11 research outputs found

    Identify the radiotherapy-induced abnormal changes in the patients with nasopharyngeal carcinoma

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    Radiotherapy (RT) is the standard treatment for nasopharyngeal carcinoma, which often causes inevitable brain injury in the process of treatment. The majority of patients has no abnormal signal or density change of the conventional magnetic resonance imaging (MRI) and computed tomography (CT) examination in the long-term follow-up after radiation therapy. However, when there is a visible CT and conventional MR imaging changes, the damage often has been severe and lack of effective treatments, seriously influencing the prognosis of patients. Therefore, the present study aimed to investigate the abnormal changes in nasopharyngeal carcinoma (NPC) patients after RT. In the present study, we exploited the machine learning framework which contained two parts: feature extraction and classification to automatically detect the brain injury. Our results showed that the method could effectively identify the abnormal regions reduced by radiotherapy. The highest classification accuracy was 82.5 % in the abnormal brain regions. The parahippocampal gyrus was the highest accuracy region, which suggested that the parahippocampal gyrus could be most sensitive to radiotherapy and involved in the pathogenesis of radiotherapy-induced brain injury in NPC patients

    Nonlinear indentation of second-order hyperelastic materials

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    The classical problem of indentation on an elastic substrate has found new applications in the field of the Atomic Force Microscopy. However, linearly elastic indentation models are not sufficiently accurate to predict the force–displacement relationship at large indentation depths. For hyperelastic materials, such as soft polymers and biomaterials, a nonlinear indentation model is needed. In this paper, we use second-order elasticity theory to capture larger amplitude deformations and material nonlinearity. We provide a general solution for the contact problem for deformations that are second-order in indentation amplitude with arbitrary indenter profiles. Moreover, we derive analytical solutions by using either parabolic or quartic surfaces to mimic a spherical indenter. The analytical prediction for a quartic surface agrees well with finite element simulations using a spherical indenter for indentation depths on the order of the indenter radius. In particular, the relative error between the two approaches is less than 1% for an indentation depth equal to the indenter radius, an order of magnitude less than that observed with models which are either first-order in indentation amplitude or those which are second-order in indentation amplitude but with a parabolic indenter profile

    Effect of Kangfuxin

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    Objective. To evaluate the efficacy and safety of Kangfuxin Solution, a pure Chinese herbal medicine, on mucositis induced by chemoradiotherapy in nasopharyngeal carcinoma patients. Methods. A randomized, parallel-group, multicenter clinical study was performed. A total of 240 patients were randomized to receive either Kangfuxin Solution (test group) or compound borax gargle (control group) during chemoradiotherapy. Oral mucositis, upper gastrointestinal mucositis, and oral pain were evaluated by Common Terminology Criteria for Adverse Events (CTCAE) v3.0 and the Verbal Rating Scale (VRS). Results. Of 240 patients enrolled, 215 were eligible for efficacy analysis. Compared with the control group, the incidence and severity of oral mucositis in the test group were significantly reduced (P=0.01). The time to different grade of oral mucositis occurrence (grade 1, 2, or 3) was longer in test group (P<0.01), and the accumulated radiation dose was also higher in test group comparing to the control group (P<0.05). The test group showed lower incidence of oral pain and gastrointestinal mucositis than the control group (P<0.01). No significant adverse events were observed. Conclusion. Kangfuxin Solution demonstrated its superiority to compound borax gargle on mucositis induced by chemoradiotherapy. Its safety is acceptable for clinical application

    Clinical Outcome and Prognostic Factors of Intensity-Modulated Radiotherapy for T4 Stage Nasopharyngeal Carcinoma

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    Objective. To analyze the clinical outcomes and prognostic factors of intensity-modulated radiotherapy (IMRT) for T4 stage nasopharyngeal carcinoma (NPC). Methods. Between March 2005 and March 2010, 110 patients with T4 stage NPC without distant metastases were treated. All patients received IMRT. Induction and/or concurrent chemotherapy were given. 47 (42.7%) patients received IMRT replanning. Results. The 5-year local recurrence-free survival (LRFS), regional recurrence-free survival (RRFS), distant metastasis-free survival (DMFS), progression-free survival (PFS), and overall survival (OS) rates were 90.1%, 97.0%, 67.5%, 63.9%, and 64.5%, respectively. Eleven patients experienced local-regional failure and total distant metastasis occurred in 34 patients. 45 patients died and 26 patients died of distant metastasis alone. The 5-year LRFS rates were 97.7% and 83.8% for the patients that received and did not receive IMRT replanning, respectively (P=0.023). Metastasis to the retropharyngeal lymph nodes (RLN) was associated with inferior 5-year OS rate (61.0% versus 91.7%, P=0.034). The gross tumor volume of the right/left lymph nodes (GTVln) was an independent prognostic factor for DMFS (P=0.006) and PFS (P=0.018). GTVln was with marginal significance as the prognostic factor for OS (P=0.050). Conclusion. IMRT provides excellent local-regional control for T4 stage NPC. Benefit of IMRT replanning may be associated with improvement in local control. Incorporating GTVln into the N staging system may provide better prognostic information

    Effect of Kangfuxin Solution on Chemo/Radiotherapy-Induced Mucositis in Nasopharyngeal Carcinoma Patients: A Multicenter, Prospective Randomized Phase III Clinical Study

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    Objective. To evaluate the efficacy and safety of Kangfuxin Solution, a pure Chinese herbal medicine, on mucositis induced by chemoradiotherapy in nasopharyngeal carcinoma patients. Methods. A randomized, parallel-group, multicenter clinical study was performed. A total of 240 patients were randomized to receive either Kangfuxin Solution (test group) or compound borax gargle (control group) during chemoradiotherapy. Oral mucositis, upper gastrointestinal mucositis, and oral pain were evaluated by Common Terminology Criteria for Adverse Events (CTCAE) v3.0 and the Verbal Rating Scale (VRS). Results. Of 240 patients enrolled, 215 were eligible for efficacy analysis. Compared with the control group, the incidence and severity of oral mucositis in the test group were significantly reduced ( = 0.01). The time to different grade of oral mucositis occurrence (grade 1, 2, or 3) was longer in test group ( &lt; 0.01), and the accumulated radiation dose was also higher in test group comparing to the control group ( &lt; 0.05). The test group showed lower incidence of oral pain and gastrointestinal mucositis than the control group ( &lt; 0.01). No significant adverse events were observed. Conclusion. Kangfuxin Solution demonstrated its superiority to compound borax gargle on mucositis induced by chemoradiotherapy. Its safety is acceptable for clinical application
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