Abstract：
Despite a high detection rate of 68Ga-prostate-specific membrane antigen (PSMA) PET/CT in biochemical recurrence (BCR) of prostate cancer, a significant proportion of men have negative 68Ga-PSMA-11 PET/CT results. Gastrin-releasing peptide receptor, targeted by the copper-chelated bombesin analog 64Cu-sarcophagine-bombesin (SAR-BBN) PET/CT, is also overexpressed in prostate cancer. In this prospective imaging study, we investigate the detection rate of 64Cu-SAR-BBN PET/CT in patients with BCR and negative or equivocal 68Ga-PSMA-11 PET/CT results. Methods: Men with confirmed adenocarcinoma of the prostate, prior definitive therapy, and BCR (defined as a prostate-specific antigen [PSA] level > 0.2 ng/mL) with negative or equivocal 68Ga-PSMA-11 PET/CT results within 3 mo were eligible for enrollment. 64Cu-SAR-BBN PET/CT scans were acquired at 1 and 3 h after administration of 200 MBq of 64Cu-SAR-BBN, with further delayed imaging undertaken optionally at 24 h. PSA (ng/mL) was determined at baseline. All PET (PSMA and bombesin) scans were assessed visually. Images were read with masking of the clinical results by 2 experienced nuclear medicine specialists, with a third reader in cases of discordance. Accuracy was defined using a standard of truth that included biopsy confirmation, confirmatory imaging, or response to targeted treatment. Results: Twenty-five patients were enrolled. Prior definitive therapy was radical prostatectomy (n = 24, 96%) or radiotherapy (n = 1, 4%). The median time since definitive therapy was 7 y (interquartile range [IQR], 4-11 y), and the Gleason score was 7 or less (n = 15, 60%), 8 (n = 3, 12%), or 9 (n = 7, 28%). The median PSA was 0.69 ng/mL (IQR, 0.28-2.45 ng/mL). Baseline PSMA PET scans were negative in 19 patients (76%) and equivocal in 6 (24%). 64Cu-SAR-BBN PET-avid disease was identified in 44% (11/25): 12% (3/25) with local recurrence, 20% (5/25) with pelvic node metastases, and 12% (3/25) with distant metastases. The κ-score between readers was 0.49 (95% CI, 0.16-0.82). Patients were followed up for a median of 10 mo (IQR, 9-12 mo). Bombesin PET/CT results were true-positive in 5 of 25 patients (20%), false-positive in 2 of 25 (8%), false-negative in 7 of 25 (28%), and unverified in 11 of 25 (44%). Conclusion: 64Cu-SAR-BBN PET/CT demonstrated sites of disease recurrence in 44% of BCR cases with negative or equivocal 68Ga-PSMA-11 PET/CT results. Further evaluation to confirm diagnostic benefit is warranted.
摘要：
尽管68Ga-前列腺特异性膜抗原（PSMA）PET/CT在前列腺癌的生化复发（BCR）中的检出率很高，相当比例的男性68Ga-PSMA-11PET/CT结果阴性.胃泌素释放肽受体,目标为铜螯合铃蛋白类似物64Cu-sarcohagine-铃蛋白（SAR-BBN）PET/CT，在前列腺癌中也过表达。在这项前瞻性成像研究中，我们调查了64Cu-SAR-BBNPET/CT在BCR和68Ga-PSMA-11PET/CT结果阴性或模棱两可的患者中的检出率。方法:男性前列腺腺癌,先前的确定性治疗，和BCR(定义为前列腺特异性抗原[PSA]水平>0.2ng/mL),且3个月内68Ga-PSMA-11PET/CT结果为阴性或模棱两可,符合纳入条件.在给予200MBq的64Cu-SAR-BBN后1和3小时获得64Cu-SAR-BBNPET/CT扫描,任选在24小时进行进一步延迟成像。在基线时测定PSA(ng/mL)。对所有PET(PSMA和铃蛋白)扫描进行视觉评估。由2名经验丰富的核医学专家在掩盖临床结果的情况下读取图像，在不和谐的情况下与第三个读者。准确性是使用包括活检确认在内的真实标准来定义的，证实性成像,或对靶向治疗的反应。结果：共纳入25例患者。先前的确定性治疗是根治性前列腺切除术（n=24，96％）或放射疗法（n=1，4％）。自明确治疗以来的中位时间为7年(四分位数间距[IQR]，4-11y)，格里森评分为7分或更低(n=15，60%)，8(n=3，12%)，或9（n=7，28%）。PSA中位数为0.69ng/mL（IQR，0.28-2.45ng/mL)。19例患者（76％）的基线PSMAPET扫描为阴性，6例（24％）的不确定。在44％（11/25）：12％（3/25）的局部复发中发现64Cu-SAR-BBNPET-aid疾病，20%（5/25）伴有盆腔淋巴结转移，12％（3/25）伴有远处转移。读者之间的κ评分为0.49（95%CI，0.16-0.82）。患者的中位随访时间为10个月(IQR，9-12个月）。25例患者中有5例（20％）的BombesinPET/CT结果为真阳性，25人中有2人假阳性（8%），25人中有7人假阴性（28%），25人中有11人(44%)未经核实。结论：64Cu-SAR-BBNPET/CT在44％的BCR病例中显示疾病复发部位，68Ga-PSMA-11PET/CT结果阴性或模棱两可。需要进一步评估以确认诊断益处。
