1.Three-dimensional modeling of modified Le Fort Ⅰ osteotomy of the maxilla and finite element analysis of postoperative occlusion
Chuqing LIU ; Yang LI ; Shaoyang BI ; Yangyang LIN
Journal of China Medical University 2024;53(1):46-50
Objective To establish a smooth three-dimensional(3D)geometric model of the maxilla based on CT data using four dif-ferent software packages,to mimic the modified Le Fort Ⅰ osteotomy and its fixation scheme,and to perform a finite element analysis of the postoperative occlusion.Methods CT data were preliminarily processed using Mimics software to produce an STL 3D model.The model was then imported into Inspire Studio software to create a smoothed PolyNURBS geometric model.SpaceClaim software was used to model the surgical osteotomy and fixation schemes.Finally,ANSYS Workbench was used to conduct a 3D finite element analysis simu-lating the patient's occlusion after surgery.Results The simulation results showed that the connection relationship of the finite element model was accurately established under the molar occlusion condition.Under a total occlusal force of 6 N,the maximum equivalent stress of the titanium plate was 73 MPa.Conclusion The maxillary modeling and analysis method used in this study can produce a smooth geometric model suitable for finite element simulation.The results of this study can provide reference for various fixation schemes in orthognathic surgery.
2.Genomic Correlates of Unfavorable Outcome in Locally Advanced Cervical Cancer Treated with Neoadjuvant Chemoradiation
Yuchun WEI ; Chuqing WEI ; Liang CHEN ; Ning LIU ; Qiuxiang OU ; Jiani C. YIN ; Jiaohui PANG ; Zhenhao FANG ; Xue WU ; Xiaonan WANG ; Dianbin MU ; Yang SHAO ; Jinming YU ; Shuanghu YUAN
Cancer Research and Treatment 2022;54(4):1209-1218
Purpose:
Neoadjuvant therapy modality can increase the operability rate and mitigate pathological risks in locally advanced cervical cancer, but treatment response varies widely. It remains unclear whether genetic alterations correlate with the response to neoadjuvant therapy and disease-free survival (DFS) in locally advanced cervical cancer.
Materials and Methods:
A total of 62 locally advanced cervical cancer (stage IB-IIA) patients who received neoadjuvant chemoradiation plus radical hysterectomy were retrospectively analyzed. Patients’ tumor biopsy samples were comprehensively profiled using targeted next generation sequencing. Pathologic response to neoadjuvant treatment and DFS were evaluated against the association with genomic traits.
Results:
Genetic alterations of PIK3CA were most frequent (37%), comparable to that of Caucasian populations from The Cancer Genome Atlas. The mutation frequency of genes including TERT, POLD1, NOS2, and FGFR3 was significantly higher in Chinese patients whereas RPTOR, EGFR, and TP53 were underrepresented in comparison to Caucasians. Germline mutations were identified in 21% (13/62) of the cohort and more than half (57%) had mutations in DNA damage repair genes, including BRCA1/2, TP53 and PALB2. Importantly, high tumor mutation burden, TP53 polymorphism (rs1042522), and KEAP1 mutations were found to be associated with poor pathologic response to neoadjuvant chemoradiation treatment. KEAP1 mutations, PIK3CA-SOX2 co-amplification, TERC copy number gain, and TYMS polymorphism correlated with an increased risk of disease relapse.
Conclusion
We report the genomic profile of locally advanced cervical cancer patients and the distinction between Asian and Caucasian cohorts. Our findings highlight genomic traits associated with unfavorable neoadjuvant chemoradiation response and a higher risk of early disease recurrence.