Incremental Prognostic Value of Apparent Diffusion Coefficient Histogram Analysis in Head and Neck Squamous Cell Carcinoma.
RATIONALE AND OBJECTIVES
We aimed to investigate the incremental prognostic value of apparent diffusion coefficient (ADC) histogram analysis in patients with head and neck squamous cell carcinoma (HNSCC) and integrate it into a multivariate prognostic model.


MATERIALS AND METHODS
A retrospective review of magnetic resonance imaging findings was conducted in patients with pathologically confirmed HNSCC between June 2012 and December 2015. For each tumor, six histogram parameters were derived: the 10th, 50th, and 90th percentiles of ADC (ADC10, ADC50, and ADC90); mean ADC values (ADCmean); kurtosis; and skewness. The clinical variables included age, sex, smoking status, tumor volume, and tumor node metastasis stage. The association of these histogram and clinical variables with overall survival (OS) was determined. Further validation of the histogram parameters as independent biomarkers was performed using multivariate Cox proportional hazard models combined with clinical variables, which was compared to the clinical model. Models were assessed with C index and receiver operating characteristic curve analyses for the 12- and 36-month OS.


RESULTS
Ninety-six patients were eligible for analysis. Median follow-up was 877 days (range, 54-1516 days). A total of 29 patients died during follow-up (30%). Patients with higher ADC values (ADC10 > 0.958 × 10-3 mm2/s, ADC50 > 1.089 × 10-3 mm2/s, ADC90 > 1.152 × 10-3 mm2/s, ADCmean > 1.047 × 10-3 mm2/s) and lower kurtosis (≤0.967) were significant predictors of poor OS (P < .100 for all). After adjusting for sex and tumor node metastasis stage, the ADC90 and kurtosis are both significant predictors of OS with hazard ratios = 1.00 (95% confidence interval: 1.001-1.004) and 0.58 (95% confidence interval: 0.37-0.90), respectively. By adding the ADC parameters into the clinical model, the C index and diagnostic accuracies for the 12- and 36-month OS showed significant improvement.


CONCLUSIONS
ADC histogram analysis has incremental prognostic value in patients with HNSCC and increases the performance of a multivariable prognostic model in addition to clinical variables.
['Li|Xiaoxia|X|', 'Yuan|Ying|Y|', 'Ren|Jiliang|J|', 'Shi|Yiqian|Y|', 'Tao|Xiaofeng|X|']
D000328:Adult D000368:Aged D038524:Diffusion Magnetic Resonance Imaging D005260:Female D006801:Humans D008297:Male D008875:Middle Aged D011237:Predictive Value of Tests D011379:Prognosis D012372:ROC Curve D012189:Retrospective Studies D000077195:Squamous Cell Carcinoma of Head and Neck D047368:Tumor Burden
histogram analysis Head and neck squamous cell carcinoma diffusion-weighted imaging