Research papersThe prediction of the treatment response of cervical nodes using intravoxel incoherent motion diffusion-weighted imaging

- The predictive role of IVIM-DWI on cervical nodal response to chemo-radiotherapy was investigated.
- Pre- and mid-treatment IVIM-DWI correlated significantly with the status of lymph nodes.
- D values at baseline and at mid-RT had greater diagnostic accuracy than ADC values.
- Perfusion-related parameters showed potential to further improve the predictive power.

PurposeTo investigate the predictive role of Intravoxel Incoherent Motion Diffusion-Weighted Imaging (IVIM-DWI) parameters on cervical nodal response to chemo-radiotherapy (CRT) of head and neck squamous cell carcinoma (HNSCC).Materials and methodsPatients with pathologically confirmed HNSCC were included in the present prospective study, having at least one positive cervical lymph node (LN). They received concomitant CRT and underwent three serial IVIM-DWI investigations: before, at mid-treatment and after treatment completion. Tissue diffusion coefficient D, perfusion-related diffusion coefficient D* and perfusion fraction f were calculated by a bi-exponential fit. The two-sided Mann-Whitney rank test was used to compare the imaging parameters of patients with regional failure (RF) and regional control (RC). A p value lower than 0.05 was considered to be statistically significant.ResultsThirty-four patients were accrued. Twenty-four out of 34 LN (70.6%) showed persistent RC after a median follow-up time of 27.6 months (range: 12.0-50.2 months), while ten cases of RF (29.4%) were confirmed with a median time of 6.8 months (range: 1.5-19.5 months). Patients with RC showed significantly lower pre-treatment D values compared to the RF patients (p = 0.038). At mid-treatment, the patients with RF showed significantly higher D values (p = 0.025), and exhibited larger percent reductions in f and the product D* × f from the baseline (p = 0.008 and <0.001, respectively). No additional information was provided by the examination at the end of treatment.ConclusionPre-treatment and mid-treatment IVIM-DWI showed potential for prediction of treatment response of cervical LN in HNSCC patients.