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Objective:To explore the influence of body mass index (BMI) changes on the doses to normal tissues and adverse reactions of the lower digestive system and urinary system in the brachytherapy for cervical cancer.Methods:Clinical data of 80 cervical cancer patients who received radical radiotherapy in our hospital from January 2020 to February 2021 were retrospectively analyzed. All patients received external beam radiation ± chemotherapy + brachytherapy. The delineation method of target areas and organs at risk (OAR) was determined based on the recommended scheme of GEC-ESTRO. The target areas included high risk (HR)-CTV and intermediate risk (IR)-CTV, and OAR consisted of rectum, sigmoid colon, bladder, and small intestine. The target area dose was evaluated by D 90% of the HR-CTV. The OAR volume dose was evaluated by using D2cm3. Correlation analysis was used to compare the dosimetric relationship between BMI and D2cm3, D1cm3 and D0.1cm3 in bladder, rectum, colon and small intestine. Logistic regression analysis was adopted to analyze the risk factors of acute and late adverse reactions in the lower gastrointestinal system and urinary system. Whether BMI was a risk factor was validated. Results:BMI was negatively correlated with the D2cm3, D1cm3 and D0.1cm3 of the small intestine ( P=0.034, 0.024, 0.034), and the correlation coefficients were -0.240, -0.255, and -0.241, respectively. Logistic regression analysis showed that BMI was not a risk factor for the occurrence of acute and late adverse reactions in the lower gastrointestinal system and urinary system. For every 1 Gy increase of D2cm3, D1cm3 and D0.1cm3 in the small intestine, the relative risk of acute adverse reactions in the lower gastrointestinal system was increased by 16.6%, 15.1%,and 12.7%, respectively. Conclusions:In brachytherapy for cervical cancer, there is a negative correlation between BMI and D2cm3, D1cm3 and D0.1cm3 of the small intestine. As the BMI of patients declines, the radiation dose to the small intestine shows an increasing trend, which may increase the risk of acute adverse reactions in the lower gastrointestinal system.
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Objective:To discuss the dosimetric contribution of the ovoid in the cervical cancer brachytherapy through the intracavity combined with interstitial(IC/IS)technique.Methods:The data on 20 patients with FIGO(2009)stageⅡ A, Ⅱ B or Ⅲ Bcervical cancer treated with radical radiotherapy in China-Japan Union Hospital of Jilin University during 2015-2017 was collected. External irradiation treatment was 45 Gy/1.8 Gy× 25 fractions. Brachytherapy was MRI-guided IC/IS brachytherapy with a prescription of 28 Gy/7 Gy× 4 fractions. All of 20 patients developed two kinds of plans, the ovoid group and the non-ovoid group. The original MRI-guided brachytherapy treatment plan was set(80 fractions)to the ovoid group. As contrast model that removed the ovoid and consisted of tandem combined with needles set to the non-ovoid group was built, and the same physicist designed the plan to make the dose of D90% for high-risk clinical target volume(HR-CTV)similar to the ovoid group. The dosimetric differences of the D90% and D98% for HR-CTV, D90% and D98% for intermediate-risk clinical target volume(IR-CTV)and D2 cm 3 for the bladder, rectum, sigmoid colon and small intestines between two groups of plans were analyze by paired t-test. Results:Compared with the ovoid group, the non-ovoid group showed no significant difference on HR-CTV D90%( P>0.05), but the HR-CTV D98%(6.99±0.60 vs. 6.78±0.76), IR-CTV D90%(4.71±0.58 vs. 4.26±0.57) and D98%(3.77±0.58 vs. 3.26±0.59) of the non-ovoid group decreased significantly( t=3.906, 9.860, 8.636, P<0.05). The sigmoid colon showed no significant difference( P>0.05), while the bladder (5.29±0.67 vs. 4.92±0.74), rectum (3.72±0.69 vs. 3.35±0.92) and small intestines (3.05±1.37 vs. 2.98±1.34) D2 cm 3of the non-ovoid group decreased significantly( t=8.758, 7.543, 8.059, P<0.05). Conclusions:Ovoid is very important for IC/IS technique in cervical cancer brachytherapy. Reasonable optimization of the dose weight ratio of the ovoid and the needle can bring better clinical benefits.
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In China, COVID-19 epidemic is currently showing a sporadic state, and the task of epidemic prevention is still arduous. Brachytherapy (BT) plays a critical role in the treatment of cancer. For some cancer receiving radiotherapy, use of BT can not be replaced or excessively delayed. Nevertheless, the recommendations or guidelines regarding the application of BT during COVID-19 epidemic have been rarely reported. In this article, a few recommendations on the application of BT during COVID-19 epidemic were retrieved and the work experience of Department of Radiation Oncology, China-Japan Union Hospital of Jilin University in the early epidemic period was summarized, aiming to provide relevant reference for the use of high-dose-rate BT for malignant tumor patients during COVID-19 epidemic.
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The main treatment options for cervical cancer include surgery and/or radiotherapy combined with chemotherapy. Radiotherapy consists of external beam radiotherapy and brachytherapy (BT). BT contains high-dose-rate (HDR-BT) and low-dose-rate brachytherapy (LDR-BT). The prognosis of cervical cancer is relatively good. However, some patients experience substantial treatment failures, such as intra-pelvic and/or extra-pelvic recurrences. Recurrent cervical cancer (RCC) has poor prognosis due to lack of effective and safe approach. In 2002, Professor Wang Junjie introduced CT-guidance into the field of LDR-BT, and fully applied 3D printing technology in BT in 2015, which met the requirement of preoperative LDR-BT planning, and significantly improving the precision, quality and efficiency of BT. In 2018, Professor Wang Junjie proposed the concept of stereotactic ablation brachytherapy (SABT). Chinese experts have attempted to treat RCC with BT for nearly two decades and accumulated certain clinical experience. Based on the 3D-printing template (3D-PT) assisted CT-guidance, the standard and consensus of BT for RCC were established, including the indications, dosimetric requirements, technological procedures and radiation protection, etc. At present, there is still a lack of phage Ⅲ clinical and evidence-based medicine for the treatment of RCC with 3D-PT guidance, which requires prospective multi-center, randomized studies to improve the evidence-based level of BT.
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Objective:To explore the application of 3D printing technology-assisted standardized applicator in the image-guided adaptive brachytherapy (IGABT) for cervical cancer.Methods:Twenty-three patients with stage Ⅲ B cervical cancer with extensive paracervical invasion after external irradiation (45 Gy/25f) were treated with IGABT, and the prescription dose was 7 Gy/f×4f. According to the regression of tumor on MRI before and after external irradiation, the range of brachytherapy was determined, and the under dose area of standard intracavitary/interstitial applicator (IC+ IS) was estimated. The virtual transperineal needle channel was inserted in the under dose area, the angle, spacing and depth of implantation were optimized. The auxiliary templates were designed with graphic design software, and 3D printing technology was utilized to print the auxiliary templates. The auxiliary templates were closely combined with the standardized applicator. Under the anesthesia condition, ultrasound-guided applicator was completed, and patients were scanned with MRI image after operation. The MRI images were introduced into treatment planning system (TPS) to delineate the target area and organs at risk, and the treatment plans were optimized to complete the plan evaluation and treatment. Results:The average printing time of templates was (3.5±1.0) h, 382 implant needles were inserted guided by auxiliary templates, (4.2±1.5) template-guided implant needles were used in each fraction and the weight ratio was (16.49±9.50)%. The total dose of HR-CTV D 90% EQD 2Gy, α/ β=10 was (90.45±3.03) Gy, and IR-CTV D 90% EQD 2Gy, α/ β=10 was (66.46±3.68) Gy. The D 2cm 3 EQD 2Gy, α/ β=3 of the bladder, rectum, small intestine and sigmoid colon were (82.69±2.60) Gy, (73.20±2.52) Gy, (69.35±3.32) Gy and (69.39±3.27) Gy, respectively, all of which met the clinical dose requirements. The 1-and 2-year local control rates were 96% and 87%, 87% and 70% for the distant metastasis-free survival rates, and 96% and 78% for thea overall survival rates, respectively. Conclusion:The auxiliary applicators made by 3D printing technology can effectively compensate for the dose insufficiency of the standard applicator in the paracervical and other areas during the clinical brachytherapy in patients with stage Ⅲ B cervical cancer, providing an effective method for the brachytherapy of advanced cervical cancer.
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Stereotactic body radiotherapy (SBRT) has become an important radiotherapy technology. In recent years, with the continuous improvement of the mechanical properties of the linear accelerator (LINAC), LINAC-based SBRT is gradually emerging. In this article, the history, technological progress, radiation physics, clinical application of LINAC-based SBRT were elaborated, aiming to promote the development of LINAC-based SBRT.
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Objective:To explore the clinical efficacy and adverse reactions of the combination of external beam radiotherapy followed by three-dimensional intracavitary brachytherapy in patients with inoperable locally advanced rectal cancer.Methods:Clinical data of 11 patients with inoperable locally advanced rectal cancer, 7 male and 4 female, admitted to China-Japan Union Hospital of Jilin University from 2013 to 2015 were retrospectively analyzed. All patients received pelvic external irradiation (50 Gy in 25 fractions), followed by a three-dimensional intracavitary brachytherapy boost (15-20 Gy in 3-4 fractions, 1 fraction/week). External beam radiotherapy was used to boost the dose to the perirectal lymph nodes (60-66 Gy in 30-33 fractions). All patients received concurrent chemotherapy with Capecitabine during external beam radiotherapy. Efficacy evaluation was performed using the RECIST standard. Survival and local control rates were calculated using the Kaplan- Meier method. Early and late radiotherapy responses were assessed using the RTOG lesion grading criteria. Results:The CTV D 90% EQD 2 Gy of HDR 3D-ICBT among 11 patients was (21.3±1.60) Gy. The complete response (CR) and partial response (PR) rates were 64% and 27%, respectively, yielding an objective response rate (CR+PR) of 91%. With a median follow-up time of 36 months, the 1-, 2-, and 3-year overall survival rates were 82%, 64% and 46%, respectively. The 1-, 2-, 3-year disease-free survival rates were 64%, 45% and 27%, respectively. The 3-year local control rate was 46%. One patient presented with lung metastases after 8 months, 7 patients experienced grade 1-2 acute intestinal reactions and 5 patients developed grade 1-2 acute bladder reactions, only one patient had grade 2 myelosuppression; long-term grade 1-2 intestinal reactions occurred in 5 patients, and 1 patient had long-term grade 1-2 bladder reaction. All the radiation-induced toxicities were alleviated by medication administration. Conclusions:External beam radiotherapy followed by three-dimensional intracavitary brachytherapy can be a safe and effective surrogate in patients with inoperable locally advanced rectal cancer, which yields reliable clinical efficacy and tolerable adverse reactions.
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Objective:To measure the effect of applicator materials on absorbed dose in water from HDR afterloading 192Ir source by using three-dimensional printed holder (3DPH) and synthetic single-crystal diamond detector (SSCDD). Methods:SSCDD and plastic implants were fixed on the 3DPH in turn. The central axis of SSCDD was perpendicular to that of plastic implant needle on the same plane. The actual residence dwell position measured using source position simulator was 248 mm, which was consistent with the maximum response dwell position measured in a point by point way. The materials for measurement included 304 stainless steel, polyphenylene sulfone resins (PPSU), polymethyl methacrylate (PMMA) and 3-D printed polylactic acid (PLA), respectively. The attenuation of absorbed dose in water with different thickness or filling ratio was measured.Results:The linear fitting formula of relative dose varying with thickness (mm) for 304 stainless steel and PPSU materials were y=-0.029 7 x+ 1.000 3 and y=-0.002 3 x + 1.010 2, respectively. And the goodness-of-fits were 0.925 3 and 0.722 2, respectively. The effect on dose of PMMA materials within 10 mm was less than 1%. The linear fitting formula of relative dose varying with filling ratio (%) for PLA materials with 10 mm thickness was y=-0.000 4 x+ 1.024 6, with a goodness-of-fit of 0.854 5. Conclusions:The effect of applicator materials on the absorbed dose arising from afterloading 192Ir source should attract enough attention of both developers and clinical users, especially with regard to high-density materials like 304 stainless steel and new technology materials such as 3D printed polylactic acid.
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Brachytherapy plays a key role in the radical radiotherapy of cervical cancer.The time concept was introduced in the 3D brachytherapy according to ICRU report No.89 for cervical cancer treatment.4D brachtherapy,as an adaptive brachytherapy,was formally proposed in this report.In this article,relevant data were searched based on ICRU report No.89 combined with the experience in our center to analyze,summarize and conclude the chapters related to target contouring,aiming to provide evidence for the colleagues who perform the brachytherapy in patients with cervical cancer.
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Radiotherapy is an important part of the postoperative adjuvant therapy of cervical cancer. Along with the persistent development of radiotherapy techniques, the application of brachytherapy has been more and more used as a boost to external beam radiotherapy. In this artical, the indications of postoperative radiotherapy and the application of brachytherapy were reviewed.
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Radiotherapy is an important part of the postoperative adjuvant therapy of cervical cancer.Along with the persistent development of radiotherapy techniques,the application of brachytherapy has been more and more used as a boost to external beam radiotherapy.In this artical,the indications of postoperative radiotherapy and the application of brachytherapy were reviewed.
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Objective To observe the effect of hypoxia on the expression of epithelial growth factor receptor (EGFR) and cell apoptosis of breast and cervical cancer xenografts in nude mouse models.Methods The nude mouse models with MCF-7 and HeLa xenografts were established.The degree of hypoxia and EGFR expression were observed by confocal microscopy.The influence of EGFR expression on cell apoptosis under hypoxia was observed by TUNEL assay.Results EGFR expression was either up-regulated or down-regulated in the MCF-7 and HeLa cells with high degree of hypoxia.Furthermore,the degree of apoptosis was reduced in tumor tissues with high EGFR expression compared with that in those with low expression of EGFR.Conclusion The hypoxia in MCF-7 and HeLa cells exerts heterogeneous effect on EGFR expression.Under hypoxic conditions,EGFR exoression is negatively correlated with cell apoptosis.
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This paper made a detailed interpretation about the radiobiology-related contents in the ICRU report No.89,aiming to provide reference to resolve the problems related to radiobiology for the colleagues occupied in the brachytherapy for cervical cancer.
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In this article,the content of radiation physics in the ICRU report No.89 were interpreted in details,aiming to provide reference in the radiation physics for radiologists performing brachytherapy for cervical cancer patients.
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The role of three-dimensional brachytherapy (3D-BT) in the radical treatment of cervical cancer has been widely recognized. Obtaining the image information through simulated positioning is a key step of 3D-BT.Currently, MRI/CT positioning has been commonly applied in clinical practice, which has respective limitations when applied in radiosurgery. Consequently, it is of necessity to explore an accurate, highly efficient and convenient positioning approach. Besides MRI and CT, ultrasound is a novel positioning method in clinical settings. Through literature review, the application of ultrasound in 3D-BT was summarized, aiming to provide reliable reference for clinicians.
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Precise implantation of applicator is the key step of brachytherapy in cervical cancer patients. The imaging guidance can guarantee the accuracy of applicator placement. At present, the imaging approaches used to guide the applicator placement mainly include ultrasound, CT and X-ray, and MRI and laparoscopy have been applied in certain institutions. There has been no consensus on the standard imaging technique. In this paper, nearly 50 articles and surveys were reviewed to demonstrate that ultrasound-guided placement is of clinical value and guiding significance. Therefore, the application of ultrasound-guided applicator placement in the brachytherapy for cervical cancer was summarized and reviewed.
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The development of a treatment plan is one of the critical steps in the three-dimensional (3D) brachytherapy for cervical cancer.This article reviews more than 40 papers on the treatment plan design of high-dose-rate brachytherapy for cervical cancer and summarizes the principles and methods for developing a treatment plan of 3D brachytherapy.There are many difficult points in 3D brachytherapy.The doses delivered to tumor and normal tissues need to be balanced by considering many different factors under different conditions.In addition,there are still some uncertain factors for developing the treatment plan of 3D brachytherapy,which needs further exploration and research in the future.It can provide some references for colleagues in 3D brachytherapy for cervical cancer.
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Objective To report a simple method for determination of dwell position offset of ring applicator using GafchromicTM EBT3 film and ImageJ software. Methods In the dummy plan, this study reconstructed the ring applicator point by point manually according to the MR line marker, the most distal reconstruction point was at the end of marker, set the offset to zero. The first, eleventh, and twenty-third dwell positions were activated with the step length of 2. 5 mm. A setup image was designed to immobilize the ring applicator. The setup image was composed of two perpendicular thin lines and a circular with a diameter of 16 mm. GafchromicTM EBT3 film was fixed behind the setup image by plastic tapes. After irradiation, a ruler was put on the bottom of the irradiated film as a plotting scale. Photos were taken with the help of a vertical camera using a tripod. The file was imported into ImageJ software and the coordinate values were obtained by semi-automatic recognition of the center of exposure area. The test was repeated five times at one week interval to evaluate the uncertainty. For every time, each dwell position was measured five times. Results The angle between the radius of the first dwell position and the x-axis was 43° in the dummy plan, and (46. 8 ± 0. 9)° for actual measurement. The offset was 0. 9 mm for the ring applicator combined with the MR according to calculation. The distances between the first,the eleventh and the twenty-third dwell positions and the center of the ring were ( 12. 9 ± 0. 1 ) mm, ( 12. 5 ± 0. 1 ) mm, (12. 4 ± 0. 1) mm, respectively. Conclusions Using GafchromicTM EBT3 film and the ImageJ software is a simplified method to validate the dwell position offset of the ring applicator.
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Radiation oncology is a multidisciplinary clinical subject.It is necessary to focus on cultivating practical talents in the development of radiation oncology disciplines.The traditional teacheroriented teaching methods ignore the students' overall learning status and the ability of innovation and thinking.This paper explores improvement measures of training talents from multiple perspectives through an integrative system,which includes interdisciplinary collaborative teaching methods that are supplemented by group discussions,and an open examination way centering on the medical record.Meanwhile,its practical application has also been explored.
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Nuclear epithelial growth factor receptor (EGFR) plays an important role in the development, metastasis, treatment, and prognosis of cancer. Radiotherapy, one of the main therapies for malignant tumor, causes EGFR transfer into the nucleus along with tumor therapy, thereby reducing radiosensitivity. Insight into the biological characteristics and functions of nuclear EGFR has an important reference value for improving radiosensitivity. Therefore, this article elaborates on EGFR transport into the nucleus,the features of nuclear EGFR,and its relationship with radiosensitivity and clinical targeted therapy.