Repeatability of quantitative MR fingerprinting for T1 and T2 measurements of metastatic bone in prostate cancer patients

Mihaela Rata; Matthew R Orton; Nina Tunariu; Andra Curcean; Julie Hughes; Erica Scurr; Matthew Blackledge; James d'Arcy; Yun Jiang; Vikas Gulani; Dow-Mu Koh

doi:10.1007/s00330-024-11162-z

Repeatability of quantitative MR fingerprinting for T₁ and T₂ measurements of metastatic bone in prostate cancer patients

Eur Radiol. 2024 Nov 6. doi: 10.1007/s00330-024-11162-z. Online ahead of print.

Authors

Mihaela Rata^{1

2}, Matthew R Orton^{3

4}, Nina Tunariu^{3

4}, Andra Curcean³, Julie Hughes³, Erica Scurr³, Matthew Blackledge⁴, James d'Arcy⁴, Yun Jiang⁵, Vikas Gulani⁵, Dow-Mu Koh^{3

4}

Affiliations

¹ Department of Radiology, MRI Unit, The Royal Marsden NHS Foundation Trust, London, UK. Mihaela.Rata@rmh.nhs.uk.
² Division of Radiotherapy and Imaging, The Institute of Cancer Research, London, UK. Mihaela.Rata@rmh.nhs.uk.
³ Department of Radiology, MRI Unit, The Royal Marsden NHS Foundation Trust, London, UK.
⁴ Division of Radiotherapy and Imaging, The Institute of Cancer Research, London, UK.
⁵ Department of Radiology, University of Michigan, Ann Arbor, Michigan, USA.

PMID: 39505736
DOI: 10.1007/s00330-024-11162-z

Abstract

Objectives: MR fingerprinting (MRF) has the potential to quantify treatment response. This study evaluated the repeatability of MRF-derived T₁ and T₂ relaxation times in bone metastasis, bone, and muscle in patients with metastatic prostate cancer.

Materials and methods: This prospective single-centre study included same-day repeated MRF acquisitions from 20 patients (August 2019-October 2020). Phantom and human data were acquired on a 1.5-T MR scanner using a research MRF sequence outputting T₁ and T₂ maps. Regions of interest (ROIs) across three tissue types (bone metastasis, bone, muscle) were drawn on two separate acquisitions. Repeatability of T₁ and T₂ was assessed using Bland-Altman plots, together with repeatability (r) and intraclass correlation (ICC) coefficients. Mean T₁ and T₂ were reported per tissue type.

Results: Twenty patients with metastatic prostate cancer (mean age, 70 years ± 8 (standard deviation)) were evaluated and bone metastasis (n = 44), normal-appearing bone (n = 14), and muscle (n = 20) ROIs were delineated. Relative repeatability of T₁ measurements was 6.9% (bone metastasis), 32.6% (bone), 5.8% (muscle) and 21.8%, 32.2%, 16.1% for T₂ measurements. The ICC of T₁ was 0.97 (bone metastasis), 0.94 (bone), 0.96 (muscle); ICC of T₂ was 0.94 (bone metastasis), 0.94 (bone), 0.91 (muscle). T₁ values in bone metastasis were higher than in bone (p < 0.001). T₂ values showed no difference between bone metastasis and bone (p = 0.5), but could separate active versus treated metastasis (p < 0.001).

Conclusion: MRF allows repeatable T₁ and T₂ measurements in bone metastasis, bone, and muscle in patients with primary prostate cancer. Such measurements may help quantify the treatment response of bone metastasis.

Key points: Question MR fingerprinting has the potential to characterise bone metastasis and its response to treatment. Findings Repeatability of MRF-based T₁ measurements in bone metastasis and muscle was better than for T₂. Clinical relevance MR fingerprinting allows repeatable T₁ and T₂ quantitative measurements in bone metastasis, bone, and muscle in patients with primary prostate cancer, which makes it potentially applicable for disease characterisation and assessment of treatment response.

Keywords: Bone; MR fingerprinting; Metastasis; Prostate cancer.