Article Figures & Data
Figures
- Fig 1.
Comparison of diffusion-weighted imaging (DWI) and cellular density between high and low apparent diffusion coefficient (ADC) groups (A and F). Contrast-enhanced T1-weighted image with regions of interest surrounding enhancing regions that were pathologically diagnosed as primary central nervous system non-Hodgkin lymphoma. Arrow indicates enhancing region subjected to stereotactic biopsy. DWI (B and G), black and white ADC map (C and H), color ADC map (D and I), and biopsy specimens (E and J) from patient 2 (low ADC group) and patient 17 (high ADC group) (hematoxylin-eosin, original magnification ×100).
- Fig 2.
Scatterplots of cellular density measurements versus 25th percentile (ADC25%, A) and mean ADC (ADCmean, B) values within contrast-enhancing tumor regions for all 18 subjects included in this study, demonstrating statistically significant inverse correlations (ADC25%, R = −0.47, P = .05; ADCmean, R = −0.54, P = .02).
- Fig 3.
A and B, Patient outcome as a function of ADC25% stratification into low and high groups. Kaplan Meier analysis (A) of progression-free survival (PFS) for patients stratified into the low ADC25% group (<692, blue line) with a mean progression time of 9.4 months versus those stratified into high ADC25% group (>692, red line) with a mean progression time of 30.0 months (P = .02, logrank test). Kaplan Meier plot (B) of overall survival (OS) for patients stratified into the low ADC25% group (<692, blue line) with a mean survival of 15.8 months versus those stratified into high ADC25% group (>692, red line) with a mean survival of 30.9 months (P = .01, logrank test). C and D, Patient outcome as a function of minimum ADC value shows a statistically significant difference in PFS and OS between low and high groups (P < .05).
Tables
Patient No. ADC Group Age (yr)/Sex No. Enhancing Lesions Response to Tx ADC25% ADCmin ADCmean Overall Cellularity 1 Low 45/F MP PD 534 156 637 High 2 Low 82/F SG PD 541 167 745 High 3 Low 57/M MP PD 646 191 894 High 4 Low 61/M MP PR 528 214 877 High 5 Low 62/F MP PD 589 280 681 High 6 Low 54/M MP PD 638 338 749 Low 7 Low 70/M SG PR 623 367 719 High 8 Low 54/F SG CR 688 456 805 High 9 Low 26/M SG CR 692 398 835 High 10 High 52/F MP CR 693 294 779 Low 11 High 43/F SG CR 725 371 876 High 12 High 81/M MP CR 822 411 959 Low 13 High 53/F MP CR 831 414 873 Mixed 14 High 68/M MP CR 842 479 1016 Low 15 High 61/F MP CR 772 510 781 Low 16 High 53/M MP CR 741 525 891 Low 17 High 56/F MP CR 815 609 893 Mixed 18 High 67 mol/L SG CR 906 614 933 Low -
Note:—ADC indicates apparent diffusion coefficient; MP, multiple; SG, single; Tx, treatment; PD, progressive disease; PR, partial response; CR, complete response; ADC25%, 25th percentile ADC value; ADCmin, minimum ADC value; ADCmean, mean ADC value.
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a Patients are stratified on the basis of the median 25th percentile value.
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Age (yr) MMSE KPS Days to Tx Months to F/U MRI No. Tx to F/U MRI Change CE Volume Months to Progression Months to Death Low ADC 56.7 (15.6) 25.2 (6.11) 62.2 (6.67) 13.8 (14.6) 8.3 (14) 2.00 (1.41) 2.50 (2.88) 9.4 (12.0) 15.8 (9.87) High ADC 59.3 (11.3) 25.7 (4.50) 66.7 (5.00) 13.4 (11.7) 4.0 (8.0) 1.70 (0.70) 3.92 (2.39) 30.0 (18.0) 30.9 (17.0) Pvalue .70 .83 .13 .94 .39 .53 0.37 <.01 .03 -
Note:—MMSE indicates pretherapeutic Mini-Mental State Examination score; KPS, Karnovsky performance status; Days to Tx, mean number of days between initial diagnosis by MR imaging and initiation of methotrexate-based chemotherapy; Months to F/U MRI, mean number of months between pre- and intratherapeutic MR imaging; No. Tx to F/U MRI, mean number of methotrexate treatments between pre- and intratherapeutic MR imaging; Change CE, difference in enhancing volume between pre-and posttherapeutic imaging series; Months to Progression, mean number of months to progression based on MR imaging if event occurred; Months to Death, mean number of months to death if event occurred.
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a All data are presented as mean (± SD). Patients are stratified based on median 25th percentile value.
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ADCmin Change ADCmin ADC25% Change ADC25% ADCmean Change ADCmean Low ADC 258 (109) −18.7 (219) 608 (62) 84.7 (114) 771 (87.7) 116 (106) High ADC 469 (107) −120 (224) 794 (67) −55.5 (84.7) 889 (77.0) −42 (74) P value <.01 .31 <.01 .04 <.01 .01 -
Note:—Change ADCmin indicates the difference between pre- and posttherapeutic ADCmin values (negative values signify net decrease in value); Change ADC25%, difference between pre- and posttherapeutic ADC25% values; Change ADCmean, difference between pre- and posttherapeutic ADCmean values.
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a All data are presented as mean (SD). All ADC values are reported as 100 × 10−6 mm2/s.
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