Diffusion-weighted imaging of prostate cancer: Correlation between apparent diffusion coefficient values and tumor proliferation

Purpose To investigate whether the apparent diffusion coefficient (ADC) values of prostate cancer (PCa) are able to reflect tumor proliferation. Materials and Methods The clinical and pathological information for 38 patients with PCa and 33 patients with benign prostate hyperplasia (BPH) were studied. Examination of the patients was performed using a 1.5 T superconducting magnetic scanner equipped with a pelvic phased‐array multicoil. Diffusion‐weighted images (DWIs) were acquired using an echo‐planar imaging sequence. The ADC values of PCa, BPH, and peripheral zone (PZ) were calculated. The cellularity of PCa was recorded based on hematoxylin and eosin staining. The proliferating cell nuclear antigen (PCNA) was detected using an immunohistochemical technique. Results The ADC values of PCa, BPH, and PZ were 49.32 ± 12.68 × 10−5 mm2/s, 86.73 ± 26.75 × 10−5 mm2/s, and 126.25 ± 27.21 × 10−5 mm2/s, respectively. The ADC values of PCa were lower than those of BPH and PZ (P < 0.05). The cellularity and PCNA labeling index (LI) of PCa were higher than those of BPH (P < 0.05). The ADC values of PCa were negatively correlated with those of cellularity and PCNA LI (r = −0.646 and −0.446, respectively; P < 0.05). Conclusion The ADC values of PCa can reveal the differences in proliferative activity between PCa and BPH. These values are therefore able to predict the proliferative rate of variously differentiated prostate cancers. J. Magn. Reson. Imaging 2009;29:1360–1366. © 2009 Wiley‐Liss, Inc.