title: Diffusion-weighted MRI for detecting prostate tumour in men at increased genetic risk.
abstract: BACKGROUND
  Diffusion-weighted (DW)-MRI is invaluable in detecting prostate cancer. We determined its sensitivity and specificity and established interobserver agreement for detecting tumour in men with a family history of prostate cancer stratified by genetic risk.
  
  
  METHODS
  51 men with a family history of prostate cancer underwent T2-W + DW-endorectal MRI at 3.0 T. Presence of tumour was noted at right and left apex, mid and basal prostate sextants by 2 independent observers, 1 experienced and the other inexperienced in endorectal MRI. Sensitivity and specificity against a 10-core sampling technique (lateral and medial cores at each level considered together) in men with >2× population risk based on 71 SNP analysis versus those with lower genetic risk scores was established. Interobserver agreement was determined at a subject level.
  
  
  RESULTS
  Biopsies indicated cancer in 28 sextants in 13/51 men; 32 of 51 men had twice the population risk (>0.25) based on 71 SNP profiling. Sensitivity/specificity per-subject for patients was 90.0%/86.4% (high-risk) vs. 66.7%/100% (low-risk, observer 1) and 60.0%/86.3% (high-risk) vs. 33.3%/93.8% (low-risk, observer 2) with moderate overall inter-observer agreement (kappa = 0.42). Regional sensitivities/specificities for high-risk vs. low-risk for observer 1 apex 72.2%/100% [33.3%/100%], mid 100%/93.1% [100%/97.3%], base 16.7%/98.3% [0%/100%] and for observer 2 apex 36.4%/98.1% [0%/100%], mid 28.6%/96.5% [100%/100%], base 20%/100% [0%/97.3%] were poorer as they failed to detect multiple lesions.
  
  
  CONCLUSIONS
  Endorectal T2W + DW-MRI at 3.0 T yields high sensitivity and specificity for tumour detection by an experienced observer in screening men with a family history of prostate cancer and increased genetic risk.
authors.affiliation: CRUK and EPSRC Cancer Imaging Centre, Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Downs Road, Surrey SM2 5PT, UK.
authors.forename: Nandita M
authors.initials: NM
authors.lastname: deSouza
authors.affiliation: CRUK and EPSRC Cancer Imaging Centre, Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Downs Road, Surrey SM2 5PT, UK.
authors.forename: Veronica A
authors.initials: VA
authors.lastname: Morgan
authors.affiliation: Genetics and Epidemiology, Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Downs Road, Surrey SM2 5PT, UK.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Bancroft
authors.affiliation: Department of Radiology, Royal Marsden NHS Foundation Trust, Downs Road, Surrey SM2 5PT, UK.
authors.forename: S Aslam
authors.initials: SA
authors.lastname: Sohaib
authors.affiliation: CRUK and EPSRC Cancer Imaging Centre, Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Downs Road, Surrey SM2 5PT, UK.
authors.forename: Sharon L
authors.initials: SL
authors.lastname: Giles
authors.affiliation: Genetics and Epidemiology, Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Downs Road, Surrey SM2 5PT, UK.
authors.forename: Zsofia
authors.initials: Z
authors.lastname: Kote-Jarai
authors.affiliation: Genetics and Epidemiology, Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Downs Road, Surrey SM2 5PT, UK.
authors.forename: Elena
authors.initials: E
authors.lastname: Castro
authors.affiliation: Department of Histopathology, Royal Marsden NHS Foundation Trust, Downs Road, Surrey SM2 5PT, UK.
authors.forename: Steven
authors.initials: S
authors.lastname: Hazell
authors.affiliation: CRUK and EPSRC Cancer Imaging Centre, Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Downs Road, Surrey SM2 5PT, UK.
authors.forename: Maysam
authors.initials: M
authors.lastname: Jafar
authors.affiliation: Genetics and Epidemiology, Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Downs Road, Surrey SM2 5PT, UK.
authors.forename: Rosalind
authors.initials: R
authors.lastname: Eeles
keywords: ADC, apparent diffusion coefficient; DW, diffusion-weighted; Detection; Diffusion-weighted; FoV, field of view; Genetic risk; HIPAA, Health Insurance Portability and Accountability Act; MRI; MRI, magnetic resonance imaging; PSA, prostate specific antigen; Prostate cancer; SNP, single nucleotide polymorphism; STARD, Standards for the Reporting of Diagnostic Accuracy Studies; Screening; TE, time to echo; TR, repetition time; TRUS, transrectal ultrasound; iCOGS, Illumina Collaborative Oncological Gene-Environment Study