Barr Richard G, Memo Richard, Schaub Carl R
Northeast Ohio Medical University, Rootstown, OH 44512, USA.
Ultrasound Q. 2012 Mar;28(1):13-20. doi: 10.1097/RUQ.0b013e318249f594.
This prospective study was to evaluate shear wave elastography (SWE) in the detection of prostate cancer (PC).
Patients scheduled for a transrectal ultrasound (TRUS) biopsy of the prostate because of elevated prostate-specific antigen levels or abnormal digital rectal examination result underwent a standard TRUS and SWE. A second TRUS examination and sextant biopsy by a second physician blinded to SWE results was then performed. Pathologic result was reviewed, and sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) were calculated.
A total of 53 patients (318 sextants) participated in the study. Mean age was 64.2 years (range, 53-79 years). A total of 26 foci of PC were detected in 11 patients (20.7%). On the basis of the receiver operating characteristic curve, a value of 37 kPa was used as the cutoff between benign and malignant. This produced a sensitivity of 96.2% (25/26), a specificity of 96.2% (281/292), a PPV of 69.4% (25/36), and an NPV of 99.6% (281/282). Six (55%) of 11 false-positive samples were secondary to benign calcifications. The Young modulus of PC ranged from 30 to 110 kPa (mean [SD], 58.0 [20.7] kPa). At the patient level, if a cutoff of 40 kPa was used, all PCs would have been detected, and the positive biopsy rate would be 11 (50%) of 22 compared to 11 (20.8%) of 53 without SWE--a 140% increase in the positive biopsy rate.
Shear wave elastography has a high sensitivity, specificity, PPV, and NPV for the detection of PC. With a high PPV, patients with elevated prostate-specific antigen levels or abnormal results in the digital rectal examination and negative SWE may not require biopsy. This could significantly reduce the negative biopsy rate in PC detection.
本前瞻性研究旨在评估剪切波弹性成像（SWE）在前列腺癌（PC）检测中的应用。
因前列腺特异性抗原水平升高或直肠指检结果异常而计划接受经直肠超声（TRUS）引导下前列腺穿刺活检的患者，先进行标准的TRUS和SWE检查。然后由另一位对SWE结果不知情的医生进行第二次TRUS检查和分区活检。对病理结果进行回顾，并计算敏感性、特异性、阴性预测值（NPV）和阳性预测值（PPV）。
共有53例患者（318个分区）参与研究。平均年龄为64.2岁（范围53 - 79岁）。11例患者（20.7%）共检测到26个PC病灶。根据受试者操作特征曲线，将37 kPa作为良恶性的临界值。其敏感性为96.2%（25/26），特异性为96.2%（281/292），PPV为69.4%（25/36），NPV为99.6%（281/282）。11例假阳性样本中有6例（55%）继发于良性钙化。PC的杨氏模量范围为30至110 kPa（平均[标准差]，58.0 [20.7] kPa）。在患者层面，如果采用40 kPa的临界值，所有PC都能被检测到，阳性活检率将为22例中的11例（50%），而未使用SWE时为53例中的11例（20.8%）——阳性活检率提高了140%。
剪切波弹性成像在PC检测中具有较高的敏感性、特异性、PPV和NPV。鉴于较高的PPV，前列腺特异性抗原水平升高或直肠指检结果异常且SWE为阴性的患者可能无需进行活检。这可显著降低PC检测中的阴性活检率。
