前列腺癌腫瘤侵襲性與藉由磁振造影(MRI)計算身體組成因子的相關性

簡佑軒、邵翊紘、沈鼎文¹、王俐人¹、張英勛、莊正鏗、馮思中

林口長庚紀念醫院 外科部 泌尿外科；¹林口長庚紀念醫院 影像診療部

Body composition factors measured on MRI correlates with tumor aggressiveness of prostate cancer

Yu-Hsuan Chien, I-Hung Shao, Ting-Wen Shen¹, Li-Jen Wang¹, Ying-Hsu Chang, Cheng-Keng Chuang, See-Tong Pang

Division of Urology, Department of Surgery, Linkou Chang Gung Memorial Hospital, Taoyuan, Taiwan; Department of Medical Imaging and Intervention¹, Linkou Chang Gung Memorial Hospital, Taoyuan, Taiwan

Purpose: The association between obesity and the aggressiveness of prostate cancer has been shown in several recent studies. However, instead of body mass index (BMI), visceral fat is thought to play a more important role in prostate carcinogenesis. This study aims to examine the relationship between body composition factors, by measuring visceral fat distribution on magnetic resonance imaging (MRI), and the aggressiveness of prostate cancer.

Materials and Methods: This study included sixty patients who had undergone radical prostatectomy with positive surgical margin. Pre-treatment MRI was reviewed by radiologists to measured the volume of pelvic cavity, prostate gland, seminal vesicles, bladder, peri-rectal space and rectum on consecutive axial T1-weighted image, which help to calculate pelvic fat volume (PFV), peri-rectal fat volume (PRFV), and peri-prostate fat volume (PPFV). Subcutaneous fat thickness and poses muscle area was measured on axial T2-weighted image. We has correlated these body composition parameters with initial prostate specific antigen (iPSA), grade(Gleason score; GS), tumor extra-capsular extension and biochemical failure free survival rate.

Results: The mean pelvic fat volume, peri-rectal fat volume and peri-prostate fat volume were 111.9 ± 47.7 mm², 43.7 ± 24.5 mm² and 68.2 ± 30.1 mm² respectively. The initial prostate specific antigen (iPSA) level was significantly correlated with BMI(ρ = 0.292, p = 0.027), pelvic fat volume(ρ = 0.393, p = 0.004) and peri-rectal fat volume(ρ = 0.447, p = 0.001). The Gleason score was significantly correlated with BMI(ρ = 0.334, p = 0.011). Tumor extra-capsular extension was significantly correlated with peri-prostate fat volume(p = 0.047). Univariate analysis and multivariate analysis both revealed no significant correlation between any body composition factors and biochemical failure free survival rate.

Conclusions: Body composition factors measured on MRI, including pelvic fat volume, peri-rectal fat volume and peri-prostate fat volume, showed a significant correlation with prostate cancer aggressiveness. This could be useful for predicting the prognosis of patient undergone radical prostatectomy.