BACKGROUND:Chitosan has a place in the biomedical field due to its good biological properties and unique physicochemical properties,especially in tissue engineering and drug delivery with good application prospects.OBJECTIVE:To summarize the research progress of the role of chitosan in the repair and regeneration of oral soft and hard tissues.METHODS:A computerized search of CNKI and PubMed databases was performed with the search terms"chitosan,oral mucosal diseases,periodontal diseases,tissue regeneration,bacteriostatic,drug carrier,wound healing"in Chinese and English.The search time limit was from 2010 to 2024.After screening according to the inclusion and exclusion criteria,88 articles were finally included for summary analysis.RESULTS AND CONCLUSION:Chitosan is a promising biomaterial in bone and pulp regeneration as it has the ability to stimulate the recruitment and adhesion of osteogenic progenitor cells and dental pulp stem cells.Chitosan prevents caries,periodontal disease,and candidiasis by inhibiting Streptococcus pyogenes,Porphyromonas gingivalis,and Candida in the oral cavity.Chitosan nanocomposites have higher stability,better biocompatibility,and slow-release properties of drugs and can be enhanced by combining with other chemical reagents to enhance their anticancer properties.Chitosan possesses drug delivery,antibacterial activity,hemostasis and wound healing,which in turn can block the erosion of wounds by saliva and oral flora,relieve pain,repair and promote wound healing.Chitosan promotes the deposition of calcified material,which is conducive to the remineralisation of enamel and dentin.

BACKGROUND:Chitosan has a place in the biomedical field due to its good biological properties and unique physicochemical properties,especially in tissue engineering and drug delivery with good application prospects.OBJECTIVE:To summarize the research progress of the role of chitosan in the repair and regeneration of oral soft and hard tissues.METHODS:A computerized search of CNKI and PubMed databases was performed with the search terms"chitosan,oral mucosal diseases,periodontal diseases,tissue regeneration,bacteriostatic,drug carrier,wound healing"in Chinese and English.The search time limit was from 2010 to 2024.After screening according to the inclusion and exclusion criteria,88 articles were finally included for summary analysis.RESULTS AND CONCLUSION:Chitosan is a promising biomaterial in bone and pulp regeneration as it has the ability to stimulate the recruitment and adhesion of osteogenic progenitor cells and dental pulp stem cells.Chitosan prevents caries,periodontal disease,and candidiasis by inhibiting Streptococcus pyogenes,Porphyromonas gingivalis,and Candida in the oral cavity.Chitosan nanocomposites have higher stability,better biocompatibility,and slow-release properties of drugs and can be enhanced by combining with other chemical reagents to enhance their anticancer properties.Chitosan possesses drug delivery,antibacterial activity,hemostasis and wound healing,which in turn can block the erosion of wounds by saliva and oral flora,relieve pain,repair and promote wound healing.Chitosan promotes the deposition of calcified material,which is conducive to the remineralisation of enamel and dentin.

Objective To analyze the factors influencing the deterioration of nutritional status after radiotherapy/radiochemotherapy for esophageal cancer,so as to provide reference for nutritional management during antitumor therapy.Methods A total of 106 patients with esophageal cancer who received radiotherapy or radiochemotherapy at Anqing First People's Hospital of Anhui Medical University from Dec.2017 to Dec.2023 were enrolled.Patients'gender,age,surgical history,timing of radiotherapy intervention,synchronous chemoradiotherapy,radiotherapy dose,clinical stage,initial nutritional status,and performance status score were collected.The patient generated subjective global assessment scale(PG-SGA)scores were monitored before and after antitumor treatment.According to the nutritional status at the beginning of enrollment and at the end of radiotherapy,the patients were assigned to deterioration group or non-deterioration(stable or improved)group.The clinical characteristics of the 2 groups were compared.The factors influencing the deterioration of nutritional status were screened by logistic regression analysis.The correlation between nutritional status deterioration and adverse reactions(radiation esophagitis,pulmonary infection,neutropenia,thrombocytopenia,and elevated aminotransferase)was analyzed by Spearman correlation analysis.Results There were no significant differences in gender,radiotherapy dose,initial nutritional status,or performance status score between the 2 groups for the deterioration of nutritional status after radiotherapy(all P＞0.05).The proportions of patients with previous surgical history of esophageal cancer,synchronous chemoradiotherapy,initiation of radiotherapy at less than 90%of target calorie requirement,and clinical stage Ⅳ were significantly higher in the deterioration group than those in the non-deterioration group(all P＜0.05).Logistic regression analysis showed that clinical stage Ⅳ(odds ratio[OR]=4.684,95%confidence interval[CI]1.252-17.519,P=0.022)and previous surgical history of esophageal cancer(OR=7.338,95%CI 1.878-28.666,P=0.004)were the independent adverse risk factors for the deterioration of nutritional status after radiotherapy/radiochemotherapy.The timing of radiotherapy intervention was also an independent risk factor for the deterioration of nutritional status,and taking the tolerance of 70%-90%target energy as the reference level,starting radiotherapy when the tolerance of 90%-100%target energy had the optimal protection of nutritional status(OR=0.166,95%CI 0.050-0.551,P=0.003).Spearman correlation analysis showed that the deterioration of nutritional status was positively correlated with elevated transaminases after radiotherapy(rs=0.283,P=0.003),while it was not correlated with the other adverse reactions(all P＞0.05).Conclusion Under the standard nutritional intervention model,patients with previous surgery and recurrent metastatic esophageal cancer who receive radiotherapy/chemoradiotherapy are still at risk of nutritional status deterioration.Tolerance to 90%-100%target energy requirement may be a more appropriate timing for radiotherapy intervention.When the nutritional status deteriorates during treatment,it is necessary to be alert to the elevated transaminases.

Objective To explore the effects of image registration using various regions of interest(ROI)on the setup error for nasopharyngeal carcinoma(NPC)patients who were immobilized individually.Methods Forty-three NPC patients who required radiotherapy were enrolled.The patients were immobilized with customized plastic foam and thermoplastic mask,and CBCT verification was performed once a week.In CBCT images,ROI was divided into the whole ROI(ROIPTV)and 7 local ROI containing different cervical structures(ROIsphenoid sinus,ROIatlantoaxial,ROIneck3,ROIneck4,ROIneck5,ROIneck6,and ROIneck7),which were then used for registrations with localized CT image.The setup errors in superior-inferior(SI),left-right(LR),anterior-posterior(AP),Pitch,Roll,and Yaw directions were recorded.Results In SI direction,the setup errors within 0.3 cm accounted for 89.74%for ROIneck7,and more than 90%for the other ROI.The proportion of setup errors within 0.3 cm gradually increased with the neck upward in LR direction,and they were 76.78%,81.70%,85.26%,and above 90%for ROIneck7,ROIneck6,ROIneck5,and the other ROI,respectively.In AP direction,the proportions of setup errors within 0.3 cm were less than 90%,except for ROIatlantoaxial and ROIneck3.The setup errors of ROIsphenoid sinus,ROIatlantoaxial,ROIneck3,and ROIneck4 were significantly positively correlated with ROIPTV in SI direction,and the correlation coefficients(R)were 0.94,0.95,0.90,and 0.83,respectively.In LR direction,there were positive correlations between the setup errors of ROIatlantoaxial and ROIsphenoid sinus(R=0.95),ROIneck3 and ROIsphenoid sinus(R=0.91),ROIPTV and ROIneck3(R=0.91).The setup errors of ROIPTV in AP direction were positively correlated with ROIatlantoaxial vertebrae and ROIneck3(R=0.88,0.90).The margins of all ROIs ranged from 0.38 cm to 1.01 cm.The extension of ROIneck6 and ROIneck7 in AP direction exceeded 0.9 cm,and the extension of ROIneck7 reached 0.95 cm in SI direction.Conclusion ROIPTV and ROIsphenoid sinus,ROIatlantoaxial,ROIneck3 are significantly correlated in SI,LR,and AP directions.The setup error of nasopharyngeal carcinoma patients gradually increases with the neck down.The nasopharyngeal and cervical regions need to be expanded in segments when patients are immobilized individually.

Objective:To explore the genetic basis of eighteen patients with tetrahydrobiopterin deficiency (BH4D) from Gansu Province.Methods:Eighteen patients diagnosed with BH4D at Gansu Provincial Maternal and Child Health Care Hospital from January 2018 to December 2021 were selected as the study subjects. Whole exome sequencing was carried out, and candidate variants were verified by Sanger sequencing.Results:All of the thirty-six alleles of the eighteen patients were successfully determined by molecular genetic testing. Sixteen patients were found to harbor variants of the PTS gene, and two had harbored variants of the QDPR gene. Ten variants were detected in the PTS gene, with the most common ones being c. 259C>T (34.38%) and c. 286G>A (15.63%). Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the c. 259C>T was classified as a pathogenic variant, whilst the c. 286G>A, c. 166G>A, c. 200C>T, c. 272A>G, c. 402A>C, c. 421G>T, c. 84-291A>G and c. 317C>T were classified as likely pathogenic variants. A novel c. 289_290insCTT variant was classified as likely pathogenic (PM1+ PM2_Supporting+ PM3+ PP3+ PP4). The two variants (c.478C>T and c. 665C>T) detected in the QDPR gene were both classified as variants of uncertain significance (PM1+ PM2_Supporting+ PP3+ PP4). Conclusion:Genetic testing has clarified the pathogenic variants in these BH4D patients, which has enabled timely and accurate clinical intervention and treatment, and provided a reference for genetic counseling and reproductive guidance for their families.

Objective:To explore the diagnostic values of urinary levels of CXCL9/SCr and CXCL10/SCr in kidney transplant rejection patients.Method:From March 2021 to July 2022, the relevant clinical data were retrospectively reviewed for 120 recipients undergoing kidney transplant biopsy at Tianjin First Central Hospital. According to the results of pathological examinations, they were assigned into three groups of rejection (72 cases), BK virus nephropathy (BKVN, 16 cases) and transplant nephropathy (32 cases). Renal function stable group (20 cases) was selected as control group. And 72 recipients in rejection group were divided into three sub-groups of ≥1A T cell mediated rejection (TCMR, 28 cases) ,antibody-mediated rejection (AMR, 32 cases) and borderline TCMR (10 cases). Subgroup analysis of rejection group was performed for clarifying the differences among various rejection types. The specificity and sensitivity of urinary CXCL9/SCr and CXCL10/SCr were evaluated by receiver operator characteristic (ROC) curve and their correlations examined.Result:No significant difference existed in general profiles among four groups. No difference existed between urinary CXCL9/SCr and CXCL10/SCr between rejection and BKVN groups. And the values of these two groups were higher than those of transplant nephropathy and renal function stable groups ( P<0.01). In subgroup analysis of rejection, urinary CXCL9/SCr and CXCL10/SCr values in rejection group were higher than those in borderline TCMR and AMR groups ( P<0.01). No difference existed between borderline TCMR and AMR groups. Urinary CXCL9/SCr had an AUC of 0.938 and a threshold of 0.482 μg/mol while urinary CXCL10/SCr had an AUC of 0.89n and a threshold of 5.516 μg/mol. Urinary CXCL9/SCr and CXCL10/SCr had a high linear correlation. Conclusion:Urinary CXCL9/SCr and CXCL10/SCr may be employed as early non-invasive detection markers for RT rejection sensitivity and specificity.

Objective To investigate the clinical application of 3D printed bolus with specific density in breast cancer radiotherapy,and to evaluate its effects on dose distribution and positioning.Methods Forty post-mastectomy patients undergoing intensity-modulated radiotherapy were randomly enrolled for 3D printed bolus(n=20)and conventional bolus(n=20),and all patients were fixed in the supine position using styrofoam.Conventional positioning was performed based on in-room lasers and body markers,with daily Catalyst HD optical surface monitoring combined with weekly CBCT verification.The absolute dose,patients'skin surface dose,surgical incision,planned field,target area doses(VCTV50Gy,VPTV50Gy)and organs-at-risk doses in patients with different boluses were recorded,and the conformity index and homogeneity index were calculated,and the setup errors using CBCT and Catalyst HD were also analyzed.Results The difference in absolute dose between different boluses was trivial,but the skin surface dose with 3D printed bolus was significantly higher than with conventional bolus[(54.83±0.44)Gyvs(54.43±0.51)Gy,P<0.05].Patients with 3D printed boluses had a higher conformity index than with conventional boluses(0.69±0.04 vs 0.65±0.02).For different boluses,there was no significant difference in VCTV50 Gy,while the VPTV50 Gy and organs-at-risk doses were lower in those with 3D printed bolus than conventional boluses(P<0.05),with heart Vmean of 9.68%±3.24%vs11.43%±3.60%.In patients with 3D printed boluses,both planned field arrangement and surgical incision affected the target doses,and the doses of the target area without an internal breast wrap was greater than those with internal breast wrap(P<0.05).When the field was not wrapped around the internal breast,the surgical incisions only affected VPTV50 Gy,and the VPTV50 Gy was greater with the transverse fusiform incision than with the oblique vertical incision(P<0.05),which were 95.58%±0.51%vs95.44%±0.71%.The optical monitoring accuracies with different boluses differed only in the left-right direction(P<0.05),with(0.08±0.57)cm and(-0.15±0.46)cm for 3D printed and conventional boluses.Conclusion Compared with conventional bolus,3D printed bolus can improve dose distribution and optical monitoring accuracy.The surgical incision and planned field arrangement under 3D-printed bolus would exert effects on target doses.

Objective:To evaluate the safety of double and a half layered esophagojejunal anastomosis in radical gastrectomy.Methods:This prospective, multi-center, single-arm study was initiated by the Affiliated Cancer Hospital of Zhengzhou University in June 2021 (CRAFT Study, NCT05282563). Participating institutions included Nanyang Central Hospital, Zhumadian Central Hospital, Luoyang Central Hospital, First Affiliated Hospital of Henan Polytechnic University, First Affiliated Hospital of Henan University, Luohe Central Hospital, the People's Hospital of Hebi, First People's Hospital of Shangqiu, Anyang Tumor Hospital, First People's Hospital of Pingdingshan, and Zhengzhou Central Hospital Affiliated to Zhengzhou University. Inclusion criteria were as follows: (1) gastric adenocarcinoma confirmed by preoperative gastroscopy;(2) preoperative imaging assessment indicated that R0 resection was feasible; (3) preoperative assessment showed no contraindications to surgery;(4) esophagojejunostomy planned during the procedure; (5) patients volunteered to participate in this study and gave their written informed consent; (6) ECOG score 0–1; and (7) ASA score I–III. Exclusion criteria were as follows: (1) history of upper abdominal surgery (except laparoscopic cholecystectomy);(2) history of gastric surgery (except endoscopic submucosal dissection and endoscopic mucosal resection); (3) pregnancy or lactation;(4) emergency surgery for gastric cancer-related complications (perforation, hemorrhage, obstruction); (5) other malignant tumors within 5 years or coexisting malignant tumors;(6) arterial embolism within 6 months, such as angina pectoris, myocardial infarction, and cerebrovascular accident; and (7) comorbidities or mental health abnormalities that could affect patients' participation in the study. Patients were eliminated from the study if: (1) radical gastrectomy could not be completed; (2) end-to-side esophagojejunal anastomosis was not performed during the procedure; or (3) esophagojejunal anastomosis reinforcement was not possible. Double and a half layered esophagojejunal anastomosis was performed as follows: (1) Open surgery: the full thickness of the anastomosis is continuously sutured, followed by embedding the seromuscular layer with barbed or 3-0 absorbable sutures. The anastomosis is sutured with an average of six to eight stitches. (2) Laparoscopic surgery: the anastomosis is strengthened by counterclockwise full-layer sutures. Once the anastomosis has been sutured to the right posterior aspect of the anastomosis, the jejunum stump is pulled to the right and the anastomosis turned over to continue to complete reinforcement of the posterior wall. The suture interval is approximately 5 mm. After completing the full-thickness suture, the anastomosis is embedded in the seromuscular layer. Relevant data of patients who had undergone radical gastrectomy in the above 12 centers from June 2021 were collected and analyzed. The primary outcome was safety (e.g., postoperative complications, and treatment). Other studied variables included details of surgery (e.g., surgery time, intraoperative bleeding), postoperative recovery (postoperative time to passing flatus and oral intake, length of hospital stay), and follow-up conditions (quality of life as assessed by Visick scores).Result:[1] From June 2021 to September 2022,457 patients were enrolled, including 355 men and 102 women of median age 60.8±10.1 years and BMI 23.7±3.2 kg/m2. The tumors were located in the upper stomach in 294 patients, mid stomach in 139; and lower stomach in 24. The surgical procedures comprised 48 proximal gastrectomies and 409 total gastrectomies. Neoadjuvant chemotherapy was administered to 85 patients. Other organs were resected in 85 patients. The maximum tumor diameter was 4.3±2.2 cm, number of excised lymph nodes 28.3±15.2, and number of positive lymph nodes five (range one to four. As to pathological stage,83 patients had Stage I disease, 128 Stage II, 237 Stage III, and nine Stage IV. [2] The studied surgery-related variables were as follows: The operation was successfully completed in all patients, 352 via a transabdominal approach, 25 via a transhiatus approach, and 80 via a transthoracoabdominal approach. The whole procedure was performed laparoscopically in 53 patients (11.6%), 189 (41.4%) underwent laparoscopic-assisted surgery, and 215 (47.0%) underwent open surgery. The median intraoperative blood loss was 200 (range, 10–1 350) mL, and the operating time 215.6±66.7 minutes. The anastomotic reinforcement time was 2 (7.3±3.9) minutes for laparoscopic-assisted surgery, 17.6±1.7 minutes for total laparoscopy, and 6.0±1.2 minutes for open surgery. [3] The studied postoperative variables were as follows: The median time to postoperative passage of flatus was 3.1±1.1 days and the postoperative gastrointestinal angiography time 6 (range, 4–13) days. The median time to postoperative oral intake was 7 (range, 2–14) days, and the postoperative hospitalization time 15.8±6.7 days. [4] The safety-related variables were as follows: In total, there were 184 (40.3%) postoperative complications. These comprised esophagojejunal anastomosis complications in 10 patients (2.2%), four (0.9%) being anastomotic leakage (including two cases of subclinical leakage and two of clinical leakage; all resolved with conservative treatment); and six patients (1.3%) with anastomotic stenosis (two who underwent endoscopic balloon dilation 21 and 46 days after surgery, the others improved after a change in diet). There was no anastomotic bleeding. Non-anastomotic complications occurred in 174 patients (38.1%). All patients attended for follow-up at least once, the median follow-up time being 10 (3–18) months. Visick grades were as follows: Class I, 89.1% (407/457); Class II, 7.9% (36/457); Class III, 2.6% (12/457); and Class IV 0.4% (2/457).Conclusion:Double and a half layered esophagojejunal anastomosis in radical gastrectomy is safe and feasible.

Objective:To evaluate the safety of double and a half layered esophagojejunal anastomosis in radical gastrectomy.Methods:This prospective, multi-center, single-arm study was initiated by the Affiliated Cancer Hospital of Zhengzhou University in June 2021 (CRAFT Study, NCT05282563). Participating institutions included Nanyang Central Hospital, Zhumadian Central Hospital, Luoyang Central Hospital, First Affiliated Hospital of Henan Polytechnic University, First Affiliated Hospital of Henan University, Luohe Central Hospital, the People's Hospital of Hebi, First People's Hospital of Shangqiu, Anyang Tumor Hospital, First People's Hospital of Pingdingshan, and Zhengzhou Central Hospital Affiliated to Zhengzhou University. Inclusion criteria were as follows: (1) gastric adenocarcinoma confirmed by preoperative gastroscopy;(2) preoperative imaging assessment indicated that R0 resection was feasible; (3) preoperative assessment showed no contraindications to surgery;(4) esophagojejunostomy planned during the procedure; (5) patients volunteered to participate in this study and gave their written informed consent; (6) ECOG score 0–1; and (7) ASA score I–III. Exclusion criteria were as follows: (1) history of upper abdominal surgery (except laparoscopic cholecystectomy);(2) history of gastric surgery (except endoscopic submucosal dissection and endoscopic mucosal resection); (3) pregnancy or lactation;(4) emergency surgery for gastric cancer-related complications (perforation, hemorrhage, obstruction); (5) other malignant tumors within 5 years or coexisting malignant tumors;(6) arterial embolism within 6 months, such as angina pectoris, myocardial infarction, and cerebrovascular accident; and (7) comorbidities or mental health abnormalities that could affect patients' participation in the study. Patients were eliminated from the study if: (1) radical gastrectomy could not be completed; (2) end-to-side esophagojejunal anastomosis was not performed during the procedure; or (3) esophagojejunal anastomosis reinforcement was not possible. Double and a half layered esophagojejunal anastomosis was performed as follows: (1) Open surgery: the full thickness of the anastomosis is continuously sutured, followed by embedding the seromuscular layer with barbed or 3-0 absorbable sutures. The anastomosis is sutured with an average of six to eight stitches. (2) Laparoscopic surgery: the anastomosis is strengthened by counterclockwise full-layer sutures. Once the anastomosis has been sutured to the right posterior aspect of the anastomosis, the jejunum stump is pulled to the right and the anastomosis turned over to continue to complete reinforcement of the posterior wall. The suture interval is approximately 5 mm. After completing the full-thickness suture, the anastomosis is embedded in the seromuscular layer. Relevant data of patients who had undergone radical gastrectomy in the above 12 centers from June 2021 were collected and analyzed. The primary outcome was safety (e.g., postoperative complications, and treatment). Other studied variables included details of surgery (e.g., surgery time, intraoperative bleeding), postoperative recovery (postoperative time to passing flatus and oral intake, length of hospital stay), and follow-up conditions (quality of life as assessed by Visick scores).Result:[1] From June 2021 to September 2022,457 patients were enrolled, including 355 men and 102 women of median age 60.8±10.1 years and BMI 23.7±3.2 kg/m2. The tumors were located in the upper stomach in 294 patients, mid stomach in 139; and lower stomach in 24. The surgical procedures comprised 48 proximal gastrectomies and 409 total gastrectomies. Neoadjuvant chemotherapy was administered to 85 patients. Other organs were resected in 85 patients. The maximum tumor diameter was 4.3±2.2 cm, number of excised lymph nodes 28.3±15.2, and number of positive lymph nodes five (range one to four. As to pathological stage,83 patients had Stage I disease, 128 Stage II, 237 Stage III, and nine Stage IV. [2] The studied surgery-related variables were as follows: The operation was successfully completed in all patients, 352 via a transabdominal approach, 25 via a transhiatus approach, and 80 via a transthoracoabdominal approach. The whole procedure was performed laparoscopically in 53 patients (11.6%), 189 (41.4%) underwent laparoscopic-assisted surgery, and 215 (47.0%) underwent open surgery. The median intraoperative blood loss was 200 (range, 10–1 350) mL, and the operating time 215.6±66.7 minutes. The anastomotic reinforcement time was 2 (7.3±3.9) minutes for laparoscopic-assisted surgery, 17.6±1.7 minutes for total laparoscopy, and 6.0±1.2 minutes for open surgery. [3] The studied postoperative variables were as follows: The median time to postoperative passage of flatus was 3.1±1.1 days and the postoperative gastrointestinal angiography time 6 (range, 4–13) days. The median time to postoperative oral intake was 7 (range, 2–14) days, and the postoperative hospitalization time 15.8±6.7 days. [4] The safety-related variables were as follows: In total, there were 184 (40.3%) postoperative complications. These comprised esophagojejunal anastomosis complications in 10 patients (2.2%), four (0.9%) being anastomotic leakage (including two cases of subclinical leakage and two of clinical leakage; all resolved with conservative treatment); and six patients (1.3%) with anastomotic stenosis (two who underwent endoscopic balloon dilation 21 and 46 days after surgery, the others improved after a change in diet). There was no anastomotic bleeding. Non-anastomotic complications occurred in 174 patients (38.1%). All patients attended for follow-up at least once, the median follow-up time being 10 (3–18) months. Visick grades were as follows: Class I, 89.1% (407/457); Class II, 7.9% (36/457); Class III, 2.6% (12/457); and Class IV 0.4% (2/457).Conclusion:Double and a half layered esophagojejunal anastomosis in radical gastrectomy is safe and feasible.

Objective:To explore the influence of the contours of different parts of the human body on the setup errors of Catalyst HD optical surface imaging (OSI) system-guided radiotherapy.Methods:Using the 3D printing technology, arc- and oval arc-shaped phantoms with base angles of 5°-45° (step length: 5°) were designed to simulate the contours of different body parts of patients. A Catalyst HD system was employed for monitoring, during which the gains and integration time of the system were adjusted. The treatment couches were manually moved (range: -5 mm to 5 mm, with a step length of 2 mm). The ratios of transverse to longitudinal dimensions of all phantoms were recorded. The recorded items also included couch value errors in the anterior-posterior (AP), inferior-superior (SI), and left-right (LR) directions for transversely and longitudinally placed phantoms, as well as the setup errors monitored using the Catalyst HD system. Then, this study presented an analysis of the correlation between phantoms for different body contours and the gains and integration time of the Catalyst HD system. The purpose was to compare the setup errors under the two different placement conditions of phantoms and to analyze the correlation between the monitored values of the Catalyst HD system and couch values.Results:There was a significant linear negative correlation between the gain and the logarithm of integration time required for monitoring using the Catalyst HD system, with a slope of -0.001. There was a certain functional relationship between the intercept and the ratio of the transverse to longitudinal dimensions of the phantoms. Under the same gain, the integration time decreased with an increase in the base angles of phantoms. The Catalyst HD system showed different monitoring accuracy under different placement conditions of the phantoms ( Z = -8.59 to -0.02, P < 0.05), with the monitoring accuracy in the LR and AP directions higher in the transverse position. The correlation between the monitored values of the Catalyst HD system and the actual couch values increased in the LR and SI directions with an increase in the base angle of the phantoms, showing a strong correlation in the case of base angles of ≥ 25°. Furthermore, the correlation was always significant in the AP direction ( R > 0.9). Conclusions:When the best surface images are obtained using the Catalyst HD system, the gains and integration time of the system are correlated with body surface contours. The Catalyst HD system shows high monitoring accuracy in the AP direction. This system shows high accuracy in all directions when the ratios of transverse to longitudinal dimensions are ≤ 2 or the base angles ≥ 25°.