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Lee CH, Taupitz M, Asbach P, Lenk J, Haas M. Clinical utility of combined T2-weighted imaging and T2-mapping in the detection of prostate cancer: a multi-observer study. Quant Imaging Med Surg 2020; 10:1811-1822. [PMID: 32879859 DOI: 10.21037/qims-20-222] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Background To evaluate the clinical utility of combined T2-weighted imaging and T2-mapping for the detection of prostate cancer. Methods Forty patients underwent multiparametric magnetic resonance imaging (mpMRI) and T2-mapping of the prostate. Three readers each reviewed two sets of images: T2-weighted fast spin-echo (FSE) sequence (standard T2), and standard T2 in combination with T2-mapping. Each reader assigned probability scores for malignancy to each zone [peripheral zone (PZ) or transition zone (TZ)]. Inter-observer variability for standard T2 and combined standard T2 with T2-mapping were assessed. Diagnostic accuracy was compared between standard T2 and combined standard T2 with T2-mapping. Results There was fair agreement between all three readers for standard T2 [intraclass correlation coefficient (ICC) =0.56] and combined standard T2 with T2-mapping (ICC =0.58). There was no significant difference in the area under the receiver operator characteristics curve for standard T2 compared to combined standard T2 with T2-mapping (0.89 vs. 0.82, P=0.31). Sensitivity (Sn) for combined standard T2 with T2-mapping was significantly higher compared to standard T2 alone (73.0% vs. 49.2%, P=0.006). Specificity (Sp) for combined standard T2 with T2-mapping was borderline significantly lower compared to standard T2 alone (89.3% vs. 94.9%, P=0.05). There was no significant differences between the negative predictive values (NPVs) and positive predictive values (PPVs) (P=0.07, P=0.45). Conclusions Combination of T2-weighted imaging and T2-mapping could potentially increase Sn for prostate malignancy compared to T2-weighted imaging alone.
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Affiliation(s)
- Chau Hung Lee
- Department of Radiology, Charite-Universitätsmedizin Berlin, Campus Benjamin Franklin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,Department of Radiology, Tan Tock Seng Hospital, Singapore, Singapore
| | - Matthias Taupitz
- Department of Radiology, Charite-Universitätsmedizin Berlin, Campus Benjamin Franklin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Patrick Asbach
- Department of Radiology, Charite-Universitätsmedizin Berlin, Campus Benjamin Franklin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Julian Lenk
- Department of Radiology, Charite-Universitätsmedizin Berlin, Campus Benjamin Franklin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Matthias Haas
- Department of Radiology, Charite-Universitätsmedizin Berlin, Campus Benjamin Franklin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
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Lee CH. Quantitative T2-mapping using MRI for detection of prostate malignancy: a systematic review of the literature. Acta Radiol 2019; 60:1181-1189. [PMID: 30621443 DOI: 10.1177/0284185118820058] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Chau Hung Lee
- 1 Department of Radiology, Charite - Universitätzsmedizin Berlin, Berlin, Germany
- 2 Department of Radiology, Tan Tock Seng Hospital, Singapore
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Adams LC, Bressem KK, Jurmeister P, Fahlenkamp UL, Ralla B, Engel G, Hamm B, Busch J, Makowski MR. Use of quantitative T2 mapping for the assessment of renal cell carcinomas: first results. Cancer Imaging 2019; 19:35. [PMID: 31174616 PMCID: PMC6555952 DOI: 10.1186/s40644-019-0222-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 05/27/2019] [Indexed: 12/19/2022] Open
Abstract
Background Correct staging and grading of patients with clear cell renal cell carcinoma (cRCC) is of clinical relevance for the prediction of operability and for individualized patient management. As partial or radial resection with postoperative tumor grading currently remain the methods of choice for the classification of cRCC, non-invasive preoperative alternatives to differentiate lower grade from higher grade cRCC would be beneficial. Methods This institutional-review-board approved cross-sectional study included twenty-seven patients (8 women, mean age ± SD, 61.3 ± 14.2) with histopathologically confirmed cRCC, graded according to the International Society of Urological Pathology (ISUP). A native, balanced steady-state free precession T2 mapping sequence (TrueFISP) was performed at 1.5 T. Quantitative T2 values were measured with circular 2D ROIs in the solid tumor portion and also in the normal renal parenchyma (cortex and medulla). To estimate the optimal cut-off T2 value for identifying lower grade cRCC, a Receiver Operating Characteristic Curve (ROC) analysis was performed and sensitivity and specificity were calculated. Students’ t-tests were used to evaluate the differences in mean values for continuous variables, while intergroup differences were tested for significance with two-tailed Mann-Whitney-U tests. Results There were significant differences between the T2 values for lower grade (ISUP 1–2) and higher grade (ISUP 3–4) cRCC (p < 0.001), with higher T2 values for lower grade cRCC compared to higher grade cRCC. The sensitivity and specificity for the differentiation of lower grade from higher grade tumors were 83.3% (95% CI: 0.59–0.96) and 88.9% (95% CI: 0.52–1.00), respectively, using a threshold value of ≥110 ms. Intraobserver/interobserver agreement for T2 measurements was excellent/substantial. Conclusions Native T2 mapping based on a balanced steady-state free precession MR sequence might support an image-based distinction between lower and higher grade cRCC in a two-tier-system and could be a helpful addition to multiparametric imaging. Electronic supplementary material The online version of this article (10.1186/s40644-019-0222-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Lisa C Adams
- Department of Radiology, Charité, Charitéplatz 1, 10117, Berlin, Germany.
| | - Keno K Bressem
- Department of Radiology, Charité, Hindenburgdamm 30, 12203, Berlin, Germany
| | | | - Ute L Fahlenkamp
- Department of Radiology, Charité, Charitéplatz 1, 10117, Berlin, Germany
| | - Bernhard Ralla
- Department of Urology, Charité, Charitéplatz 1, 10117, Berlin, Germany
| | - Guenther Engel
- Department of Radiology, Charité, Charitéplatz 1, 10117, Berlin, Germany
| | - Bernd Hamm
- Department of Radiology, Charité, Charitéplatz 1, 10117, Berlin, Germany
| | - Jonas Busch
- Department of Radiology, Charité, Charitéplatz 1, 10117, Berlin, Germany
| | - Marcus R Makowski
- Department of Radiology, Charité, Charitéplatz 1, 10117, Berlin, Germany
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Chatterjee A, Oto A. Future Perspectives in Multiparametric Prostate MR Imaging. Magn Reson Imaging Clin N Am 2019; 27:117-130. [DOI: 10.1016/j.mric.2018.08.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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5
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Performance of T2 Maps in the Detection of Prostate Cancer. Acad Radiol 2019; 26:15-21. [PMID: 29731420 DOI: 10.1016/j.acra.2018.04.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 02/15/2018] [Accepted: 04/02/2018] [Indexed: 11/20/2022]
Abstract
RATIONALE AND OBJECTIVES This study compares the performance of T2 maps in the detection of prostate cancer (PCa) in comparison to T2-weighted (T2W) magnetic resonance images. MATERIALS AND METHODS The prospective study was institutional review board approved. Consenting patients (n = 45) with histologic confirmed PCa underwent preoperative 3-T magnetic resonance imaging with or without endorectal coil. Two radiologists, working independently, marked regions of interests (ROIs) on PCa lesions separately on T2W images and T2 maps. Each ROI was assigned a score of 1-5 based on the confidence in accurately detecting cancer, with 5 being the highest confidence. Subsequently, the histologically confirmed PCa lesions (n = 112) on whole-mount sections were matched with ROIs to calculate sensitivity, positive predictive value (PPV), and radiologist confidence score. Quantitative T2 values of PCa and benign tissue ROIs were measured. RESULTS Sensitivity and confidence score for PCa detection were similar for T2W images (51%, 4.5 ± 0.8) and T2 maps (52%, 4.5 ± 0.6). However, PPV was significantly higher (P = .001) for T2 maps (88%) compared to T2W (72%) images. The use of endorectal coils nominally improved sensitivity (T2W: 55 vs 47%, T2 map: 54% vs 48%) compared to the use of no endorectal coils, but not the PPV and the confidence score. Quantitative T2 values for PCa (105 ± 28 milliseconds) were significantly (P = 9.3 × 10-14) lower than benign peripheral zone tissue (211 ± 71 milliseconds), with moderate significant correlation with Gleason score (ρ = -0.284). CONCLUSIONS Our study shows that review of T2 maps by radiologists has similar sensitivity but higher PPV compared to T2W images. Additional quantitative information obtained from T2 maps is helpful in differentiating cancer from normal prostate tissue and determining its aggressiveness.
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McGrath DM, Lee J, Foltz WD, Samavati N, van der Kwast T, Jewett MAS, Chung P, Ménard C, Brock KK. MR elastography to measure the effects of cancer and pathology fixation on prostate biomechanics, and comparison with T 1, T 2 and ADC. Phys Med Biol 2017; 62:1126-1148. [PMID: 28092638 DOI: 10.1088/1361-6560/aa52f4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
MRI is under evaluation for image-guided intervention for prostate cancer. The sensitivity and specificity of MRI parameters is determined via correlation with the gold-standard of histopathology. Whole-mount histopathology of prostatectomy specimens can be digitally registered to in vivo imaging for correlation. When biomechanical-based deformable registration is employed to account for deformation during histopathology processing, the ex vivo biomechanical properties are required. However, these properties are altered by pathology fixation, and vary with disease. Hence, this study employs magnetic resonance elastography (MRE) to measure ex vivo prostate biomechanical properties before and after fixation. A quasi-static MRE method was employed to measure high resolution maps of Young's modulus (E) before and after fixation of canine prostate and prostatectomy specimens (n = 4) from prostate cancer patients who had previously received radiation therapy. For comparison, T 1, T 2 and apparent diffusion coefficient (ADC) were measured in parallel. E (kPa) varied across clinical anatomy and for histopathology-identified tumor: peripheral zone: 99(±22), central gland: 48(±37), tumor: 85(±53), and increased consistently with fixation (factor of 11 ± 5; p < 0.02). T 2 decreased consistently with fixation, while changes in T 1 and ADC were more complex and inconsistent. The biomechanics of the clinical prostate specimens varied greatly with fixation, and to a lesser extent with disease and anatomy. The data obtained will improve the precision of prostate pathology correlation, leading to more accurate disease detection and targeting.
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Affiliation(s)
- Deirdre M McGrath
- Radiation Medicine Program, Princess Margaret Hospital, University Health Network, Toronto, Ontario M5G 2M9, Canada
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van Houdt PJ, Agarwal HK, van Buuren LD, Heijmink SWTPJ, Haack S, van der Poel HG, Ghobadi G, Pos FJ, Peeters JM, Choyke PL, van der Heide UA. Performance of a fast and high-resolution multi-echo spin-echo sequence for prostate T 2 mapping across multiple systems. Magn Reson Med 2017; 79:1586-1594. [PMID: 28671331 DOI: 10.1002/mrm.26816] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Revised: 05/18/2017] [Accepted: 06/09/2017] [Indexed: 12/27/2022]
Abstract
PURPOSE To evaluate the performance of a multi-echo spin-echo sequence with k-t undersampling scheme (k-t T2 ) in prostate cancer. METHODS Phantom experiments were performed at five systems to estimate the bias, short-term repeatability, and reproducibility across all systems expressed with the within-subject coefficient of variation (wCV). Monthly measurements were performed on two systems for long-term repeatability estimation. To evaluate clinical repeatability, two T2 maps (voxel size 0.8 × 0.8 × 3 mm3 ; 5 min) were acquired at separate visits on one system for 13 prostate cancer patients. Repeatability was assessed per patient in relation to spatial resolution. T2 values were compared for tumor, peripheral zone, and transition zone. RESULTS Phantom measurements showed a small bias (median = -0.9 ms) and good short-term repeatability (median wCV = 0.5%). Long-term repeatability was 0.9 and 1.1% and reproducibility between systems was 1.7%. The median bias observed in patients was -1.1 ms. At voxel level, the median wCV was 15%, dropping to 4% for structures of 0.5 cm3 . The median tumor T2 values (79 ms) were significantly lower (P < 0.001) than in the peripheral zone (149 ms), but overlapped with the transition zone (91 ms). CONCLUSIONS Reproducible T2 mapping of the prostate is feasible with good spatial resolution in a clinically reasonable scan time, allowing reliable measurement of T2 in structures as small as 0.5 cm3 . Magn Reson Med 79:1586-1594, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Petra J van Houdt
- Department of Radiation Oncology, the Netherlands Cancer Institute, Amsterdam, the Netherlands
| | - Harsh K Agarwal
- Philips Research NA, Cambridge, Massachusetts, USA.,National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Laurens D van Buuren
- Department of Radiation Oncology, the Netherlands Cancer Institute, Amsterdam, the Netherlands
| | | | - Søren Haack
- Department of Clinical Engineering, Aarhus University Hospital, Aarhus, Denmark
| | - Henk G van der Poel
- Department of Urology, the Netherlands Cancer Institute, Amsterdam, the Netherlands
| | - Ghazaleh Ghobadi
- Department of Radiation Oncology, the Netherlands Cancer Institute, Amsterdam, the Netherlands
| | - Floris J Pos
- Department of Radiation Oncology, the Netherlands Cancer Institute, Amsterdam, the Netherlands
| | | | - Peter L Choyke
- National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Uulke A van der Heide
- Department of Radiation Oncology, the Netherlands Cancer Institute, Amsterdam, the Netherlands
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Yamada I, Yoshino N, Hikishima K, Miyasaka N, Yamauchi S, Uetake H, Yasuno M, Saida Y, Tateishi U, Kobayashi D, Eishi Y. Colorectal carcinoma: Ex vivo evaluation using 3-T high-spatial-resolution quantitative T2 mapping and its correlation with histopathologic findings. Magn Reson Imaging 2017; 38:174-181. [DOI: 10.1016/j.mri.2016.12.028] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2016] [Revised: 12/31/2016] [Accepted: 12/31/2016] [Indexed: 01/13/2023]
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Determination of the Association Between T2-weighted MRI and Gleason Sub-pattern: A Proof of Principle Study. Acad Radiol 2016; 23:1412-1421. [PMID: 27639626 DOI: 10.1016/j.acra.2016.07.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 04/20/2016] [Accepted: 07/01/2016] [Indexed: 11/20/2022]
Abstract
RATIONALE AND OBJECTIVES The study aimed to determine the relationship between T2-weighted magnetic resonance imaging (MRI) signal and histologic sub-patterns in prostate cancer areas with different Gleason grades. MATERIALS AND METHODS MR images of prostates (n = 25) were obtained prior to radical prostatectomy. These were processed as whole-mount specimens with tumors and the peripheral zone was annotated digitally by two pathologists. Gleason grade 3 was the most prevalent grade and was subdivided into packed, intermediate, and sparse based on gland-to-stroma ratio. Large cribriform, intraductal carcinoma, and small cribriform glands (grade 4 group) were separately annotated but grouped together for statistical analysis. The log MRI signal intensity for each contoured region (n = 809) was measured, and pairwise comparisons were performed using the open-source software R version 3.0.1. RESULTS Packed grade 3 sub-pattern has a significantly lower MRI intensity than the grade 4 group (P < 0.00001). Sparse grade 3 has a significantly higher MRI intensity than the packed grade 3 sub-pattern (P < 0.0001). No significant difference in MRI intensity was observed between the Gleason grade 4 group and the sparse sub-pattern grade 3 group (P = 0.54). In multivariable analysis adjusting for peripheral zone, the P values maintained significance (packed grade 3 group vs grade 4 group, P < 0.001; and sparse grade 3 sub-pattern vs packed grade 3 sub-pattern, P < 0.001). CONCLUSIONS This study demonstrated that T2-weighted MRI signal is dependent on histologic sub-patterns within Gleason grades 3 and 4 cancers, which may have implications for directed biopsy sampling and patient management.
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Kwon KT, Wu HH, Shin T, Cukur T, Lustig M, Nishimura DG. Three-dimensional magnetization-prepared imaging using a concentric cylinders trajectory. Magn Reson Med 2013; 71:1700-10. [PMID: 23818212 DOI: 10.1002/mrm.24823] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Revised: 04/15/2013] [Accepted: 04/30/2013] [Indexed: 11/11/2022]
Abstract
PURPOSE To develop new magnetization-prepared imaging schemes based on a three-dimensional (3D) concentric cylinders trajectory. METHODS The 3D concentric cylinders trajectory, which is robust to off-resonance effects and timing delays while requiring fewer excitations than a comparable 3D Cartesian (3DFT) sequence, is used as the readout for magnetization-prepared sequences exploiting its inherently centric-ordered structure. Two applications: (i) T1 -weighted brain imaging with an inversion-recovery-prepared radiofrequency-spoiled gradient-echo (IR-SPGR) sequence, (ii) non-contrast-enhanced (NCE) peripheral angiography with a magnetization-prepared balanced steady-state free precession (bSSFP) sequence are presented to demonstrate the effectiveness of the proposed method. For peripheral angiography, the scan efficiency is further improved by interleaving different preparations at different rates and by carefully designing the sampling geometry for an efficient parallel imaging method. RESULTS In vivo brain scans with an IR-SPGR sequence and lower extremity scans with a magnetization-prepared bSSFP sequence for NCE peripheral angiography both demonstrate that the proposed sequences with concentric cylinders effectively capture the transient magnetization-prepared contrast with faster scan times than a corresponding 3DFT sequence. The application of peripheral angiography also shows the feasibility of the proposed interleaving schemes and parallel imaging method. CONCLUSION The 3D concentric cylinders trajectory is a robust and efficient readout that is well-suited for magnetization-prepared imaging.
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Affiliation(s)
- Kie Tae Kwon
- Department of Electrical Engineering, Magnetic Resonance Systems Research Laboratory, Stanford University, Stanford, California, USA
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Simpkin CJ, Morgan VA, Giles SL, Riches SF, Parker C, deSouza NM. Relationship between T2 relaxation and apparent diffusion coefficient in malignant and non-malignant prostate regions and the effect of peripheral zone fractional volume. Br J Radiol 2013; 86:20120469. [PMID: 23426849 DOI: 10.1259/bjr.20120469] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE To establish whether T2 relaxation and apparent diffusion coefficient (ADC) in normal prostate and tumour are related and to investigate the effects of glandular compression from an enlarged transition zone (TZ) on peripheral zone (PZ) T2 and ADC by correlating them with the peripheral zone fractional volume (PZFV). METHODS 48 consecutive patients prospectively underwent multiecho T2 weighted (T2W) (echo times 20, 40, 60, 80, 100 ms) and diffusion-weighted (b=0, 100, 300, 500, 800 s mm(-2)) endorectal MRI. In 43 evaluable patients, single slice whole PZ, TZ and tumour (focal hypointense signal on T2W images in a biopsy-positive octant) regions of interest were transferred to T2 and ADC maps by slice matching. T2 and ADC values were correlated, and PZ values were correlated with PZFV. RESULTS T2 and ADC values were significantly different among groups [T2 mean±standard deviation (SD) PZ, 149±49 ms; TZ, 125±26 ms; tumour, 97±23 ms; PZ vs TZ, p=0.002; PZ vs tumour, p<0.0001; TZ vs tumour, p<0.0001; ADC×10(-6) mm(2) s(-1) mean±SD PZ, 1680±215; TZ, 1478±139; tumour, 1030±205; p<0.0001]. Significant positive correlations existed between T2 and ADC for PZ, TZ, PZ and TZ together, but not for tumour (r=0.515, p<0.0001; r=0.300, p=0.03; r=0.526, p<0.0001; and r=0.239, p=0.32, respectively). No significant correlation existed between PZFV and PZ T2 (r=0.10, p=0.5) or ADC (r=0.03, p=0.8). CONCLUSION The correlation between T2 and ADC that exists in normal prostate is absent in tumour. PZ compression by an enlarged TZ does not alter PZ T2 or ADC to affect tumour-PZ contrast. ADVANCES IN KNOWLEDGE Microstructural features of tumours alter diffusivity independently of their effects on T2 relaxation.
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Affiliation(s)
- C J Simpkin
- Cancer Research UK/EPSRC Imaging Centre, Institute of Cancer Research, Sutton, UK
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Foltz WD, Wu A, Chung P, Catton C, Bayley A, Milosevic M, Bristow R, Warde P, Simeonov A, Jaffray DA, Haider MA, Ménard C. Changes in apparent diffusion coefficient and T2 relaxation during radiotherapy for prostate cancer. J Magn Reson Imaging 2012; 37:909-16. [PMID: 23097411 DOI: 10.1002/jmri.23885] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2012] [Accepted: 09/14/2012] [Indexed: 12/26/2022] Open
Abstract
PURPOSE To evaluate regional and temporal changes in apparent diffusion coefficient (ADC) and T2 relaxation during radiation therapy (RT) in patients with low and intermediate risk localized prostate cancer. MATERIALS AND METHODS Seventeen patients enrolled on a prospective clinical trial where MRI was acquired every 2 weeks throughout eight weeks of image-guided prostate IMRT (78 Gy/39 fractions). ADC and T2 quantification used entire prostate, central gland, benign peripheral zone, and tumor-dense regions-of-interest, and mean values were evaluated for common response trends. RESULTS Overall, the RT responses were greater than volunteer measurement repeatability, and week 6 appeared to be an optimum time-point for early detection. RT effects on the entire prostate were best detected using ADC (5-7% by week 2, P < 0.0125), effects on peripheral zone were best detected using T2 (19% reduction at week 6; P = 0.004) and effects on tumors were best detected using ADC (14% elevation at week 6; P = 0.004). CONCLUSION ADC and T2 may be candidate biomarkers of early response to RT warranting further investigation against clinical outcomes.
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Affiliation(s)
- Warren D Foltz
- Radiation Medicine Program, Princess Margaret Hospital, and Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada.
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