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Objective:To investigate the application of artificial intelligence based on the neural network radiation field in repair of soft tissue defects at lower limbs.Methods:A retrospective analysis was performed of the 23 patients who had been admitted to Department of Orthopedic Surgery, Renmin Hospital of Wuhan University from June 2020 to May 2022 for soft tissue defects at lower limbs. There were 14 males and 9 females, aged (38.6±6.7) years. Causes for soft tissue defects: traffic injury in 9 cases, benign or malignant primary soft tissue tumor in 6 cases, mechanical injury in 4 cases, crush injury in 2 cases, and chronic ulcer in 2 cases. Defect locations: the thigh in 3 cases, the lower leg in 7 cases, and the ankle and distal foot in 13 cases. The areas of soft tissue defect ranged from 6.0 cm×3.8 cm to 14.7 cm×12.8 cm. The defects were repaired and reconstructed by transplantation of an anterolateral femoral free flap in 7 cases and a pedicled flap in 16 cases with the assistance of artificial intelligence based on the neural network radiation field, a cutting-edge artificial intelligence algorithm that can quickly construct and process three-dimensional model images through volume rendering under the radiation field. The flap survival rate, aesthetic satisfaction before and after treatment, time for skin flap harvesting and transplantation, functional recovery of lower limbs and incidence of complications were recorded.Results:All the 23 patients were followed up for 32(28, 36) weeks. All the flaps were harvested smoothly and survived. The time for flap harvesting and transplantation was 65.8(50.0, 76.0) min. The aesthetic satisfaction scored (2.3±0.7) points before treatment and (8.4±1.6) points 4 weeks after treatment, showing a statistically significant difference ( P<0.05). The skin flaps healed well with no complications such as hematoma or infection in all but one patient who suffered from superficial necrosis at the distal skin flap due to venous crisis but healed with a scar. On average, the functional recovery of lower limbs scored 23.7(22.0, 25.0) points at 12 weeks after operation according to the Enneking evaluation system, and the functional recovery of lower limbs was 79% (23.7/30.0). Conclusion:Application of artificial intelligence based on the neural network radiation field can achieve ideal results in repair of soft tissue defects at lower limbs, due to its advantages of rapid and accurate surgical procedures, limited damage to the donor site, and a short learning curve.
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Objective:To test the relative response of a detector matrix used for measuring of the dose distribution in radiotherapy in order to ensure the accuracy and reliability of dose distribution measurement result.Methods:The two adjacent detectors can be irradiated at the same radiation dose by translating the detector matrix. The relative response of each detector to the reference detector can be obtained by combining the recursive algorithm. At the same time, the measurement data at different test steps are corrected to the reference step by setting the reference step, which correct the influence on the relative response result caused by the variation of the radiation condition and the detector response.Results:Based on the actual test of a 32 × 32 detector matrix, the relative response of each detector of the detected detector matrix to the reference detector varied from 0.896 to 1.077, with the expanded uncertainty of the relative response result being 0.8% ( k=2). Conclusions:On the premise of no known distribution of a radiation field, the relative response relationship of each detector of a detector matrix can be obtained by this method accurately and expediently, which provides a basic method for the performance evaluation of the detector matrix. The same idea can also be used to determine the relative response relationship of other detector matrices for different measurement purposes.
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Objective:To evaluate the radiation dose to the injured persons in a radiological accident, provide the guidance on the diagnosis and treatment of radiation injury, and provide the basis for determination of the level of radiological accident.Method:Firstly, the air-absorbed dose rates at 206 locations surrounding a X-ray device were measured by using LiF (Mg, Cu, P) thermoluminescence detectors and self-made radiation field measuring frames. Secondly, the spatial distribution of radiation level was obtained by fitting the inverse square law between absorbed dose rate and distance, which is used as the basis of dose estimation. Finally, based on the actual working conditions of injured operators, a parameter calculation method was proposed for estimating hand skin absorbed dose.Results:The air-absorbed dose rate surrounding X-ray beam outlet was higher than 1.0 mGy/h. The maximum air-absorbed dose rate value in the space of within 200 cm outside X-ray beam outlet was 262 μGy/h and the minimum value was 2.1 μGy/h, 2 orders of magnitude higher than environmental background level. During normal operation, the total absorbed doses to the hand skin of two injured female operators were 36.9 and 16.9 Gy, respectively. During extreme operation, the hand skin-received total absorbed doses to the two operators were 85.2 and 38.9 Gy, respectively. Under the occupational health standard GBZ 106-2020, the two persons had acute radiation skin injury of grade Ⅲ or Ⅳ on their hands.Conclusions:The results of hand skin exposure doses provide effective support for diagnosis and treatment of radiation injuries and for the determination of radiological accident level. The method used in radiation field reconstruction and dose estimation mentioned in this study can provide reference for the treatment in the similar radiological accident.
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Objective To explore the absorbed dose to the common tissues of subjects in four clinical CT scanning modes and the spatial distribution of the radiation field in chest scanning, in order to provide a basis for the radiation protection of subjects and the space in the machine room. Methods A thermoluminescence detector (TLD) was used to measure the absorbed doses to the eye lens, thyroid gland, gonad, chest and abdominal skins of the anthropomorphic phantom in four CT scanning modes. The TLD was used to monitor the air kerma at different positions from the CT diagnostic table during chest spiral scanning. Results The absorbed doses to the eye lens, thyroid gland, gonad, chest and abdominal skins of the anthropomorphic phantom in four CT scanning modes were 0.040-64.818 mGy, 0.154-10.155 mGy, 0.028-0.154 mGy, 0.443-17.141 mGy, and 0.093-14.346 mGy, respectively. The maximum air kerma value of the space radiation field during chest scanning was 0.049 mGy, and the farther the distance from the CT tube, the smaller the value. Conclusion The absorbed doses to the common tissues of subjects examined by the four CT scanning modes generally do not exceed the threshold doses. The dose received by the companion of the subject during a single chest CT scan was small. In order to minimize radiation hazards, shielding measures can be taken in CT scanning to reduce the absorbed doses to the tissues of the subject, and the companion of the subject should appropriately increase the distance from the tube and the diagnostic table.
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Introduction: Computerized Treatment planning system (TPS) is an integral part of radiation treatment procedure. The main part of treatment planning system is a calculation algorithm incorporated in the Treatment Planning System. Various algorithms used in the TPS have capabilities and limitation on specific situations. Objective: The objective of the work is to analyse the depth dose distribution generated by different dose calculation algorithms used in TPS in regions of low and high dose gradient. Materials and Methods: Four different dose calculation algorithms used for treatment planning such as Modified Clarkson, Sector integration, Fast Fourier Transform, Convolution- Superposition algorithm were used to generate the percentage depth dose distribution in a water phantom up to 25 cm depth. The values are compared with experimental results using Radiation Field Analyser. The PDD values also generated at build up region and the values were compared with experimental results using a Parallel plate ionization chamber. Results: The results show that the dose calculated by different algorithms shows difference at build up region and at larger depths.
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Objective: To carry out comparative study on energy respond characteristics of 4 kinds of medical diagnostic X-ray dosimeters that included general new imported equipment and domestic equipment.Methods: In the standard radiation field of secondary standard dosimetry laboratory(SSDL)of IAEA,substitution method was adopted to complete contrast measurement of 10 kinds of X-ray diagnosis radiations which voltage were 60-150 kV,tube current were 10 mA and 2.5 mmAl was used as filterable addition.Results: The results of energy respond performances of domestic RD-98 diagnosis dosimeter and imported dosimeter indicated that all of these responses of different energy to dose were within ±5％when X-ray range was 6-150 kV.Conclusion: The energy response characteristics of 4 kinds of new diagnosis X-ray dosimeter were better,and the response of different energy to dose conforms to the requirement of IEC in diagnosis dosimeters of semiconductor detector and air ionization chamber.
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Objective:To discuss the influence factor of induced radioactivity radiation field of high-energy medical linear accelerator and its safeguard measures.Methods: The simulation test was applied to research the radiation level of the induced radioactivity for high-energy medical linear accelerator; and to research the influences of different factors, such as radiation dose, range of exposure and site of exposure and so on, on the changes of radiation field.Results: The research showed that the high-energy X-ray radiation field strength would increase with the increasing of radiation dose, while reduce with the increasing of radiation time; and the obviously reductive trend appeared after radiated 5minutes. Meanwhile, radiation intensity would reduce with the increasing of irradiated area, but the reductive trend was not totally proportional in accordance with the increasing of irradiated area. Additionally, the head part of linear accelerator could produce the most intensity of radiation field on exposure site, and the farther away the head part of linear accelerator, the intensity the lower; and the reductive trend would increase when the distance exceeded 150cm.Conclusion: The induced radioactive radiation field intensity of high-energy medical linear accelerator has some characteristics of change. The effective safeguard measures were to reduce the work time in equipment room, reduce the adjustment time of patient position and choose reasonable exposure site and dose, and all of these measures can reduce the radiation injury.
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Objective To establish the standard X/γ radiation fields with respect to the wrist dosimeter calibration curve as required by the international electrotechnial commission (IEC) technical specifications and the relevant national standard.Methods Air-kerma rate was determined in the X-ray beams,137Cs and 60Co radiation fields by a standard dosimeter.The wrist thermduminescent dosimetry (TLD) dosimeter was calibrated with personal dose equivalent values Hp (0.07) on the organization for standardization(ISO) wrist-phantom based on the radiation fields.Results The standard X/γ radiation field for the wrist dosimeter irradiation was established.Conclusions Established X/γ standard radiation field can be used for suc h technical services as wrist dosimeter calibration curve and energy response characteristics experiment.
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Objective To develop the method for testing the consistency of irradiation field produced by the active spot scanning proton and heavy ion accelerator.Methods Calibration of the EBT3 films were carried out with the calibrated ion beam to establish the dose calibration curve.According to the different proton and carbon ion energies (proton:94.29,150.68,212.62 McV;carbon ion:175.99,283.43,412.54 MeV/u),EBT3 films were located in the solid water phantoms in each therapy room,respectively.Finally,the irradiated EBT3 films were scanned and the radiation field size's deviation and flatness were analyzed.Results In different conditions,radiation field size's deviations were all less than 2 mm and the flatness parameters were all controlled below the 5％.Conclusions EBT3 films can be used to test the active spot scanning proton and heavy ion accelerator's radiation field uniformity.
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Objective To study the radiation dose distribution in the X-ray room,and provide the strategy of radiation protection for the medical staff and the patient’s nursing who had to enter the room while the X-ray was exposing.Methods The thermolumi-nescent dosemeters(TLDs)was placed around the center of the X-ray tube with the same level of the bed.Then,exposure parame-ters,including the X-ray tube voltage value and the field of view,were changed for different groups while exposing.All of the TLDs were taken back to the lab for analysis.Results The differences between the two groups which had the same distance in different di-rections were statistically significant (P <0.01).With the same radiographic condition and direction,the radiation dose on the site of 10 cm from X-ray tube center was the maximum,while the site of 120 cm was the minimum.With the same radiographic condition and distance,the radiation dose on the anode side of the X-ray tube in the room was relative lower,while the site behind the X-ray tube was relative higher.With the same voltage value,distance and direction,the same sites that had the smaller FOV(34 cm×34 cm) received lower radiation dose than those with larger FOV(52.6 cm× 52.6 cm).Meanwhile,the sites with the voltage of 70 kV re-ceived the lower radiation dose than that with the voltage value of 120 kV.Conclusion In the X-ray room,the medical staff and the patient’s nursing can choose the area on the right side(anode side),keep far away from the X-ray tube center,avoid the rear of the X-ray tube and the cathodic direction of the X-ray tube to reduce the radiation dose.
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Objective:According to the technical standard of ISO and current regulations in China, the X/γ standard calibration quality for the finger-ring dosimeter irradiation was established in Beijing SSDL, it can ensure the traceability of surveillance data within countrywide.Methods: Air kerma-rate was determined in the X-ray beams,137Cs and60Co by a standard dosimeter, combined transfer coefficientHp(0.07) provided by standards, and confirmed condition of X/γ standard calibration quality for the finger-ring dosimeter irradiation. Using finger-ring TLD dosimeter verified the radiation beam qualities Hp on the ISO finger-phantom.Results: The linearity and energy response of the TLD dosimeter met ISO and national standard in Beijing SSDL.Conclusion: The X/γ standard radiation field can be used for the calibration of finger-ring dosimeter standard curves and experiment of research, and can further promote the comparability and reliability of the surveillance data.
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Objective To compare the single-shot fields irradiated by three focusing modes of γ-knife and explore the approaches for improving the quality of stereotactic radiosurgery.Methods GAFCHROMIC(R) EBT3 mode flushing-free film was used to measure the single-shot fields irradiated by multi-source static focusing modes,multi-source single-axis rotating focusing mode and single-source double-axis rotating focusing mode of γ-knife.Also the uniformity and penumbra of the single-shot fields were compared.Results The 2D dose distribution of the single-shot fields irradiated by three focusing modes of γ-knife was different.In the axis (x,y,z),the rang of penumbra axial length ratios of multisource static focusing modes,multi-source single-axis rotating focusing mode and single-source double-axis rotating focusing mode were 0.13-0.48,0.17-0.33 and 0.28-0.54,in the diagonal direction of the wings plane (NSD,PSD),were 0.31-0.39,0.38-0.43 and 0.54-0.72,respectively;the penumbra axial length ratio of single-source double-axis rotating focusing mode was bigger than in multi-source static focusing modes and multi-source single-axis rotating focusing mode.On the no-wings plane,the area ratios of 80％ dose curve enveloped and 50％ dose curve enveloped(A80％/A50％)were 0.40,0.47 and 0.19,on the wings plane,were 0.61,0.53 and 0.35,respectively.The field uniformity of multi-source static focusing modes and multi-source single-axis rotating focusing mode were superior to single-source doubleaxis rotating focusing mode.Conclusions Considering dose distribution of the single-shot fields,the multi-source static focusing modes devices and the multi-source single-axis rotating focusing mode devices should be preferred,when important tissues and organs are adjacent to the target areas.Compared with single-source double-axis rotating focusing mode,both multi-source static focusing modes and multi-source single-axis rotating focusing mode could make more target areas to be surrounded by high dose region.
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Objective: The reliability of multiple exposure technique in QA imaging was evaluated by combining IP plate of X-ray radiography and homemade QA verification plate. Methods: The QA verification films with different properties derived from placing the QA verification plate and the IP plate on corresponding location were compared with established traditional QA methods. Results: The data from verification films of light and radiation field overlapping derived from combining QA verification plate and IP plate were analyzed by eFilm software in 10cm×10cm radiation field. The results were similar with that of 3D water tank scanning, and were basically same with the analytical results collected from the PTW 2D-ARRAY729 matrix. Conclusion:Using described method in this paper, the result was accurate, the operation was easy, and the cost was low. This method was of good practicability.
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Objective To compare the analytical result of different kinds of film dose analysis software for the same gamma knife,analyze the reasons of difference caused,and explore the measurements and means for quality control and quality assurance during testing gamma knife and analyzing its result.Methods To test the Moon Deity gamma knife with Kodak EDR2 film and γ-Star gamma knife with GAFCHROMIC(R) EBT film,respectively.All the validation films are scanned to proper imagine format for dose analysis software by EPSON PERFECTION V750 PRO scanner.Then imagines of Moon Deity gamma knife are analyzed with Robot Knife Adjuvant 1.09 and Fas-09 1.0,and imagines of γ-Star gamma knife with Fas-09 and MATLAB 7.0.Results There is no significant difference in the maximum deviation of radiation field size ( Full Width at Half Maximum,FWHM) and its nominal value between Robot Knife Adjuvant and Fas-09 for Moon Deity gamma knife (t = -2.133,P ＞0.05).The analysis on the radiation field' s penumbra region width of collimators which have different sizes indicated that the differences are significant (t = - 8.154,P ＜ 0.05 ).There is no significant difference in the maximum deviation of FWHM and its nominal value between Fas-09 and MATLAB for γ-Star gamma knife ( t = - 1.384,P ＞0.05 ).However,following national standards,analysis of φ4 mm width of collimators can obtain different results according to the two kinds software,and the result of Fas-09 is not qualified while MATLAB is qualified.The analysis on the radiation field' s penumbra region width of collimators which have different sizes indicates that the differences are significant ( t = 3.074,P ＜ 0.05 ).The imagines are processed with Fas-09.The analysis of imagine in the pre-and the post-processing indicates that there is no significant difference in the maximum deviation of FWHM and its nominal value ( t = 0.647,P ＞ 0.05 ),and the analytical result of the radiation field' s penumbra region width indicates that there is no significant difference as well ( t = -0.627,P ＞ 0.05 ).Conclusion The study shows that different kinds of film dose analysis software may have some differences in analysis of the same gamma knife validation film,and the results may lead to the different decisions in accordance with national standard.
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PURPOSE: To suggest the optimal radiation fields after a surgical resection based on a nationwide survey on the principles of radiotherapy for rectal cancer in the Korean Patterns of Care Study. MATERIALS AND METHODS: A consensus committee, composed of radiation oncologists from 18 hospitals in Seoul Metropolitan area, developed a survey format to analyze radiation oncologist's treatment principles for rectal cancer after a surgical resection. The survey format included 19 questions on the principles of defining field margins, and was sent to the radiation oncologists in charge of gastrointestinal malignancies in all Korean hospitals (48 hospitals). Thirty three (69%) oncologists replied. On the basis of the replies and literature review, the committee developed guidelines for the optimal radiation fields for rectal cancer. RESULTS: The following guidelines were developed: superior border between the lower tip of the L5 vertebral body and upper sacroiliac joint; inferior border 2~3 cm distal to the anastomosis in patient whose sphincter was saved, and 2~3 cm distal to the perineal scar in patients whose anal sphincter was sacrificed; anterior margin at the posterior tip of the symphysis pubis or 2~3 cm anterior to the vertebral body, to include the internal iliac lymph node and posterior margin 1.5~2 cm posterior to the anterior surface of the sacrum, to include the presacral space with enough margin. Comparison with the guidelines, the replies on the superior margin coincided in 23 cases (70%), the inferior margin after sphincter saving surgery in 13 (39%), the inferior margin after abdominoperineal resection in 32 (97%), the lateral margin in 32 (97%), the posterior margins in 32 (97%) and the anterior margin in 16 (45%). CONCLUSION: These recommendations should be tailored to each patient according to the clinical characteristics such as tumor location, pathological and operative findings, for the optimal treatment. The adequacy of these guidelines should be proved by following the Korean Patterns of Care Study.
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Humans , Anal Canal , Cicatrix , Consensus , Lymph Nodes , Radiotherapy , Rectal Neoplasms , Sacroiliac Joint , Sacrum , SeoulABSTRACT
The authors report a 12-year-old boy who had developed subfrontal recurrence of a medulloblastoma followed by postoperative whole neuroaxis irradiation. The remission persisted for about 3 years after posterior fossa surgery and radiotherapy. Then the tumor recurred in the frontal base, but local recurrence in the posterior fossa was not observed. Operative removal of the metastasis was carried out and the pathological finding was same as medulloblastoma in the posterior fossa. A pitfall of conventional whole brain radiation port is the base of the anterior cranial fossa. Then the entire subarachnoid space should be included in the postoperative radiation field for the treatment of medulloblstoma.
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Child , Humans , Male , Brain , Cranial Fossa, Anterior , Medulloblastoma , Neoplasm Metastasis , Radiotherapy , Recurrence , Subarachnoid SpaceABSTRACT
1128 esophageal carcinoma patients were treated by radiation therapy from Jaunary 1978 to December 1981. 64 cases with new focuses in superior and inferior margin of radiative field were 2.9% and 1.6% and in another region was 1.2%. 54 cases were retreated by radiation therapy. The 1-,2-,3- and 5 years survival rates were 53.7%,24.1%,13.5% and 5.8%. We think that new focus outside radiative fields was great different from local recurrence and uncontral cancers. Those patients can still be treated by radical radiation therapy. It is reasonable to prolong 3cm in length above and below the lesion for initial radiotherapy.