BACKGROUND:A number of in vitro experiments have confirmed that the tricalcium silicate not only can be closely integrated with the dentin through self-curing process, but also can induce dentin remineralization in the physiological environment, thereby effectively blocking the dentinal tubules.
OBJECTIVE:To further verify the effects of tricalcium silicate solution on the occlusion of dentinal tubules.
METHODS:Thirty-six dentinal discs were made of free first premolars from orthodontic patients, and divided into three pretreatment groups randomly. The teeth were soaked in pretreatment solution for 2 minutes, namely 0.29 mol/L ethylene diamine tetraacetie acid, 6%citric acid, and rinsed ultrasonical y with deionized water 20 minutes, respectively. Every above-mentioned group was randomly assigned into experimental group (tricalcium silicate), control group (sodium fluoride) and blank group, and corresponding materials in each group were used to coat the outer dentinal tubules (2 minutes/time). Then, the dentinal discs were saved in artificial saliva in a 37 observed using scanning electron microscope. Diameter and area of open dentinal tubules were calculated.
RESULTS AND CONCLUSION:After pretreatment, the dentinal tubules were at open state;except for the blank control group to maintain the original state, acid etching and ethylene diamine tetraacetie acid pretreatment solutions had a stronger capacity of demineralization, which led to the dentinal tubules open. After the dentinal tubules were treated with sodium fluoride and tricalcium silicate, there were varying degrees of sediments, and open dentinal tubule area and average diameter in the sodium fluoride and tricalcium silicate groups were lower than those in the control group (P<0.05). The dentinal tubule treated with tricalcium silicate was almost entirely closed homogeneously, and occasional y, a single open dentinal tubule was seen. Open dentinal tubule area and average diameter in the tricalcium silicate group were significantly lower than those in the sodium fluoride group (P<0.05). The findings verify that dentin occlusion using tricalcium silicate is superior to that using sodium fluoride;and dentin tubule pretreatment with acid etching or ethylene diamine tetraacetie acid is beneficial to desensitization effects.

Objective To compare the dosimetric difference between RapidArc and fixed gantry angle dynamic IMRT (dIMRT) for central-type lung cancer radiotherapy. Methods Therapy for 10 patients previously treated with dIMRT was replanned with RapidArc. Dose prescription was 66 Gy/33 fraction. Comparative endpoints were planning target volume (PTV) dose, doses to surrounding structures,number of monitor units, and treatment delivery time. Results There was no significant dosimetric difference between RapidArc and dIMRT. Compared with dIMRT, RapidArc slightly elevated target volume dose, lung V5, V10. The average values of lung V20, V30 and heart V30 were larger in dIMRT than those in RapidArc. The number of monitor units was reduced by 32% and the treatment time by 66% in RapidArc.Conclusions Both RapidArc and dIMRT plans could meet the clinical therapy needs. RapidArc could achieve similar target coverage and sparing of organs at risk, with fewer monitor units and shorter delivery time than dIMRT.

Objective To analyze relevant clinical and dosimetric factors associated with radiation pneumonitis in patients with stage Ⅲ non-small cell lung cancer after they received radical radiotherapy.Methods A total of 126 patients with stage Ⅲ non-small cell lung cancer who received precision radiotherapy in Peking University Cancer Hospital were analyzed from January 2013 to December 2014.Data were collected including various clinical factors (including sex,age,histological type,tumor location,history of diabetes,history of hypertension,history of smoking,the season patients received treatment,ECOG performance status before treatment,chemotherapy before radiotherapy,concurrent chemotherapy and the classification of radiation pneumonitis),as well as related dosimetric parameters [including GTV,lung volume (LV),bilateral V5,V10,V20,V30 and MLD].SPSS 19.0 software was used to analyze the relation between correlation factors and radiation pneumonitis (RP≥2).Results Among the patients,31 cases (24.6％) had occurrance of radiation pneumonitis ≥ 2.Univariate analysis showed that age,ECOG performance status before treatment,concurrent chemotherapy and GTV/LV ratio were significantly correlated with RP ≥ 2 (R =0.157-0.222,P ＜ 0.05).Further multivariate Logistic regression showed that age,concurrent chemotherapy and GTV/LV ratio were significantly correlated (Wald =4.754,6.422,14.79,P ＜ 0.05).Conclusions In patients with stage Ⅲ non-small cell lung cancer after receiving thoracic radical radiotherapy,increasing age and GTV/LV ratio≥3.2％ are risk factors of RP≥2.The concurrent chemotherapy with low-dose paclitaxel might also increase the risk of RP≥2.

Background and objective Twice-daily radiation concurrent with chemotherapy is one of the standard methods for limited-stage small cell lung cancer. hTe study was to evaluate the feasibility of chemotherapy concurrent with dose-escalating twice-daily radiotherapy by simultaneous integrated boost intensity-modulated radiation therapy (SIB-IMRT) approach in patients with limited-stage small cell lung cancer. Methods Patients with limited-stage small cell lung cancer were included, treated with twice-daily radiotherapy by SIB-IMRT concurrent with chemotherapy of etoposide plus cisplatin. Dose escalation was conducted by“classical”3+3 methods with three patients enrolled in each dose level. The therapeutic gross tumor volume (GTV) was treated according to three consecutive dose levels i.e., 45 Gy at 1.5 Gy twice daily, 50 Gy at 1.67 Gy twice daily and 54 Gy at 1.8 Gy twice daily. hTe planning target volume (PTV) received a dose of 45 Gy delivered in 30 fractions of 1.5 Gy. hTe primary endpoints were acute toxicities. hTe secondary endpoints included overall survival (OS), pro-gression-free survival (PFS) and loco-regional failure-free survival (LRFFS) at 1-year of follow-up. Results Twenty men and six women were included. hTe median age was 52 (30-68) months. 12 patients experienced grade 2 acute esophagitis, and 1 patient developed grade 3 acute esophagitis. Only 3 patients developed Grade 2 pneumonitis. Grade 3 or higher radiation-related pneumonia was not observed. None died of treatment-related causes. With median follow-up of 11.2 months (3.2-36.2 months), 1-year OS, PFS and LRFFS were 89.0%, 51.0%and 85.0%, respectively. Conclusion Dose escalation for twice-daily radiation concurrent with chemotherapy in LS-SCLC has been safely achieved up to 54 Gy for GTV using SIB-IMRT technique.

Background and objective Concurrent twice-daily radiotherapy with chemotherapy of EP regimen is one of the current standard treatments for limited-stage small cell lung cancer. However, the safely tolerated dose of standard chemotherapy for Chinese patients is not decided. hTis study was to evaluate the toxicity and the maximum tolerated dose (MTD) of etoposide and cisplatin concurrent with thoracic radiation therapy for patients with limited-stage small cell lung cancer. Methods Patients with histologically proven limited-stage small cell lung cancer (LS-SCLC) were eligible. hTe pa-tients underwent thoracic radiotherapy (45 Gy, 1.5 Gy bid, 30 fractions for 3 weeks) delivered concurrently with etoposide (100 mg/m2 iv, days 1-3) and cisplatin dose escalating from the two levels ( 70 mg/m2 and 75 mg/m2 on d1). hTe primary end-points were hematologic toxicities during treatment. hTe secondary endpoints were non-hematologic toxicities, overall survival (OS) and progression-free survival (PFS). According to Common Terminology Criteria for Adverse Events 4.0 (CTC-AE 4.0), maximum tolerant dosage (MTD) was deifned as the highest safely tolerated dose at which no more than one patient out of six experiences dose-limiting toxicity (Grades 4 hematologic), with the next higher dose having at least two out of six patients experience dose-limiting toxicity. Results From January 2013 to August 2016, 20 patients were enrolled in this study. hTe median age was 49.5 (30-68). Atfer the ifrst 6 patients were enrolled in Arm 1 (70 mg/m2 on d1), one patient had Grade 4 neu-tropenia. Another 14 patients were enrolled in Arm 2 (75 mg/m2 on d1), one patient had Grade 4 neutropenia. hTe MTD was determined to be etoposide (100 mg/m2 iv, d1-d3) and cisplatin dose (75 mg/m2 on d1). 4 patients had≥Grade 3 neutropenia and 1 patients had≥Grade 3 acute esophagitis in Arm 1. 10 patients had≥Grade 3 neutropenia and no patient had≥Grade 3 acute esophagitis in Arm 2. All patients with a median follow-up time was 9.0 months, median OS and PFS were not achieved, 1-year OS and PFS were 91%and 61%, respectively. Conclusion hTe MTD of RT with concurrent chemotherapy of EP regi-men for patients with LS-SCLC was etoposide (100 mg/m2 iv, d1-d3) and cisplatin dose (75 mg/m2 on d1).

Background and objective With the rapid development of technology, stereotactic radiotherapy has been widely used. In a cohort of medically operable non-small cell lung cancer patients receiving stereotactic body radiation therapy (SBRT) survival rates“potentially equivalent to those of surgery”have been reported. Removing the ifeld lfattening iflter, Clinac is capable of delivering dose rates much higher than conventional linac as well as reducing the treatment time. hTe goals of this work were to report safety and effcacy of SBRT treatment using a lfattening iflter-free model for non-small cell lung cancer (NSCLC) with small lesions. Methods From December 2011 to December 2013, 31 NSCLC patients who were T1-2N0M0, solitary pulmonary recurrence atfer surgery, and stage IV with oligo metastasis were enrolled, receiving SBRT treatment (60 Gy/8 f or 48 Gy/4 f ) applying a lfattening iflter-free model. Results Compared with conventional technique, lfat-tening iflter-free model shortened the treating time with equivalent target dose and normal tissue dose. hTe median follow-up time is 19.4 mo. hTe 1-yr local control, regional control, distant control, progression free survival and overall survival rates were 96.8%, 96.8%, 83.9%, 77.4%and 96.8%. hTe most common side effects were radiation pneumonitis (29%grade 1, 3.2%grade 2) and chest pain (12.9%grade 1, 6.5%grade 2). Conclusion hTe use of lfattening iflter-free model in SBRT for small lesions of NSCLC patients is safe and effective. Long time follow-up and additional studies are still needed to validate our conclusions.

Humans ; Botulinum Toxins, Type A/therapeutic use* ; Esotropia/drug therapy* ; Neuromuscular Agents ; Injections ; Treatment Outcome ; Oculomotor Muscles