Department of Nuclear Medicine, the First Affiliated Hospital of Guangzhou Medical University, 151 Yanjiangxi Road, Guangzhou, 510120, Guangdong Province, China.
Department of Nuclear Medicine, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, 160 Pujian Road, Shanghai, 200127, China.
Eur J Nucl Med Mol Imaging. 2024 Jan;51(2):581-589. doi: 10.1007/s00259-023-06466-z. Epub 2023 Oct 11.
The objective of this study was to evaluate the diagnostic performance and image quality of total-body positron emission tomography/computed tomography (PET/CT) imaging using a half-dose of [ Ga]Ga-prostate specific membrane antigen ([ Ga]Ga-PSMA) radiotracer, compared to conventional short axial field-of-view PET/CT imaging using a full dose of [ Ga]Ga-PSMA.
This retrospective study enrolled 52 patients with biochemical recurrent (BCR) prostate cancer after radical prostatectomy who underwent total-body PET/CT with a half-dose (0.9-1.1 MBq/kg) of [ Ga]Ga-PSMA. These patients were matched by baseline characteristics to another 52 BCR patients after prostatectomy who underwent conventional PET/CT with a full dose (1.8-2.2 MBq/kg) of [ Ga]Ga-PSMA. The half-dose group was further divided into 5-min (G5) and 2-min (G2) acquisition subgroups. Image quality was assessed through subjective analysis using a 5-point scale and objective measurements of standard uptake value maximum (SUVmax), standard uptake value mean (SUVmean), background variation (BV) of the liver, blood pool, and parotid glands. Additionally, SUVmax and tumor-to-background ratio (TBR) were calculated for lesions.
No significant difference in subjective image quality was found between the G2 and full-dose groups (p > 0.05). PET/CT image quality was significantly higher for the G5 versus G2 (p < 0.001) and full-dose groups (p < 0.001). TBR did not differ between the G2 and full-dose groups (4.23 ± 5.21 vs 4.22 ± 3.97, p = 0.99). Liver BV was significantly lower for G2 versus full-dose groups (0.16 ± 0.03 vs 0.20 ± 0.05, p < 0.001).
Total-body PET/CT with a half-dose [ Ga]Ga-PSMA yields image quality superior or comparable to that of conventional PET/CT. The utilization of total-body [ Ga]Ga-PSMA PET/CT meets the diagnostic demands of BCR patients, particularly those who exhibit reduced tolerance to prolonged horizontal positioning and scan durations, while simultaneously reducing radiation exposure for the subjects.
本研究旨在评估使用半剂量[Ga]Ga-前列腺特异性膜抗原（[Ga]Ga-PSMA）放射性示踪剂进行全身正电子发射断层扫描/计算机断层扫描（PET/CT）成像的诊断性能和图像质量，与使用全剂量[Ga]Ga-PSMA 进行常规短轴向视野 PET/CT 成像相比。
这项回顾性研究纳入了 52 例接受根治性前列腺切除术后生化复发（BCR）的前列腺癌患者，这些患者接受了全身[Ga]Ga-PSMA 半剂量（0.9-1.1 MBq/kg）的 PET/CT。这些患者通过基线特征与另外 52 例接受前列腺切除术后全剂量（1.8-2.2 MBq/kg）[Ga]Ga-PSMA 常规 PET/CT 的 BCR 患者相匹配。半剂量组进一步分为 5 分钟（G5）和 2 分钟（G2）采集亚组。通过使用 5 分制进行主观分析和测量标准摄取值最大值（SUVmax）、标准摄取值平均值（SUVmean）、肝脏、血池和腮腺的背景变异（BV），对图像质量进行评估。此外，还计算了病变的 SUVmax 和肿瘤与背景比（TBR）。
G2 组和全剂量组之间的主观图像质量无显著差异（p>0.05）。与 G2 组和全剂量组相比，G5 组的 PET/CT 图像质量显著更高（p<0.001）。G2 组与全剂量组之间的 TBR 无差异（4.23±5.21 比 4.22±3.97，p=0.99）。G2 组的肝脏 BV 明显低于全剂量组（0.16±0.03 比 0.20±0.05，p<0.001）。
全身[Ga]Ga-PSMA PET/CT 半剂量可获得优于或等同于常规 PET/CT 的图像质量。全身[Ga]Ga-PSMA PET/CT 的应用满足了 BCR 患者的诊断需求，特别是那些对长时间水平定位和扫描持续时间耐受性降低的患者，同时减少了受检者的辐射暴露。
