Objective To explore the consistency of time-of-flight (TOF) technology of PET/MRI and PET/CT for max standardized uptake value (SUVmax) of body malignant tumors.Methods A retrospective analysis of TOF-PET/CT and TOF-PET/MR imaging data about twenty patients with body malignant tumors was performed.Patients were divided into two groups (each n=10),including PET/CT first and sequentially PET/MR group and PET/MR first and sequentially PET/CT group.Bland-Altman figure was used to evaluate consistency of SUVmax of malignant lesions between TOF-PET/CT and TOF-PET/MR.Multi-way ANOVA was used to analysis effect of machine type and exam order on SUVmaxof malignant lesions in TOF-PET/CT and TOF-PET/MR.Results SUVmax of malignant lesions in TOF-PET/CT and TOF-PET/MR had good consistency in two groups (PET/CT first and sequentially PET/MR group:Mean difference was 3.06,95％CI was [-7.5,13.6];PET/MR first and sequentially PET/CT group:Mean difference was 3.0,95％CI was [-2.4,8.3]).SUVmax was not influenced by machine type (F=0.005,P=0.95),but exam order (F=46.00,P＜0.001).Conclusion PET/MR and PET/CT with TOF technology have comparative diagnostic value in SUVmaxof body malignant lesions.SUVmax of body malignant lesions increases in delay time,which is not related to machine type,but exam time.

Objective To study the therapeutic effect and safety of orthokeratology in the teenagers with high myopia.Methods A retrospective cohort study was carried out.The clinical data of 120 eyes from 60 high myopia patients wearing orthokeratology contact lens for 1 year in Henan Eye Hospital from June 2013 to June 2014 was analyzed,and the data of contemporaneous 118 eyes from 59 matched high myopia patients wearing conventional glasses were used as controls.The initial spherical equivalent (SE) of all the patients was-6.00 to-9.00 D.The maximum correction amplitude of the orthokeratology contact lens was set as 6.00 D based on the Regulation of China Food & Drug Administration.The contact lenses were worn for 1 month firstly and then the conventional glasses were used at daytime and contact lenses were consecutively worn at night for 1 year in the contact lenses group,and only glasses were worn in the conventional glasses group.The uncorrective visual acuity (UCVA),SE,corneal fluorescein staining were examined 1 week,1 month,3 months,6 months and 12 months after wearing lenses.The changes of corneal endothelial cells were examined 6 and 12 months after wearing lenses.Results The UCVA was improved and SE was reduced 1 month and 3,6 and 12 months after wearing lenses in comparison with 1 week after wearing lenses in the contact lenses group (all at P＜0.01);while no significant change was seen in UCVA in the conventional glasses group (all at P＞0.05).Compared with wearing contact lenses,the SE was increased in various time points after wearing glasses in the conventional glasses group (all at P＜0.01).The axial length and SE extended by (0.08±0.12)mm and (0.19±0.21)D in the contact lenses group and those in the conventional glasses group were (0.29±0.14)mm and (0.69±0.27)D,showing significant differences between the two groups (t =10.024,5.691,both at P＜0.01).No significant differences were found in corneal endothelial cell density,percentage of hexagonal cells and coefficient of variation of corneal endothelial cells in various time points after wearing contact lenses (corneal endothelial cell density:Fgroup =0.090,P =0.769;Ftime =0.133,P =0.563.percentage of hexagonal cells:Fgroup =0.071,P=0.836;Ftime =1.091,P =0.203.coefficient of variation:Fgroup =0.107,P =0.734;Ftime =1.948,P =0.156).The incidence of corneal fluorescein staining was 31.67％ in the contact lens group,which was much higher than 3.51％ in the conventional glasses group (x2 =97.910,P =0.001).Conclusions Compared with wearing only conventional glasses,orthokeratology can improve UCVA and control axial length extension in juvenile with high myopia,but orthokeratology is more likely to damage the corneal superficial layer.

Objective: To study the more safe and accurate guidance scheme of cone beam computed tomography (CBCT) in nasopharyngeal carcinoma. Methods: CBCT was regularly performed on 87 patients with nasopharyngeal carcinoma in Meizhou People's Hospital from November 2014 to August 2015. For each patient, 10 times CBCT scans were obtained pre-treatment. All the setup errors were obtained and analysed on the orientation X (left and right), Y (head and foot) and Z (vertical) axis. Results: With the increase of the number of CBCT scans, there was no statistically significant difference among the mean setup errors of the 10 times scans in X (left and right) and Y (head and foot) directions (all P > 0.05). And there was no statistically significant difference among the mean setup errors of 6 times scans in Z (vertical) direction, but from the beginning of the 7th, the systematic error in Z direction was increasing, the system error of the 7th, 8th, 9th, 10th time was 0.140, 0.292, 0.461, and 0.640 mm. Moreover, the difference of the mean systematic errors among the first 7 times was statistically significant (H = 15.232, P = 0.019), and the differences of the mean systematic errors among the first 8, 9 and 10 times were statistically significant (all P < 0.05). Conclusions Non-consecutive scans of CBCT could reduce the systematic and random errors. The appropriate frequency of application of CBCT based on the change law of setup errors is an ideal CBCT guidance scheme for nasopharyngeal carcinoma.

Objective To investigate the physics technique and quality assurance (QA) during radiotherapy in the institutions from the East Guangdong province,aiming to provide reference for the construction of radiotherapy discipline and rational allocation of resources in the primary hospitals from the eastern Guangdong province.Methods From March 15 to May 20,2016,the general conditions,radiotherapy equipment,available technique and quality assurance (QA) in the medical institutions from eastern Guangdong were investigated and analyzed by online combined with on-spot surgery.Results There were 8 institutions which provided radiotherapy with 966 ward beds,a daily capacity of 632 patients and 222 radiotherapy practitioners.Radiotherapy equipment included 12 linear accelerators,5 after-loading devices,1γ-knife,8 CT simulators and 9 radiotherapy planning systems.Five institutions performed IMRT/VMAT,IGRT and ART.Dose verification was performed before precision radiotherapy delivery in all institutions except for 1 center.QA procedures were missing for the linear accelerators,CT simulators and after-loading devices.Short-term advanced studies and hand-by-hand teaching were the main approaches for staff professional training.Conclusions The resource allocation for radiotherapy in the medical centers from the eastern Guangdong province is scarce.The technique and QC levels greatly differ among different institutions.Standard QA protocols are urgently to be established and implemented.Extensive attentions should be paid to the the professional training for technicians.

Objective To analyze set-up errors for irradiation of nasopharyngeal carcinoma by using kilo-voltage cone beam computed tomography (kV-KBCT) scanning, and to calculate the external margin from planning target volume (PTV) of nasopharyngeal carcinoma. Methods A total of 150 nasopharyngeal carcinoma patients in Meizhou People's Hospital from December 2014 to November 2016 were treated by image-guided radiation therapy (IGRT), kV-KBCT, CT image scanning matcthed by bone and grey alignment. PTV of nasopharyngeal carcinoma was also calculated. Results According to PTV formula, the external distance before radiotherapy guided by grey alignment was 0.5 mm in X-axis, 0.4 mm in Y-axis, 0.8 mm in Z-axis. While the distance was 0.1 mm in X-axis, 0.5 mm in Y-axis, 1.7 mm in Z-axis guided by bone alignment. After radiotherapy, the external distance guided by grey alignment was 0.4 mm in X-axis, 0.5 mm in Y-axis, 0.9 mm in Z-axis. While the distance was 0.1 mm in X-axis, 0.9 mm in Y-axis, 2.0 mm in Z-axis guided by bone alignment. There was no significant difference in set-up errors of 3 directions and 2 aligned ways before and after treatment.Conclusions The PTV within 3 mm is safe when IGRT is used for directing radiotherapy of nasopharyngeal carcinoma,and kV-KBCT is an effective image equipment.

Ambystoma mexicanum/immunology* ; Amputation ; Animals ; Biomarkers/metabolism* ; Blastomeres/immunology* ; Cell Lineage/immunology* ; Connective Tissue Cells/immunology* ; Epithelial Cells/immunology* ; Forelimb ; Gene Expression ; High-Throughput Nucleotide Sequencing ; Humans ; Immunity ; Peroxiredoxins/immunology* ; Regeneration/immunology* ; Regenerative Medicine/methods* ; Single-Cell Analysis/methods*