Interval changes of histogram-derived diffusion indices predict treatment response to induction chemotherapy in head and neck cancer: a feasibility study

Abstract

Background: This retrospective study investigated whether the interval change of apparent diffusion coefficient (∆ADC) [baseline and after the first cycle of induction chemotherapy (ICT)] can be used as a valid predictive imaging biomarker of the treatment response to ICT in head and neck cancer (HNC). Methods: A total of 19 consecutive patients with HNC who underwent diffusion-weighted magnetic resonance imaging (DWI) at baseline and after the first cycle of ICT were included. Whole-tumor ADC histogram parameters (mean, median, kurtosis, skewness, entropy, minimal, maximum, 25th percentile, and 75th percentile) were obtained. The correlations of ∆ADC histogram parameters, volume, T-stage, N-stage, and age with the treatment response were examined using the Mann-Whitney U test. The predictive value of histogram parameters was examined using receiver operating characteristic (ROC) curves.Results: Responders showed significantly higher values of ∆ADC 25 (0.19±0.23) and ∆ADC min (1.78±2.98) than non-responders (−0.09±0.15 and −0.73±0.36; P=0.035 and 0.009, respectively). When ∆ADC 25 and ∆ADC min were used for predicting the treatment response, the area under the ROC curve was 0.850/0.933 with a sensitivity of 73.3%/80.0% and specificity of 100%/100% (P=0.036 and 0.009, respectively).Conclusions: ∆ADC 25 and ∆ADC min derived from whole-tumor histogram analysis are valuable imaging biomarkers for the early prediction of the ICT response in HNC.

Thyroid artery embolization of large solitary symptomatic benign thyroid nodules through transradial approach

“…On these images, regions of interest (ROI) were manually defined on CT or MRI. ROI area measurements for each slice were multiplied by the image–slice thickness and summed to generate volumes ( 11 - 13 ). For ultrasound, the nodule volume was calculated as V = πabc/6 (where V is the volume, a is the largest diameter, and b and c are the two perpendicular diameters).…”