present. The mean cpm was overall significantly higher in needles with PCa (263 ± 396 cpm) compared to needles without PCa (73 ± 44 cpm, p < 0.001). In one patient with moderate PSMA uptake (SUV_max 8.7), 13 out of 24 needles had increased counts (100–200 cpm) but only signs of inflammation and PSMA expression in benign glands on IHC. Excluding this case, ROC analysis resulted in an AUC of 0.81, with an optimal cut-off to confirm PCa at 75 cpm (sens/spec of 65.1%/87%). In all 4 patients with PCa, the first or second PSMA PET-guided needle was positive for sigPCa with high counts (156–2079 cpm).

Conclusions

[¹⁸F]PSMA-1007 uptake in PCa can be used to confirm accurate lesion sampling of the dominant tumor intraoperatively. This technique could improve confidence in imaging-based biopsy guidance and reduce the need for saturation biopsy.

Trial registration number

NCT03187990, 15/06/2017.

中文翻译：

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热针可在疑似前列腺癌患者中使用 [18F]PSMA-1007 PET/CT 引导活检术确认准确的病灶取样

目的

前列腺特异性膜抗原 (PSMA) 靶向 PET 越来越多地用于对前列腺癌 (PCa) 进行高精度分期，以检测显着的 PCa (sigPCa)。[ ⁶⁸  Ga]PSMA-11 PET/MRI 引导的活检显示出有希望的结果，但由于图像融合受损，采样误差也持续受到限制。我们旨在评估术中量化核心活检中 [ ¹⁸ F]PSMA-1007 PET/CT 摄取的可能性，以作为准确病灶取样的即时确认。

方法

在这项 IRB 批准的前瞻性概念验证研究中，我们连续纳入了 5 名疑似 PCa 患者。所有人都接受了 [ ¹⁸ F]PSMA-1007 PET/CT 扫描，随后立即进行 PET/CT 引导和饱和模板活检（PET 后 3.1 ± 0.3 小时）。活检芯中的活性在伽马光谱仪中测量为每分钟计数 (cpm)。Pearson 检验用于将计数与组织病理学 (WHO/ISUP)、肿瘤长度和免疫组织化学 (IHC) 上的膜性 PSMA 表达相关联。

结果

113 针中有 43 针存在 PCa。与没有 PCa 的针头相比（73 ± 44 cpm， p  < 0.001），带有 PCa 的针头的平均 cpm 总体显着更高（263 ± 396 cpm ）。_{在一名具有中度 PSMA 摄取（SUV最大}8.7）的患者中，24 根针中有 13 根针数增加（100-200 cpm），但在 IHC 上只有良性腺体中的炎症和 PSMA 表达迹象。排除这种情况，ROC 分析得出的 AUC 为 0.81，确认 PCa 的最佳截止值为 75 cpm（感官/规格为 65.1%/87%）。在所有 4 名 PCa 患者中，第一个或第二个 PSMA PET 引导的针对 sigPCa 呈阳性，且计数高（156-2079 cpm）。

结论

[ ¹⁸ F]PSMA-1007 在 PCa 中的摄取可用于确认术中优势肿瘤的准确病灶取样。这种技术可以提高对基于成像的活检指导的信心，并减少对饱和活检的需求。

试用注册号

NCT03187990，2017 年 6 月 15 日。