Focused Diffusion-Weighted Imaging in Prostate Cancer FODIP

Godley, Keith (2017) Focused Diffusion-Weighted Imaging in Prostate Cancer FODIP. Doctoral thesis, University of East Anglia.

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Background: MRI of the prostate is used to detect and localise prostate cancer and diffusion weighted imaging (DWI) is a routine sequence. The purpose of the study was to determine the diagnostic accuracy of high b-value DWI through meta-analyses. Additionally, the aim was to determine the diagnostic accuracy of a novel combined small field-of-view (FOV) and high b-value DWI sequence for detecting and localising prostate cancer.

Material and Methods: Meta-analyses of diagnostic test accuracy of high b-value DWI, and T2WI and DWI combined, were performed conforming to the PRISMA statement. A prospective observational diagnostic test accuracy study of 40 patients who underwent 3T MRI with small- (sDWI) and conventional (cDWI) FOV and subsequent radical prostatectomy were included. Two blinded readers assessed the lesion and sectoral-based accuracy of both sequences using radical prostatectomy (RP) specimens as reference standard. Apparent Diffusion Coefficient (ADC) of benign and malignant tissue was assessed.

Results: The sensitivity, specificity and area-under-curve (AUC) of the high b-value DWI, and T2WI and DWI meta-analyses were 0.59, 0.92, and 0.92; and 0.68, 0.84 and 0.83, respectively. There were 83 prostate cancers detected in the RP specimens and half of prostate sectors contained tumour. Sensitivity of cDWI alone was significantly higher than sDWI (0.62 vs 0.45, p=<0.001), but specificity was lower (0.88 vs 0.92, p=<0.001). The AUC was not significantly different (0.76 vs 0.73, p=0.164). The interobserver reliability of cDWI was substantial (κ = 0.63) and sDWI was moderate (κ = 0.59). The median mean ADC of tumours was significantly lower than non-tumour tissue for both sequences (p=<0.001). The ADC of tumour was significantly lower with sDWI (960 x 10-6 mm2/sec vs 766 x 10-6 mm2/sec, p=<0.001).

Conclusion: Conventional DWI outperformed small-FOV DWI imaging at lesion detection, but there may be clinical benefit for small-FOV at excluding tumour, particularly in a pre-biopsy population.

Item Type: Thesis (Doctoral)
Faculty \ School: Faculty of Medicine and Health Sciences > Norwich Medical School
Depositing User: Bruce Beckett
Date Deposited: 23 Jul 2018 10:28
Last Modified: 23 Jul 2018 10:28


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