Spinal multiparametric MRI and DEXA changes over time in men with prostate cancer treated with androgen deprivation therapy: a potential imaging biomarker of treatment toxicity.
OBJECTIVE
To explore changes in bone mineral density (BMD) measured by DEXA and MRS fat fraction (FF), Dixon FF, and ADC in lower spinal vertebral bodies in men with prostate cancer treated with androgen deprivation therapy (ADT).


METHODS
Twenty-eight men were enrolled onto a clinical trial. All received ADT. DEXA imaging was performed at baseline and 12 months. L-spine MRI was done at baseline and 6 months.


RESULTS
The number of patients who underwent DEXA, Dixon, ADC, and MRS at baseline/follow-up were 28/27, 28/26, 28/26, and 22/20. An increase in FF was observed from T11 to S2 (average 1 %/vertebra). There was a positive correlation between baseline MRS FF and Dixon FF (r = 0.85, p < 0.0001) and a negative correlation between MRS FF and ADC (r = -0.56, p = 0.036). Over 6 months, MRS FF increased by a median of 25 % in relative values (p = 0.0003), Dixon FF increased (p < 0.0001) and ADC values decreased (p = 0.0014). Men with >5 % BMD loss after 1 year had triple the percentage increase in MRS FF at 6 months (61.1 % vs. 20.9 %, p = 0.19).


CONCLUSIONS
Changes are observed on L-spine MRI after 6 months of ADT. Further investigation is warranted of MRS change as a potential predictive biomarker for later BMD loss.


CONCLUSIONS
• Spinal marrow fat fraction increases after 6 months of androgen deprivation therapy. • More inferior vertebral bodies tend to have higher fat fractions. • MRS fat fraction changes were associated with later changes in DEXA BMD.
Department of Radiation Oncology, Calvary Mater Newcastle, Newcastle, New South Wales, Australia. jarad.martin@calvarymater.org.au.|School of Medicine and Public Health, University of Newcastle, Newcastle, New South Wales, Australia. jarad.martin@calvarymater.org.au.|Centre for Advanced Imaging, University of Queensland, Brisbane, Queensland, Australia. jarad.martin@calvarymater.org.au.
Jarad
J
Martin
Hunter New England Imaging, Newcastle, New South Wales, Australia.
Jameen
J
Arm
Department of Radiation Oncology, Calvary Mater Newcastle, Newcastle, New South Wales, Australia.
Joanne
J
Smart
CREDITSS, Hunter Medical Research Institute, Newcastle, New South Wales, Australia.
Kerrin
K
Palazzi
Department of Radiation Oncology, Calvary Mater Newcastle, Newcastle, New South Wales, Australia.|School of Medicine and Public Health, University of Newcastle, Newcastle, New South Wales, Australia.
Anne
A
Capp
Department of Urology, Hunter New England Health, Newcastle, New South Wales, Australia.
Paul
P
Ainsworth
Centre for Advanced Imaging, University of Queensland, Brisbane, Queensland, Australia.
Gary
G
Cowin
D015502:Absorptiometry, Photon / Q000379:methods*; D000273:Adipose Tissue / Q000473:pathology; D000368:Aged; D000726:Androgen Antagonists / Q000627:therapeutic use*; D015415:Biomarkers; D015519:Bone Density / Q000187:drug effects*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000188:drug therapy*; D013131:Spine / Q000000981:diagnostic imaging* / Q000473:pathology
D000726:Androgen Antagonists; D015415:Biomarkers
Biomarkers; Bone density; Magnetic resonance imagining; Prostate neoplasms; Toxicity