ABSTRACT. The association between cyclin D1 and survivin protein expressions with radiotherapy sensitivity in patients with nasopharyngeal carcinoma was investigated. Biopsy specimens of 72 patients with nasopharyngeal carcinoma were collected before the initiation of radiotherapy (49 cases were in the radiationsensitive group and 23 cases were in the radiation-insensitive group). Conventional hematoxylin and eosin staining was used for tissue typing. The immunohistochemical SP method was used to detect cyclin D1 and survivin protein expression levels. The IBM SPSS Statistics 20 statistical software was applied for conducting the chi-squared test and the Spearman correlation analysis. In the 72 cases, the high expression rates of cyclin D1 were 28.6% (14/49) and 69.6% (16/23) in the radiotherapy-sensitive group and in the radiotherapy-insensitive group, respectively, and the differences between groups were statistically significant (P < 0.05). The high expression rates of survivin were 34.7% (17/49) and 73.9% (17/23) in the radiotherapy-sensitive group and in the radiotherapy-insensitive group, respectively, which differed significantly (P < 0.05). The protein expressions of cyclin D1 and survivin were positively correlated (Spearman's r = 0.353, P < 0.05). Cyclin D1 and survivin expression levels were negatively correlated with the radiosensitivity of nasopharyngeal carcinoma. Cyclin D1 and survivin may be used as molecular markers to predict the sensitivity of radiotherapy.

BACKGROUND AND PURPOSE: An accurate evaluation of the World Health Organization grade is critical in pediatric intracranial tumors. Our aim was to explore the correlations between parameters derived from conventional DWI, intravoxel incoherent motion, and diffusional kurtosis imaging with histopathologic features to evaluate the accuracy of diffusion parameters for grading of pediatric intracranial tumors. MATERIALS AND METHODS:Fifty-four pediatric patients with histologically proved intracranial tumors who underwent conventional DWI, intravoxel incoherent motion, and diffusional kurtosis imaging were recruited. The conventional DWI (ADC), intravoxel incoherent motion (pure diffusion coefficient [D], pseudodiffusion coefficient [D*], perfusion fraction [f], diffusional kurtosis imaging [K], and diffusion coefficient [Dk]) parameters in the solid component of tumors were measured. The cellularity, Ki-67, and microvessel density were measured. These parameters were compared between the low-and high-grade pediatric intracranial tumors using the Mann-Whitney U test. Spearman correlations and receiver operating characteristic analysis were performed. RESULTS:The ADC, D, and Dk values were lower, whereas the K value was higher in high-grade pediatric intracranial tumors than in low-grade tumors (all, P , .001). The K value showed positive correlations (r ¼ 0.674-0.802; all, P , .05), while ADC, D, and Dk showed negative correlations with cellularity and Ki-67 (r ¼ À0.548 to À0.740; all, P , .05). The areas under the curve of ADC VOI , D VOI , Dk VOI , and K VOI were 0.901, 0.894, 0.863, and 0.885, respectively, for differentiating high-from low-grade pediatric intracranial tumors. The area under the curve difference in grading pediatric intracranial tumors was not significant (all, P . .05).CONCLUSIONS: Intravoxel incoherent motion-and diffusional kurtosis imaging-derived parameters have similar performance compared with conventional DWI in predicting pediatric intracranial tumor grade. The diffusion metrics may potentially reflect tumor cellularity and Ki-67 in pediatric intracranial tumors. ABBREVIATIONS: AUC ¼ area under the curve; D ¼ true diffusion coefficient; D* ¼ pseudodiffusion coefficient; Dk ¼ the corrected ADC without Gaussian bias; DKI ¼ diffusional kurtosis imaging; f ¼ perfusion fraction; IVIM ¼ intravoxel incoherent motion; K ¼ diffusional kurtosis; MVD ¼ microvessel density; PIT ¼ pediatric intracranial tumor; WHO ¼ World Health Organization

In this prospective study, we analyzed diffusion kurtosis imaging (DKI) parameters to predict the early response to radiotherapy in 23 nasopharyngeal carcinoma (NPC) patients. All patients underwent conventional magnetic resonance imaging (MRI) and DKI before and after radiotherapy. The patients were divided into response (RG; no residual tumors; 16/23 patients) and no-response (NRG; residual tumors; 7/23 patients) groups, based on MRI and biopsy results 3 months after radiotherapy. The maximum diameter of tumors in RG and NRG patients were similar prior to radiotherapy (p=0.103). The pretreatment diffusion coefficient (D) parameters (Daxis, Dmean and Drad) were higher in RG than NRG patients (p=0.022, p=0.027 and p=0.027). Conversely, the pre-treatment fractional anisotropy (FA) and kurtosis coefficient (K) parameters (Kaxis, Kfa, Kmean, Krad and Mkt) were lower in RG than NRG patients (p=0.015, p=0.022, p=0.008, p=0.004, p=0.001, p=0.002). The Krad coefficient (0.76) was the best parameter to predict the radiotherapy response. Based on receiver operating characteristic curve analysis Krad showed 71.4% sensitivity and 93.7% specificity (AUC: 0.897, 95% CI, 0.756-1). Multivariate analysis indicated DKI parameters were independent prognostic factors for the short-term effect in NPC. Thus, DKI predicts the early response to radiotherapy in NPC patients.

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