[Predictive value of aMAP risk score for early recurrence of small hepatocellular carcinoma after microwave ablation].

Objective: To explore the value of the aMAP risk score (age, male, albumin-bilirubin, and platelets) to predict early recurrence within one year after microwave ablation in patients with small hepatocellular carcinoma. Methods: This was a retrospective study that enrolled 142 patients diagnosed with hepatocellular carcinoma who were treated with microwave ablation in the Department of Hepatology Unit of Nanfang Hospital, Southern Medical University from July 2016 to July 2021. The cohort enrolled 121 male and 21 female patients, including 110 patients that were <60 years old. All the patients were followed-up after microwave ablation to evaluate residual tumor and recurrence of tumor by computed tomography or magnetic resonance imaging. The observation indices mainly included general data and imaging data of patients. Using the X-tile tools, patients were divided into two groups: a high aMAP score group and a low aMAP score group. Multivariate Cox regression analysis was conducted for comparison of independent risk factors. Results: Multivariate Cox regression showed that high aMAP score, maximum tumor diameter >20 mm, and high AFP were the independent risk factors of early recurrence (all P<0.05). Kaplan-Meier survival curves showed that the median recurrence-free survival was 25.5 months in the low aMAP score group and 6.1 months in the high aMAP score group (P=0.001). Conclusions: The aMAP score could predict the early recurrence within 1 year of small hepatocellular carcinoma after microwave ablation. Patients with high aMAP score should undergo rigorous postoperative follow-up evaluations..

[Study on the comparison of postoperative liver injury caused by hepatic arterial perfusion chemotherapy combined with targeted immunotherapy with hepatic arterial chemoembolization combined with targeted immunotherapy for intermediate-and advanced-stage liver cancer].

Objective: To compare the postoperative liver function injury condition in patients with intermediate-and advanced-stage hepatocellular carcinoma (HCC) treated with hepatic artery infusion chemotherapy (HAIC) and hepatic artery chemoembolization (TACE) combined with immune checkpoint inhibitors (ICIs) and multi-target tyrosine kinase inhibitors (TKIs). Methods: Patients with intermediate-and advanced-stage HCC who were admitted and treated with HAIC/TACE+ICIs+TKIs therapy at Nanfang Hospital of Southern Medical University from January 2019 to November 2021, with follow-up up to July 2023, were retrospectively enrolled. The results of liver function tests within one week before interventional surgery and on the first day after surgery were recorded. The degree of postoperative liver injury was graded according to the common terminology criteria for adverse events 5.0 (CTCAE 5.0). The treatment efficacy was evaluated according to RECIST 1.1 criteria. Measurement data were compared between groups using a t-test or a non-parametric rank sum test. Enumeration data were compared between the groups using the χ(2) test or Fisher's exact probability method. The survival condition differences were analyzed by the log-rank method. Results: This study included 82 and 77 cases in the HAIC and TACE groups. There were no statistically significant differences between the two groups of patients in terms of gender, age, physical condition score, number of tumors, presence or absence of liver cirrhosis, Child-Pugh grade, albumin-bilirubin (ALBI) grade, and combined ICIs and TKIs . The HAIC group had later tumor staging, a greater tumor burden, poorer liver reserve function, and a larger proportion of patients in stage C (81.7% vs. 63.6%), χ(2)=6.573, P = 0.01). There were 53 cases (64.6% vs. 32.5%) with a maximum tumor diameter of ≥ 10cm, χ(2)=16.441, P < 0.001), and more patients had a retention rate of ≥ 10% for indocyanine green (ICG) at 15 minutes (68.3% vs. 51.9%, P = 0.035). The postoperative incidence rate of increased levels of alanine aminotransferase, aspartate aminotransferase, and total bilirubin was significantly lower in the HAIC group than that in the TACE group (28.0% vs. 63.6%, χ(2)=20.298, P < 0.001, 54.9% vs. 85.7%, χ(2)=17.917, P < 0.001;40.2% vs. 55.8%, χ(2)=3.873, P = 0.049). The number of patients with postoperative ALBI grade 3 was significantly lower in the HAIC group than that in the TACE group (6.1% vs. 16.9%, χ(2)=4.601, P = 0.032). There was no statistically significant difference in the incidence rate of postoperative hypoalbuminemia, activated partial thromboplastin time, or increased international standardized ratio between the two groups of patients. There was no statistically significant difference in median progression-free survival (7.3 months vs. 8.2 months, P = 0.296) or median overall survival (16.5 months vs. 21.9 months, P = 0.678) between the two groups of patients. Conclusion: The incidence rate of postoperative liver injury is higher in patients with intermediate-and advanced-stage HCC treated with TACE combined with ICIs and TKIs than in patients with HAIC combined with ICIs and TKIs.

Localization of CgVPE1 in secondary cell wall formation during tracheary element differentiation in the pericarp of Citrus grandis 'Tomentosa' fruits.

MAIN CONCLUSION: CgVPE1 is important in the differentiation of TE cells in C. grandis 'Tomentosa' fruits as it may directly affects secondary cell wall construction while participating in PCD. The vacuolar processing enzyme (VPE) plays an important role in both developmental and environmentally inducible programmed cell death (PCD); it was originally identified as a cysteine protease localized in the vacuole to activate and mature vacuolar proteins in plants. Interestingly, we found a VPE called CgVPE1 to be associated with deposition of the secondary cell wall in tracheary element (TE) cells in the pericarp of Citrus grandis 'Tomentosa' fruits. We then used ultrathin sections and the TUNEL assay to verify that PCD is involved in TE development. Furthermore, CgVPE1 was found to be mainly expressed in secretory cavities and TEs in the pericarp of Citrus grandis 'Tomentosa' fruits. Immunolocalization of CgVPE1 in the pericarp indicated that CgVPE1 is mainly distributed in the central large vacuole, endoplasmic reticulum, Golgi vesicles, cytosol, and secondary wall before TE maturation. CgVPE1 appeared earlier in the endoplasmic reticulum and Golgi vesicles of TEs cells. The vesicles containing CgVPE1 near the large central vacuole and secondary wall were observed, respectively. CgVPE1 proteins content in the cytoplasm decreased sharply, while the CgVPE1 content in the secondary cell wall did not change significantly after vacuole rupture. CgVPE1 protein contents in the secondary cell wall were significantly reduced until the TE cells developed into hollow thick-walled cells. Furthermore, labeling of VPE homologues in Arabidopsis thaliana using immunoelectron microscopy with anti-CgVPE1 antibody revealed that VPE homologues were specifically distributed in the secondary cell wall of stem TEs. Overall, these results suggested that CgVPE1 is not only involved PCD during TE cell development; furthermore, it may directly participate in the construction of plant secondary cell walls.

[Analysis of the effect of microwave ablation in the treatment of small liver cancer].

Objective: To explore the clinical effect of microwave ablation in the treatment of early small liver cancer (≤3 cm). Methods: 103 cases with small liver cancer (tumor number < 3 and maximum tumor diameter < 3 cm) who underwent microwave ablation from November 2016 to November 2018 were retrospectively collected. The rate of residual lesions, recurrence rate one-year after the operation, and surgical complications were observed and grouped according to tumor size (< 2 cm and≥2 cm group) and tumor numbers (solitary and 2 ~ 3 lesion groups). The therapeutic effects of each group were compared and analyzed. Results: The tumor residual rate and one-year recurrence rate of small liver cancer after microwave ablation were 11.7% and 35.0%, respectively. The post-ablation syndrome incidence rate was 52.4%, with no serious adverse events. Compared with tumors < 2 cm, patients with≥2 cm had a higher postoperative residual rate (χ(2) = 7.651, P = 0.006), and the one-year recurrence rate of more solitary nodular tumors was lower (χ(2) = 10.125, P = 0.001). Conclusion: Microwave ablation is a safe and effective treatment for early small liver cancer, and it is more effective for small solitary nodules (< 2 cm).

[Regulatory effect of molecular targeted drugs on the immune system for liver cancer].

Molecular targeted drugs are the first choice for systemic treatment of liver cancer. In the past decade, several anti-liver cancer targeted drugs have been launched. More recently, immunotherapy has become a dazzling nova in the field of systemic treatment of liver cancer. Nivolumab and pembrolizumab have been approved as second-line treatments for patients with advanced hepatocellular carcinoma treated with sorafenib. However, the effect of single-agent treatment is always unsatisfactory in advanced liver cancer. An increasing number of evidences suggests that molecular targeted drugs have important immunomodulatory effects for liver cancer, and several targeted combined immunotherapies have also shown promising clinical effectiveness. This paper reviews the immunomodulatory effects of several molecular targeted drugs in the field of liver cancer.

Molecular mechanism concerning conformational changes of CDK2 mediated by binding of inhibitors using molecular dynamics simulations and principal component analysis.

Cyclin-dependent kinase 2 (CDK2) has been regarded as a promising drug target for anti-tumour agents. In this study, molecular dynamics (MD) simulations and principal component (PC) analysis were used to explore binding mechanism of three inhibitors 1PU, CDK, 50Z to CDK2 and influences of their bindings on conformational changes of CDK2. The results show that bindings of inhibitors yield obvious impacts on internal dynamics, movement patterns and conformational changes of CDK2. In addition, molecular mechanics generalized Born surface area (MM-GBSA) was applied to calculate binding free energies between three inhibitors and CDK2 and evaluate their binding ability to CDK2. The results show that CDK has the strongest binding to CDK2 among the current three inhibitors. Residue-based free energy decomposition method was further utilized to decode the contributions of a single residue to binding of inhibitors, and it was found that three inhibitors not only produce hydrogen bonding interactions and hydrophobic interactions with key residues of CDK2, which promotes binding of three inhibitors to CDK2, but also share similar binding modes. This work is expected to be helpful for design of efficient drugs targeting CDK2.

[Incidence and risk factors of anastomotic leak after transanal total mesorectal excision in China: a retrospective analysis based on national database].

Objective: Transanal total mesorectal excision (taTME) was a very hot topic in the first few years since its appearance, but now more introspections and controversies on this procedure have emerged. One of the reasons why the Norwegian Ministry of Health stopped taTME was the high incidence of postoperative anastomotic leak. In current study, the incidence and risk factors of anastomotic leak after taTME were analyzed based on the data registered in the Chinese taTME Registry Collaborative (CTRC). Methods: A case-control study was carried out. Between November 15, 2017 and December 31, 2020, clinical data of 1668 patients undergoing taTME procedure registered in the CTRC database from 43 domestic centers were collected retrospectively. After excluding 98 cases without anastomosis and 109 cases without complete postoperative complication data, 1461 patients were finally enrolled for analysis. There were 1036 males (70.9%) and 425 females (29.1%) with mean age of (58.2±15.6) years and mean body mass index of (23.6±3.8) kg/m(2). Anastomotic leak was diagnosed and classified according to the International Study Group of Rectal Cancer (ISREC) criteria. The risk factors associated with postoperative anastomotic leak cases were analyzed. The impact of the cumulative number of taTME surgeries in a single center on the incidence of anastomotic leak was evaluated. As for those centers with the number of taTME surgery ≥ 40 cases, incidence of anastomic leak between 20 cases of taTME surgery in the early and later phases was compared. Results: Of 1461 patients undergoing taTME, 103(7.0%) developed anastomotic leak, including 71 (68.9%) males and 32 (31.1%) females with mean age of (59.0±13.9) years and mean body mass index of (24.5±5.7) kg/m(2). The mean distance between anastomosis site and anal verge was (2.6±1.4) cm. Thirty-nine cases (37.9%) were classified as ISREC grade A, 30 cases (29.1%) as grade B and 34 cases (33.0%) as grade C. Anastomotic leak occurred in 89 cases (7.0%,89/1263) in the laparoscopic taTME group and 14 cases (7.1%, 14/198) in the pure taTME group. Multivariate analysis showed that hand-sewn anastomosis (P=0.004) and the absence of defunctioning stoma (P=0.013) were independently associated with anastomotic leak after taTME. In the 16 centers (37.2%) which performed ≥ 30 taTME surgeries with cumulative number of 1317 taTME surgeries, 86 cases developed anastomotic leak (6.5%, 86/1317). And in the 27 centers which performed less than 30 taTME surgeries with cumulative number of 144 taTME surgeries, 17 cases developed anastomotic leak (11.8%, 17/144). There was significant difference between two kinds of center (χ(2)=5.513, P=0.019). Thirteen centers performed ≥ 40 taTME surgeries. In the early phase (the first 20 cases in each center), 29 cases (11.2%, 29/260) developed anastomotic leak, and in the later phase, 12 cases (4.6%, 12/260) developed anastomotic leak. The difference between the early phase and the later phase was statistically significant (χ(2)=7.652, P=0.006). Conclusion: The incidence of anastomotic leak after taTME may be reduced by using stapler and defunctioning stoma, or by accumulating experience.

[Clinical efficacy and safety analysis of camrelizumab combined with apatinib as a second-line therapy for unresectable hepatocellular carcinoma: a multicenter retrospective study].

Objective: To analyze the clinical efficacy and safety of camrelizumab combined with apatinib as a second-line therapy for unresectable hepatocellular carcinoma (HCC). Methods: Ninety-four cases with mid-and advanced-stage HCC who received camrelizumab combined with apatinib as second-line treatment were enrolled. Routine blood test, blood biochemical indexes, tumor stage, tumor imaging characteristics, previous treatment strategies and other clinical data before treatment were documented. Imaging examination follow-up results and adverse reactions during treatment were followed up until the end of follow-up or loss of follow-up or death. Kaplan-Meier method was used to analyze the clinical efficacy. Results: As of the last follow-up, 94 cases with mid-and advanced-stage HCC had received camrelizumab combined with apatinib as second-line treatment. Among them, 15 cases were lost to follow-up, 31 cases died, and 48 cases survived. The overall remission rate was 31.9%. The overall disease control rate was 71.3%. The median time to disease-free progression was 6.6 months. The median time to disease progression was not yet available. The 1-year cumulative survival rate was 62.3%. Grade 3 and above adverse reactions mainly included were thrombocytopenia (7.4%), abdominal pain (4.3%), active hepatitis (4.3%), leukopenia (4.3%), diarrhea (3.2%), hand-foot syndrome (3.2%). All adverse reactions were effectively controlled. Conclusion: Camrelizumab combined with apatinib can effectively prolong the survival period of patients with mid-and advanced-stage HCC, and it is well tolerated.

Simvastatin is beneficial to lung cancer progression by inducing METTL3-induced m6A modification on EZH2 mRNA.

OBJECTIVE: To elucidate the molecular mechanism of Simvastatin on inhibiting malignant progression of lung cancer. PATIENTS AND METHODS: Relative levels of METTL3 and EZH2 in lung cancer tissues and adjacent normal ones were detected by quantitative real-time polymerase chain reaction (qRT-PCR). In addition, their levels in lung cancer patients with different pathological stages were determined as well. A549 cells were induced with different doses of Simvastatin for 24 h. Subsequently, relative levels of METTL3 and EZH2 in cells were detected. Proliferative and metastatic abilities in A549 cells were examined by cell counting kit-8 (CCK-8), 5-Ethynyl-2'- deoxyuridine (EdU) and transwell assay, respectively. RIP assay was conducted to detect the presence of m6A modification on EZH2 mRNA and the interaction between IGF2BP2 and EZH2. Relative levels of EZH2 and epithelial-mesenchymal transition (EMT)-associated genes (E-cadherin and N-cadherin), and metastatic abilities were detected in Simvastatin-induced A549 cells transfected with pcDNA-METTL3. RESULTS: METTL3 and EZH2 levels were upregulated in lung cancer tissues, which were higher in advanced stage lung cancer patients. Their levels, as well as cell proliferative and metastatic abilities, were dose-dependently inhibited in Simvastatin-induced A549 cells. METTL3 positively regulated EZH2 level, and m6A modification on its mRNA. Moreover, the interaction between IGF2BP2 and EZH2 could be inhibited by knockdown of METTL3. Simvastatin could abolish the role of METTL3 in regulating relative levels of EZH2 and EMT-associated genes, as well as metastatic abilities in A549 cells. CONCLUSIONS: Simvastatin induces METTL3 down-regulation in lung cancer tissues, which further influences EMT via m6A modification on EZH2 mRNA and thus inhibits the malignant progression of lung cancer.

Effects of genetic correction on the differentiation of hair cell-like cells from iPSCs with MYO15A mutation.

Deafness or hearing loss is a major issue in human health. Inner ear hair cells are the main sensory receptors responsible for hearing. Defects in hair cells are one of the major causes of deafness. A combination of induced pluripotent stem cell (iPSC) technology with genome-editing technology may provide an attractive cell-based strategy to regenerate hair cells and treat hereditary deafness in humans. Here, we report the generation of iPSCs from members of a Chinese family carrying MYO15A c.4642G>A and c.8374G>A mutations and the induction of hair cell-like cells from those iPSCs. The compound heterozygous MYO15A mutations resulted in abnormal morphology and dysfunction of the derived hair cell-like cells. We used a CRISPR/Cas9 approach to genetically correct the MYO15A mutation in the iPSCs and rescued the morphology and function of the derived hair cell-like cells. Our data demonstrate the feasibility of generating inner ear hair cells from human iPSCs and the functional rescue of gene mutation-based deafness by using genetic correction.

[Clinical analysis of delayed epistaxis after craniofacial trauma in 16 patients].

Objective:To investigate the etiology,clinical presentations,diagnosis and treatment of delayed epistaxis after craniocerebral trauma.Method:A retrospective analysis was made including 16 cases who had the traumatic carotid artery injury with massive delayed epistaxis.All of them were finally diagnosed by digital substraction angiography(DSA).Final clinical outcome,radiographic data and follow-up data were analyzed.Result:Two cases of traumatic pesudoaneurysm from internal maxillary artery were embolized with polyvinyl alcohol particles and gelatin sponge.Fourteen cases of traumatic pesudoaneurysm located in ICA cavernous segment was embolized by covered stent.The covered stent placement was successful in all 14 pseudoaneurysms.No procedure-related complications or deaths occurred during follow-up except one of the case with visual field defects and another case with vision loss.Conclusion:Patients with delayed massive epistaxis or recurrent epistaxis after craniofacial trauma which cause pesudoaneurysm should undergo CTA,MRA or DSA examination,and it is would help to get proper diagnosis and treatment as early as possible.No recurrence was found after successful endovascular techniques.

Prevalence and clinical distribution of multidrug-resistant bacteria (3537 isolates) in a tertiary Chinese hospital (January 2012-December 2013).

OBJECTIVE: Multidrug-resistant organisms (MDROs) have become a widespread serious problem in recent years. Our objective was to determine the prevalence and clinical distribution of MDROs in a tertiary care hospital in China from January 1, 2012 to December 31, 2013. METHODS: The strains were cultured according to standard methods; bacterial identification and susceptibility testing were detected by Vitek 2 system. The prevalence and clinical distribution of extended-spectrum ß-lactamases (ESBLs)-producing enterobacteriaceae, carbapenem-resistant enterobacteriaceae (CRE), multiple-drug/pan-drug resistant P. aeruginosa (MDR/PDR-PA), carbapenem-resistant A. baumannii (CR-AB), methicillin-resistant S. aureus (MRSA) and vancomycin-resistant enterococcus (VRE) were analyzed by WHONET 5.6. RESULTS: A total of 3537 (33.4%) MDROs were found among 10,594 microbial isolates. ESBLs producing E. coli (ESBLs-ECO) (1153 cases) were the most frequent MDROs, followed by CR-AB (827 cases). The proportion of acquired resistance of A. baumannii (48.9%) accounted for the highest in all the MDROs. These MDROs were mainly isolated from respiratory (70.3%) and secretions (12.7%). Various types of intensive care unit (ICU) and surgery were the main source departments. The proportion of CRE and VRE were relatively few. CRE was most isolated from respiratory tract and closed body cavity fluid, while the distribution of VRE was relatively dispersed. CONCLUSION: High prevalence of MDROs has emerged in our hospital, particular in various ICU and surgical department. The effective way to prevent the further spread of MDROs is to strengthen the protection of respiratory tract and surgical wounds.

Factors that can minimize bleeding complications after renal biopsy.

Renal biopsy is a very important diagnostic tool in the evaluation of renal diseases. However, bleeding remains to be one of the most serious complications in this procedure. Many new techniques have been improved to make it safer. The risk factors and predictors of bleeding after percutaneous renal biopsy have been extensively reported in many literatures, and generally speaking, the common risk factors for renal biopsy complications focus on hypertension, high serum creatinine, bleeding diatheses, amyloidosis, advanced age, gender and so on. Our primary purpose of this review is to summarize current measures in recent years literature aiming at minimizing the bleeding complication after the renal biopsy, including the drug application before and after renal biopsy, operation details in percutaneous renal biopsies, nursing and close monitoring after the biopsy and other kinds of biopsy methods.

PTEN hypermethylation profiles of Chinese Kazakh patients with esophageal squamous cell carcinoma.

Aberrant DNA methylation of promoter region CpG islands may serve as an alternative mechanism to genetic defects in the inactivation of tumor suppressor genes (TSGs) in human malignancies. The aim of this study was to examine the promoter methylation status of the PTEN TSG and its association with esophageal squamous cell carcinoma (ESCC) carcinogenesis in a Chinese Kazakh population, which is known to have a relatively high ESCC incidence and mortality. The methylation status of the PTEN promoter region was determined in patients with ESCC (n = 95) and healthy individuals (n = 65) using highly sensitive Sequenom Epityper assays. The methylation level of the PTEN gene was significantly higher in patients with ESCC than in healthy controls. The median methylation level was 10.0% (interquartile range [IQR]: 7.0-11.0%) in patients with ESCC and 6.0% in controls (IQR: 4.0-9.0%; P = 0.001). PTEN methylation levels were higher in male patients with ESCC than in male controls, whereas a trend toward significance was observed between female patients with ESCC and female controls (P = 0.005 and P = 0.086, respectively). The PTEN methylation level was associated with histopathological grade and lymph node metastasis in patients with ESCC (P = 0.002 and P = 0.009, respectively). To our knowledge, this is the first report to show the presence of PTEN promoter CpG hypermethylation in ESCC and its association with tumor metastasis.

Resveratrate protects human skin from damage due to repetitive ultraviolet irradiation.

BACKGROUND: Ultraviolet (UV) exposure results in the production reactive oxygen species. Resveratrol has attracted considerable attentions owing to its natural abundance and multiple biological effects. OBJECTIVE: To investigate the protective effects of resveratrate against damage to human skin induced by repetitive solar simulator ultraviolet radiation (ssUVR). MATERIALS AND METHODS: Fifteen healthy volunteers were enrolled, and six sites on the non-exposed dorsal skin of each volunteer were marked for study. Sites 1-4 were exposed to ssUVR at a dosage of 1.5 minimal erythema dose for consecutive 4 days. Immediately after each exposure, one test material (resveratrate + antioxidant, antioxidant, resveratrate, vehicle) was applied to one of the four sites. Site 5 and site 6 were marked as positive control site (UVR only) and baseline control site (no treatment, no UVR). L*a*b values were assessed preprocedure and postprocedure. Skin biopsies were taken 24 h after the last irradiation. The specimens were stained to determine the number of sunburn cells and melanin content melanin. RESULTS: On resveratrate treated sites, erythema was barely seen with only slight decrease of L value and insignificant increase of *a value. Furthermore, resveratrate significantly inhibited sunburn cell formation, and decreased Fontana-Masson staining in skin samples. CONCLUSIONS: Resveratrate exerts protective effects against repetitive ssUVR-induced sunburn and suntan.

Meta-analysis demonstrates association between Arg72Pro polymorphism in the P53 gene and susceptibility to keloids in the Chinese population.

Although there is evidence suggesting genetic susceptibility for keloids, studies investigating the association between Arg72Pro polymorphism in the P53 gene and tendency to form keloids have given variable results. We made a meta-analysis of the effects of P53 Arg72Pro polymorphism on keloid risk in the Chinese population by conducting searches of the published literature in Pubmed, Embase, CBMdisc, and CNKI databases up to June 2011. Six studies were included in the meta-analysis, with a total of 359 keloid cases and 493 healthy controls. Meta-analysis results, respectively in the PCR-reverse dot blot and PCR-RFLP subgroups, showed significant associations between P53 Arg72Pro polymorphism and susceptibility to keloid in the comparisons of Pro allele vs Arg allele (odds ratio (OR) = 2.29, 95% confidence interval (CI) = 1.45-3.60; OR = 0.74, 95%CI = 0.56-0.98); Pro/Pro vs Pro/Arg + Arg/Arg (OR = 2.91, 95%CI = 1.88-4.53; OR = 0.54, 95%CI = 0.32-0.92); Pro/Pro vs Arg/Arg (OR = 2.79, 95%CI = 1.54-5.06; OR = 0.51, 95%CI = 0.28-0.92); Pro/Pro vs Pro/Arg (OR = 2.85, 95%CI = 1.75-4.63; OR = 0.57, 95%CI = 0.32-0.99). We conclude that the Pro allele of P53 Arg72Pro polymorphism is a risk factor for keloids in the Chinese population.

Development of a novel ArcCHECK(™) insert for routine quality assurance of VMAT delivery including dose calculation with inhomogeneities.

PURPOSE: To design a versatile, nonhomogeneous insert for the dose verification phantom ArcCHECK(™) (Sun Nuclear Corp., FL) and to demonstrate its usefulness for the verification of dose distributions in inhomogeneous media. As an example, we demonstrate it can be used clinically for routine quality assurance of two volumetric modulated arc therapy (VMAT) systems for lung stereotactic body radiation therapy (SBRT): SmartArc(®) (Pinnacle(3), Philips Radiation Oncology Systems, Fitchburg, WI) and RapidArc(®) (Eclipse(™), Varian Medical Systems, Palo Alto, CA). METHODS: The cylindrical detector array ArcCHECK(™) has a retractable homogeneous acrylic insert. In this work, we designed and manufactured a customized heterogeneous insert with densities that simulate soft tissue, lung, bone, and air. The insert offers several possible heterogeneity configurations and multiple locations for point dose measurements. SmartArc(®) and RapidArc(®) plans for lung SBRT were generated and copied to ArcCHECK(™) for each inhomogeneity configuration. Dose delivery was done on a Varian 2100 ix linac. The evaluation of dose distributions was based on gamma analysis of the diode measurements and point doses measurements at different positions near the inhomogeneities. RESULTS: The insert was successfully manufactured and tested with different measurements of VMAT plans. Dose distributions measured with the homogeneous insert showed gamma passing rates similar to our clinical results (∼99%) for both treatment-planning systems. Using nonhomogeneous inserts decreased the passing rates by up to 3.6% in the examples studied. Overall, SmartArc(®) plans showed better gamma passing rates for nonhomogeneous measurements. The discrepancy between calculated and measured point doses was increased up to 6.5% for the nonhomogeneous insert depending on the inhomogeneity configuration and measurement location. SmartArc(®) and RapidArc(®) plans had similar plan quality but RapidArc(®) plans had significantly higher monitor units (up to 70%). CONCLUSIONS: A versatile, nonhomogeneous insert was developed for ArcCHECK(™) for an easy and quick evaluation of dose calculations with nonhomogeneous media and for comparison of different treatment planning systems. The device was tested for SmartArc(®) and RapidArc(®) plans for lung SBRT, showing the uncertainties of dose calculations with inhomogeneities. The new insert combines the convenience of the ArcCHECK(™) and the possibility of assessing dose distributions in inhomogeneous media.

Condyle and mandibular bone change after unilateral condylar neck fracture in growing rats.

Unilateral fracture of the condylar neck in immature subjects might lead to mandible asymmetry and condyle remodelling. A rat model was used to investigate mandibular deviation and condylar remodelling associated with condyle fracture. 72 4-week-old male rats were randomly divided into three groups: an experimental group (unilateral transverse condylar fracture induced surgically), a sham operation group (surgical exposure but no fracture), and a non-operative control group (no operation). The rats were killed at intervals up to 9weeks after surgery, and outcomes were assessed using various measures of mandible deviation, histological and X-ray observation, and immunohistochemical measures of expression levels of connective tissue growth factor (CTGF) and type II collagen (Col II). The fracture led to the degeneration of mandibular size, associated with atrophy of fractured condylar process. Progressive remodelling of cartilage and increasing expression levels of CTGF and Col II were found. The authors conclude that condylar fracture can lead to asymmetries in mandible and condyle remodelling and expression of CTGF and Col II in condylar cartilage on both the ipsilateral and the contralateral sides.

Poster - Thur Eve - 64: Evaluation of SmartArc and RapidArc for lung SBRT treatment planning and delivery.

OBJECTIVES: To evaluate the performance of RapidArc® (Eclipse 10.0.28) and SmartArc® (Pinnacle 9.0) radiotherapy plans for lung stereotactic body radiation therapy (SBRT) in terms of dosimetric plan quality, delivery efficiency, inhomogeneity corrections and accuracy of dose delivery using a custom-built heterogeneity insert for ArcCHECK™ (Sun Nuclear Corp., FL, USA). METHODS: SmartArc® and RapidArc® plans were generated for 10 patients. The quality of the plans was evaluated in terms of conformity indices (R100 and R50 ) and the dose to the organs at risk. The efficiency was evaluated in terms of the monitor units (MUs) required for a given prescription dose. For dose verification, we designed and manufactured a heterogeneity insert for ArcCHECK™ with densities that simulate soft tissue, lung, bone, and air and having multiple locations for point dose measurements. Accuracy of dose delivery was assessed using gamma analysis. RESULTS: The overall plan quality was similar when comparing SmartArc® with RapidArc®. However, RapidArc® plans required significantly more MUs-up to 72%™compared with SmartArc® plans (p<0.001). ArcCHECK™ measurements in the presence of inhomogeneities showed better agreement for SmartArc® plans. CONCLUSION: Plan quality for SmartArc® and RapidArc® was comparable. However, SmartArc® plans were more efficient, requiring significantly fewer monitor units, and were delivered more accurately in a non-homogeneous phantom. With the custom-built heterogeneity insert, ArcCHECK™ can be used efficiently to verify inhomogeneity corrections and dose delivery accuracy for lung SBRT plans.