Dechun Zheng MS, Presenter: Nothing to Disclose

Chen Yunbin MD, Abstract Co-Author: Nothing to Disclose

Xiangyi Liu BS, Abstract Co-Author: Nothing to Disclose

Weibo Chen PhD, Abstract Co-Author: Nothing to Disclose

Queenie Chan PhD, Abstract Co-Author: Nothing to Disclose

Chaobin Huang, Abstract Co-Author: Nothing to Disclose

youping xiao, Abstract Co-Author: Nothing to Disclose

Wang Ren, Abstract Co-Author: Nothing to Disclose

Jianji Pan, Abstract Co-Author: Nothing to Disclose

To prospectively evaluate dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) as a tool for assessing short-term control of chemoradiotherapy (CRT) in nasopharyngeal carcinoma (NPC).

Fifty patients with local advanced NPC scheduled for neoadjuvant chemotherapy (NAC) following intensity-modulated radiation therapy (IMRT) were studied. DCE-MRI was performed within one week before NAC and repeated one week after IMRT treatment using a 3T clinical scanner system (Achieva TX, Philips Healthcare). Clinical response was evaluated after completed CRT according to the RECIST criteria. Four kinetic parameters (Ktrans, Kep, ve and vp) were measured based on extended Tofts’ Model and compared to different clinical response groups using student T or Mann-Whitney U test.

Ktrans and Kep values were reduced after one week IMRT in patients with clinical treatment response after NAC and CRT treatment. The pretreatment Ktrans value, percentage change and difference values of Ktrans and Kep (Ktrans(Perc) and Kep(Perc), ΔKtrans and ΔKep) between pretreatment and after one week IMRT, and tumor regression after one week IMRT were all significantly larger in complete response (CR) patients than those with residual disease (partial response, PR) after radical CRT (Table 1, P < 0.05). We found out in boxplot analysis that ΔKtrans, Ktrans(Perc) and Kep(Perc) metrics were predictive imaging markers for response assessment of NPC subjects who treated with CRT, which demonstrated that patients who were CR after CRT clustered in separate regions from those were PR (Figure 1). The receiver operating characteristic (ROC, Figure 2) analyses proved that diagnosis efficacies of single Ktrans, ΔKtrans, ΔKep, Ktrans(Perc) and Kep(Perc) values ranging from 71.8 – 87.0%. And combined with tumor shrink ratio with above parameters yielded the highest diagnosis efficacy (90.2%) as well as the highest sensitivity (92.3%) and specificity (81.1%), respectively.

DCE-MRI has the potential to predict short-term control of locally advanced NPC by mean of earlier evaluating changes of tumor vascularization and volume during treatment. The Ktrans may be potential markers for predicting the response to CRT of NPC.

DCE-MRI study prior and during IMRT process is available to early predict clinical response of local advanced NPC treated with CRT. Ktrans might become non-invasive prognostic markers of NPC.

Zheng, D, Yunbin, C, Liu, X, Chen, W, Chan, Q, Huang, C, xiao, y, Ren, W, Pan, J, Prediction Response to Intensity-Modulated Radiotherapy of Nasopharyngeal Carcinoma: A Dynamic Contrast-Enhanced MR Imaging Study at 3T.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14006450.html