Prostate cancer argon-helium cryosurgery: delineation and visualization of the margin of ablation in multi-parametric MRI

Abstract

Objective To investigate the delineation and visualization of the margin of ablation for prostate cancer in multi-parametric MRI (Mp-MRI) of prostate cancer argon-helium cryosurgery.Methods Thirteen patients with suspected prostate cancer underwent Mp-MRI at a 3.0 T MR before and within one week to three months after cryosurgery.The delineation and visualization of the margin of ablation for prostate cancer in T2WI,DWI and perfusion weighted imaging (PWI) had been prospectively interpreted by 2 radiologists.ADC value was recoded in the middle of the ablation for prostate cancer.Comparisons between T2WI,DWI,PWI were evaluated using the Kruskal-Wallis test and Mann-Whitney test.Results Of the 13 cases,the margin of ablation for prostate cancer were clearly delineated in 9 on T2WI,2 on DWI and 12 on PWI.ADC value was (0.644±0.121)× 10-3 s/mm2.In the delineation and visualization of the margin of ablation for prostate cancer,the grade were 4(2 to 5),3(2 to 4) and 5(3 to 5)in T2WI,DWI and PWI,there was significant difference among them(H=0.602,P=0.022),and there were significant difference between them (P＜0.05).Conclusions Mp-MRI provides a powerful tool for noninvasive evaluation of frozen tissue created by focal cryoablation of prostate cancer.PWI is significantly superior to T2WI and DWI in the delineation and visualization of the margin of ablation for prostate cancer. Key words: Prostate Neoplasms; Magnetic resonance imaging; Cryotherapy