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 investigate the clinical efficacy and safety of anlotinib combined with radiotherapy as a third-line treatment regimen for extensive stage small-cell lung cancer (ES-SCLC) in a real-world background.Methods:Forty ES-SCLC patients enrolled in a single center of Affiliated Cancer Hospital of Xinjiang Medical University in China between November 2018 and July 2021 were treated with radiotherapy added on anlotinib as a third-line treatment regimen. Overall survival (OS), progression-free survival (PFS), safety, and quality of life were analyzed, and the survival status was statistically analyzed using Kaplan-Meier method.Results:Among the 40 patients, partial remission, stable disease, and progressive disease was confirmed in 7, 24 and 9 patients, respectively. The obtained objective remission rate (ORR) was 18%, the disease control rate (DCR) was 78%, and median PFS and median OS were 4.5 months and 9 months, respectively. The most common adverse reactions included fatigue (28%), bleeding (20%), anorexia (13%), and hand-foot syndrome (8%). Most of them were grade 1-2 in severity, 4 cases were documented as ≥grade 3, and no grade 5 toxicity was recorded.Conclusions:In the real world, radiotherapy added on anlotinib as a third-line regimen can prolong PFS and OS of the ES-SCLC patients, and the adverse reactions are generally tolerated. This combination treatment regimen is worthy of further investigation.

Objective:To investigate the overall recurrence rate and the pattern of treatment failure in thoracic esophageal cancer (TEC) patients after minimally invasive esophagectomy (MIE), and to evaluate the significance of adjuvant therapy after MIE.Methods:Clinical data of TEC patients who underwent MIE with or without neoadjuvant chemotherapy in the Fourth Hospital of Hebei Medical University between 2016 and 2018 were retrospectively analyzed. The pathology-based lymph node metastasis (LNM) rate, overall recurrence rate, and pattern of treatment failure following MIE were analyzed by SPSS 26.0 statistical software. Cox regression model was used to identify the high-risk factors for recurrent disease. Propensity score matching was performed to compare the survival of patients between the postoperative radiotherapy group and non-radiotherapy group.Results:A total of 443 eligible patients were enrolled in this study, and the pathology-based LNM rate in all groups was 42.0%. The overall recurrence rate was 34.8%. Regional lymphatic metastasis was the most frequent pattern of recurrence (24.2%), followed by distant metastasis (19.4%). Multivariate Cox regression analysis identified pT 3-4 stage and pN + stage as the independent risk factors for recurrence. At the same time, the total number of lymph nodes dissected ≥12 and the number of lymph nodes dissected ≥7 in the neck clavicle and upper mediastinum could reduce the risk of tumor recurrence. The 1-, 3-, and 5-year disease-free survival (DFS) rates in the postoperative radiotherapy group and non-radiotherapy group were 83.5%, 66.8%, 60.7%, and 79.2%, 61.6%, 57.2%, respectively ( χ2=0.13, P=0.715). The 1-, 3-, and 5-year overall survival (OS) rates in two groups were 92.0%, 72.0%, 67.5% and 84.0%, 68.0%, 55.4% , respectively ( χ2=0.43, P=0.513). Conclusions:Regional lymphatic and distant metastases are the main patterns of recurrence for TEC patients after MIE with or without neoadjuvant chemotherapy. pT 3-4 stage, pN + stage, insufficient total number of lymph node dissection and insufficient number of lymph nodes in neck supraclavicular and upper mediastinal dissection are high-risk factors for postoperative recurrence. The survival rate in the postoperative radiotherapy group tends to be higher than that in the non-radiotherapy group. Adjuvant therapy, including postoperative radiotherapy, may remain necessary.

Objective:To investigate the relationship between serum miR-501 and miR-195 levels and sensitivity to concurrent chemoradiotherapy in patients with locally advanced cervical cancer (LACC).Methods:Clinical data of 96 patients with LACC admitted to Nanyang Central Hospital from January 2020 to June 2022 were retrospectively analyzed and compared with those of 96 healthy subjects during physical examination in our hospital during the same period to compare the differences of serum miR-501 and miR-195 levels. Tumor status was reviewed at 6 months after concurrent chemoradiotherapy. Patients were divided into the sensitive and resistant groups according to the evaluation criteria of solid tumor efficacy. The relationship between serum miR-501 and miR-195 levels and the sensitivity to concurrent chemoradiotherapy in LACC patients was analyzed by univariate and multivariate analyses. The receiver operating characteristic (ROC) curve was also drawn to predict differential efficacy of concurrent chemoradiotherapy sensitivity in LACC patients. Multivariate analysis was conducted by binary logistic regression analysis. P<0.05 indicated statistically significant differences. Results:In LACC patients, serum miR-501 level was significantly higher, whereas serum miR-195 level was significantly lower than those in physical examination subjects (both P<0.05). Univariate analysis showed that serum miR-501 level at admission in the resistant group was significantly higher, whereas serum miR-195 level was significantly lower than those in the sensitive group (both P<0.05). Multivariate analysis showed that serum miR-501 and miR-195 levels were significantly correlated with the sensitivity to concurrent chemoradiotherapy in LACC patients. The area under the ROC curve (AUC) was 0.736 and 0.913, respectively. Conclusions:The higher the serum miR-501 level and the lower the serum miR-195 level before treatment, the higher the probability of resistance to concurrent chemoradiotherapy in LACC patients. Serum miR-501 and miR-195 levels of LACC patients before treatment have certain predictive value for the sensitivity to concurrent chemoradiotherapy.

Objective:To analyze the robustness of the dose of clinical target volume (CTV) and tolerance dose of normal tissues after applying in-room CT before carbon ion radiotherapy for prostate cancer.Methods:Thirty prostate cancer patients treated with carbon ion in Shanghai Proton and Heavy Ion Center from January 2020 to June 2021 were enrolled in this study. Five in-room CT images of each patient were selected randomly before treatment. Dose distributions were recalculated using the original plan on in-room CT images and dose volume histogram (DVH) parameters were obtained, including V 95% and V 90% of CTV and V 80% of rectum. The values were compared with the dosimetric parameters of the original plan. Statistical analysis was performed by paired or two independent samples t-tests. Results:The dose distribution was recalculated by applying in-room CT. The mean values of V 95% and V 90% of CTV and V 80% of rectum were 98.1%±1.2% ( P<0.001), 99.9%±0.2% ( P=0.001) and (5.8±1.6) ml ( P<0.001), respectively. The differences were statistically significant compared with those of the original plan. The frequency of V 95%≥95%, V 90%≥98% of CTV, and V 80%<10 ml of rectum was 148 (98.7%), 150 (100.0%) and 147 (98.0%), respectively. Conclusion:Based on in-room CT analysis and the patient management and positioning methods of our research center, the uncertainty of target dose and normal tissue dose in the entire process of prostate cancer carbon ion therapy is small, and the robustness is good.

Objective:To evaluate the accuracy of the optical surface imaging system (OSI) using stereotactic radiosurgery (SRS) algorithm in single-center non-coplanar treatment of multiple brain metastases.Methods:Data of phantom and 15 patients with multiple brain metastases who underwent single-center non-coplanar radiotherapy in West China Hospital of Sichuan University from February to April 2022 were retrospectively analyzed. kV/MV and OSI imaging were used for imaging of the patients and phantoms under the same non-coplanar couch angle, respectively. The accuracy of OSI imaging of the phantoms and patients was evaluated using kV/MV imaging as reference image. The difference between the OSI and kV/MV systems is defined as accuracy, and the percentage of the absolute difference ≤1.00 mm in the translational direction or ≤0.50° in the rotational direction is defined as the threshold pass rate. Origin software was used to draw radar maps and Bland-Altman plots for statistical analysis.Results:When OSI images were used for the phantom imaging, the average differences in six-dimensional directions of lateral, long, vertical, rotational, roll and pitch were 0.03 mm, -0.09 mm, -0.27 mm, 0.04°, 0.17° and -0.19°, respectively. The maximum values were -2.20 mm, -2.30 mm, -1.20 mm, 0.60°, -1.00°, and -1.00°, respectively. When OSI system was utilized for the imaging of 15 patients, the average differences in six-dimensional directions were 0.44 mm, 0.16 mm, -0.20 mm, -0.11°, 0.10°, and -0.12°, respectively. The maximum values were -1.80 mm, 2.00 mm, 0.90 mm, -0.90°, -0.70°, and 0.80°, respectively. The translational errors mainly occurred in the lateral and long directions. The qualified rates of the threshold values of the phantoms and patients were 77% and 75% in the lateral direction, 82% and 89% in the long direction, respectively. In addition, 57% and 56% of patients met the threshold conditions of ±1.00 mm and ±0.50° in the six-dimensional directions, respectively.Conclusions:The OSI system using new SRS algorithm cannot meet the high accuracy requirements of single-center non-coplanar radiotherapy for multiple brain metastasis, especially in the lateral and long directions. It is not recommended for non-coplanar image guidance.

Objective:To evaluate the feasibility of 3D reconstruction techniques based on multi-depth cameras for daily patient positioning in radiotherapy.Methods:Through region of interest (ROI) extraction, filtering, registration, splicing and other processes, multi-depth cameras (Intel RealSense D435i) were used to fuse point clouds in real-time manner to obtain the real optical 3D surface of patients. The reconstructed surface was matched with the external contour of the localization CT to complete the positioning. In this article, the feasibility of the system was validated by using multiple models. Clinical feasibility of 5 patients with head and neck radiotherapy, 10 cases of chest radiotherapy and 5 cases of pelvic radiotherapy was also validated. The data of each group were analyzed by paired t-test. Results:The system running time was 0.475 s, which met the requirement of real-time monitoring. The six-dimensional registration errors in the model experiment were (1.00±0.74) mm, (1.69±0.69) mm, (1.36±0.87) mm, 0.15°±0.14°, 0.25°±0.20°, 0.13°±0.13° in the x, y, z, rotational, pitch and roll directions, respectively. In the actual patient positioning, the mean positioning errors were (0.77±0.51) mm, (1.24±0.67) mm, (0.94±0.76) mm, 0.61°±0.41°, 0.69°±0.55°, and 0.52°±0.35° in the x, y, z, rotational, pitch and roll directions, respectively. The translational error was less than 2.8 mm, and the positioning error was the largest in the pelvic region. Conclusions:Real-time 3D reconstruction techniques based on multi-depth cameras is applicable for patient positioning during radiotherapy. The method is accurate in positioning and can detect the small movement of the patient's position, which meets the requirements of radiotherapy.

Objective:To evaluate the effect of miR-216a-5p on the radiosensitivity of liver cancer cells via targeting Krüppel-like transcription factors 12 (KLF12).Methods:Real-time reverse transcription PCR (RT-qPCR) was used to detect miR-216a-5p, KLF12 mRNA levels in normal human liver cells L-02 cells, and human hepatoma cells Huh7, HepG2, Hep3B and MHCC-97H cell lines. HepG2 cells were divided into 0, 2, 4, 6 and 8 Gy irradiation groups, and miR-216a-5p, KLF12 mRNA levels were compared among different groups. HepG2 cells overexpressing miR-216a-5p and / or KLF12 were constructed by plasmid transfection and divided into the miR-NC group (control group), miR-216a-5p group, miR-216a-5p+NC group, miR-216a-5p+KLF12 group, IR+miR-NC group, IR+miR-216a-5p group, IR+miR-216a-5p+NC group, IR+miR-216a-5p+KLF12 group, respectively. miR-216a-5p, KLF12 mRNA levels were compared among different groups. Clone formation assay was used to detect cell radiosensitivity. CCK-8 assay was employed to detect cell proliferation ability. Flow cytometry was adopted to detect cell apoptosis. Single factor ANOVA was used for inter group comparisons. LSD- t test was used for pairwise comparison. Results:Compared with L-02 cells, KLF12 mRNA levels were up-regulated, whereas miR-216a-5p levels were down-regulated in liver cancer cell lines (all P<0.05). Compared with 0 Gy group, KLF12 mRNA levels were down-regulated, whereas miR-216a-5p levels were up-regulated in 2, 4, 6, and 8 Gy groups (all P<0.05). Overexpression of miR-216a-5p or radiation therapy alone could enhance cell radiosensitivity and apoptosis levels, and reduce cell proliferation ability (all P<0.05). Simultaneous radiation treatment with overexpression of miR-216a-5p exerted more significant effects on cells (all P<0.05). Overexpression of KLF12 could partially reverse the aforementioned effects of overexpression of miR-216a-5p ( P<0.05). Conclusion:MiR-216a-5p reduces cell proliferation ability, enhances cell radiosensitivity and apoptosis via regulating KLF12.

Boron neutron capture therapy is a method based on 10B (n,α) 7Li reaction to achieve malignancy treatment. Upon entry into the human body, the 10B compound carrier can selectively enriched in tumor cells and reacts with external irradiation neutrons. Because 7Li (4 μm) and α particles (7 μm) will be deposited in a cell magnitude (10 μm), the purpose of directional local killing of tumor cells and causing less harm to normal tissue can be achieved successfully. So far, boron neutron capture therapy has been clinically studied in a variety of malignant diseases, including glioblastoma multiforme, meningeoma, head and neck cancer, lung cancer, etc. In this article, the clinical research progress of boron neutron capture treatment in head and neck carcinomas was mainly introduced.

Colorectal cancer is a common clinical malignant tumor. As the main therapeutic method of colorectal cancer, radiotherapy has a good inhibitory effect on tumor progression. In recent years, because of its good physical and biological advantages, carbon ion has shown better clinical efficacy than traditional radiotherapy in the treatment of local recurrence or distant metastasis of colorectal cancer. In this article, basic and clinical studies related to the efficacy of carbon ion therapy for the recurrence of colorectal cancer in recent years were reviewed, aiming to provide theoretical basis for preventing and reducing adverse reactions after radiotherapy and prolonging the survival of colorectal cancer patients.