The Initial Application Of MRI Based Prostate Volume-adjusted Prostate-Specific Antigen In The Diagonosis Of Prostate Disease

Backgroud and PurposeProstate cancer(PCa)screening is driven by serum prostate-specific antigen(PSA),which was considered as tumor marker of PCa.However,PSA is not specific to PCa.Because elevated PSA can also be caused by benigh prostatic disease such as benigh prostatic hyperplasia(BPH).PSA adjusted by prostate volume,such as PSAD(PSA adjusted for total gland volume),PSAT(PSA adjusted for voume of transition zone)play an important role in the diagonosis of prostate disease.The purpose of this study was to determine whether serum PSA adjusted by prostate and transition zone volumes estimated from MRI can improve the diagnosis of PCa from BPH,determine the degree of malignancy of PCa,and predict capsule invasion of PCa.Material and MethodTwo groups of patients were included in this study.The PCa patient group included 308 patient diagnosed wity PCa by TRUS-guided prostate biopsy between January 2016 to December 2017 in our hospital.The BPH patient group included 170 patient who was randomly selected from patients pathological diagnosis of BPH by prostate biopsy or transurethral resection of the prostate(TURP)at the same time.Data collected for this study included: general information,serum PSA,free PSA,F/T,pathological reports of prostate biopsy,TURP,Radical prostatectomy,and data of prostate MRI.All included cases were divided into three groups: BPH,low Gleson score(GS?7)PCa,and high Gleason score(GS>7)PCa.The PSA related parameters of the three groups were compared and analyzed.ResultsA total of 478 cases were included in this study.This study included 170 patients in the BPH group,151 patients in low Gleason scores(GS?7)of PCa,and 157 cases in high Gleason scores(GS ?8)of PCa.PSAD,PSAT,(F/T)/PSAD,(F/T)/PSAT were statistically different between BPH and PCa,and had higher diagnostic value for the diagnosis of PCa(AUC all> 0.8)than PSA and F/T in PSA range 4-10ng/ml.And PSAD?0.17 ± 0.02,PSAT?0.38±0.02,(F/T)/PSAD ? 1.02,(F/T)/PSAT ? 0.38 suggested that it may be PCa in PSA range 4-10ng/ml.At PSA 10-20 ng/ml,PSAD,PSAT,(F/T)/PASD,(F/T)/PSAT were statistically different between BPH and PCa,and had higher diagnostic value for the diagnosis of PCa(AUCs all >0.9)and all of them were significantly larger than PSA and F/T.PSAD had the best effect to discriminate between high GS PCa and low GS PCa in PSA range 4-20 ng/ml.The best cut off of PSAD in predicting the high GS PCa in PSA range 4-20ng/ml was PSAD ? 0.25,and its sensitivity was 0.882 and specificity was 0.300.In the prediction of prostate cancer capsule invasion,PSA,Gleason score,and the percentage of positive needles in prostate biopsy have good predictive value.The logistic regression equation predicting capsule invasion is:Logit(P)=-8.637+0.587*Gleason+0.106*PSA+3.238*percentage of positive needles in prostate biopsy.The overall accuracy of this logistic regression equation predicting capsule invasion is 77%.Conclusion(1)PSAD,PSAT,(F/T)/PSAD,(F/T)/PSAT have higher diagnostic value for distinguish BPH and PCa in PSA 4-20ng/ml.And within PSA 4-10ng/ml,PSAD?0.17±0.02,PSAT?0.38±0.02,(F/T)/PSAD?1.02,(F/T)/PSAT?0.38 may indicate prostate cancer.(2)PSAD is best for distinguishing between high GS PCa and low GS PCa in the range of PSA 4-20 ng/ml.The best cut off of PSAD in predicting the high GS PCa in PSA range 4-20ng/ml was PSAD?0.25,and its sensitivity was 0.882 and specificity was 0.300.(3)PSA,Gleason score,and the percentage of positive needles in prostate biopsy have good predictive value in predicting capsule invasion of PCa.The logistic regression equation predicting capsule invasion is:Logit(P)=-8.637+0.587*Gleason+0.106*PSA+3.238*percentage of positive needles in prostate biopsy.The overall accuracy of this logistic regression equation predicting capsule invasion is 77%.