Objective:To investigate the correlations of urinary adverse reactions with dose to the bladder and urethra during external pelvic irradiation for locally advanced cervical cancer.Methods:This study retrospectively collected relevant dosimetric parameters and urinary symptoms, such as frequent, urgent, and painful urination, from locally advanced cervical cancer patients treated with external pelvic irradiation in the Department of Oncology, Affiliated Hospital of Guizhou Medical University. The dosimetric parameters examined in this study included the maximum, minimum, and mean doses to bladder and urethra (i.e., Dmax, Dmin and Dmean), mean doses received in an area of 0.1, 1, and 2 cm 3 around the planning target volume, D0.1 cm 3, D1 cm 3, D2 cm 3, and percentages of irradiated volumes in the whole organ volume under doses of 5, 10, 15, 20, 25, 30, 35, 40, 45, 50 Gy, V5 Gy, V10 Gy, V15 Gy, V20 Gy, V25 Gy, V30 Gy, V35 Gy, V40 Gy, V45 Gy, V50 Gy. Then the correlations between urinary symptoms and these dosimetric parameters were analyzed using the independent-sample t-test and the Logistic regression model. Results:The median volumes of bladder and urethra were 294.8 and 4.71 cm 3, respectively. Patients were divided into two groups based on the median division. The univariate analysis showed that urethral Dmax, Dmin, Dmean, V5 Gy, V10 Gy, V15Gy, V20 Gy, V25 Gy, V30 Gy, V35 Gy, V40 Gy, V45 Gy and V50 Gy correlated with urinary complications ( t = 14.30, 21.65, 32.19, 33.36, 16.62, 17.91, 21.52, 20.11, 12.27, 37.25, 30.18, 36.24 and 21.98, P<0.05). The multivariate analysis further indicates that urethral D2 cm 3, V20 Gy, V40 Gy and Bladder V40 Gy, D1 cm 3, D2 cm 3 were independent predictors of grade 2 urinary adverse reactions ( P<0.05). Conclusions:This study reported the correlations of relevant dosimetric parameters of urethra with urinary toxicity during external pelvic irradiation. It holds that urethral D2 cm 3, V20 Gy and V40 Gy should be restricted to minimize the risks of grade 2 urinary complications.

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 analyze the clinical characteristics of long-term survival patients with advanced non-small cell lung cancer (NSCLC) treated with chemotherapy combined with primary tumor radiotherapy, and to establish a Nomogram prognostic model, aiming to provide a certain reference for making a decision about the treatment of advanced NSCLC.Methods:A retrospective analysis was made on the data of 260 NSCLC patients who participated in two prospective clinical studies from January 2003 to May 2012 and the data of 138 NSCLC patients admitted to the Affiliated Cancer Hospital of Guizhou Medical University from January 2014 to August 2020. The former 260 cases were used as a training set and the latter 138 cases were used as the validation set. The overall survival (OS) of ≥ 18 months was defined as long-term survival (LTS). The clinical characteristics of LTS patients were compared with those with OS less than 18 months. The clinical characteristics and treatment-related parameters between the two types of patients were compared using the χ2 test. A multivariate analysis was made using logistic regression, and a nomogram model was built using RStudio. Results:The median OS of the training set was 13.4 months (95% CI: 11.9-14.9), with 1-, 2-, and 3-year OS rates of 55.4%, 19.1%, and 11.9%, respectively. In the training set, 87 cases had LTS and were classified as the LTS group, while 173 cases had OS less than 18 months and were classified as the non-LTS group. The univariate analysis showed that the prognostic factors affecting LST included the KPS score, T status, the number of metastatic organs, the number of metastatic lesions, brain metastasis, bone metastasis, the number of chemotherapy cycles, the biologically effective dose (BED) to the primary tumor, hemoglobin level, platelet count, plasma D-dimer, fibrinogen level, lactate dehydrogenase, and lung immune prognostic index (LIPI; χ2=4.72-12.63, P < 0.05). The multivariable analysis showed that the independent prognostic factors of LTS included a number of chemotherapy cycles ≥ 4, BED ≥ 70 Gy, platelets ≤ 220×10 9/L, D-dimer ≤ 0.5 mg/L, and a good LIPI score ( P= 0.002, 0.036, 0.005, 0.008, and 0.002). A nomogram model was established using the meaningful parameters obtained in the multivariable analysis, determining that the training and validation sets had a consistency index (C-index) of 0.750 and 0.727, respectively. As shown by the analytical result of the corrected curves, for the advanced NSCLC patients treated with thoracic radiotherapy, their LTS probability predicted using the nomogram prognostic model was highly consistent with their actual LTS probability. Both the analytical result of the receiver operating characteristic (ROC) curves and the decision curve analysis (DCA) result showed that the composite prediction model was more beneficial than a single prediction model. Conclusions:For patients with advanced NSCLC treated with thoracic radiotherapy, the independent prognostic factors of LTS included the number of chemotherapy cycles, BED, platelet count, pre-chemotherapy D-dimer, and LIPI score. The Nomogram prognostic model built based on these prognostic factors is a convenient, intuitive, and personalized prediction model used to screen patients who can benefit from thoracic radiotherapy.

Objective:To explore the potential mechanism of PD-1 inhibitor P on RIMI from the perspective of immune microenvironment.Methods:To establish a mouse model of radiation-induced myocardial injury (RIMI), twenty C57BL/6 mice were randomly divided into 4 groups, 5 in each group. Group A was the healthy control group; Group B was the PD-1 inhibitor group; Group C was the simple irradiation group, with a heart irradiation of 15 Gy; Group D was the irradiation+ PD-1 inhibitor group. One month after irradiation, the mice were anesthetized and sacrificed. The morphological changes of myocardial tissues were observed by HE staining. The myocardial fibrosis was assessed by Masson staining. CD 3+ , CD 3+ CD 4+ , CD 3+ CD 8 lymphocyte subsets and cytokines (IL-4, IL-6, IL-17A, TNF-α, TGF-β 1 and INF-γ) levels were determined by flow cytometry. The apoptosis rate of myocardial cells was detected by TUNE. Results:One month after irradiation, there was no obvious myocardial fibrosis in group B, and collagen fibers were distributed in the interstitium of myocardial cells in groups C and D. Semi-quantitative analysis results showed that the myocardial collagen volume fraction (CVF) of groups A, B, C and D were (1.97±0.36)%, (2.83±1.03)%, (5.39±0.77)% and (7.72±1.43)%, respectively. The CVF between group A and group B was similar ( P=0.314), and the differences in CVF between the other groups were statistically significant (all P<0.05). Compared with group A, the absolute value and percentage of CD 3+ T lymphocytes were significantly increased in groups B, C and D (all P<0.01). The values in group D were significantly higher than those in group B and group C (all P<0.01); The absolute value and percentage of CD 3+ CD4 T lymphocytes were similar among four groups (all P>0.05); The absolute value and percentage of CD 3+ CD 8 T lymphocytes in group D were significantly higher than those in groups A, B and C (all P<0.001). The expression levels of IL-6, IL-17A, and TGF-β 1 in group D were significantly higher compared with those in groups A, B and C (all P<0.001). The apoptotic index was gradually increased in four groups, and the differences in apoptotic index among four groups were statistically significant (all P<0.001). Conclusion:PD-1 inhibitors can aggravate RIMI by promoting myocardial immune inflammatory response.

Objective:To analyze the radiotherapy-related factors affecting the survival of non-small cell lung cancer (NSCLC) patients complicated with malignant pleural effusion (MPE)(MPE-NSCLC).Methods:From 2007 to 2019, 256 patients pathologically diagnosed with MPE-NSCLC received primary treatment. Among them, 117 cases were enrolled in this study. All patients were divided into two groups according to the radiation dose (<63 Gy and≥63 Gy). Propensity score matching (PSM) was performed to further adjust the confounding factors (Calipers value=0.1). The impact of radiotherapy-related factors on the overall survival (OS) was analyzed by Kaplan—Meier method, log-rank test and Cox’s regression model. Results:Primary tumor radiotherapy significantly prolonged the OS ( P<0.001). The radiation dose escalation (36.0-44.1 Gy, 45.0-62.1 Gy, 63.0-71.1 Gy) of primary tumor significantly prolonged the OS ( P<0.001). The corresponding median OS were 5, 13 and 18 months, respectively. Before the PSM, univariate analysis suggested that radiation dose ≥63 Gy, gross tumor volume (GTV)<157.7 cm 3 and stations of metastatic lymph node (S-mlN)≤5 were significantly associated with better OS (all P<0.05) and T 4N 3 was significantly associated with worse OS ( P=0.018). After the PSM, univariate analysis indicated that radiation dose ≥63 Gy was significantly associated with better OS ( P=0.013) and S-mlN ≤5 had a tendency to prolong the OS ( P=0.098). Prior to the PSM, multivariate analysis showed that radiation dose ≥63 Gy was an independent favorable factor of OS ( HR=0.566, 95% CI 0.368-0.871, P=0.010) and GTV<157.7 cm 3 had a tendency to prolong the OS ( HR=0.679, 95% CI 0.450-1.024, P=0.065). After the PSM, multivariate analysis revealed that radiation dose ≥63 Gy was still an independent favorable factor of OS ( HR=0.547, 95% CI 0.333~0.899, P=0.017). No ≥grade 4 radiation toxicity occurred. The incidence rates of grade 3 radiation esophagitis and pneumonitis were 9.4% and 5.1%, respectively. Conclusion:For MPE-NSCLC, radiotherapy dose of primary tumor may play a key role in improving OS on the basis of controllable MPE.

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 retrospectively analyze the clinical efficacy and safety of three-dimensional radiotherapy for the primary tumors in patients with stage Ⅳ non-small cell lung cancer complicated with malignant pleural effusion (MPE-NSCLC).Methods:A total of 198 patients who were initially pathologically diagnosed with MPE-NSCLC from January 2007 to April 2018 were enrolled and divided into the untreated group ( n=45), drug group ( n=57) and radiotherapy group ( n=96), respectively. The short-term efficacy, overall survival (OS) and adverse events in the drug and radiotherapy groups were analyzed. The OS rate was analyzed by Kaplan-Meier method and log-rank test. Clinical prognosis was evaluated by multivariate Cox′s regression model. Results:In the radiotherapy group, the objective response rate and non-response rate was 54% and 46%, significantly better than 25% and 75% in the drug group ( P=0.007). In the radiotherapy group, the 1-, 2-, 3-, 5-year OS and median survival was 47%, 18%, 6%, 1% and 12 months, remarkably higher than 15%, 3%, 2%, 0% and 5 months in the drug group, respectively (all P<0.001). Multivariate Cox′s regression analysis showed that radiotherapy for the primary tumors was an independent prognostic factor to prolong the OS ( P<0.001). Radiotherapy at a dose of ≥63 Gy and 4-6 cycles of chemotherapy tended to prolong the OS ( P=0.063 and 0.071). The OS of patients with EGFR mutation receiving radiotherapy combined with molecular target therapy was significantly better than that of those with unknown EGFR status treated with radiotherapy and chemotherapy ( P=0.007). Addition of radiotherapy for the primary tumors did not significantly increase the incidence of adverse events ( P>0.05). Conclusion:Addition of three-dimensional radiotherapy for the primary tumors in MPE-NSCLC patients may prolong the OS and yield tolerable adverse events.

Objective:To investigate the primary tumor volume change and timing of radiotherapy for patients with stage Ⅳ non-small cell lung cancer with EGFR mutation during molecular targeted therapy.Methods:Simulated CT scanning measurement and analysis were performed to observe the volume changes of primary tumors before and after treatment with a time interval of 10 days in this prospective study. Positioning and volume measurement were terminated when the volume change was 5% or less between two time points before and after treatment or 90 days after treatment. Primary tumor radiation therapy was then performed, acute radiation-induced injury was recorded, and the implementation and simulation of related parameters of radiotherapy plans were compared.Results:Twenty-nine of 30 cases were included in the analysis (1 case dropped off). After EGFR-TKIs treatment, the volume of all primary tumors was decreased, but the shrinking rate was inconsistent with the speed. Until the last simulated CT scanning, the maximum and minimum shrinking rates were 90% and 28%, respectively. There was no case of termination within 30 days of treatment, and the average tumor volume was significantly decreased within 40 days and the average tumor volume significantly differed every 10 days ( P<0.001). After 40 days, the volume shrinking rate of primary tumors ≤5% gradually appeared, and one patient presented with a volume shrinking rate of >5% on 90 days. During this time, the average volume shrinking rate slowed down and became stable, ranging from 49.15% to 54.77%. Moreover, the average volume continued to gradually shrink after slight increase at 70 days. There was no significant difference in the average volume every 10 days ( P>0.05). After the termination of simulated CT scanning, the dose of primary tumor was (69±7) Gy for patients receiving radiotherapy. Two patients had grade 2 acute radiation-induced pneumonitis and 3 patients had grade 3 acute radiation-induced pneumonitis. In addition, 1 patient had grade 2 radiation-induced esophagitis. According to the technology and dose parameters of radiotherapy plan, simulated radiotherapy plans before and 40 days after EGFR-TKIs treatment were designed. The timing of implementation plan was significantly better than that before EGFR-TKIs treatment (all P<0.05), whereas it was similar to that at 40 days after EGFR-TKI treatment ( P>0.05). Conclusions:The primary tumor shrinking rate is gradually slowed down over time after EGFR-TKIs treatment in patients with stage Ⅳ non-small cell lung cancer. The average tumor volume is significantly decreased within 40 days and then the shrinking rate becomes slow. The tumor shrinking rate of each case is inconsistent. Radiotherapy at 40 days after treatment is probably the optimal timing to obtain high dose and control radiation-induced injury.

Objective To analyze the survival and toxicity after concurrent chemoradiotherapy in patients of different ages with stage Ⅳ non-small cell lung cancer (NSCLC).Methods Clinical data of 282 NSCLC patients in two prospective studies were retrospectively analyzed,who completed the protocol (at least 2 cycles of chemotherapy and thoracic radiation doses of ≥36 Gy).Among them,44 patients were assigned into in the young group (≤ 45 years old),161 patients in the middle-age group (46-64 years old) and 77 patients in the elderly group (≥ 65 years old).The clinical characteristics of patients among different groups were analyzed by x2 test.The overall survival (OS) was calculated by Kaplan-Meier method.Stratified analysis was performed by Log-rank test.Multi-factor prognosis analysis was conducted by Cox's proportional hazards regression model.Results The incidence of NSCLC in the male patients in the elderly group was higher than that in the middle-age and young groups.The 1-,2-,3-and 5-year OS did not significantly differ among different groups (P=0.810).The OS did not significantly differ among patients of the same gender,pathological type,T stage,N stage,metastasis status,same chemotherapy cycle,primary tumor dose and comprehensive treatment and short-term response (all P＞0.05).The incidence of adverse events did not considerably differ among different groups.Multivariate analysis demonstrated that age was not an independent factor for survival (P＞ O.05).Conclusion Patients of different ages with stage Ⅳ NSCLC obtain similar survival benefits and adverse events after concurrent chemoradiotherapy.

Objective To investigate the impact of the changes of posttreatment karnofsky performance status (KPSpost) on the overall survival (OS) for patients with stage Ⅳ non-small cell lung cancer (NSCLC) underwent concurrent chemoradiation.Methods A total of 279 patients (male 198 and female 81) with histological confirmed stage Ⅳ NSCLC were enrolled in this study with a median age of 58 years old (range 22 to 80 years old).There were 166 cases of squamous carcinoma,87 cases of adenocarcinoma,and 22 cases of unclassified carcinoma,respectively.All enrolled patients received more than 2 cycles of chemotherapy and more than 36 Gy of concurrent radiotherapy.Kaplan-Meier method and Log-rank test were applied to evaluate OS.Multivariate analyses were carried out by the Cox proportionalhazard model.Chi-square test and logistic regression analysis were used to explore the related factors of KPSpost.Results There were 198 patients with improved KPSpost and 81 patients with decreased KPSpost,respectively.Univariate and multivariate analyses indicated that the improvement of KPSpost was associated with longer OS.Logistic regression analysis showed that the improvement of KPSpost was positively related with treatment of more than 4-6 cycles chemotherapy concurrent with over 63 Gy radiation to primary tumor.The improvement of KPSpost also correlated positively with disease control rate (DCR),but negatively with PLT toxicity and radiation esophagitis.Conclusions KPSpost was an independent prognostic factor of OS for patients with stage Ⅳ NSCLC underwent concurrent chemoradiation.Chemotherapy of 4-6 cycles and concurrent over 63 Gy radiotherapy dose to primary tumor,as well as DCR were positive factors for KPSpost improvement.However,stage 3-4 PLT toxicities and radiation esophagitis decreased the KPSpost.