Keywords:
Diagnostic or prognostic study, Retrospective, Outcomes, Treatment effects, Radiation therapy / Oncology, Chemotherapy, MR-Functional imaging, MR-Diffusion/Perfusion, Oncology, Head and neck, Head and Neck, Performed at one institution
Authors:
A. Leben1, A. Novakovic1, D. Pirnat2, K. Surlan Popovic1, M. Garbajs1; 1Ljubljana/SI, 2Velenje/SI
DOI:
10.26044/ecr2020/C-07195
Results
In all patients, radiological tumour response to CRT was determined 2.5-3 months post-therapy – 3 out of 19 (16%) patients had disease recurrence (PR) and 16 (84%) patients had CR to treatment.
Average parameter values and the illustrative example of a responder and non-responder with multiparametric MRI maps are shown in Table 1 and Figure 1 and 2, respectively.
|
Complete response |
Partial response |
|
Arithmetic mean |
Standard deviation |
Arithmetic mean |
Standard deviation |
D(×10-3 mm2/s) |
0.57 |
0.13 |
0.84 |
0.13 |
D*(×10-3 mm2/s) |
18.16 |
3.48 |
14.13 |
6.14 |
f |
0.15 |
0.08 |
0.14 |
0.06 |
ADC(×10-3 mm2/s) |
0.77 |
0.10 |
1.02 |
0.05 |
Table 1: IVIM and ADC parameter values (arithmetic mean, standard deviation) separately according to treatment response. Diffusion coefficient (D), perfusion-related diffusion coefficient (D*), perfusion fraction (f), apparent diffusion coefficient (ADC).
Lower values of IVIM parameter D showed to be significant predictor of treatment outcome for treatment with CRT (p = 0.004). IVIM parameters D* (p = 0.118) and f (p = 0.753) were not significantly different regarding treatment response.
ADC values were significantly (p < 0.001) lower in patients with CR compared to patients demonstrating PR.
ROC curve analysis showed parameter D (area under the curve – AUC = 0.948; sensitivity 100%, specificity 66.7%, at chosen threshold D = 0.83) as the only good outcome predictor for distinguishing patients with CR and PR (Figure 3).
ROC curves for parameters D* and f did not yield promising results in terms of using parameters as outcome predictors (AUC 0.708 and 0.510 for D* and f, respectively).
IVIM parameter D strongly correlated with ADC (r = 0.871, p < 0.001) and D* inversely correlated with ADC (r = -0.567, p = 0.011).