Article Figures & Data
Figures
- Fig 1.
Sample case demonstrating measurement methods. A, Manual clinical transaxial (2D) measurements. Largest dimension identified on axial images and perpendicular short axis dimension performed and reported in the clinical radiology report and used for derivation of tumor response. B, Semiautomated 2D measurements. Tumor margins are traced (red outline) on each image, and automated 2D measurements (largest long axis dimension and perpendicular short axis dimension, blue lines) are automatically derived, along with tumor volume in the mint Lesion software package. C, Semiautomated 2D measurements and volumes performed during the treatment course. Imaging performed after cycles 2, 4, 6, and 8.
- Fig 2.
Sample case demonstrating clinical 2D measurements (clinical CP) and semiautomated 2D and volumetric measurements (semiautomated CP) during the treatment course. Note that in this case, although there were differences in orientation of the measurements with the semiautomated process, response classification was the same compared with manual clinical CP measurements.
- Fig 3.
Sample case demonstrating clinical 2D measurements (clinical CP) and semiautomated 2D and volumetric measurements (semiautomated CP) during the treatment course. In this case, per protocol, imaging progression based on clinical CP (A) was called after cycle 8 (33.2% increase in CP). With semiautomated CP (B), progressive disease would have been called (based solely on imaging) after cycle 2 (28% increase). This is due to a different section choice as a maximum transaxial dimension and slightly different measurement orientation (B, cycle 2). Subsequently, however, on the basis of a protocol comparing with smallest CP during treatment (baseline), stable disease would have been called. Note that although the CP increased 28% (PD) after cycle 2, the tumor volume only increased 9% (SD). Such discrepancies were common when comparing treatment-response strategies.
- Fig 4.
Clinically derived tumor CP versus semiautomated software–derived tumor CP for all time points with a linear trendline (r = 0.74, P < .0001).
- Fig 5.
Bland-Altman plot demonstrating bias between clinical and semiautomated tumor CP for all time points. The solid line indicates a mean bias between techniques. Dashed lines indicate ±2 SDs of the mean (95% limits of agreement). Overall, clinical CP measured less than semiautomated CP (mean bias, −2.5). Outliers (>1.96 SDs) were predominantly noted in larger tumors.
- Fig 6.
Correlation of percentage change from prior examination in clinical CP versus semiautomated CP (r = 0.36, P = .011).
- Fig 7.
Bland-Altman plot demonstrating bias between the percentage change in clinical and semiautomated tumor CP from a prior examination. The solid line indicates mean bias between techniques. Dashed lines indicate ±2 SDs of the mean (95% limits of agreement). Overall, percentage change in clinical CP was smaller than the percentage change in semiautomated CP (mean bias, −1.5%, 95% limits of agreement, −59.9, +56.8) between time points.
Tables
- Table 1:
Response assessment classifications of 50 MR imaging time points for 3 tumor-management strategiesa
Clinical CP Semiautomated CP Volume (25/50) Volume (40/65) PR SD PD PR SD PD PR SD PD PR SD PD Clinical CP PR 0 0 0 0 0 0 0 0 0 SD 2 25 14 2 23 16 1 32 8 PD 0 2 7 0 2 7 0 3 6 Concordance 64% 60% 76% Semiautomated CP PR 2 0 0 1 1 0 SD 0 20 7 0 25 2 PD 0 5 16 0 9 12 Concordance 76% 76% Volume PR 1 1 0 SD 0 25 0 PD 0 9 14 Concordance 80% ↵a Two different tumor-response criteria were applied to the volume data (25/50 uses the same criteria as used for CP-response determinations, 40/65 denotes PR as >65% decrease from baseline and PD as >40% increase from the prior lowest tumor size). Unless otherwise noted, values represent the number of MR imaging time points.
- Table 2:
Descriptive statistics of the percentage change in tumor size from baseline or nadir to follow-up examination (assigned per clinical protocol) for each response assessment classification per tumor measurement strategy
TRC Mean (%) Standard Deviation (%) Minimum (%) Maximum (%) CPc CPsa Vol1 Vol2 CPc CPsa Vol1 Vol2 CPc CPsa Vol1 Vol2 CPc CPsa Vol1 Vol2 PD 57 83 75 79 64 78 81 59 27 18 9 42 227 224 271 271 SD 6 14 16 8 13 28 32 20 -27 -68 -73 51 25 91 83 39 Note:—CPc indicates clinical cross-product; CPsa, semiautomated cross-product; Vol1, volume (25/50% tumor response criteria); Vol2, volume (40/65% tumor response criteria).
