Jain Harsh, Sood Rajeev, Faridi Mohammad Shazib, Goel Hemant, Sharma Umesh
Department of Urology & Renal Transplant, Atal Bihari Vajpayee Institute of Medical Sciences & Dr Ram Manohar Lohia Hospital, New Delhi, India.
Cent European J Urol. 2021;74(3):315-320. doi: 10.5173/ceju.2021.0084.R3. Epub 2021 Jul 8.
Prostate-specific membrane antigen (PSMA) positron emission tomography/ computed tomography (PET-CT) is widely used as a staging tool for patients with prostate cancer (PCa). The objective of the study is to assess the diagnostic accuracy of 68Ga-PSMA-PET/CT for PCa, which may help us avoid unnecessary biopsies in patients with intermediate prostate-specific antigen (PSA) levels.
In this prospective study, 81 patients suspected of PCa, with either raised PSA between 4-20 ng/ml or abnormal digital rectal examination (DRE) findings were included. 68Ga-PSMA-PET/CT was performed for all patients followed by transrectal ultrasound (TRUS) guided prostate biopsy. SUVmax (maximum standardized uptake value) was measured and correlated with biopsy results.
Out of 81 patients, 31 (38.3%) patients were found to have malignancy on biopsy. Median SUVmax of biopsy positive patients was 10.4 (IQR 6.5-16.1) and biopsy negative patients (n=50) was 3.5 (IQR 1-4.9), (p <0.001). At a cut-off of 6.15, 68GA-PSMA-PET/CT demonstrated sensitivity of 84%, specificity of 80%, positive predictive value of 72.2%, negative predictive value of 88.9% and accuracy of 81.5% with an AUC of 0.876 (95% CI: 0.799-0.953, p <0.001).
The 68Ga-PSMA-PET/CT helps to localize suspicious lesions and improving the detection of primary prostate cancer. Our findings indicate a significant correlation of SUVmax values with biopsy results. We were also able to determine a cut-off value of SUVmax below which prostate biopsy can be avoided in selected patients.
前列腺特异性膜抗原（PSMA）正电子发射断层扫描/计算机断层扫描（PET-CT）被广泛用作前列腺癌（PCa）患者的分期工具。本研究的目的是评估68Ga-PSMA-PET/CT对PCa的诊断准确性，这可能有助于我们避免对前列腺特异性抗原（PSA）水平处于中等范围的患者进行不必要的活检。
在这项前瞻性研究中，纳入了81例疑似PCa的患者，这些患者的PSA在4-20 ng/ml之间升高或直肠指检（DRE）结果异常。对所有患者进行了68Ga-PSMA-PET/CT检查，随后进行经直肠超声（TRUS）引导下的前列腺活检。测量了最大标准化摄取值（SUVmax）并将其与活检结果相关联。
在81例患者中，31例（38.3%）经活检发现患有恶性肿瘤。活检阳性患者的SUVmax中位数为10.4（四分位间距6.5-16.1），活检阴性患者（n = 50）为3.5（四分位间距1-4.9），（p <0.001）。在截断值为6.15时，68GA-PSMA-PET/CT显示出84%的敏感性、80%的特异性、72.2%的阳性预测值、88.9%的阴性预测值和81.5%的准确性，曲线下面积（AUC）为0.876（95%置信区间：0.799-0.953，p <0.001）。
68Ga-PSMA-PET/CT有助于定位可疑病变并提高原发性前列腺癌的检测率。我们的研究结果表明SUVmax值与活检结果存在显著相关性。我们还能够确定一个SUVmax的截断值，低于该值时在选定患者中可避免进行前列腺活检。
