PURPOSE: Tumor contact length (TCL) is defined as the amount of prostate cancer in contact with the prostatic capsule.
Comparing to existing predictors of extra-capsular extension (ECE), we evaluated the ability of MRI-determined TCL to predict microscopic ECE.
MATERIALS AND METHODS: A total 111 consecutive patients, who had MR/US-fusion targeted biopsy-proven prostate cancer and underwent radical prostatectomy (RP) in 1/2010-7/2013, were retrospectively analysed. The median of patient age, prostate specific antigen (PSA), and clinical stages were 64years, 8.9ng/ml, and cT1 (n=93, 84%)/cT2 (n=18, 16%). Post-RP pathological analysis confirmed pT2 (n=71, 64%) and pT3 (n=40, 36%). We evaluated: 1) in RP specimen, the correlation of microscopic ECE with pathological cancer volume, pathological-TCL and Gleason score; 2) correlation between the microscopic ECE and MR-TCL; and 3) ability of pre-operative variables in predicting microscopic ECE.
RESULTS: The logistic regression analysis revealed that the pathological-TCL (0.821) superiorly correlates with microscopic ECE compared to the predictive power of pathological cancer volume (0.685). Spearman correlation between the pathological-TCL and MRI-TCL was r= 0.839 (p< 0.0001). Analysis of area under curve [AUC] of receiver operative characteristics (ROC) demonstrated that MRI-TCL [0.88] outperformed cancer core involvement on targeted-biopsy [0.70] and Partin tables [0.63] in prediction of microscopic ECE. With a threshold of MRI-TCL of 20 mm, the accuracy to diagnose microscopic-ECE was superior to accuracy of conventional MRI-criteria (82% versus 67%, p=0.015). Predicted probability plots curve (Figure-6) of ECE according to MRI-TCL was developed.
CONCLUSION: MRI-determined tumor contact length could be the promising quantitative predictor of microscopic ECE.
Baco E, Rud E, Vlatkovic L, Svindland A, Eggesbø HB, Hung AJ, Matsugasumi T, Bernhard JC, Gill IS, Ukimura O. Are you the author?
Oslo University Hospital Aker, Department of Radiology, Oslo, Norway.
Reference: J Urol. 2014 Aug 20. pii: S0022-5347(14)04257-8.