ObjectiveTo compare planning quality,treatment efficiency and delivery accuracy for initial treated nasopharyngeal carcinoma (NPC) with step & shoot intensity modulated radiation therapy (ssIMRT) and volumetric modulated arc therapy (VMAT).These results will help make a clinic choice of the therapeutical technique.MethodsTwenty-six NPC cases were planned with the same dose prescription and objective constrains by means of 9-field ss-IMRT and VMAT respectively.Compare:( 1 ) plan dosimetric distribution,conformity index and homogeneity index of the targets,the average dose,maximum dose and interested dose-volume histograms of organs at risk (OAR) et al;(2) delivery times of the therapy plans ;(3) the accuracy of treatment plans dose verification.ResultsBoth therapeutical plans can achieve the clinic dosimetric demands.Compared to ss-IMRT,VMAT had less inferior target coverage.The CI and HI of the PGTV was 0.57 and 0.08 ( ss-IMRT),0.48 and 0.12 (VMAT) respectively ( t =-4.52,- 8.33,P =0.000,0.000).Except of brain stem,VMAT had higher mean dose and maximum dose of OARs than ss-IMRT (t=-9.57 - -3.71,P=0.000 -0.001).The spinal cord D1cc and parotids D50％ were increased by 11.9％ and 6.5％ averagely.The treatment times of ss-IMRT and VMAT were 803.7 s and 389.3 s respectively (t =24.12,P =0.000),while V MAT decreasing by 51.6％.The pass ratios of γ (3mm,3％ ) from the dose verification were 99.4％ (ss-IMRT) and 98.0％ (VMAT) respectively ( t =5.19,P =0.000).ConclusionsThe dose distribution of VMAT for initial treated nasopharyngeal carcinoma can achieve the clinic demands,but slightly worse than 9-field ss-IMRT.VMAT has the advantage of high efficiency and dosimetric accuracy.

Objective To evaluate the dosimetry of high-energy electron beams by using GafChromic EBT film. Methods The percent depth doses of electron beams of 4 MeV,6 MeV,8 MeV,10MeV, 12 MeV and 15 MeV were measured with EBT. The results were then compared with the measurements with diode detector in RFA and parallel plate chamber in water tank. Results The percent depth dose curves using EBT film had a good agreement with those using the other two detectors. Furthermore, no differences were found between up-right and tilt setup methods. When film upper edge is higher than water surface, a sharp drop of measurement results using EBT film was observed in comparison with those from diode detector in build-up region. Conclusions EBT film can be applied to measure percent depth doses of high-energy electron beams. During the EBT film measurements, the film should be tilted at the angle of 5degrees to the central axis of the field. When choosing up-right setup method, the edge of the film should be parallel to the water surface.

ObjectiveTo test a three-dimensional dose verification system,which reconstructing dose to anatomy based on modeling and online measurements ( RDBMOM ),and to evaluate the accuracy and feasibility of its application in clinical intensity-modulated radiotherapy (IMRT) quality assurance.Methods Phantom plans of regular and irregular fields were selected for the testing.All test plans were implemented and the dose distributions were measured using the thimble ion-chamber and two-dimensional ion-chamber array,the accuracy of RDBMOM were then evaluated by comparing the corresponding results.Two practical treated nasopharyngeal carcinoma IMRT plans were verified with RDBMOM and the clinic significancy were valued.ResultsCompared with measurements of the thimble ion-chamber,deviations of RDBMOM were within 1％ in all tested cases except small field of 3 cm ×3 cm.The largest deviation of reconstructed dose in IMRT cases was 2.12％.The dose profile reconstructed by RDBMOM coincided with the measurement using two-dimensional ion-chamber array.The γ rates (3％/3 mm) were 94.56％ - 100％.The RDBMOM verification of IMRT cases shown that the γ rate ＞ 99％ in total and ＞ 98％ in planning target volume,deviation in D95 ＜0.4％,but the largest deviations in mean dose of the parotids and lens were 2.97％ and 59.58％ respectively.ConclusionsAccuracy of the tested system satisfies the demand of IMRT dose verification.RDBMOM is able to provide information of volumetric dosimctry and anatomical location of dose error,which is benefit for evaluating the clinical value of verification results.

Objective To study the imaging performance and mechanism of acute patellofemoral joint impingent syndrome.Meth-ods The MR images and clinical data of acute patellofemoral joint impingent syndrome were analysed retrospectively in 10 patients, which were confirmed by clinic .MRI and DR examination were performed in all patients,in which 6 patients had complete knee ar-throscopy material.The imaging performance and mechanism of acute patellofemoral joint impingent syndrome were summarized re-spectively.Results All cases had clear history of buckling ectropion trauma;Patellar dislocation or subluxation were detected in 9 cases on DR examination,10 cases on MRI;Patellar medial fracture or osteochondral fracture caused by acute slipped patella was de-tected in 1 case on DR examination,2 cases (3 places)on MRI;Medial patellar retinaculum injury were detected in 10 cases on MRI,which were corresponding to that on surgery.Articular injury and subchondral marrow edema in particular parts of joint (an-terolateral of lateral femoral and medial patellar)were detected in 9 cases on MRI.MRI features of articular cartilage injury were confirmed by arthroscopy.MRI showed ACL or PCL injury in 3 cases,meniscus tear in 4 cases,which were quite consistent with the arthroscopy findings.Conclusion MRI can effective display joint cartilage damage,subchondral marrow edema in particular parts of the joint,which is useful to clinical prediction and treatment at early stage.

Objective To analyze the risk factors of incision infection and spinal canal hematoma after lumbar spinal posterior surgery.Methods Data of 33 patients with incision infection and 25 patients with spinal canal hematoma after posterior surgery for lumbar spinal disease from January 2010 to December 2014 were retrospectively analyzed.For the patients with incision infection,20 of them were males and 13 were females,with an average age of 58.85±8.76 years (range 38-79 years).Of these patients,5 were diagnosed with lumbar disc herniation,9 with lumbar spondylolisthesis,15 with lumbar spinal stenosis and 4 with lumbar vertebral fracture.For patients with spinal canal hematoma,17 of them were males and 8 were females,with a mean age of 60.96±11.37 (range,38-77).The diagnoses of them were lumbar disc herniation in 18 patients,spondylolisthesis in 3 patients and spinal stenosis in 4 patients.From the same period database,patients who underwent lumbar posterior lumbar surgery with no postoperative complications were selected by 3:1 ratio as the control group according to age,gender and diagnosis.Results For patients with incision infection,it was found that diabetes mellitus,preoperative RBC,hemoglobin,total protein,albumin,serum calcium,operation time,number of segment fusion,intraoperative blood loss,postoperative WBC,RBC,hemoglobin and platelet were significantly different from those with non-infection group.Moreover,multivariate logistic analysis showed that diabetes mellitus (OR=3.716,P=0.032),preoperative serum calcium (OR＜ 0.001,P=0.001),intraoperative blood loss (OR=1.002,P=0.014),postoperative hemoglobin (OR=0.923,P=0.018) and postoperative platelet (OR=1.007,P=0.017) were independent risk factors for postoperative incision infection.For patients with spinal canal hematoma,it was found that patients' preoperative total protein,albumin,serum calcium,platelet,operation time,intraoperative blood loss and postoperative total protein were significantly different from non-hematoma group.Multivariate logistic analysis showed that preoperative serum calcium (OR＜ 0.001,P=0.001),preoperative total protein (OR=1.298,P=0.043),intraoperative blood loss (OR=1.003,P=0.021) and postoperative total protein (OR=1.080,P=0.028) were independent risk factors for postoperative spinal canal hematoma.Conclusion The preoperative diabetes mellitus,serum calcium,intraoperative blood loss,postoperative hemoglobin and platelet were important risk factors for lumbar incision infection.And preoperative serum calcium,total protein,intraoperative blood loss and postoperative total protein were the risk factors for spinal canal hematoma.

Objective To investigate the application significance of 3.0T MR three dimensional double-echo steady state(3D-DESS) and three dimensional-true fast imaging with steady-state procession(3D-True FISP) sequences in diagnosis of wrist cartilage of rheumatoid arthritis (RA).Methods 26 patients who were clinically diagnosed with RA underwent wrist MR scans with 3D-DESS and 3D-True FISP sequences, while both sequences' scanning were achieved on 20 of them.340 articular-surface morphological conditions' were observed,which were divided into level 0, level 1 and level 2 damages according to morphological performance,and recorded on 3D-DESS and 3D-True FISP sequence respectively.The diagnostic differences in the number of lesions were compared for two sequences.Results The numbers were 79 and 50 for level 1 damage and 23 and 33 for level 2 damage on 3D-DESS and 3D-True FISP sequence respectively (P<0.05).The artifacts were showed in 14 patients on 3D-True FISP,and only two patients on 3D-DESS.Conclusion 3D-DESS sequence does better than 3D-True FISP in displaying RA wrist cartilage,which is able to provide certain help for treatment and prognosis evaluation of RA.

Objective:To inspect the dosimetry characteristic of a 2-D ionization chamber array and its response to oblique incident electron beam.And to discuss feasibility to using it to validate the electron arc therapy plan.Materials and methods:(1)The 2-D ionization chamber array was calibrated referring to a themble chamber,comparing the response to electron beams with incidence angle ranged from-50°to 50°.(2)Phantom test plans of 6 and 10MeV electron beam arc therapy were designed,with the beam rotation arcs of 30°,60°and 90° respectively,symmetric to the Central axis of 0°gantry angle.Dose distribution of each plan was verifled with the 2-D array.Results:(1)Measurement differences between the central detector of the array and the thimble chamber were less than 2%,under the planned oblique inddent 6/10MeV electron beam.(2)For the all test plans,dose error was less than 3%at dmax in the symmetric axis of the electron beam arcs.Off-axis dose error was less than 2%within the central 70%area of the profile in non-rotating direction,and smaller than 1.5%in the rotational direction.The measured dose distribution had good agreement with the TPS calculation in isodose curves between 100%and 20%.The gammapass rates(△D=5%,△d=5cm)were 99.98%、99.89%、99.74%、98.64%、99.16%and 99.44%respectively for 6 and 10 MeV plans with electron beam arcs of 30°,60°and 90°.Conclusion:it is practicable using the tested 2-D ionization chamber array to verify and validate the electron beam arc therapy plan.

Objective:To isolate and prepare the reference substances of phloroglucinol derivatives from Dryopteris fragrans by semi-preparation HPLC. Methods:After reflux extraction of Dryopteris fragrans with petroleum ether,the extracting solution was con-centrated and separated by silica gel column chromatography,and then isolated by semi-preparation HPLC. The isocratic elution was carried out using acetonitrile as the mobile phase at 3. 0 ml·min-1 and the injection volume was 0. 5 ml. Two phloroglucinol deriva-tives were isolated. Results:The chemical structure of the two phloroglucinol derivatives respectively was aspidin BB with the purity of 98. 81% and aspidin PB with the purity of 98. 57% by ultra high performance liquid chromatography. Conclusion:The isolation of as-pidin BB and aspidin PB by semi-preparation HPLC is simple and fast with the purity over 98%,which can be used to prepare the ref-erence substances.

Objective To investigate the prognostic effects and failure patterns of different clinical target volumes of IMRT in definitive chemoradiotherapy for cervical and upper-thoracic esophageal cancer,in order to provide a reference for radiotherapy target area delineation.Methods A retrospective analysis was performed on the clinical data of 132 patients with cervical and upper-thoracic esophageal cancer who received definitive IMRT and concurrent chemotherapy in our hospital from 2010 to 2014.Seventy-one patients received elective nodal irradiation (ENI) and the other 61 patients received involvedfield irradiation (IFI).The Kaplan-Meier method was used to calculate local control (LC),progressionfree survival (PFS) and overall survival (OS) rates.The significant difference was evaluated by the logrank test.The prognostic factors were determined by Cox univariate and multivariate analyses.Results The last follow-up time was December 2017,the median follow-up time was 59.5 (14.2-95.8) months.Follow-up rate was 99.2％.For the ENI and IFI groups,the 1-,3-,5-year LC were 77.5％,58.8％,48.8％ vs.64.3％,29.1％,26.2％ (x2=9.68,P=0.002),PFS were 68.6％,37.7％,25.9％ vs.47.5％,17.2％,3.6％ (x2=11.39,P=0.001),OS were 81.7％,53.9％,31.3％ vs.70.5％,31.9％,16.3％ (x2=7.70,P =0.006),respectively.In multivariate analysis,T stage,N stage,and RT field were independent factors for LC,PFS and OS(P＜0.05).The total failure rates,local-regional recurrent rate in ENI group were lower than those in IFI group (x2 =13.23,5.24,P＜0.05).No significant differences were found in acute radiation esophagitis,pneumonitis and myelosuppression (Grades ≥ 3) between the two groups(P＞0.05).Conclusions Compared with IFI,ENI can significantly reduce local-regional recurrence and distant metastasis and improve the long-term survival for cervical and upper-thoracic esophageal cancer patients who received definitive chemoradiotherapy.

Objective:To analyze whether involved-field irradiation (IFI) was associated with improved survival and reduced treatment-related adverse events compared with elective nodal irradiation (ENI) in Chinese patients with esophageal squamous cell carcinoma receiving radiotherapy.Methods:Literature review was conducted from CNKI, Wanfang Data, PubMed, Embase, Web of Science and Cochrane Central databases (until July 31, 2022). Relevant data were collected according to the inclusion and exclusion criteria. Primary outcomes included overall survival (OS) rate and treatment-related adverse events. Secondary outcomes included progression-free survival (PFS) rate and local control rate (LCR). Risk of bias was assessed using the Cochrane Risk of Bias tool. The quality of the results was assessed by using the meta analysis of Evidence Evaluation and Grading of Recommendations, Assessment, Development and Evaluations (GRADE) methods.Results:A total of 7 articles with 918 patients were included of which 465 received IFI and 453 received ENI. The 1-, 2-, 3-and 5-year OS rates in the IFI group were not significantly different from those in the ENI group (1-year OS rate: RR=1.00, 95% CI=0.94-1.07, P=0.97, high certainty; 2-year OS rate: RR=1.01, 95% CI=0.90-1.13, P=0.90, high certainty; 3-year OS rate: RR=0.86, 95% CI=0.71-1.05, P=0.14, high certainty; 5-year OS rate: RR=0.76, 95% CI=0.42-1.37, P=0.36, low certainty). In the IFI group, patients with ≥grade 2 acute radiation esophagitis ( RR=0.71, 95% CI=0.58-0.87, P=0.001, high certainty), ≥grade 3 acute radiation esophagitis ( RR=0.39, 95% CI=0.24-0.64, P<0.001, high certainty) and ≥grade 2 acute radiation pneumonitis ( RR=0.72, 95% CI=0.52-0.99, P=0.04, high certainty) were significantly lower compared with those in the ENI group. However, no significant differences were observed in the incidence of ≥grade 3 late radiation esophagitis, ≥grade 3 acute radiation pneumonitis and ≥grade 3 late radiation pneumonitis between two groups. No significant differences were noted in the 1-, 2-, 3-PFS rates and LCR between two groups. Conclusions:For Chinese patients with esophageal squamous cell carcinoma, IFI and ENI yield similar efficacy in terms of OS, PFS and LCR. However, IFI has a lower incidence of ≥grade 2 acute radiation esophagitis, ≥grade 3 acute radiation esophagitis and ≥grade 2 acute radiation pneumonitis than ENI.