Objective To observe the effects of porous polylactic acid/polyglycolic acid copolymer(PLGA) filling into extraction socket on the regeneration of alveolar bone in rats.Methods Sixty male Wistar rats were divided into experimental group and control group(n=30).PLGA scaffold was immediately implanted in the mandibular incisor root sockets after removal of incisor teeth.Soft X-ray photography,structural observation,light microscopy were used to evaluate the effects of composite on bone healing in a rat tooth extraction socket.Results The relative lengths of residual alveolar ridge in the experimental group 4,8 weeks after operation were shorter than that in the control group,and there were significant differences between the experimental group and the control group(P

Objective To investigate the clinical value of Fluorine-18-fluorodeoxyglucose (18 F-FDG) PET/CT examination to predict the prognosis of patients after colorectal cancer operation.Methods The retrospective cross-sectional study was adopted.The clinicopathological data of 80 patients with colorectal cancer who were admitted to the First Hospital of Nanjing Medical University from March 2007 to October 2015 were collected.Eighty patients received first preoperative 18 F-FDG PET/CT examination and underwent operations under decisions of patients and their families,and then adjuvant chemotherapy were performed according to the patients' condition.Observation indicators included:(1) preoperative imaging examination,(2) situations of treatment and follow-up,(3) analysis of prognostic factors.The patients were followed up by outpatient examination and telephone interview once every 3 months within postoperative 1 year,once every half a year within postoperative 2 years and then once a year up to May 2016.The follow-up included tumor recurrence or progression and survival of patients.Tumor-free survival time was from postoperative day 1 to tumor recurrence or progression and death or end of follow-up.Overall survival time was from postoperative day 1 to death or end of follow-up.Measurement data with skewed distribution were represented as M (Qn) and M (range).The optimal cutoff point of tumor-free survival of maximum standardized uptake value (SUVmax),mean standardized uptake value (SUV),metabolism of volume (MTV) and total lesion of glycolysis (TLG) were investigated using the ROC curve analysis,and calculating area under the curve (AUC).The median was used as a cutoff point if there was smaller AUC.The Kaplan-Meier method and Log-rank test were respectively used for survival analysis and univariate analysis,and COX proportional hazards model for multivariate analysis.Results (1) Results of preoperative imaging examination:results of PET/CT in patients with colorectal cancer showed there were circumscribed thickening of bowel wall,intestinal cavity strictures,fuzzy fat space around the some lesions,enlarged lymph node and 18 F-FDG uptake increased abnormally.The SUV SUV MTV and TLG of 80 patients were 11.83(4.26,35.42),7.06(2.38,20.92),20.47 cm3 (1.29 cm3,161.50 cm3) and 138.58 (14.17,857.89),respectively.ROC curve showed that the AUC of SUV SUV MTV and TLG were 0.453,0.448,0.815 and 0.749 [95％ confidence interval (CI):0.307-0.600,P ＞0.05;0.303-0.594,P ＞ 0.05;0.717-0.913,P ＜ 0.05;0.635-0.863,P ＜ 0.05],respectively.The median SUVmax (11.83) and SUV (7.06) were used as the cutoff points due to smaller AUC of SUVmax and SUV.The cutoff point of MTV was 18.79 cm3 (sensitivity =86.2％ and specificity =68.3％),and the cutoff point of TLG was 142.05 (sensitivity =75.9％ and specificity =70.7％).(2) Situations of treatment and follow-up:among 80 patients,13 underwent the radical resection of colorectal cancer and resection of liver metastasis and 67 underwent radical resection of colorectal cancer.Sixty-two patients received postoperative chemotherapy,including 45 with chemotherapy regimens of capecitabine and 17 with fluorouracil.Eighty patients were followed up for 41.8 months (range,6.5-109.1 months).During the follow-up,29 patients had tumor recurrence or progression,and 19 patients were dead.The median tumor-free survival time,1-,3-and 5-year tumor-free survival rates in 80 patients were 19.5 months (range,2.0-109.1 months),73.7％,36.3％ and 18.8％,respectively.The median overall survival time,1-,3-and 5-year overall survival rates were 31.8 months (range,3.3-109.1 months),76.3％,37.5％ and 20.0％,respectively.(3) Analysis of prognostic factors:results of univariate analysis showed that tumor location,N staging,M staging,clinical staging,postoperative chemotherapy,MTV and TLG were relative factors affecting postoperative tumor-free survival rate (HR =3.469,5.325,5.295,8.605,2.630,7.388,5.155,95％ CI:1.522-7.906,2.256-12.568,2.405-11.657,2.969-24.937,1.063-6.504,2.550-21.403,2.178-12.204,P ＜ 0.05).The tumor location,tumor differentiation,N staging,M staging,clinical staging,MTV and TLG were relative factors affecting postoperative overall survival rate (HR =2.697,2.814,3.083,2.916,4.193,5.450,4.876,95％ CI:1.011-7.197,1.121-7.062,1.166-8.149,1.140-7.454,1.386-12.678,1.581-18.786,1.727-13.766,P ＜ 0.05).In multivariate analysis,stage Ⅲ-Ⅳ of clinical staging and TLG≥ 142.05 were independent risk factors affecting postoperative tumor-free survival rate (HR =9.879,3.569,95％ CI:1.854-22.836,1.127-11.306,P＜0.05).The stage M1,stage Ⅲ-Ⅳ of clinical staging and TLG≥ 142.05 were independent risk factors affecting postoperative overall survival rate (HR =4.522,9.315,10.120,95％ CI:1.223-16.717,1.338-24.864,2.385-12.947,P＜0.05).Conclusion TLG through 18 F-FDG PET/CT examination is an independent prognostic factor affecting postoperative tumor-free survival rate and overall survival rate in patients with colorectal cancer after curative resection,and it has certainly reference value for prognosis.

Objective: To compare the dosimetric data between the preoperative plans and postoperative verification in personalized 3D printed template-assisted and computed tomography (CT) image-guided 125-iodine seed implantation for supraclavicular metastatic tumor, and to evaluate the accuracy and feasibility at the dosimetry level.Methods: A total of 14 patients with supraclavicular metastatic tumor (including 15 lesions) who received 3D printed template assisted and CT image-guided 125-iodine seed implantation in Department of Radiation Oncology of Peking University Third Hospital from January to September 2016 were enrolled.There were 8 males and 6 females, aged from 46 to 79 years (mean age: 59.9 years).The Karnofsky performance score (KPS) was from 60 to 90 (median of 80).There were one patient who had not received radiotherapy before, and one patient had received radiotherapy, but the dose was unknown.The remaining 12 patients had received radiotherapy, with the median of 60 Gy (20-70 Gy), and one of them with the dose unknown.All the patients underwent preoperative enhanced CT scan, preoperative planning design, 3D printing template, puncture and particle implantation, the prescription dose from 110 Gy to 150 Gy.Comparisons of the dosimetric parameters between the postoperative verification and preoperative plans were made by paired t-test.The dose parameters inclu-ded D90, V100, V150, V200, matched peripheral dose (mPD), conformal index (CI), and external index (EI).The agreement was evaluated between the preoperative planning and postoperative actual dose parameters using Bland-Altman analysis.Bland-Altman plot showed the difference against the average of preoperative planning and postoperative actual dose parameters with limits of agreement (LoA) (broken lines).Results: The difference of all the data between pre-and postoperation, included D90, V100, V150, V200, mPD, and CI, which was not statistically significant (P>0.05).EI was statistically significant (P<0.05).There was poor consistency of D90, V100, V150, V200, and mPD, but better consistency of CI and EI.Conclusion: Personalized 3D printed template-assisted and CT image-guided 125-iodine seed implantation for supraclavicular metastatic tumor is accurate and feasible.

Objective To compare the pre-and post-operative tumor target volume and to examine the consistency in physical dosimetric parameters of organs at risk (OAR) following 3D-printed coplanar template (3D-PCT)-assisted and CT-guided radioactive seed implantation.Methods The 3D-printed coplanar template was designed using a computer software, and the coordinate system was established where the center was used as the basis for setting the x axis and y axis.Crosses defining the center of treatment were drawn on the patient''s body and matched with the corresponding central point, x axis, and y axis of the coplanar template.3D-PCT-assisted and CT-guided radioactive seed implantation was performed based on the pre-operative plan, and the pre-operative, operative, and post-operative plans were designed to evaluate the target tumor volume and the normal dose received by the tissues.In addition, dosimetric parameters, including D90(minimum dose received by 90% of the gross target volume), V100, V150, V200(percentage of GTV that received 100%, 150%, and 200% of the prescribed dose, respectively), minimum peripheral dose (MPD), conformal index (CI), external index (EI), and homogeneity index (HI) in the pre-operative and post-operative plans were also assessed and compared using the Wilcoxon test. Results Fourteen patients treated in our institution from August to October, 2016 were included in this study. The median age of the patients was 61.5 years, and the median Karnofsky Performance Scale score was 80. A total of 14 lesions from the 14 patients were treated by seed implantation in the neck (n=4), chest (n=3), abdomen (n=5), and pelvis (n=2). Of the 14 patients that underwent implantation, 8 had previously received radiation therapy, and 6 had not received radiation therapy. Dosage optimization was performed for all patients during the operation. The median activity of the implanted seeds was 0.625 mCi (0.55-0.75 mCi,1 Ci=3.7×1010 Bq), and the preoperatively planned median number of needling and implanted seeds were 9(4-34) and 45.5(10-162), respectively. However, the actual median number of needling and implanted seeds were 9.5(4-34) and 45.5(10-162), respectively. Dosimetric analysis showed that there were no significant changes in tumor volume (P=0.135), D90(P=0.208), MPD (P=0.104), V100(P=0.542), V150(P=0.754), V200(P=0.583), CI (P=0.426), EI (P=0.326), and HI (P=0.952) after implantation. Conclusions 3D-PCT guidance and dosage optimization can result in good consistency between pre-and post-operative plans for radioactive seed implantation. 3D-PCT is a convenient and cheap technique suitable for large-scale clinical application.

BACKGROUND:At present, some neurological imaging methods, including MRI, fMRI, 2-(1-(6-[(2-[18F]fluoroethyl)(methyl)amino]-2-naphthyi) ethylidene) malononitrile (18F-FDDNP) positron emission tomography (PET), are helpful but not specific for the diagnosis of Alzheimer disease (AD). 18F-FDG is a special marker of beta-amyloid (Aβ), thus AD can be diagnosed by 18F-FDDNP PET at early period.OBJECTIVE: To evaluate the role of 18F-FDDNP PET in the diagnosis of AD, and establish reliable clinical biological indexes for the diagnosis of AD patients.DESIGN: A controlled analysis.SETTINGS : Department of Geriatric Neurology and Department of Nuclear Medicine, the General Hospital of Chinese PLA. PARTICIPANTS: Patients visiting the General Hospital of Chinese PLA from May 2004 to March 2005 were selected. Informed consents were obtained from all the participants. ① AD group (n =7): (74.88±12.03) years old; Accorded with the criteria related to diagnosis of AD in NINCDS/ADRDA (National Institute of Neurological and Communicative Disorders and Stroke/Alzheimer Disease and Related Disease Association) and revision of Diagnostic and statistical Manual (DSM-Ⅳ, 4th ed.); brain CT or magnetic resonance imaging (MRI) examination displayed that inter-uncus distance of temporal lobes was ≥ 30 mm. ② Vascular dementia group (n =6): (73.83±4.75) years old; Accorded with the diagnostic criteria of NINDS-AIREN (National Institute of Neurological Diseases and Stroke, USA) and DSM-Ⅳ for vascular dementia; Inter-uncus distance of temporal lobes ＜ 30 mm. ③ Control group (n =6): (71.17±3.71) years old; Without rarefaction of white matter; Intelligence examination was normal.METHODS: PET was performed in all the subjects. PET scanner type was SEIMENS ECAT EXACT HR. The tracer selected was 18F-FDDNP which had radiochemical purity higher than 95% and error of radioactivity measurement lower than 10%. The images were collected at 5, 25 and 45 minutes after injection of 18F-FDDNP. Horizontal and coronary tomograms of brain were obtained after reconstruction.MAIN OUTCOME MEASURES: Characteristics of 18F-FDDNP brain PET images.RESULTS: ① In the control group, signs of obvious atrophy of brain were not seen. At about 45 minutes, the radioactivity in cortex and subcortical nucleus groups was essentially cleared and the structures of brain could not be differentiated clearly. ② In the vascular dementia group, brain atrophy and enlargement of ventricular system to various degrees could be seen. The clearance of radioactivity at three time points was similar to that in the control images. ③ In the AD group, the brain was obviously atrophied and the ventricular system was enlarged. The clearance of radioactivity at the three time points was significantly different from the images of other two groups. The radioactivity in cortex and hippocampus was cleared slower. At 45 minutes, the gray matter could still be clearly differentiated from the white matter, but the radioactivity in corpus striatum and thalamus was not higher than that in cortex and much radioactivity retention could be seen in cortex and hippocampus.CONCLUSION: 18F-FDDNP PET brain images can differentiate AD and vascular dementia, and it is an effective imaging index for the diagnosis of AD.

Objective To evaluate the roles of positron emission tomography (PET) with N-methyl [11C]2-(4' -methylaminophenyi-6-hydroxybenzathiazole) (11C-PIB) in the early diagnosis of Alzheimer's disease (AD).Methods Six AD patients,7 mild cognitive impairment (MCI) patients and 6 normal controls (NC) were diagnosed and assessed with brain PET with 11C-PIB.The emission images obtained at 5,25 and 45 min after 11C-PIB administration were analysed.Results Using visual analysis to summarize the characteristics of the imagings of each group: comparing to NC,the AD patients show high 11C -PIB up take,and low clearance rate of 11C-PIB at 45 min.The imagings of MCI group show heterogeneous,overlapping with AD and NC group.The statistical analysis shows: in AD group,the standard uptake value (SUV) ratio of parietal lobe,frontal lobe,temporal lobe,occipital lobe and hippocampal at 45 min was 1.91±0.21,2.09±0.41,1.92±0.35,1.66±0.41,1.55±0.28 respectively,and were higher than that of NC group (value being 1.48±0.53,1.57±0.64,1.36±0.53,1.27±0.40,1.17±0.33) with statistical significance,t=8.114,5.620,5.705,3.650 and 2.866,P=0.0001,0.0002,0.0002,0.0045 and 0.0170 respectively.In MCI group,the SUV ratio of parietal lobe,frontal lobe,temporal lobe,occipital lobe and hippocampal at 45 min was 1.48 ± 0.53,1.57 ± 0.64,1.36±0.53,1.27 ± 0.40,1.17±0.33 respectively,and were higher than that of NC group,but there was no statistical significance.Conclusion 11C-PIB PET imaging can differentiate AD patients from normal and anticipate the transformation of MCI patients.

Objective To establish a model for the calculation of biologically effective dose (BED) and EQD2 (Equivalent dose in 2 Gy fractions) in radioactive seed implantation brachytherapy.Methods The BED formula for EBRT(external beam radiotherapy) and for continuous low dose-rate irradiation established under the L-Q model were introduced.The EDQ2 formula for the continuous low dose-rate irradiation (radioactive seed implantation) was established according to the definition of EQD2 and the formula of BED.The α/β values of common tissues and the Tr 1/2 values reported in the literature were summarized.The EDQ2 formula were further simplified by using the actual values.The empirical formula of EDQ2 for early reaction tissues and late reaction tissues were proposed,named as Wang-Peng empirical formula.EDQ2≈ (10/12) D (Wang-Peng Formula 1) was fit for early response tissue,and EDQ2≈ D/2 (Wang-Peng Formula 2) for late reaction tissues.Further examples on the clinical applications of the proposed formula were given,including primary lung cancer,supraclavicular lymph node metastasis of esophageal cancer and celic lymph node metastasis of cervical carcinoma.Results According to the Wang-Peng empirical formula,the EDQ2 of the late reaction tissue adjacent to the tumor was only about half that of the tumor tissue,so the radioactive seed implantation brachytherapy naturally protected the late reaction tissue by the biological equivalent dose.The actual calculation,showed that the empirical formula of early reaction tissue was more accurate,but the empirical formula of late reaction orgtissue was less inaccurate and could only be roughly estimated.Conclusions The BED calculation formula introduced here and the set of EQD2 calculation formula and Wang-Peng empirical formula established here were theoretically feasible and could be used for the conversion and superposition between the physical dose of radioactive seed implantation brachytherapy and the external irradiation dose.But it should be careful to apply the formula,pay attention to the default conditions,and carefully interpret the calculated results.

Objective To compare the preoperative and postoperative dosimetric results of radioactive seed implantation assisted by 3D printing template in the treatment of chest malignant tumor, and to examine the effect this technique on the precision of radioactive seed implantation.Methods A total of 21 patients who received 3D printing template-assisted CT-guided 125I seed implantation for chest tumors in 2016 were included in the study.The prescribed dose of the treatment was 110-180 Gy.Preoperative planning, individual template production, and puncture and seed implantation were performed in all patients, and the postoperative dosimetric results were then compared with the preoperative plan by assessing various dosimetric parameters including D90, MPD, V100, V150, CI, EI, and HI of gross tumor volume (GTV), D2cc of the spinal cord and aorta, and Dmean and V20 of the affected side of the lung.Statistical analysis was performed using the Wilcoxon non-parametric test.Results A total of 21 3D printing templates were designed and produced.The mean GTV volume (preoperative) of all patients was 77.1 cm3, and the mean number of implanted seeds was 68.In addition, the mean D90 of the postoperative GTV was 147.3 Gy.There were slight changes in the dosimetric parameters after treatment (P>0.05).Conclusions 3D printing template allows for accurate positioning and implantation of radioactive seeds during the treatment of chest tumor.Postoperative dosimetric parameters were consistent with those in the preoperative planning, indicating that the 3D printing template provides high precision for the treatment of chest tumor.

Objective To understand genetic distribution, drug resistance, molecular typing and the epidemiological relativeness between strains of the Shigella boydii virulence. Methods Nine Shigella boydii strains were isolated form stool samples of patients with diarrhea from the Enteric Disease Clinic of the Second Hospital of Tianjin Medical University in June-October 2015. The strains were identified by biochemical test and serum agglutination test. Antibiotics susceptibility test was carried out using the Kirby-Bauer method. Polymerase chain reaction was used for detecting virulence genes. Pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) technique were used to determine the epidemiological relationship between nine Shigella boydii strains. Results There were three subtypes in nine isolated Shigella boydii samples, including one, three and five isolates inⅠ,Ⅱ,Ⅳsubtypes respectively. All of the 9 isolates were multi-drug resistant. The resistant rate of these strains for ampicillin was 100%(9/9), and then the resistant rates of these strains for ceftazidime, streptomycin, gentamicin, trimethoprim/sulfamethoxazole, cefotaxime, ceftriaxone, norfloxacin and levofloxacin were 1/9, 4/9, 4/9, 4/9, 5/9, 5/9, 6/9, 6/9 and 6/9, respectively. All of these strains were sensitive to amikacin, cefperazone-sulbactam and imipenem. The ipaH was carried by all the testing strains, and none of the strains carried the sen, set1A, set1B, ial, virA, icsA and SigA. The detective rates of pic, sepA and sat were 4/9, 5/9 and 7/9 strains, respectively. Nine shigella boydii strains were divided into 8 PFGE types. The similarity between the spectrums of PFGE was 63.21%-100%. Multilocus sequence typing showed that six isolates were belonged to ST648, two isolates were ST131 and one isolate was ST10. Conclusion Nine isolates of Shigella boydii (divided into three subtyping) isolated from our hospital are multi-drug resistant and they have distant relationships, belonging to the dissemination of case.

Objective To compare the dose distribution of postoperative plans with preoperative plans for 3D printing guide template assist radioactive seeds implantations,and explore the accuracy of treatment at dosimetry level.Methods A total of fourteen patients registered from Dec 2015 to Mar 2016 who were applied with 3D printing guide template assisted radioactive seed implantations in the hospital were included in this study.The preoperative planning design and 3D printing template production were performed for all patients.The dose related parameters including D90％,minimum peripheral dose (MPD),V100％,V150％,V200％,conformal index (CI),external index (EI),and homogeneity index (HI) were compared between pre-and post-operation.The paired t-test was used to perform the statistical analysis.Results A total of fourteen 3D printing individual templates were produced which included 16 treatment areas.Compared with preoperative plans,the mean value of V100％,Dg0％ and V150％ decreased while the mean value of V200％ and MPD increased in postoperative plans.However,there was no significant difference between the two groups except for V100％ (t =2.451,P ＜0.05).The differences of CI,EI,HI between two groups were not statistically significant (P ＞ 0.05).Conclusions The validation of actual dose distribution in postoperation assistied by 3D printing template in seed implantation shows that most of parameters could meet the expectation of preoperative plans,which indicates the improvement in accuracy for this new type of treatment.