IVIM Parameters on MRI Could Predict ISUP Risk Groups of Prostate Cancers on Radical Prostatectomy

Chun-Bi Chang; Yu-Chun Lin; Yon-Cheong Wong; Shin-Nan Lin; Chien-Yuan Lin; Yu-Han Lin; Ting-Wen Sheng; Chen-Chih Huang; Lan-Yan Yang; Li-Jen Wang

doi:10.3389/fonc.2021.659014

IVIM Parameters on MRI Could Predict ISUP Risk Groups of Prostate Cancers on Radical Prostatectomy

Front Oncol. 2021 Jul 1:11:659014. doi: 10.3389/fonc.2021.659014. eCollection 2021.

Authors

Chun-Bi Chang^{1

2}, Yu-Chun Lin^{2

3}, Yon-Cheong Wong^{1

2}, Shin-Nan Lin^{1

2}, Chien-Yuan Lin⁴, Yu-Han Lin³, Ting-Wen Sheng^{2

5}, Chen-Chih Huang^{2

5}, Lan-Yan Yang⁶, Li-Jen Wang^{2

5}

Affiliations

¹ Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, College of Medicine, Chang Gung University, Taoyuan, Taiwan.
² Department of Medical Imaging and Radiological Sciences, Chang Gung University, Taoyuan, Taiwan.
³ Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Taoyuan, Taiwan.
⁴ Department of Clinical Science, General Electric (GE) Healthcare, Taipei, Taiwan.
⁵ Department of Medical Imaging and Intervention, New Taipei Municipal TuCheng Hospital, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan.
⁶ Biostatistics Unit of Clinical Trial Center, Chang Gung Memorial Hospital, Taoyuan, Taiwan.

Abstract

Purpose: To elucidate the usefulness of intravoxel incoherent motion (IVIM)/apparent diffusion coefficient (ADC) parameters in preoperative risk stratification using International Society of Urological Pathology (ISUP) grades.

Materials and methods: Forty-five prostate cancer (PCa) patients undergoing radical prostatectomy (RP) after prostate multiparametric magnetic resonance imaging (mpMRI) were included. The ISUP grades were categorized into low-risk (I-II) and high-risk (III-V) groups, and the concordance between the preoperative and postoperative grades was analyzed. The largest region of interest (ROI) of the dominant tumor on each IVIM/ADC image was delineated to obtain its histogram values (i.e., minimum, mean, and kurtosis) of diffusivity (D), pseudodiffusivity (D*), perfusion fraction (PF), and ADC. Multivariable logistic regression analysis of the IVIM/ADC parameters without and with preoperative ISUP grades were performed to identify predictors for the postoperative high-risk group.

Results: Thirty-two (71.1%) of 45 patients had concordant preoperative and postoperative ISUP grades. D_mean, D*_kurtosis, PF_kurtosis, ADC_min, and ADC_mean were significantly associated with the postoperative ISUP risk group (all p < 0.05). D_mean and D*_kurtosis (model I, both p < 0.05) could predict the postoperative ISUP high-risk group with an area under the curve (AUC) of 0.842 and a 95% confidence interval (CI) of 0.726-0.958. The addition of D*_kurtosis to the preoperative ISUP grade (model II) may enhance prediction performance, with an AUC of 0.907 (95% CI 0.822-0.992).

Conclusions: The postoperative ISUP risk group could be predicted by D_mean and D*_kurtosis from mpMRI, especially D*_kurtosis. Obtaining the biexponential IVIM parameters is important for better risk stratification for PCa.

Keywords: ISUP grade; IVIM; diffusivity; kurtosis; perfusion fraction; prostate cancer; pseudodiffusivity.