Multiparametric MRI identifies and stratifies prostate cancer lesions: implications for targeting intraprostatic targets.
OBJECTIVE
To assess the ability of multiparametric (mp) MRI (mp-MRI) to identify, stratify, and localize biopsy-proven prostate cancer lesions in a risk-stratified patient population.


METHODS
We retrospectively analyzed 57 patients who had mp-MRI and core needle biopsy during diagnostic prostate cancer evaluation. The MRI sequences were scored for suspicion of cancer with a previously described system. Distributions of mp-MRI scores were compared across National Comprehensive Cancer Network prostate cancer risk groups. The mp-MRI-identified lesions were compared with the location of positive core needle biopsies to assess mp-MRI localization of true lesions.


RESULTS
The mp-MRI scoring system identified lesions in 84% (48/57) of the patients, including 100% (12/12) in the high-risk group. Scores assigned to lesions in patients in intermediate- and high-risk groups were statistically higher than those in the low-risk group, with a relative risk of 6.72 (95% confidence interval: 2.32-19.51, p<0.001) of having an aggressive score assigned in high-risk patients compared with the low-risk patients. In comparing the localization data from core needle biopsy, 68% of the patients had an MRI-identified lesion in or within one adjacent sextant of the same prostate hemigland, including 85% of aggressive lesions.


CONCLUSIONS
Use of mp-MRI at the time of diagnosis can identify intraprostatic lesions and assign suspicion for high-risk disease. These data show that high-risk patients are more likely to have suspicious imaging-identified lesions that correlate to the location of biopsy-proven prostate cancer. At this time, the use of mp-MRI to define focal targets represents a complementary tool to patient evaluation for focal therapy strategies.
Department of Radiation Oncology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA; Medical Scientist Training Program, University of California Los Angeles, Los Angeles, CA.
Erik S
ES
Anderson
Department of Radiology, University of California Los Angeles, Los Angeles, CA.
Daniel J A
DJ
Margolis
School of Medicine, University of California, Irvine, CA.
Shane
S
Mesko
Department of Radiation Oncology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA.
Robyn
R
Banerjee
Department of Radiation Oncology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA.
Pin-Chieh
PC
Wang
Department of Radiation Oncology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA; Jonsson Comprehensive Cancer Center, Los Angeles, CA.
D Jeffrey
DJ
Demanes
Department of Radiation Oncology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA.
Patrick
P
Kupelian
Department of Radiation Oncology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA; Jonsson Comprehensive Cancer Center, Los Angeles, CA. Electronic address: mkamrava@mednet.ucla.edu.
Mitchell
M
Kamrava
D000230:Adenocarcinoma / Q000175:diagnosis / Q000473:pathology* / Q000532:radiotherapy; D000328:Adult; D000368:Aged; D001918:Brachytherapy / Q000379:methods*; D006801:Humans; D061705:Image-Guided Biopsy; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D016012:Poisson Distribution; D011471:Prostatic Neoplasms / Q000175:diagnosis / Q000473:pathology* / Q000532:radiotherapy; D012189:Retrospective Studies
Index lesion; MRI-based planning; Multiparametric MRI; Prostate cancer; mp-MRI scoring