Objective:To assess the application value of low-dose contrast agent combined with bolus tracking technique in radiotherapy localization for nasopharyngeal carcinoma (NPC).Methods:One hundred patients with NPC for radiotherapy localization were enrolled prospectively and randomly divided into observation ( n = 50) and control ( n = 50) group using random number table. All patients in the control group underwent routine computerized tomography (CT) for radiotherapy localization with an intravenous bolus of 80 ml iodinated contrast media. Images were obtained at a fixed delay of 50 s from the beginning of contrast injection. Patients in the observation group underwent CT scan using a bolus tracking technique with an intravenous bolus of 50-60 ml iodinated contrast media. By observing the time-CT value monitoring curve, the scanning was manually triggered when the peak fell. The score of image quality, enhanced CT value, iodine contrast dose, and dose calculation variance of planning target volume were compared between the two different dose groups. The differences of dose were compared using independent sample t-tests and the differences in graph scores were compared using Wilcoxon rank sum tests. Results:The dosage of iodine contrast agent in the observation group was 28.75% less than that in the control group, and the difference achieved statistical significance ( t=-42.11, P<0.001). The enhanced CT value of carotid artery and jugular vein in the control group increased 32.58% and 21.02% compared with patients in the observation group, respectively ( t=-8.11 and -4.82, P<0.001 for both). No statistically significant differences in the enhanced CT value were found for the gross tumor volume (GTV) of nasopharynx or sternocleidomastoid between the two groups ( P>0.05). The images in both groups can met the requirements of target volume delineation, and the difference of subjective score was not statistically significant ( Z=-1.36, P=0.175). There were no significant differences in the signal-to-noise ratio (SNR) or contrast-to-noise ratio (CNR) of nasopharynx between the two groups ( P>0.05). The results of subjective score and GTV target area showed high consistency between the two doctors with a κ value of 0.77. The differences in dose calculation variance of planning target volume between the two different dose groups was also not statistically significant ( P>0.05). Conclusions:In the radiotherapy localization for nasopharyngeal carcinoma, the application of low-dose contrast agent combined with bolus tracking technique could obtain good images for target delineation and effectively reduce the intake of iodine contrast agent and the risk of adverse reactions. Based on these results, low-dose contrast agent combined with bolus tracking technique has wide range of application.

Objective:To evaluate the effect of different reconstruction points of intrauterine applicator on the source dwell positions and plan dosimetry in intracavitary brachytherapy for cervical cancer.Methods:Clinical data of 43 patients with cervical cancer who had completed radical radiotherapy in Liuzhou Workers' Hospital from May 2020 to October 2022 were retrospectively analyzed. Among 43 patients, aged 32-79 years, 40 cases were diagnosed with squamous carcinoma and 3 cases of adenocarcinoma. All patients received external irradiation for 50.4 Gy / 28 fractions and CT-guided intracavitary brachytherapy (45° intrauterine applicator) was 36 Gy / 6 fractions. Brachytherapy was performed by using Fletcher applicator, the curvature of intrauterine applicator were 15°, 30°and45°. Two sets of brachytherapy plans were simulated for each patient. One set of plans extracted the simulated CT positioning images and the original plan of the patient's brachytherapy. The reconstruction point of the curved part of the 45° intrauterine applicator was adjusted to slice-by-slice reconstruction. The plan was optimized to meet clinical requirements according to the prescription, which was called the slice-by-slice group. In the other set of plans, slice-by-slice group was used as a template. The reconstruction points of the curved section of the 45° intrauterine applicator were adjusted to 1, 3, 5, and 7, without modifying the applicator weights and other parameters, which was called the average group 1, 3, 5 and 7. The deviation analysis of 15°, 30° and 45° intrauterine applicator with different number of reconstruction points was carried out, the reconstruction deviation of 45°, 30° and 15° intrauterine applicator at different reconstruction points was compared. Paired-sample t-test or Wilcoxon signed rank test were used to compare the differences in high-risk clinical target volume (HR-CTV) D 50%, D 90%, D 100%, V 100%, V 150%, V 200% and conformity index (CI) as well as D 2 cm3, D 1 cm3 and D 0.1 cm3 in bladder, rectum, and small intestine between two groups of 45° intrauterine applicator. Results:The reconstruction deviation in the average group was mainly from the vertical direction of the 45° intrauterine applicator. The mean reconstruction deviations of 45° (1, 3, 5, 7 reconstruction points), 30° (1, 3, 5 reconstruction points) and 15° (1, 2 reconstruction points) were 1.30 mm, 0.32 mm, 0.14 mm and 0.08 mm; 0.57 mm, 0.14 mm and 0.06 mm; 0.14 mm and 0.06 mm, respectively. There was no significant difference in the parameters of high-risk clinical target volume (HR-CTV) in the slice-by-slice group compared with the average group 5 and 7 (all P>0.005), and no significant difference was found between the average group 5 and 7 (all P>0.005). There were no statistically significant differences in bladder and rectum doses between the slice-by-slice group and the average groups or within the average groups (all P>0.005). The parameters of small intestine in the slice-by-slice group were higher than those of the average group 1, the difference was statistically significant ( P=0.002,<0.001,<0.001). The dose of small intestine in the slice-by-slice group was not statistically significant compared with those in the average group 5 and 7 (both P>0.005). The dose of small intestine in the average group 5 was not statistically significant compared with that in the average group 7 ( P>0.005). The small intestine dose deviations of D 0.1 cm3, D 1 cm3 and D 2 cm3 in the average groups at 1 reconstruction point were 2.41%±1.70%, 1.95%±1.27% and 1.71%±1.10%, respectively. Conclusion:The number of reconstruction points is recommended to be no less than 1, 3 and 5 of the curved part of the 15°, 30°and 45° Fletcher intrauterine applicator, respectively, during intracavitary brachytherapy for cervical cancer.

Objective:To evaluate the effectiveness and feasibility of 3D ResSE-Unet-based intelligent delineation of clinical target volume (CTV) in postoperative adjuvant radiotherapy for breast cancer.Methods:A total of 974 cases of breast cancer treated in the Cancer Diagnosis and Treatment Center of the Fourth Affiliated Hospital of Guangxi Medical University from September 2018 to June 2022 were enrolled in this study, including 614 cases receiving total mastectomy and 360 cases treated with breast-conserving surgery. They were divided into a training set, a validation set, and a testing set. The training set consisted of 874 cases and was used to build a model of 3D ResSE-Unet-based intelligent CTV delineation. The validation set comprised 40 cases and was used to evaluate the feasibility and effectiveness of the clinical application of AI-based CTV design in the radiotherapy for breast cancer. The testing set was composed of 60 cases and was used to test the accuracy of intelligent CTV. The Wilcoxon rank test was used to compare the Dice similarity coefficient (DSC), 95% Hausdorff distance (HD95), and average surface distance (ASD) obtained using the intelligent delineation model.Results:The intelligent delineation model showed high precision. The CTV of cases treated with total mastectomy (CTV cw) and the CTV of cases treated with breast-conserving surgery (CTV b) had DSCs greater than 0.80 and greater than 0.88, respectively. Therefore, compared with CTV cw, CTV b had a higher DSC (0.91 ± 0.03 vs.0.83 ± 0.05, t = 7.11, P < 0.05). Both CTV cw and CTV b had lower HD 95 [(7.56 ± 3.42) mm vs.(8.77 ± 5.89) mm] and ASD [(1.85 ± 0.71) mm vs.(1.86 ± 0.83)mm], without statistically significant difference ( P > 0.05). The left/right supraclavicular and infraclavicular CTV (CTV2) had DSCs greater than 0.8. CTV2 also had low average HD95 and ASD, without statistically significant difference ( P > 0.05). Conclusions:The 3D ResSE-Unet-based intelligent CTV delineation has better consistency and feasibility in postoperative adjuvant radiotherapy for breast cancer, especially the CTVs after breast-conserving surgery.

Objective:To analyze the correlation between the monitor units and pass rate of plan dose verification in the volumetric intensity modulated arc therapy (VMAT) plan.Methods:VMAT plans for 20 patients with nasopharyngeal carcinoma (NPC) and 30 patients with cervical cancer who underwent radiotherapy at Liuzhou Workers' Hospital from January to October 2020 were retrospectively chosen. The Detector 1500 array and Octavius 4D phantom from German PTW company were used for dose measurement. The pass rates of dose verification of relevant plans were analyzed under the conditions of 3%/2 mm and 2%/2 mm. The correlation between the monitor units and pass rate of plan dose verification in VMAT plans was assessed by Pearson's bivariate correlation analysis.Results:Under the condition of 3%/2 mm, the correlation coefficients between the monitor units and gamma pass rate were -0.873 ( P<0.001), -0.800 ( P<0.001), -0.781 ( P<0.001), -0.493 ( P=0.006) for NPC_1Arc, NPC_2Arc, NPC_1Arc+NPC_2Arc and Cervix_2Arc, respectively. Under the condition of 2%/2 mm, the correlation coefficients between the monitor units and gamma pass rate were -0.842 ( P<0.001), -0.770 ( P<0.001), -0.748 ( P<0.001) and -0.531 ( P=0.003) for NPC_1Arc, NPC_2Arc, NPC_1Arc+NPC_2Arc and Cervix_2Arc, respectively. Conclusion:Significant negative correlation can be observed between the monitor units and plan dose verification pass rate in VMAT plan.

Humans ; East Asian People ; Nausea/drug therapy* ; Vomiting/drug therapy* ; Antineoplastic Agents/adverse effects* ; Neoplasms/drug therapy*

Objective:To study the differences in the dosimetry and delivery time between helical tomotherapy (HT) and volumetric modulated arc therapy (VMAT) in postoperative radiotherapy of synchronous bilateral breast cancer (SBBC) and to explore the feasibility of clinical application of the HT technology.Methods:A retrospective analysis was conducted for nine SBBC patients who underwent modified radical postoperative radiotherapy in the Fourth Affiliated Hospital of Guangxi Medical University from February 2017 to May 2022. For each patient, the Precision planning system was used to formulate the HT plan, and the RayStation planning system was employed to develop the VMAT plan. All plans obtained were divided into HT group and VMAT group according to plan type. The paired sample t-test was used to compare the dosimetric parameters of the target volume and organ at risk (OAR) and delivery time between the two radiotherapy technologies. Results:The plans of both groups could meet the clinical treatment requirements. The coverage ( D95% and V100%), conformity index (CI), average dose ( Dmean), and median dose ( D50%) of the target volumes in the HT group were better than those in the VMAT group, and the differences were statistically significant ( t=-3.21, -3.39, -5.03, 3.76, 4.97, P < 0.05). The differences in the maximum dose ( D2%), minimum dose ( D98%), high dose volumes ( V107% and V110%), and homogeneity index (HI) of the target volumes between the two groups were not statistically significant ( P > 0.05). Regarding the OAR, the V20 and Dmean of both lungs in the HT group were significantly lower than those in the VMAT group, but the irradiation volume V5 of both lungs in the HT group was significantly higher than that in the VMAT group ( t=-3.01, 3.83, -2.81, P < 0.05). Moreover, V20, V30, V40, and Dmean of heart and the V20 and Dmean of liver in the HT group were significantly lower than those in the VMAT group, with statistically significant differences ( t=3.76, -2.83, -2.74, 5.93, 4.57, 4.48, P < 0.05). There was no significant difference in the radiation doses to other OARs (spinal cord, thyroid gland, and humerus head, P > 0.05). The delivery time of the HT group was significantly higher than that of the VMAT group ( t = 11.32, P < 0.05). Conclusions:Compared with VMAT, HT has greater dosimetric advantages, and can provide higher target coverage, conformability and average dose, and significantly reduce the overall radiation doses to both lungs, heart, and liver in OARs. However, the irradiation volume V5 at low-dose areas of both lungs and the delivery time in the HT group are higher than those in the VMAT group, but still meet the clinical treatment requirements. Therefore, it is feasible to apply the HT technology to the modified radical postoperative radiotherapy of SBBC.

Objective: To explore the changes in liver function of Tibetan youth living in plateau with different body mass index (BMI) during the early stage of migration to the plain, and to provide scientific basis for high attitude de adaptation. Methods: A total of 3 035 Tibetan youth who firstly migrated to the plain (Shaanxi) from the plateau (Tibet) were selected as the research subjects, and were screened for symptoms of plateau de adaptation. Participants were divided into four groups: underweight, normal weight, overweight and obese, and received liver function test on the 3rd, 6th, 9th dayafter migration, respectively. Chi square test was used to detect the abnormal rate of liver function indicators among each group, and binary Logistic regression analysis was used to explore the relationship between BMI and abnormal liver function indicators. Results: The alanine aminotransferase(ALT), Aspartate aminotransferase(AST), γ glutamyl transpeptidase (GGT) of overweight Tibetan male and obese Tibetan male and female adolescents, the total bile acid (TBA) of overweight Tibetan male and obese Tibetan female were higher than those of the normal weight group at the early stage of de adaptation( P <0.05). With the de adaptation for 3, 6, 9 days, the indexes showed an overall upward trend, including: direct bilirubin (DBIL) in overweight male and female adolescents, total protein (TP) and globulose (GLOB) in obese female adolescents( P <0.05). The abnormal rate of overweight group (male ALT: 13.9%), obesity group (male and female ALT, GGT: 34.3%, 26.7%, 11.4%, 13.3%; female AST:10.0%) was significantly higher than that in underweight (2.8%, 3.5%, 0, 1.0%, 1.5%) and normal group(3.5%, 3.4%, 0.9%, 3.6%, 4.1%)( χ 2=48.07, 20.55, 20.55, 17.93, 10.23 , P <0.05). Binary Logistic regression analysis showed that after adjusting for age and gender, overweight was positively correlated with abnormal ALT( OR=2.10, 95%CI =1.20-3.62). Obesity was positively correlated with abnormal ALT( OR=5.50, 95%CI =4.23-7.40) and GGT( OR=4.10, 95%CI =2.03-6.74)( P <0.05). Conclusion During the early stage of migration to the plain among Tibetan youth living on the plateau, changes in liver function indicators are related to BMI. Overweight and obese Tibetans have a higher abnormal rate of liver damage indicators. It is suggested that individuals with high risk of obesity should undergo health examination and medical supervision when migrates from plateau to plain.

The integrity of lysosomes is of vital importance to survival of tumor cells. We demonstrated that LW-218, a synthetic flavonoid, induced rapid lysosomal enlargement accompanied with lysosomal membrane permeabilization in hematological malignancy. LW-218-induced lysosomal damage and lysosome-dependent cell death were mediated by cathepsin D, as the lysosomal damage and cell apoptosis could be suppressed by depletion of cathepsin D or lysosome alkalization agents, which can alter the activity of cathepsins. Lysophagy, was initiated for cell self-rescue after LW-218 treatment and correlated with calcium release and nuclei translocation of transcription factor EB. LW-218 treatment enhanced the expression of autophagy-related genes which could be inhibited by intracellular calcium chelator. Sustained exposure to LW-218 exhausted the lysosomal capacity so as to repress the normal autophagy. LW-218-induced enlargement and damage of lysosomes were triggered by abnormal cholesterol deposition on lysosome membrane which caused by interaction between LW-218 and NPC intracellular cholesterol transporter 1. Moreover, LW-218 inhibited the leukemia cell growth

Objective:To observe the clinical effect of extracorporeal shock wave treatment in the treatment of functional disorders after a palm crush injury.Methods:Forty patients who had experienced a hand crush injury more than 3 months previously were randomly divided into a control group and a combination group, each of 20. Both groups were given routine joint mobilization, ultrasound treatment, muscle strength training and occupational therapy every day in ten day units for 2 months. The combination group also received extracorporeal shock wave therapy three times a week for the two months. Before the experiment and after one and two months of treatment, both groups′ upper limb functioning was evaluted using the DASH score, grip strength and hand flexibility in the 9-hole wood board test.Results:After 2 months of treatment, significant improvement was observed in all of the measurements with both groups. The average scores of the combination group on all three tests were by then significantly better than the control group′s averages.Conclusions:Adding extracorporeal shock wave therapy to routine rehabilitation can improve the rough and fine functioning of a crushed hand.

Objective: To evaluate the dosimetric effects of set-up errors on nasal NK/T cell lymphoma by introducing set-up errors into the radiotherapy planning system for dose reconstruction. Methods: Ten patients with nasal NK/T cell lymphoma were recruited. A non-coplanar volumetric modulated arc therapy plan was designed for CT image and clinical target area of each patient. After the completion of the plan, the set-up errors were introduced into the radiotherapy plan by changing the ISO of the treatment, and dose calculation was performed to reconstruct the dose distribution. Results: With the increase of system set-up errors, the dose of target was decreased and the order affected by set-up errors in different directions was: left-right direction> head-foot direction> front-rear direction. When the translational set-up errors in each direction were -3 mm to 3 mm and the rotating set-up errors were -3° to 3°, the range of dose change in all targets was less than ±3%. When the set-up errors in all directions were ≤ 3 mm, the dose of organ at risk was less than or similar to the prescribed dose. When the set-up errors were> 3 mm, the doses of lens, spinal cord, parotid gland and optic nerve gradually exceeded the prescribed dose. Only when the rotating set-up errors were ≥ 3°, the dose of lens exceeded the prescribed dose. Special attention should be paid to the influence of the greater set-up errors in the left and right direction on lens, spinal cord and parotid gland, as well as on the spinal cord due to the larger set-up errors in the front and rear direction. After the actual set-up errors were introduced from our department, it exerted slight effect on the irradiation dose of GTV and CTV, which was less than ±2%. In a few cases, the dose of organ at risk potentially exceeded the prescribed dose limit, and special attention should be diverted to overdose of the lens and optic nerve. Conclusions The set-up errors will result in target dose deficiency and overdose of organ at risk in nasal NK/T cell lymphoma, especially upon the set-up errors in the left and right direction. The effect of 3 mm and 3° set-up errors on target and organ at risk is limited. Therefore, it is recommended to maintain the single direction set-up errors within 3 mm and 3°. The actual set-up errors introduced from our department exert little effect on the target dose, but a small number of organs are at risk of exceeding the prescribed dose limit. It is necessary to increase the evaluation of the extension region of organ at risk.