Preoperative evaluation of the association of ADC with diffusion-weighted imaging and PSA in prostate cancer

Abstract

Objective To study the changes of the apparent diffusion coefficient (ADC) values and the association with serum prostate specific antigen (PSA) in prostate cancer patients. Methods Diffusion-weighted echo-planar imaging (EPI) sequences were performed in 47 patients with biopsy proved locally confined prostate cancer,age ranged from 56 to 86 years.t-PSA range,f-PSA range and F/T range in serum of all patients were 1.41-603.16 ng/ml,0.10-12.29 ng/ml and 0.01-0.36,respectively.The patients'clinical staging were 2 cases of stage A,18 cases of stage B and 27 cases of stage C,among which 1 cases were well differentiated (Gleason 2-4), 23 were moderately differentiated (Gleason 5-7) and 23 were poorly differentiated(Gleason 8-10),respectively.Images were obtained with a diffusion factor of 800 s/mm2.According to the pathological results obtained by ultrasound guided systemic biopsy,the locations of the prostate cancerous region were marked as one or more of the sextants.The ADC values of every region and whole gland were measured and analyzed with ROC curve.Correlations between the ADC and t-PSA,f-PSA,F/T ratios were analyzed.Results Acceptable images for ADC measurement were obtained in all cases.The mean ADC values of cancerous and noncancerous regions in 47 prostate patients were(1.29±0.28)×10-3mm2/s and (1.78+0.32)×10-3mm2/s and significant difference was noted in ADC values between cancerous and noncancerous regions(t=13.58,P＜0.01).Negative correlation was found between the ADC values and t-PSA,f-PSA,(γ=-0.353,P＜0.01;γ=-O.401.P＜0.01).There were no significant associations between the ADC values and F/T(γ=-0.123,P＞0.05). Conclusions The ADC values in cancerous regions were negatively correlated with t-PSA,f-PSA. Measurement of ADCs,combined with serum PSA,might be useful to accurate location and preoperative assessment of tumor. Key words: Prostatic neoplasms; Carcinoma; Magnetic resonance imaging; Prostate specific antigen