Abstract. The purpose of this study was to evaluate the accuracy of diffusion-weighted imaging (DWI) for predicting locoregional failure of chemoradiotherapy in patients with head and neck squamous cell carcinoma (HNSCC). A comprehensive search was conducted through the EMBASE, PubMed and Cochrane Library databases for relevant publications. Stata software was used to calculate the pooled sensitivity, specificity, likelihood ratios and diagnostic odds ratios, and to construct a summary receiver operating characteristics (sROC) curve for DWI. A total of 9 studies comprising 421 patients were included. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and diagnostic odds ratio were 0.82 [95% confidence interval (CI): 0.72-0.88], 0.70 (95% CI: 0.62-0.77), 2.7 (95% CI: 2.1-3.6), 0.26 (95% CI: 0.17-0.41), and 10.48 (95% CI: 5.35-20.53), respectively. The area under the sROC curve was 0.84 (95% CI: 0.81-0.87). Therefore, DWI appears to be a promising imaging modality for predicting local failure of chemoradiotherapy in patients with HNSCC.
IntroductionHead and neck squamous cell carcinoma (HNSCC) accounts for ~3% of all malignancies (1). Currently, chemoradiotherapy (CRT) is considered as a good approach to the treatment of locally advanced HNSCC. However, ~25-30% of patients have local residual disease or develop relapse at the primary or lymph node sites after treatment (2), which represents a challenge in the management of HNSCC. Therefore, there is a need for biomarkers that can provide accurate and timely prediction of therapeutic outcome prior to treatment or in the early stages of treatment, with discontinuation of ineffective approaches and timely application of alternative therapeutic strategies.Recently, diffusion-weighted imaging (DWI) was proposed as an imaging biomarker for predicting treatment outcome in multiple malignancies, including rectal cancer (3), breast cancer (4) and glioblastoma (5). DWI quickly measures the Brownian motion of extracellular water molecules in biological tissues, which may be quantified with the apparent diffusion coefficient (ADC) (6). Previous studies demonstrated that higher pretreatment ADCs were correlated with poor response to treatment (7,8). In addition, due to its ability to depict the range of ADCs, ADC histograms may be used to evaluate the heterogeneity of the whole tumor. This feature enables evaluation of the degree of necrosis and viability, which may be crucial when planning a radiation dose boost (9).Over the past few years, a number of studies have investigated the role of DWI in predicting response to CRT in patients with HNSCC. Given the varied characteristics of the patients and studies, individual studies are unable to provide a reliable estimate of DWI performance for the prediction of treatment response. Hence, the present meta-analysis was performed to determine the diagnostic performance of DWI for the prediction of locoregional failure of CRT in patients with HNSCC, which may be helpful in optimizing the managem...