Nine-year Follow-up for a Study of Diffusion-weighted Magnetic Resonance Imaging in a Prospective Prostate Cancer Active Surveillance Cohort.
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Date
2016-06-01ICR Author
Author
Henderson, DR
de Souza, NM
Thomas, K
Riches, SF
Morgan, VA
Sohaib, SA
Dearnaley, DP
Parker, CC
van As, NJ
Type
Journal Article
Metadata
Show full item recordAbstract
BACKGROUND: In active surveillance (AS) for prostate cancer there are few data on long-term outcomes associated with novel imaging markers. OBJECTIVE: To determine long-term outcomes with respect to the apparent diffusion coefficient (ADC) derived from diffusion-weighted magnetic resonance imaging (DW-MRI) in a prospective AS cohort. Early results have already been published; we now present findings with long-term follow-up. DESIGN, SETTING, AND PARTICIPANTS: A subset of patients (n=86) underwent pre-enrolment DW-MRI in a prospective AS study between 2002 and 2006. Inclusion criteria were untreated prostate cancer, clinical T1/T2a/N0M0, Gleason ≤ 3+4, and prostate-specific antigen (PSA) <15 ng/ml. Protocol follow-up was by biopsy at 18-24 mo and then every 24 mo, with regular PSA measurement. INTERVENTION: Men underwent baseline DW-MRI in addition to standard sequences. ADC was measured from the index lesion on T2-weighted images. To avoid influencing treatment decisions, DW-MRI sequence results were not available to the AS study investigators. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Baseline ADC was analysed with respect to time to radical treatment (TRT) and time to adverse histology (TAH). Kaplan-Meier analysis and univariate and multivariate regression analyses were performed. RESULTS AND LIMITATIONS: The median follow-up was 9.5 yr (interquartile range 7.9-10.0 yr). On univariate analysis, ADC below the median was associated with shorter TAH (hazard ratio [HR] 2.13, 95% confidence interval [CI] 1.17-3.89; p<0.014) and TRT (HR 2.54, 95% CI 1.49-4.32; p<0.001). Median TRT was 9.3 yr (95% CI 7.0-11.6 yr) for patients with ADC above the median and only 2.4 yr (95% CI 1.5-6.0 yr) for ADC below the median. For TRT, addition of ADC to a multivariate model of baseline variables resulted in a significant improvement in model fit (HR 1.33, 95% CI 1.14-1.54; p<0.001). Receiver operating characteristic analysis for TRT revealed an area under the curve of 0.80 (95% CI 0.70-0.88). The number of variables included in the multivariate model was limited by sample size. CONCLUSIONS: Long-term follow-up for this study provides strong evidence that ADC is a useful marker when selecting patients for AS. Routine DW-MRI is now being evaluated in our ongoing AS study for initial assessment and as an alternative to repeat biopsy. PATIENT SUMMARY: Before entering a study of close monitoring for the initial management of prostate cancer, patients had a type of magnetic resonance imaging scan that looks at the movement of water within cancers. These scans may help in predicting whether patients should receive close monitoring or whether immediate treatment should be given.
Collections
Subject
Prostate
Humans
Adenocarcinoma
Prostatic Neoplasms
Disease Progression
Prostate-Specific Antigen
Diffusion Magnetic Resonance Imaging
Biopsy
Brachytherapy
Prostatectomy
Area Under Curve
Logistic Models
Proportional Hazards Models
Follow-Up Studies
Prospective Studies
ROC Curve
Time Factors
Aged
Middle Aged
Male
Watchful Waiting
Neoplasm Grading
Research team
Clinical Academic Radiotherapy (Dearnaley)
Stereotactic and Precision Body Radiotherapy
Language
eng
Date accepted
2015-10-05
License start date
2016-06
Citation
European urology, 2016, 69 (6), pp. 1028 - 1033
Publisher
ELSEVIER SCIENCE BV