OBJECTIVE: To study effective methods for reducing lung V₅, V₁₀, and mean lung dose (MLD) in the design of volumetric modulated arc therapy for central lung cancer by using different arc configurations and dose-limiting blocks designs. METHODS: Five groups of plans were designed for the enrolled patients. Group A used a full-arc field. Group B used a partial-arc field. Groups C, D, and E used full-arc fields with vertical-length, semi-ring, and triangular dose-limiting blocks added respectively. The dosimetric similarities of target areas and the dosimetric differences in lung V₅, V₁₀, V₂₀, and MLD among the groups were compared. RESULTS: Compared with group A, groups B, C, D, and E had decreased homogeneity and conformity of the target area, but significantly lower V₅ and V₁₀ of the whole lung. The MLD of groups C, D, and E was lower than that of group A. CONCLUSION Using a full-arc field combined with dose-limiting blocks can effectively reduce lung V₅, V₁₀, MLD, and monitor units (MU).
Lung Neoplasms/radiotherapy* ; Humans ; Radiotherapy, Intensity-Modulated/methods* ; Radiotherapy Planning, Computer-Assisted/methods* ; Radiotherapy Dosage ; Lung/radiation effects*

Objective:To investigate the clinical value of Delphian lymph node (DLN) metastasis (DLNM) in predicting regional lymph node involvement in patients with intrathyroidal papillary thyroid carcinoma (PTC).Methods:Clinical and pathological data from 345 consecutive patients with pathologically confirmed DLN status, who underwent initial surgical treatment at the Department of Surgical Oncology, First Affiliated Hospital of Zhejiang University School of Medicine between Jan 2020 and Dec 2022, were retrospectively analyzed.Results:DLNM was identified in 61 patients (17.7%). Univariate analysis revealed significant associations between DLNM and male sex, elevated preoperative thyroglobulin levels, larger tumor size, maximum tumor diameter >10 mm, bilateral lesions, multifocality, lymphovascular invasion, and lymph nodes metastases in pretracheal, paratracheal, and lateral cervical(all P ≤0.001). Elevated thyroglobulin antibody levels ( χ2=6.201, P=0.013) and Hashimoto's thyroiditis ( χ2=11.340, P<0.001) were protective factors for DLNM. Multivariate analysis identified male sex, lymphovascular invasion, pretracheal, and paratracheal lymph node metastases ( χ2=6.689, P=0.010; χ2=8.163, P=0.004; χ2=7.605, P=0.006; χ2=8.324, P=0.004) as independent risk indicators for DLNM. Patients with DLNM exhibited significantly higher risks of lymph nodes metastases in pretracheal ( χ2=27.307, P<0.001), paratracheal ( χ2=38.697, P<0.001), and lateral cervical ( χ2=36.459, P<0.001). Conclusion:DLNM demonstrates predictive value for both central compartment and lateral cervical lymph node metastases, warranting particular attention to meticulous dissection of the prelaryngeal region during surgery.

Objective:To analyze the changes and significance in clinical cardiac indicators of early cardiac myocardial dysfunction and cardiac substructure dose during conventional radiotherapy for N 2-N 3 non-small cell lung cancer (NSCLC) with mediastinal lymph node metastases. Methods:The data of 34 NSCLC patients with lymph node metastases in regions 4-8 admitted to the Affiliated Cancer Hospital of Guizhou Medical University from June 2022 to August 2023 were observed and analyzed. All patients were treated with volumetric modulated arc therapy with a prescribed dose of 60-70 Gy. Cardiac troponin T (cTnT) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) were measured at 6 time points: within 1 week before radiotherapy ( t0); when the cumulative radiotherapy dose reaches 20 Gy ( t20), 40 Gy ( t40), 60 Gy ( t60) during radiotherapy; within 1 week after radiotherapy ( tp); 1 month after radiotherapy( tp1). Left ventricular global longitudinal strain (LVGLS) and left atrial global longitudinal strain (LAGLS) were assessed at 4 time points: t0, t40, tp and tp1, respectively. The changes in cardiac indicators at different time points during radiotherapy and their correlation with substructure doses were analyzed using analysis of variance, linear regression analysis, and Pearson correlation. Results:The correlation between cardiac substructure dose and mean heart dose (MHD) in the study cohort in the descending order was as follows: left ventricle ( B=0.43, P<0.001), right ventricle ( B=0.37, P=0.002), left atrium ( B=0.16, P<0.001), and right atrium ( B=0.15, P=0.001). There were significant differences in the changes of LVGLS and LAGLS across different time points ( F=3.13, P=0.029; F=17.18, P<0.001). At 1 month after radiation, LAGLS was significantly decreased compared to pre-radiation levels ( P=0.009), whereas no significant difference was observed in LVGLS ( P=1.000). No significant differences were observed in the changes of cTnT and NT-proBNP across different time points (all P>0.05). Significant correlations were identified between cTnT and right ventricle mean dose at t40 ( r=0.38, P=0.025), as well as between NT-proBNP and right atrium mean dose at t60 and tp ( r=0.54, P=0.001; r=0.41, P=0.016). Conclusions:At present, there is no significant difference between the sensitive serum markers of myocardial injury and LVGLS in detecting early myocardial injury. LAGLS may hold substantial clinical value. There is uncertainty about radiation injury and repair of various cardiac substructures.

Objective:To investigate the clinical value of Delphian lymph node (DLN) metastasis (DLNM) in predicting regional lymph node involvement in patients with intrathyroidal papillary thyroid carcinoma (PTC).Methods:Clinical and pathological data from 345 consecutive patients with pathologically confirmed DLN status, who underwent initial surgical treatment at the Department of Surgical Oncology, First Affiliated Hospital of Zhejiang University School of Medicine between Jan 2020 and Dec 2022, were retrospectively analyzed.Results:DLNM was identified in 61 patients (17.7%). Univariate analysis revealed significant associations between DLNM and male sex, elevated preoperative thyroglobulin levels, larger tumor size, maximum tumor diameter >10 mm, bilateral lesions, multifocality, lymphovascular invasion, and lymph nodes metastases in pretracheal, paratracheal, and lateral cervical(all P ≤0.001). Elevated thyroglobulin antibody levels ( χ2=6.201, P=0.013) and Hashimoto's thyroiditis ( χ2=11.340, P<0.001) were protective factors for DLNM. Multivariate analysis identified male sex, lymphovascular invasion, pretracheal, and paratracheal lymph node metastases ( χ2=6.689, P=0.010; χ2=8.163, P=0.004; χ2=7.605, P=0.006; χ2=8.324, P=0.004) as independent risk indicators for DLNM. Patients with DLNM exhibited significantly higher risks of lymph nodes metastases in pretracheal ( χ2=27.307, P<0.001), paratracheal ( χ2=38.697, P<0.001), and lateral cervical ( χ2=36.459, P<0.001). Conclusion:DLNM demonstrates predictive value for both central compartment and lateral cervical lymph node metastases, warranting particular attention to meticulous dissection of the prelaryngeal region during surgery.

Objective:To analyze the changes and significance in clinical cardiac indicators of early cardiac myocardial dysfunction and cardiac substructure dose during conventional radiotherapy for N 2-N 3 non-small cell lung cancer (NSCLC) with mediastinal lymph node metastases. Methods:The data of 34 NSCLC patients with lymph node metastases in regions 4-8 admitted to the Affiliated Cancer Hospital of Guizhou Medical University from June 2022 to August 2023 were observed and analyzed. All patients were treated with volumetric modulated arc therapy with a prescribed dose of 60-70 Gy. Cardiac troponin T (cTnT) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) were measured at 6 time points: within 1 week before radiotherapy ( t0); when the cumulative radiotherapy dose reaches 20 Gy ( t20), 40 Gy ( t40), 60 Gy ( t60) during radiotherapy; within 1 week after radiotherapy ( tp); 1 month after radiotherapy( tp1). Left ventricular global longitudinal strain (LVGLS) and left atrial global longitudinal strain (LAGLS) were assessed at 4 time points: t0, t40, tp and tp1, respectively. The changes in cardiac indicators at different time points during radiotherapy and their correlation with substructure doses were analyzed using analysis of variance, linear regression analysis, and Pearson correlation. Results:The correlation between cardiac substructure dose and mean heart dose (MHD) in the study cohort in the descending order was as follows: left ventricle ( B=0.43, P<0.001), right ventricle ( B=0.37, P=0.002), left atrium ( B=0.16, P<0.001), and right atrium ( B=0.15, P=0.001). There were significant differences in the changes of LVGLS and LAGLS across different time points ( F=3.13, P=0.029; F=17.18, P<0.001). At 1 month after radiation, LAGLS was significantly decreased compared to pre-radiation levels ( P=0.009), whereas no significant difference was observed in LVGLS ( P=1.000). No significant differences were observed in the changes of cTnT and NT-proBNP across different time points (all P>0.05). Significant correlations were identified between cTnT and right ventricle mean dose at t40 ( r=0.38, P=0.025), as well as between NT-proBNP and right atrium mean dose at t60 and tp ( r=0.54, P=0.001; r=0.41, P=0.016). Conclusions:At present, there is no significant difference between the sensitive serum markers of myocardial injury and LVGLS in detecting early myocardial injury. LAGLS may hold substantial clinical value. There is uncertainty about radiation injury and repair of various cardiac substructures.

Objective:To explore the radiological damage to cells induced by the delayed particles of 9C-ions for heavy ion therapy, as well as the microdosimetric distribution and biological effects of these particles on a single model of V79 Chinese hamster lung cells. Methods:The Monte Carlo program was employed to simulate the endonuclear absorbed doses of α particles with various energies (3-10 MeV) transported in cells (cell radius RC = 10 μm, nucleus radius RN = 5 μm). Then, the result were compared with the S values ( SN←N, SN←Cy, and SN←CS) derived using the medical internal radiation dose (MIRD) method to demonstrate the feasibility of Monte Carlo simulations. Finally, the energy deposition of the delayed particles of 9C-ions generated at three sites (i.e., on the surface and in the cytoplasm and nucleus of the V79 cell model) during their transport in targets was simulated, and the result ing cell surviving fraction was analyzed. Results:Monte Carlo and MIRD method yielded differences in S values of 1.91%-4.95% for SN←N (nucleus to nucleus), 1.48%-5.11% for SN←Cy (cytoplasm to nucleus), and -1.99% to 0.80% for SN←CS(surface to nucleus), indicating highly consistent S values derived using both method(differences < 6%). When a 9C-ion decayed on the surface of the V79 cell model and the produced secondary particles entered the cell, the average endonuclear absorbed dose was 10 -2 Gy orders of magnitude, with a cell surviving fraction of about 88%. In the case where decay occurred in the cytoplasm, the cell surviving fraction was about 80%. However, when the 9C ion decayed in the nucleus, α particles had short ranges and deposited most of their energy in the cell (mean endonuclear absorbed dose: 0.1 Gy). In this case, severe cell damage was induced, with the cell surviving fraction reducing to about 53%. Conclusions:9C-ions emit secondary charged particles due to decay, among which α particles cause great damage to cells when entering the nucleus and trigger evident biological effects.

Objective:To investigate the effects of oocyte maturation trigger using follicle-stimulating hormone (FSH) plus human chorionic gonadotropin (hCG) on clinical outcomes of in vitro fertilization/intracytoplasmic sperm injection and embryo transfer (IVF/ICSI-ET) in gonadotropin-releasing hormone agonist (GnRH-a) cycles. Methods:The retrospective cohort study included 682 patients aged up to 40 years with normal ovarian response who underwent IVF/ICSI-ET at Department of Reproductive Medicine, Women and Children's Hospital, Xiamen University School of Medicine between Feburary 2016 and April 2017. Patients were grouped by whether oocyte maturation was triggered with 250 μg recombinant hCG (r-hCG) plus 300 U urinary FSH (uFSH, dual trigger group, n=439) or 250 μg r-hCG alone (r-hCG group, n=243). The main observation indexes were the clinical pregnancy rate and the live birth rate, and the secondary observation indexes were the high-quality embryo rate, the implantation rate, the biochemical pregnancy rate, the abortion rate, etc. Results:There were no statistically significant differences between the two groups in age, infertility duration, body mass index (BMI), anti-Müllerian hormone (AMH), total dosage and duration of gonadotropin (Gn) used, number of embryos transferred (all P>0.05). The live birth rate, the clinical pregnancy rate, the miscarriage rate, the normal fertilization rate, the cleavage rate, the embryo formation rate and the high-quality embryo rate were not significantly different between the two groups (all P>0.05). The implantation rate [40.47% (191/472)] and the biochemical pregnancy rate [64.20% (156/243)] were higher in dual trigger group than in r-hCG group [32.42% (272/893), P=0.003; 55.35% (272/893), P=0.025]. Conclusion:Dual trigger of oocyte maturation with 250 μg r-hCG plus 300 U uFSH has no benefit on the clinical pregnancy rate and the live birth rate, but could improve the implantation rate and the biochemical pregnancy rate in women undergoing short-acting GnRH-a protocol in IVF/ICSI-ET.

Objective:To investigate the effects of oocyte maturation trigger using follicle-stimulating hormone (FSH) plus human chorionic gonadotropin (hCG) on clinical outcomes of in vitro fertilization/intracytoplasmic sperm injection and embryo transfer (IVF/ICSI-ET) in gonadotropin-releasing hormone agonist (GnRH-a) cycles. Methods:The retrospective cohort study included 682 patients aged up to 40 years with normal ovarian response who underwent IVF/ICSI-ET at Department of Reproductive Medicine, Women and Children's Hospital, Xiamen University School of Medicine between Feburary 2016 and April 2017. Patients were grouped by whether oocyte maturation was triggered with 250 μg recombinant hCG (r-hCG) plus 300 U urinary FSH (uFSH, dual trigger group, n=439) or 250 μg r-hCG alone (r-hCG group, n=243). The main observation indexes were the clinical pregnancy rate and the live birth rate, and the secondary observation indexes were the high-quality embryo rate, the implantation rate, the biochemical pregnancy rate, the abortion rate, etc. Results:There were no statistically significant differences between the two groups in age, infertility duration, body mass index (BMI), anti-Müllerian hormone (AMH), total dosage and duration of gonadotropin (Gn) used, number of embryos transferred (all P>0.05). The live birth rate, the clinical pregnancy rate, the miscarriage rate, the normal fertilization rate, the cleavage rate, the embryo formation rate and the high-quality embryo rate were not significantly different between the two groups (all P>0.05). The implantation rate [40.47% (191/472)] and the biochemical pregnancy rate [64.20% (156/243)] were higher in dual trigger group than in r-hCG group [32.42% (272/893), P=0.003; 55.35% (272/893), P=0.025]. Conclusion:Dual trigger of oocyte maturation with 250 μg r-hCG plus 300 U uFSH has no benefit on the clinical pregnancy rate and the live birth rate, but could improve the implantation rate and the biochemical pregnancy rate in women undergoing short-acting GnRH-a protocol in IVF/ICSI-ET.

Objective:To study the effects of gantry acceleration limitations of a linear accelerator (linac) on the dosimetry of volumetric modulated arc therapy (VMAT) plans, machine efficiency, and dose verification result of VMAT plans and to explore the optimal selection of gantry motion models in the Pinnacle treatment planning system.Methods:Ten cases of nasopharyngeal carcinoma, non-small cell lung cancer, sigmoid adenocarcinoma with retroperitoneal lymph node metastasis, and invasive ductal carcinoma of the breast were each selected for this study. Then two models were set up in the Pinnacle v9.10 treatment planning system, namely the one allowing gantry acceleration and the one limiting gantry acceleration. The same field arrangement, optimized target parameters, and optimized weights of VMAT plans were adopted in the two models, in order to analyze the dosimetric variations in targets and organs at risk (OARs) and compare the differences in treatment time and gamma passing rates.Results:The treatment time of the enrolled patients under the model allowing gantry acceleration was significantly lower than that of the patients under the model limiting gantry acceleration was adopted ( t=-6.751, -0.209, -19.523, -28.999; P< 0.05) and decreased by 15.27%, 18.07%, 19.71%, and 28.75%, respectively. Meanwhile, the conformity and uniformity of target areas were affected, while there was no statistical significance in the gamma passing rates in the validation of VMAT plans ( P>0.05). For the cases of nasopharyngeal carcinoma (NPC), the maximum dose to brainstem PRV increased by 1.25%. For the cases of lung cancer, the maximum dose to the spinal cord and lung V20 increased by 1.19% and 1.21%, respectively, while lung V5 decreased by 1.21%. For the cases of sigmoid adenocarcinoma with retroperitoneal lymph node metastasis, the mean doses to bilateral kidneys, livers, small intestine, and colon all increased. For the cases of breast cancer, lung V10 on the opposite side of cancer increased by 1.66% and the mean dose to the lungs on the same side of cancer decreased by 7.45%. Conclusions:The model allowing gantry acceleration allows the treatment time to be significantly shortened and the treatment efficiency improved. Although this model had the shortcomings such as affecting the conformity and uniformity of target areas to a certain extent and increasing the doses to some OARs, clinical requirements for dosimetry were still met. Therefore, it is recommended to use the model allowing gantry acceleration in the Pinnacle planning system.

Objective To investigate the influence factors of tumor diameter and related prognostic factors on the prognosis of hilar cholangiocarcinoma.Methods The retrospective case-control study was conducted.The clinicopathological data of 240 patients who underwent resection of hilar cholangiocarcinoma in the West China Hospital of Sichuan University between January 1995 and January 2013 were collected,including 104 patients with tumor diameter ≤ 2 cm (8 with tumor diameter ≤ 1 cm and 96 with 1 cm ＜ tumor diameter ≤ 2 cm),85 with 2 cm ＜ tumor diameter ≤ 3 cm and 51 with tumor diameter ＞ 3 cm (40 with 3 cm ＜ tumor diameter ≤ 4 cm and 11 with tumor diameter ＞ 4 cm).Observation indicators:(1) surgical situations;(2) follow-up situations;(3) risk factors analysis affecting the prognosis of patients;(4) correlation analysis between related prognostic indicators and tumor diameter.The follow-up using outpatient examination and telephone interview was performed to detect the survival up to August 2016.The survival curve and survival rate were respectively drawn and calculated by the Kaplan-Meier method,and the Log-rank test was used for survival analysis.The prognostic factors and correlation between related prognostic indicators and tumor diameter were respectively analyzed using the COX proportional hazard model and logistic regression model.Results (1) Surgical situations:240 patients underwent successful resection of hilar cholangiocarcinoma and lymph node dissection.Of 73 patients with postoperative complications,1 died of intraperitoneal infection induced to systemic infection and multiple organ failure,1 diel of renal failure,and other patients were cured by symptomatic treatment.(2) Follow-up situations:240 patients were followed up for 12.0-98.0 months,with a median time of 47.4 months.The overall median survival time,1-,3-and 5-year overall survival rates were respectively 30.6 months,81％,47％ and 29％.The median survival time and 5-year survival rate were 46.5 months,34％ in patients with tumor diameter ≤ 2 cm and 30.5 months,30％ in patients with 2 cm ＜ tumor diameter ≤ 3 cm and 13.8 months,20％ in patients with tumor diameter ＞ 3 cm,respectively,with a statistically significant difference (x2 =17.83,P＜0.05).Results of further analysis showed the median survival time and 5-year survival rate were 31.3 months,38％ in patients with tumor diameter ≤ 1 cm and 46.5 months,34％ in patients with 1 cm ＜ tumor diameter ≤ 2 cm,respectively,with no statistically significant difference (x2=1.16,P＞O.05).The median survival time and 1-year survival rate were 14.7 months,62％ in patients with 3 cm ＜ tumor diameter ≤ 4 cm and 13.0 months,55％ in patients with tumor diameter ＞ 4 cm,respectively,with no statistically significant difference (x2 =2.34,P＞O.05).(3) Risk factors analysis affecting the prognosis of patients:univariate analysis showed that tumor diameter,surgical margin,lymph node metastasis,vascular invasion and histological differentiation were the related factors affecting patients' prognosis [hazard ratio (HR)=1.456,8.714,1.737,2.246,1.665;95％ confidence interval (C I):1.212-1.748,5.558-13.663,1.311-2.301,1.494-3.378,1.375-2.016,P ＜ 0.05].The multivariate analysis showed that 2 cm ＜ tumor diameter ≤ 3 cm,tumor diameter ＞ 3 cm,R1 resection,lymph node metastasis and low-differentiated tumor were the independent risk factors affecting poor prognosis of patients (HR =1.559,1.868,7.410,1.521,2.274,95％ CI:1.125-2.160,1.265-2.759,4.497-12.212,1.136-2.037,1.525-3.390,P＜0.05).(4) Correlation analysis between related prognostic indicators and tumor diameter:the results of univariate analysis showed that there was a correlation between lymph node metastasis,vascular invasion,histological differentiation and T staging of American Joint Committee on Cancer (AJCC) and tumor diameter of 2 cm as a cut-off point (x2 =6.063,4.950,8.770,9.069,P＜0.05).There was a correlation between surgical margin,lymph node metastasis,vascular invasion and histological differentiation and tumor diameter of 3 cm as a cut-off point (x2=10.251,9.919,5.485,15.632,P＜0.05).The results of multivariate analysis showed that lymph node metastasis and T staging of AJCC were independent related factors affecting tumor diameter of 2 cm as a cut-off point[odds ratio (OR) =1.882,2.104,95 ％CI:1.075-3.293,1.220-3.631,P＜0.05];surgical margin and lymph node metastasis were independent related factors affecting tumor diameter of 3 cm as a cut-off point (OR=3.187,2.211,95 ％CI:1.377-7.379,1.133-4.314,P＜0.05).Conclusions The 2 cm ＜ tumor diameter ≤ 3 cm,tumor diameter ＞ 3 cm,R1 resection,lymph node metastasis and low-differentiated tumor are the independent risk factors affecting the prognosis of patients with hilar cholangiocarcinoma.Three cm (T staging in De Oliveira staging system) as the second cut-off point is feasible,meanwhile,2 cm cut-off point may be become another potential tumor dividing point described in De Oliveira staging system.