Objective:To investigate the influence of ultrasonic monitoring of bladder filling levels on setup errors before fractionated radiotherapy for cervical cancer patients through a comparative analysis, and its effectiveness in improving clinical target volume (CTV) margins.Methods:A retrospective study was conducted on 1 284 error data of setup via cone beam CT (CBCT) and 6D setup error correction system from 172 cervical cancer patients treated in the Radiotherapy Department of Peking University Cancer Hospital from January 2019 to October 2023. These patients were classified into two groups: 87 (659 times of setup) with ultrasonic monitoring of bladder filling levels and 85 (625 times of setup) without ultrasonic monitoring. The setup errors, error distributions, and numbers of abnormal setups between the two groups were compared in the lateral (Lat), longitudinal (Lng), vertical (Vrt), pitch (Pitch), roll (Roll), and rotational (Rtn) dimensions. Moreover, the CTV to planning target volume(PTV) margin values in the three-dimensional direction were calculated for both groups to assess the clinical value of ultrasonic monitoring of bladder filling levels before fractionated radiotherapy.Results:Compared to the group without ultrasonic monitoring, the group with ultrasonic monitoring exhibited lower median values of setup errors in all six-dimensional directions and smaller upper and lower interquartile ranges ( Z = -10.86 to -6.34, P<0.05). The group with ultrasonic monitoring manifested more concentrated setup errors in various directions and statistically significantly reduced numbers of abnormal setups ( χ2=15.33, P<0.05). Moreover, CTV-PTV margins of the group with ultrasonic monitoring displayed reduced CTV-PTV margin values by 0.55, 1.52, and 1.26 mm in the Vrt, Lng, and Lat directions, respectively. Conclusions:Pre-radiotherapy ultrasonic monitoring of bladder filling levels in cervical cancer patients can significantly improve the repeatability of setup, thus notably reducing the incidence of abnormal setups. Theoretically, it can narrow the range from the CTV to the PTV, thereby minimizing radiation exposure to healthy tissues and ultimately enhancing radiotherapy precision for cervical cancer and reducing radiation damage.

Objective:To investigate the influence of ultrasonic monitoring of bladder filling levels on setup errors before fractionated radiotherapy for cervical cancer patients through a comparative analysis, and its effectiveness in improving clinical target volume (CTV) margins.Methods:A retrospective study was conducted on 1 284 error data of setup via cone beam CT (CBCT) and 6D setup error correction system from 172 cervical cancer patients treated in the Radiotherapy Department of Peking University Cancer Hospital from January 2019 to October 2023. These patients were classified into two groups: 87 (659 times of setup) with ultrasonic monitoring of bladder filling levels and 85 (625 times of setup) without ultrasonic monitoring. The setup errors, error distributions, and numbers of abnormal setups between the two groups were compared in the lateral (Lat), longitudinal (Lng), vertical (Vrt), pitch (Pitch), roll (Roll), and rotational (Rtn) dimensions. Moreover, the CTV to planning target volume(PTV) margin values in the three-dimensional direction were calculated for both groups to assess the clinical value of ultrasonic monitoring of bladder filling levels before fractionated radiotherapy.Results:Compared to the group without ultrasonic monitoring, the group with ultrasonic monitoring exhibited lower median values of setup errors in all six-dimensional directions and smaller upper and lower interquartile ranges ( Z = -10.86 to -6.34, P<0.05). The group with ultrasonic monitoring manifested more concentrated setup errors in various directions and statistically significantly reduced numbers of abnormal setups ( χ2=15.33, P<0.05). Moreover, CTV-PTV margins of the group with ultrasonic monitoring displayed reduced CTV-PTV margin values by 0.55, 1.52, and 1.26 mm in the Vrt, Lng, and Lat directions, respectively. Conclusions:Pre-radiotherapy ultrasonic monitoring of bladder filling levels in cervical cancer patients can significantly improve the repeatability of setup, thus notably reducing the incidence of abnormal setups. Theoretically, it can narrow the range from the CTV to the PTV, thereby minimizing radiation exposure to healthy tissues and ultimately enhancing radiotherapy precision for cervical cancer and reducing radiation damage.

Scientifically preparing technical requirement for medical equipment can ensure that the purchase results meet the actual needs of the hospital.This study introduces the platform guarantee model implemented by the First Affiliated Hospital of Sun Yat-sen University in the management of medical equipment,analyzes the advantages,disadvantages,opportunities,and challenges of technical requirement preparation based on this model management,and proposes optimization strategies based on the analysis results,aiming to provide reference for the technical requirement preparation in general hospitals.

Scientifically preparing technical requirement for medical equipment can ensure that the purchase results meet the actual needs of the hospital.This study introduces the platform guarantee model implemented by the First Affiliated Hospital of Sun Yat-sen University in the management of medical equipment,analyzes the advantages,disadvantages,opportunities,and challenges of technical requirement preparation based on this model management,and proposes optimization strategies based on the analysis results,aiming to provide reference for the technical requirement preparation in general hospitals.

BACKGROUND: Preliminary study has prepared the three-dimensional silk fibroin/chitosan/nano-hydroxyapatite scaffold successfully.OBJECTIVE: To explore the mechanical properties, physical characteristics, chemical composition and antibiotic sustained-release ability of three-dimensional silk fibroin/chitosan/nano-hydroxyapatite scaffold loaded with levofloxacin. METHODS: Levofloxacin/chitosan (3:1) microspheres were constructed by emulsion settlement filter method. 5, 7.5 and 10 g of microspheres were added into 2％ of silk fibroin/chitosan/nano-hydroxyapatite mixed solution through freeze drying and chemical cross-linking to obtain the scaffolds loaded with antibiotics. The scaffolds loaded with antibiotics underwent scanning electron microscope observation, and chemical composition analysis. The sustained release, mechanical properties, porosity, water absorption expansion rate and hot water soluble loss rate were detected. RESULTS AND CONCLUSION: (1) Scanning electron microscope observed that there were drug microspheres at the inner wall of the scaffold, and the voidage was decreased with mass of microspheres increasing. (2) Energy spectrum analysis showed that the three kinds of scaffolds were rich in calcium and phosphonium ions. (3) The three kinds of scaffolds showed the same releasing trend, which presented with sudden-release effect at the former 3 days (release> 50％) , and then tended to be stable. The release rate was the slowest in the scaffold loaded with 10 g of microscopes, and the rapidest in the scaffold loaded with 5 g of microscopes. (4) With the mass of microspheres increasing, there was an increase in the compressive and tension abilities and hot water soluble loss rate, and a decrease in the porosity, mean pore size and water absorption expansion rate. (5) These results indicate that the three-dimensional tissue-engineered scaffold loaded with levofloxacin is constructed successfully by freeze drying and chemical cross-linking method, which holds good sustained-release effect and compressive ability, water absorption expansion rate and hot water soluble loss rate.

ObjectiveTo investigate clinical application of intraoperative intraperitoneal hyperthermic chemotherapy using sustained-release fluorouracil in radical gastrectomy for advanced gastric cancer.MethodsThe clinical data of 280 advanced gastric cancer patients admitted from September,2002 to September,2010 were analyzed retrospectively.They were divided into three groups randomly and followed up.The postoperative morbidity,the mortality and the overall survival rates were evaluated.ResultsThere were no significant differences in these three groups with respect to postoperative morbidity ( P ＞ 0.05 ).The incidence of recurrence in intraperitoneal chemotherapy using sustained-release fluorouracil ( treatment group) was significantly lower than those of intraperitoneal chemotherapy and operative treatment( 16.18％,37.61％ and 41.28％,P ＜0.05).The 1,3- and 5-year overall survival rates of treatment group were 85.51％,61.28％ and 53.67％,respectively,and the 1-,3- and 5-year overall survival rates were 84.11％,39.98％ and 28.12％,and 81.28％,29.88％ and 25.21％ respectively in intrapeitoneal chemotherapy group and operative group.1-year overall survival rate had no significant differences among three groups with respect to ( P＞0.05).3-and 5-year overall survival rates in treatment group were higher signfficantly than those of intraperitoneal chemotherapy and operative treatment( P＜0.05).Conclusions Intraoperative intrapeitoneal hyperthermic chemotherapy using sustained-release fluorouracil is a kind of convenient,safe,and highly effective comprehensive treatment method,and it can kill isolated intraperitoneal cancer cells.It may reduce postoperative recurrence and improve survival rates.

Objective: To further investigate the molecular mechanism of photodynamic therapy. Methods: We used cDNA microarray technique to explore the gene expression profiles of HEPG2 cells after photodynamic therapy with hematoperphyrin monomethyl ether(HMME) in HEPG2 cells. After treated with HMME for 60 min, the HEPG2 cells were irradiated with laser, and observed by microscope with H E staining. To prepare the probes, mRNA from both control and treated cells were isolated and purified, then reversely transcribed to cDNA with the incorporation of fluorecent labeled dUTP. The probes were hybridized with a cDNA microarray representing the 1 538 genes originated from human hepatocarcinoma cells. The fluorencent signals of Cy3 and Cy5 were scanned and analyzed. Results: After laser irradiation, the HEPG2 cells showed the typical feature of apoptosis. The gene expression profiles were also changed greatly. Among the 1 538 target genes, 389(2.47%) different expression genes were detected. Most of the changed genes (nearly 80%) were down regulated. They were functionally related to cell proliferation cycle, replication, metabolism and so on. Several apoptosis associated genes were detected among those up regulated genes, encoding the key proteins involved in apoptosis signal transduction, such as CCP32,AIF,Mch2. Conclusion: The HMME photodynamic therapy can initiate the apoptosis process of HEPG2 cells, which may be regulated by mitochondial pathway.[