Department of Radiology, Kurashiki Central Hospital, 1-1-1 Miwa, Kurashiki 710-8602, Japan.
Jpn J Radiol. 2011 Aug;29(7):488-94. doi: 10.1007/s11604-011-0586-6. Epub 2011 Sep 1.
The aim of this study was to determine the cutoff level of apparent diffusion coefficient (ADC) values for diagnosing prostate cancer.
A total of 45 consecutive patients with prostate cancer who underwent diffusion-weighted magnetic resonance imaging (MRI) with ADC maps before radical prostatectomy were included in this retrospective study. MRI findings were correlated retrospectively with histopathological results of surgical specimens. Comparisons of ADC values between cancer and noncancer areas were performed with the two-tailed unequal variance t-test. The cutoff ADC level was determined in a way to achieve the best accuracy for detecting prostate cancer.
The mean ADC value of all the cancer lesions (n =60) was 1.04 ± 0.31 (×10(-3) mm(2)/s). In the peripheral zone, the mean ADC values of cancer lesions and noncancer areas were 1.07 ± 0.35 and 1.94 ± 0.31, respectively (P < 0.001). In the transition zone, the mean ADC values of cancer lesions and noncancer areas were 1.00 ± 0.22 and 1.56 ± 0.14, respectively (P<0.001). The cutoff level for the ADC value was determined to be 1.35×10(-3) mm(2)/s. It provided sensitivity, specificity, and accuracy of 88%, 96%, and 93%, respectively.
The cutoff ADC level determined on the basis of the results obtained from radical prostatectomy specimens can help differentiate malignant from nonmalignant lesions.
本研究旨在确定表观扩散系数（ADC）值用于诊断前列腺癌的截断值。
回顾性分析 45 例经根治性前列腺切除术前行扩散加权磁共振成像（MRI）并获得 ADC 图的前列腺癌患者的资料。MRI 结果与手术标本的组织病理学结果进行回顾性比较。采用双尾不等方差 t 检验比较癌区和非癌区 ADC 值的差异。通过确定达到最佳诊断准确性的 ADC 截断值。
所有癌灶（n = 60）的平均 ADC 值为 1.04 ± 0.31（×10(-3) mm(2)/s）。在周边区，癌灶和非癌区的平均 ADC 值分别为 1.07 ± 0.35 和 1.94 ± 0.31（P < 0.001）。在移行区，癌灶和非癌区的平均 ADC 值分别为 1.00 ± 0.22 和 1.56 ± 0.14（P < 0.001）。ADC 值的截断水平确定为 1.35×10(-3) mm(2)/s。它提供了 88%、96%和 93%的敏感性、特异性和准确性。
基于根治性前列腺切除术后标本得出的 ADC 截断值有助于鉴别良恶性病变。
