Mean diffusivity discriminates between prostate cancer with grade group 1&2 and grade groups equal to or greater than 3.
OBJECTIVE
To test the potential ability of mean diffusivity (MD) and fractional anisotropy (FA) in discriminating between PCa of grade group (GG) 1&2, and GGs≥3.


METHODS
Diffusion Tensor Imaging (DTI) experiments at 3T in a cohort of 38 patients with PCa (fifty lesions in total) were performed, by using different diffusion weights (b values) up to 2500s/mm(2). Gleason score (GS) and GG data were correlated with DTI parameters (MD and FA) estimated in PCa. The relation between DTI measures and GS was tested by the linear correlation analysis (Pearson's coefficient). One-way analysis of variance to check the statistical significance of the difference between GG 1&2 and GGs 3, 4, 5, ≥3 was used. Results were reported for each of the three b-values ranges: 0-800s/mm(2), 0-1500s/mm(2), 0-2500s/mm(2).


RESULTS
A negative correlation was found between MD and GS. The highest linear correlation was observed when the fit was performed with data acquired in the b-values range 0-2500s/mm(2). MD values were significantly different between GG 1&2 and GG=3 and between GG 1&2 and GG ≥3. Moreover this difference is better defined when high b values (higher than b=800s/mm(2)) are used. The specificity, sensitivity and accuracy in the discrimination between GG 1&2 and GG=3 were: 90%, 66.7% and 82.4%, respectively when MD was estimated in the b-values range 0-2500s/mm(2) while these values were 85%, 58.3% and 78.4% when MD was estimated in the b-values range 0-800s/mm(2). Conversely FA did not discriminate between GG 1&2 and GG ≥3, at any investigated b-values range.


CONCLUSIONS
This study suggests that MD estimation in PCa, obtained from DTI acquired at high b-values, can contribute to the diagnosis and grading of prostate cancer while FA is not a useful parameter for this purpose.
Department of Diagnostic and Interventional Radiology, Molecular Imaging and Radiotherapy, PTV Foundation, "Tor Vergata" University of Rome, Viale Oxford 81, 00133 Rome, Italy. Electronic address: marco.nezzo@gmail.com.
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Nezzo
Physics Department, Sapienza University of Rome, Piazzale Aldo Moro 5, Rome, Italy.
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Di Trani
Department of Anatomical, Histological, Forensic and Locomotor System Science, Morfogenesis and Tissue Homeostasis, Sapienza University of Rome, Italy; CNR ISC, UOS Roma Sapienza, Physics Department Sapienza University of Rome, Italy.
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Caporale
Urology Unit, Department of Experimental Medicine and Surgery, PTV Foundation, "Tor Vergata" University of Rome, Viale Oxford 81, 00133 Rome, Italy.
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Miano
Anatomic Pathology, Department of Biomedicine and Prevention, PTV Foundation, "Tor Vergata" University of Rome, Viale Oxford 81, 00133 Rome, Italy.
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Mauriello
Urology Unit, Department of Experimental Medicine and Surgery, PTV Foundation, "Tor Vergata" University of Rome, Viale Oxford 81, 00133 Rome, Italy.
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Bove
CNR ISC, UOS Roma Sapienza, Physics Department Sapienza University of Rome, Italy.
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Capuani
Department of Diagnostic and Interventional Radiology, Molecular Imaging and Radiotherapy, PTV Foundation, "Tor Vergata" University of Rome, Viale Oxford 81, 00133 Rome, Italy.
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Manenti
D000704:Analysis of Variance; D016880:Anisotropy; D056324:Diffusion Tensor Imaging / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
Diffusion tensor imaging; Grade group; MD; Magnetic resonance imaging; Prostate cancer