Departments of Nuclear Medicine.
Medical Oncology, BRAIRCH.
Nucl Med Commun. 2020 Nov;41(11):1183-1188. doi: 10.1097/MNM.0000000000001268.
Both bone-scan and cross-sectional imaging are indicated in the staging of high-risk prostate cancer (PCa). However, 68Ga-prostate-specific membrane antigen (PSMA)-PET/computed tomography (CT) has proven to be an excellent tracer for detection of skeletal metastases. The aim of this study was to assess if adding skeletal imaging (with 18F-Fluoride-PET/CT) to 68-Ga-PSMA-PET/CT had any impact on high-risk PCa staging.
Fifty treatment-naive, histopathologically proven, high-risk (European Association of Urology) PCa patients underwent both 68-Ga-PSMA-PET/CT and 18F-Fluoride-PET/CT for staging.
Fluoride-PET/CT detected significantly a higher number of skeletal metastases/patient than PSMA-PET/CT (median 4.5/patient vs 3.0; Wilcoxan-signed-rank-test, P = 0.060) and there was a significantly higher proportion of only Fluoride-avid than only PSMA-avid lesions (McNemar-test P < 0.001). No significant advantage was seen in patient-wise metrics. Most lesions missed by PSMA-PET/CT were in flat bones (25/33). serum prostate specific antigen (S.PSA) showed positive correlation with both, the number of lesions [r(PSMA)-0.555 (P = 0.006) and r(Fluoride)-0.622 (P = 0.001)] as well as tumor to background ratio (TBR) [[r-0.706 (P < 0.001) and 0.516 (P = 0.010)]. Median TBR was significantly higher in PSMA-PET/CT (22.77 vs 16.30; P < 0.001). All three patients with only Fluoride-avid lesions (also not identified in bone-scan) showed biochemical response with additional therapy.
Though, Fluoride-PET/CT detected a higher absolute number of lesions than PSMA-PET/CT, no significant advantage was seen in patient-wise metrics. Fluoride-PET/CT added second-line management in only 3/50 patients, which could have been reduced to 1/50, with more sensitive evaluation of flat bones in PSMA-PET-CT. Therefore, additional skeletal imaging is not needed with 68-Ga-PSMA-PET/CT in initial staging of high-risk PCa.
骨扫描和横断面成像都适用于高危前列腺癌（PCa）的分期。然而，68Ga-前列腺特异性膜抗原（PSMA）-PET/CT 已被证明是检测骨转移的极佳示踪剂。本研究旨在评估在 68Ga-PSMA-PET/CT 基础上增加骨骼成像（18F-氟化物-PET/CT）是否会对高危 PCa 的分期产生任何影响。
50 例未经治疗、组织病理学证实的高危（欧洲泌尿外科学会）PCa 患者均接受 68Ga-PSMA-PET/CT 和 18F-氟化物-PET/CT 进行分期。
氟化物-PET/CT 检测到的骨转移灶数明显多于 PSMA-PET/CT（中位数 4.5/例比 3.0；Wilcoxan 符号秩检验，P=0.060），并且只有氟化物阳性的病变比例明显高于只有 PSMA 阳性的病变（McNemar 检验，P<0.001）。患者指标未见明显优势。PSMA-PET/CT 遗漏的大多数病变位于扁骨（25/33）。血清前列腺特异性抗原（S.PSA）与病变数量呈正相关[r（PSMA）-0.555（P=0.006）和 r（氟化物）-0.622（P=0.001）]以及肿瘤与背景比值（TBR）[r-0.706（P<0.001）和 0.516（P=0.010）]。PSMA-PET/CT 的中位 TBR 明显较高（22.77 比 16.30；P<0.001）。仅氟化物阳性的 3 例患者（在骨扫描中也未发现）在接受额外治疗后显示生化反应。
尽管氟化物-PET/CT 检测到的病变数量明显多于 PSMA-PET/CT，但患者指标未见明显优势。氟化物-PET/CT 仅在 50 例患者中的 3 例中增加了二线治疗，这可能通过在 PSMA-PET-CT 中更敏感地评估扁骨而减少到 1/50。因此，在高危 PCa 的初始分期中，68Ga-PSMA-PET/CT 不需要额外的骨骼成像。
