Predicting biochemical recurrence in patients with high-risk prostate cancer using the apparent diffusion coefficient of magnetic resonance imaging

We aimed to investigate whether the apparent diffusion coefficient (ADC) value in diffusion-weighted magnetic resonance imaging predicts the prognoses of patients with high-risk prostate cancer.

A total of 157 patients with high-risk prostate cancer (based on D'Amico's criteria) were included in the analysis. Patients underwent preoperative 3.0 Tesla magnetic resonance imaging within 2 months before radical prostatectomy. Those who received neoadjuvant hormone therapy (33 persons) or radiation therapy (18 persons) were excluded. The ADC of the tumor calculated from 2 b-values (0 and 1,000 s/mm(2)) was measured. Areas under receiver operating characteristics curves were calculated to maximize the accuracy of the ADC value. Based on the obtained cutoff value, the patients were stratified into 2 groups: Group A consisted of patients with ADC values <746×10(-6) mm(2)/s and group B comprised those with ADC values ≥746×10(-6) mm(2)/s.

Group A showed higher rate of lymph positive and biochemical recurrence (BCR) rates than group B. Kaplan-Meier analysis showed that the BCR-free survival rate of group A was much lower than that of group B (p<0.001). On Cox proportional regression analyses, ADC group A (hazard ratio [HR], 3.238, p=0.002) and pathologic lymph node positive (HR, 2.242; p=0.009) were independent predictors of BCR.

In patients with high-risk prostate cancer, ADC value is significantly associated with BCR-free survival. Therefore, the ADC value is a useful tool for predicting the prognoses of these high-risk patients.

Investigative and clinical urology. 2017 Jan 09 [Epub]

Min Young Yoon, Juhyun Park, Jeong Yeon Cho, Chang Wook Jeong, Ja Hyeon Ku, Hyeon Hoe Kim, Cheol Kwak

Department of Urology, Seoul National University Hospital, Seoul, Korea., Department of Radiology, Seoul National University Hospital, Seoul, Korea.