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Quantitative aspects of diffusion-weighted magnetic resonance imaging in rectal cancer response to neoadjuvant therapy Cover

Quantitative aspects of diffusion-weighted magnetic resonance imaging in rectal cancer response to neoadjuvant therapy

Radiology and Oncology
Volume 51 (2017): Issue 3 (September 2017)
By: Thiago Bassaneze,  José Eduardo Gonçalves,  Juliano Ferreira Faria,  Rogério Tadeu Palma and  Jaques Waisberg  
Open Access
|Jun 2017

Figures & Tables

Figure 1

Sample of a T2-weighted MRI, DW-MRI (b-value 1000 s/mm2), and ADC map from a locally advanced rectal tumor. The red arrows point to different aspects of the left lateral pre-CRT tumor area. The yellow arrows point to the cancer shrinkage in the post-CRT. Pre- and post-CRT ADC values were 0.92 × 10−3 mm2/s and 1.50 × 10−3 mm2/s, with pCR in the surgical specimen.
Sample of a T2-weighted MRI, DW-MRI (b-value 1000 s/mm2), and ADC map from a locally advanced rectal tumor. The red arrows point to different aspects of the left lateral pre-CRT tumor area. The yellow arrows point to the cancer shrinkage in the post-CRT. Pre- and post-CRT ADC values were 0.92 × 10−3 mm2/s and 1.50 × 10−3 mm2/s, with pCR in the surgical specimen.

Figure 2

Correlation between ADC values and final T staging. (A) The pre-CRT ADC values were similar in the different groups (blue bars, (p > 0.05), although post-CRT ADC values differed in each group (green bars, p < 0.01); statistical significance (*). (B) Post-CRT ADC values with a moderate negative correlation and slope different from zero degrees (Spearman’s Rho = -0.54; 95% confidence interval -0.75 to -0.24). (C) Box plot analysis between post-CRT ADC values and final T staging. The pCR ADC-median value (1.53 × 10’−3 mm2/s) is far away from the lower and upper boundaries of the non-pCR box (p < 0.01).
Correlation between ADC values and final T staging. (A) The pre-CRT ADC values were similar in the different groups (blue bars, (p > 0.05), although post-CRT ADC values differed in each group (green bars, p < 0.01); statistical significance (*). (B) Post-CRT ADC values with a moderate negative correlation and slope different from zero degrees (Spearman’s Rho = -0.54; 95% confidence interval -0.75 to -0.24). (C) Box plot analysis between post-CRT ADC values and final T staging. The pCR ADC-median value (1.53 × 10’−3 mm2/s) is far away from the lower and upper boundaries of the non-pCR box (p < 0.01).

Figure 3

Receiver operating characteristic (ROC) curve and histogram in patients with rectal carcinoma with a normal distribution. (A) The optimal post-CRT ADC cutoff value 1.49 × 10−3 mm2/s (area under the curve = 0.95). (B) Histogram. The mean post-CRT ADC values of patients with pCR was 1.53 (± 1.96 × 0.15 × 10−3 mm2/s) and of patients with non-pCR 1.16 (± 1.96 × 0.19 × 10−3 mm2/s); the area in gray highlights the possible overlap in these values.
Receiver operating characteristic (ROC) curve and histogram in patients with rectal carcinoma with a normal distribution. (A) The optimal post-CRT ADC cutoff value 1.49 × 10−3 mm2/s (area under the curve = 0.95). (B) Histogram. The mean post-CRT ADC values of patients with pCR was 1.53 (± 1.96 × 0.15 × 10−3 mm2/s) and of patients with non-pCR 1.16 (± 1.96 × 0.19 × 10−3 mm2/s); the area in gray highlights the possible overlap in these values.

Calculation of diagnostic performance of conventional T2W MRI and combined set of conventional T2W MRI in addition to DWI for the diagnosis of complete rectal cancer response to neoadjuvant therapy

T2W95% CIT2W + DWI95% CI
Sensitivity%86.9(0.65−0.96)96.1(0.78−0.99)
Specificity%50(0.20−0.79)71.4(0.30−0.94)
PPV%80(0.58−0.92)92.6(0.74−0.98)
NPV%62.5(0.25−0.89)83.3(0.36−0.99)
Accuracy%75.7(0.57−0.88)81.8(0.63−0.92)

The patients’ clinical characteristics and patohystologic characteristics of the tumor

AllpCRnon-pCR
Average age, years59.6 ±11.558.5 ±11.259.9 ±11.8
Gender

= number of individuals; CRT = chemoradiotherapy; pCR = pathologic complete response
   Male18513
   Female15213
Clinical T stage pre-CRT (MRI classification)

= number of individuals; CRT = chemoradiotherapy; pCR = pathologic complete response
   T2312
   T323518
   T4716
Average tumor distance to the anus (cm)

= number of individuals; CRT = chemoradiotherapy; pCR = pathologic complete response

5.1 (± 2.2)6.1 (± 1.3)4.8 (± 2.3)
Type of resection

= number of individuals; CRT = chemoradiotherapy; pCR = pathologic complete response
   Low anterior resection15312
   Abdominoperineal resection15411
   Pelvic exenteration303
Histologic grade (biopsy)

= number of individuals; CRT = chemoradiotherapy; pCR = pathologic complete response
   Well differentiated624
   Moderately differentiated23419
   Poorly differentiated413
DOI: https://doi.org/10.1515/raon-2017-0025 | Journal eISSN: 1581-3207 | Journal ISSN: 1318-2099
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Language: English
Page range: 270 - 276
Submitted on: Dec 6, 2016
|
Accepted on: Jun 1, 2017
|
Published on: Jun 25, 2017
Published by: Association of Radiology and Oncology
In partnership with: Paradigm Publishing Services
Publication frequency: 4 issues per year
Keywords:
rectal cancer,
neoadjuvant therapy,
diffusion MRI
Related subjects:
Medicine,
Clinical medicine,
Internal medicine,
Haematology, oncology,
Radiology

© 2017 Thiago Bassaneze, José Eduardo Gonçalves, Juliano Ferreira Faria, Rogério Tadeu Palma, Jaques Waisberg, published by Association of Radiology and Oncology
This work is licensed under the Creative Commons Attribution 4.0 License.

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