Gupta Manoj, Choudhury Partha Sarathi, Rawal Sudhir, Goel Harish Chandra, Singh Amitabh, Talwar Vineet, Sahoo Saroj Kumar
Department of Nuclear Medicine, Rajiv Gandhi Cancer Institute and Research Centre, Sector-5, Rohini, Delhi, (110085), India.
Hell J Nucl Med. 2017 Sep-Dec;20 Suppl:156.
Current imaging modalities for prostate cancer (PC) had limitations for risk stratification and staging. Magnetic resonance imaging (MRI) frequently underestimated lymphatic metastasis while bone scintigraphy often had diagnostic dilemmas. Prostatic specific membrane antigen (PSMA) positron emission tomography-computed tomography (PET/CT) has been remarkable in diagnosing PC recurrence and staging. We hypothesized it can become one-stop-shop for initial risk stratification and staging.
Ninety seven PSMA PET-CT studies were re analysed for tumor node metastases (TNM) staging and risk stratification of lymphatic and distant metastases proportion. The histopathology of 23/97 patients was available as gold standard. Chi-square test was used for proportion comparison. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), over-estimation, under-estimation and correct-estimation of T and N stages were calculated. Cohen's kappa coefficient (k) was derived for inter-rater agreement.
Lymphic or distant metastases detection on PSMA PET/CT increased significantly with increase in risk category. PSMA PET/CT sensitivity, specificity, PPV and NPV for extra prostatic extension (EPE), seminal vesicle invasion (SVI) and lymphatic metastases were 63.16%, 100%, 100%, 36.36% & 55%, 100%, 100%, 25% and 65.62%, 99.31%, 87.50%, 97.53%, respectively. Cohen's kappa coefficient showed substantial agreement between PSMA PET/CT and histopathological lymphic metastases (κ 0.734) however, it was just in fair agreement (κ 0.277) with T stage. PSMA PET/CT over-estimated, under-estimated and correct-estimated T and N stages in 8.71%, 39.13%, 52.17% and 8.71%, 4.35%, 86.96% cases, respectively.
We found that PSMA PET/CT has potential for initial risk stratifications with reasonable correct estimation for N stage. However, it can underestimate T stage. Hence, we suggest that PSMA PET/CT should be used for staging and initial risk stratification of PC as one-stop-shop with regional MRI in surgically resectable cases.
目前用于前列腺癌（PC）的成像方式在风险分层和分期方面存在局限性。磁共振成像（MRI）经常低估淋巴转移，而骨闪烁显像常常存在诊断难题。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）在诊断PC复发和分期方面表现出色。我们推测它可以成为初始风险分层和分期的一站式检查方法。
对97例PSMA PET-CT研究进行重新分析，以确定肿瘤淋巴结转移（TNM）分期以及淋巴和远处转移比例的风险分层。97例患者中有23例的组织病理学结果可作为金标准。采用卡方检验进行比例比较。计算T和N分期的敏感性、特异性、阳性预测值（PPV）、阴性预测值（NPV）、高估、低估和正确估计情况。计算科恩kappa系数（k）以评估评分者间的一致性。
PSMA PET/CT上淋巴或远处转移的检测随着风险类别的增加而显著增加。PSMA PET/CT对前列腺外扩展（EPE）、精囊侵犯（SVI）和淋巴转移的敏感性、特异性、PPV和NPV分别为63.16%、100%、100%、36.36%以及55%、100%、100%、25%和65.62%、99.31%、87.50%、97.53%。科恩kappa系数显示PSMA PET/CT与组织病理学淋巴转移之间有实质性一致性（κ 0.734），然而，它与T分期仅为中等一致性（κ 0.277）。PSMA PET/CT分别在8.71%、39.13%、52.17%的病例中高估、低估和正确估计T分期，在8.71%、4.35%、86.96%的病例中高估、低估和正确估计N分期。
我们发现PSMA PET/CT在初始风险分层方面具有潜力，对N分期有合理的正确估计。然而，它可能低估T分期。因此，我们建议在可手术切除的病例中，PSMA PET/CT应与局部MRI一起作为PC分期和初始风险分层的一站式检查方法。
