Usefulness of a Pharmacokinetic Model Based on Dynamic Contrast-enhanced MRI for the Detection and Localization of Prostate Cancer

Department of Radiology, Ulsan University Hospital, South Korea From the Department of Radiology, Asan Medical Center, University of Ulsan, South Korea. Received May 17, 2007; Accepted August 2, 2007 Address reprint requests to : Jeong Kon Kim, M.D., Department of Radiology, Asan Medical Center, University of Ulsan, 388-1 Poongnap-dong, Songpa-gu, Seoul 138-736, South Korea. Tel. 82-2-3010-4355 Fax. 82-2-476-0090 E-mail: rialto@ amc.seoul.kr Purpose: To investigate the usefulness of a pharmacokinetic model based on dynamic contrast-enhanced (DCE) MR imaging for the detection and localization of prostate cancer. Materials and Methods: Forty-four patients that had undergone radical prostatectomy for prostate cancer and dynamic contrast enhanced (DCE) MR imaging (slice thickness, 4 mm; time resolution of each set, 5 seconds), were enrolled in the study. From the pharmacokinetic model, the time of arrival, and the parameters Ah, Kep, and Kel were extracted and were compared for cancerous tissue and non-cancerous tissue in the central gland and peripheral zone. The diagnostic performance of each parameter for differentiating cancerous tissue from non-cancerous tissue was evaluated using receiver-operating-characteristics analysis. Results: The Kep and Kel values were significantly greater in cancerous tissue (0.13 sec1 ± 0.14 and 1.59 × 103 sec1 ± 1.35 × 103) than in non-cancerous tissue from the central gland (0.03 sec1 ± 0.02 and 0.26 × 103 sec1 ± 1.24 × 103) and peripheral zone (0.04 sec1 ± 0.07 and 0.58 × 103 sec1 ± 1.98 ×103) (p < 0.05). The area under the ROC curve for differentiating cancerous from non-cancerous tissue was 0.850 (95% CI, 0.778-0.876) for Kep and 0.814 (95% CI, 0.737-0.876) for Kel. Conclusion: Kep and Kel are useful perfusion parameters for the differentiation of prostate cancerous tissue from non-cancerous tissue.