Efficacy and Safety of Chemotherapy Combined with Stereotactic Radiotherapy in the Treatment of Nasopharyngeal Carcinoma.

BACKGROUND The aim of this study was to investigate the efficacy and safety of chemotherapy (CT) combined with stereotactic radiotherapy (SRT) in the treatment of nasopharyngeal carcinoma (NPC). MATERIAL AND METHODS A total of 329 NPC patients without any previous treatment were included in this study between January 2009 and November 2013. These patients were divided into three groups: CT group (n=114), SRT group (n=109), and CT + SRT group (n=106). Contrast-enhanced nasopharyngeal computed tomography (CT)/magnetic resonance (MR) scan was performed on the third month after treatment. Short-term efficacy was evaluated according to the Response Evaluation Criteria in Solid Tumors (RECIST). Toxicity was graded according to the Acute Radiation Morbidity Scoring Criteria (RTOG) and the World Health Organization (WHO) toxicity grading scale. Overall survival (OS), progression free survival (PFS), and incidence rate of acute toxicity (grade ≥3) were calculated after a 24 month follow-up. RESULTS Total response rate of all patients was 85.41%. Compared with the CT group and the SRT group, the CT + SRT group showed a substantially improved efficacy in NPC treatment. The incidence rate of the acute toxicity in the CT + SRT group was slightly higher than in the CT group and the SRT group, but the difference was not statistically significant. No treatment-related deaths were observed. The CT + SRT group had the highest two-year OS and PFS, followed by the CT group and the SRT group. CONCLUSIONS It was shown that NPC patients treated with CT + SRT had better short- and long-term efficacy than those treated with CT or SRT alone.

Radiation-induced gray matter atrophy in patients with nasopharyngeal carcinoma after intensity modulated radiotherapy: a MRI magnetic resonance imaging voxel-based morphometry study.

BACKGROUND: Gray matter (GM) damage after radiotherapy (RT) in nasopharyngeal carcinoma (NPC) patients can result in cognitive impairment, while there may be no visible brain tissue change according to the conventional magnetic resonance imaging (MRI). This study investigated radiation-induced GM volume differences between NPC patients who received RT and those who did not. METHODS: High-resolution brain structural MRI data from two groups of patients were acquired. The pre-RT group was composed of 56 newly diagnosed but not yet medically treated NPC patients, while the after-RT group consisted of 40 NPC patients who had completed RT more than 1 year ago. Voxel-based morphometry (VBM) was applied to assess GM volumes. Two sample t-test was used to analyze GM volumes voxel-by-voxel using the VBM8 toolbox built in the SPM software. Radiation-induced cortical volume alteration in all NPC patients after RT and dosimetry of 36 patients were analyzed. RESULTS: Compared to pre-treatment group, cortical volumes of GM were significantly smaller in the left hippocampus, the right pulvinar and the right middle temporal gyrus (MTG, P<0.001, AlphaSim correction, cluster size ≥157). The mean dose (Dmean) for bilateral hippocampal heads were significantly higher than other different parts of the brain (P<0.001). No significant correlations between the GM volume in any brain regions and the mean dose of corresponding position of these brain regions were observed (P>0.05). CONCLUSIONS: Radiation to the NPC patients can not only induce damage of the hippocampus, but also other secondary damages of GM.

Numb Gene Enhances Radiation Sensitivity of Nonsmall Cell Lung Cancer Stem Cells.

OBJECTIVE: To study the effects of Numb gene expression on radiation sensitivity of nonsmall cell lung cancer (NSCLC) stem cells. MATERIALS AND METHODS: The side population (SP) cells A549-SP were transfected with pcDNA3.1 (pcDNA3.1 group), pcDNA-Numb (pcDNA-Numb group) and shRNA-Numb (shRNA-Numb group). Real-time quantitative polymerase chain reaction and Western blot were performed to determine Numb expression; MTT method was used to measure the proliferation activity change of the NSCLC stem cells both before and after irradiation with different doses of 60Coγ ray; Hoechst staining and Annexin V-FITC/PI were used to detect the apoptosis of the NSCLC stem cells; and colony-forming assay was used to determine the effect of Numb expression on radiation sensitivity of the NSCLC stem cells. RESULTS: Increased mRNA and protein expressions of the A549-SP cells were found in the pcDNA-Numb group, and decreased mRNA and protein expressions were found in the shRNA-Numb group. The optical density value of the cells decreased in the pcDNA-Numb group but increased in the shRNA-Numb group. The cells with over-expressed Numb showed obvious nuclear condensation and fragmentation; the apoptosis rate increased significantly. The cells with knockdown Numb showed less nuclear damage; the apoptosis rate significantly decreased. After irradiation, the cells in the pcDNA-Numb group showed decreased survival rate, clonality, and the values of D0, Dq, N, and SF2; whereas the cells in the shRNA-Numb group showed the opposite trend. CONCLUSIONS: Radiation sensitivity of NSCLC stem cells was enhanced with the increase of Numb expression. Determination of Numb expression helped to evaluate the response of lung cancer to radiotherapy, which was important for guiding tumor treatment clinically.

Numerical magnitude processing in abacus-trained children with superior mathematical ability: an EEG study.

Distance effect has been regarded as the best established marker of basic numerical magnitude processes and is related to individual mathematical abilities. A larger behavioral distance effect is suggested to be concomitant with lower mathematical achievement in children. However, the relationship between distance effect and superior mathematical abilities is unclear. One could get superior mathematical abilities by acquiring the skill of abacus-based mental calculation (AMC), which can be used to solve calculation problems with exceptional speed and high accuracy. In the current study, we explore the relationship between distance effect and superior mathematical abilities by examining whether and how the AMC training modifies numerical magnitude processing. Thus, mathematical competencies were tested in 18 abacus-trained children (who accepted the AMC training) and 18 non-trained children. Electroencephalography (EEG) waveforms were recorded when these children executed numerical comparison tasks in both Arabic digit and dot array forms. We found that: (a) the abacus-trained group had superior mathematical abilities than their peers; (b) distance effects were found both in behavioral results and on EEG waveforms; (c) the distance effect size of the average amplitude on the late negative-going component was different between groups in the digit task, with a larger effect size for abacus-trained children; (d) both the behavioral and EEG distance effects were modulated by the notation. These results revealed that the neural substrates of magnitude processing were modified by AMC training, and suggested that the mechanism of the representation of numerical magnitude for children with superior mathematical abilities was different from their peers. In addition, the results provide evidence for a view of non-abstract numerical representation.