Abstract
Background The Restriction Spectrum Imaging restriction score (RSIrs) has demonstrated higher diagnostic accuracy for clinically significant prostate cancer (csPCa) than conventional DWI. Both diffusion and T2 properties of prostate tissue inform the RSI signal, and studies have shown that each may be valuable for csPCa discrimination.
Purpose To determine whether prostate T2 varies across RSI compartments and in the presence of csPCa, and to evaluate whether consideration of compartmental T2 (cT2) improves csPCa detection over RSIrs alone.
Study Type Retrospective.
Population Two cohorts (46 and 195 patients) scanned for csPCa.
Field Strength/Sequence 3T multi-b-value DWI acquired at multiple TEs.
Assessment cT2 values were computed from multi-TE RSI data and compared between RSI model compartments. csPCa detection was compared between RSIrs and a logistic regression model (LRM) for predicting the probability of csPCa using cT2 in combination with RSI measurements.
Statistical Tests Two-sample t-tests (α=0.05) were used to compare cT2 values between compartments and between patients with and without csPCa. Area under the receiver operating characteristic curve (AUC) was used to evaluate csPCa detection performance.
Results In both cohorts, T2 differed (p<0.05) across all RSI compartments (C1, C2, C3, C4). Voxel-level data from cohort 1 showed that T2 differed between normal and cancerous tissue in C1, C2, C3 (p<0.001). Whole-prostate T2 differed between patients with and without csPCa in C3 (p=0.02). In cohort 2, whole-prostate T2 differed in C1 (p=0.01), C3 (p=0.01), and C4 (p<0.01). Consideration of cT2 improved csPCa discrimination compared to diffusion alone, but not compared to RSIrs [cohort 1: 0.80 vs 0.70 (diffusion) and 0.80 (RSIrs), cohort 2: 0.72 vs 0.65 (diffusion) and 0.72 (RSIrs)].
Data Conclusion Significant differences in cT2 were observed between normal and cancerous prostatic tissue. With our data, however, consideration of cT2 did not significantly improve cancer detection performance over RSIrs alone.
Competing Interest Statement
M.E.H. reports honoraria from Multimodal Imaging Services Corporation and research funding from GE Healthcare. R.R.P. has an equity interest in CorTechs Labs and Curemetrix, serves on the scientific advisory board of Imagine Scientific, and has received consulting fees from Bayer and research funding from GE Healthcare. A.M.D. is a founder of and holds equity in CorTechs Labs, Inc, and serves on its scientific advisory board; he also is a member of the scientific advisory board of Human Longevity, Inc, and receives funding through research agreements with GE Healthcare. T.M.S. reports honoraria from CorTechs Labs, Varian Medical Systems, WebMD, GE Healthcare, and Janssen; has an equity interest in CorTechs Labs, Inc, and serves on its scientific advisory board; and has received in-kind research support from GE Healthcare via a research agreement with the University of California, San Diego. These companies might potentially benefit from the research results. The terms of these arrangements have been reviewed and approved by the University of California, San Diego in accordance with its conflict-of-interest policies.
Funding Statement
This work was supported, in part, by the National Institutes of Health (NIH/NIBIB K08EB026503, NIH UL1TR000100), the American Society for Radiation Oncology, the Prostate Cancer Foundation (PCF20YOUN01), and the U.S. Department of Defense (DOD/CDMRP PC220278).
Author Declarations
I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.
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IRB of University of California San Diego gave ethical approval for this work.
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Footnotes
The only thing I added is the "MS" after Mariluz Rojo Domingo in the author list.
Data Availability
All data produced in the present study are available upon reasonable request to the authors.
