Objective To systematically evaluate the changes in axial length and treatment zone diameter among my-opic patients wearing orthokeratology lenses with different back optic zone diameters.Methods A comprehensive litera-ture search was conducted on PubMed,Embase,the Cochrane Library,Web of Science,Wangfang Med Online and CNKI databases in both Chinese and English to identify randomized controlled trials or controlled trials investigating orthokeratol-ogy lenses with varying back optical zone diameters.The literature was thoroughly reviewed by two researchers,who ex-tracted relevant data and conducted a methodological quality evaluation.Finally,meta-analysis was performed using Rev-Man 5.3 software.In all the included studies,orthokeratology lenses with a conventional back optic zone diameter were taken as the control group,while orthokeratology lenses with a reduced back optic zone diameter were utilized as the ex-perimental group.Results Eight studies involving 437 patients(459 eyes)with myopia were included.The results of me-ta-analysis showed that the axial length changes in the experimental group were significantly lower than those of the control group after wearing orthokeratology lenses for 6 months and 12 months(6 months:MD=-0.09,95％CI:-0.10 to-0.07,Z=10.50,P＜0.05;12 months:MD=-0.11,95％CI:-0.13 to-0.09,Z=12.19,P＜0.05);significant differ-ences in treatment zone diameter were observed between the experimental and control groups at various time points follow-ing orthokeratology lens wearing(MD=-0.82,95％CI:-1.04 to-0.59,Z=7.03,P＜0.05).Conclusion Orthoker-atology lenses designed with smaller back optical zone diameters can effectively delay axial length growth in myopic pa-tients,but their long-term efficacy needs to be confirmed.

Objective: To compare the dosimetric parameters of target volumes and organs at risk between volumetric-modulated arc therapy (VMAT) and intensity-modulated radiotherapy (IMRT) for left sided breast cancer after breast-conserving surgery by a meta-analysis. Methods: Literature search was performed to include related studies to analyze the dosimetric parameters of target volumes and organs at risk. Results: A total of 11 studies involving 154 patients were included in meta-analysis. There were no significant differences in D_mean, HI of PTV-Whole breast and PTV-Boost. Comparing to IMRT, VMAT increased the conformity index (CI) of PTV-Whole breast (P=0.000) and PTV-Boost (P=0.002). When the mean volume of target volumes was≤634 cm³, there were no significant differences in D_mean, V₅, V₂₀ of the heart and left sided lung, V₃₀ of the heart, D_mean of the right sided lung and breast between VMAT and IMRT.When the mean volume of target volumes was>634 cm³, the D_mean(P=0.037), V₅(P=0.005) and V₂₀(P=0.030) of the heart in IMRT was lower than VMAT, but the V₃₀(P=0.001) of heart in VMAT was lower than IMRT.IMRT showed significantly lower D_mean(P=0.013), V₅(P=0.000), V₂₀(P=0.000) of the left sided lung, and D_mean(P=0.001) of the right sided lung than VMAT.There were no significant differences in D_mean of the right sided breast. Conclusions There were no significant differences in dosimetric parameters of target volumes between VMAT and IMRT.When the mean volume of target volumes was≤634 cm³, there were no significant differences in dosimetric parameters of organs at risk. When the mean volume of target volumes was>634 cm³, IMRT has some advantages in protection of the heart and lung.

Objective To investigate the dosimetric comparison of target volumes and organs at risk (OAR) between volumetric-modulated arc therapy (VMAT) and intensity-modulated radiotherapy (IMRT) for esophageal cancer by a meta-analysis.Methods A literature search was performed to collect the clinical studies on dosimetric comparison between VMAT and IMRT.The primary endpoints of interest were dosimetric parameters of target volumes and OAR, number of monitor units (MUs), and treatment time (TT).Results A total of 17 studies involving 323 patients were included in this meta-analysis.When the total dose was>50.4 Gy, VMAT showed significantly lower mean dose (Dmean) of gross tumor volume (GTV) and maximum dose (Dmax) of planning target volume (PTV) than IMRT (P=0.009;P=0.039).There were no significant differences in Dmean, V30, and V40 of the heart, Dmax of the spinal cord, and V5, V10, and Dmean of the lung between VMAT and IMRT (P>0.05).VMAT showed significantly lower V15, V20, and V30 of the lung than IMRT (P=0.001;P=0.000;P=0.023).When the single dose was 1.8 Gy and 2.0 Gy, VMAT showed significantly lower TT (reduced by 323.5 s and 193.7 s) and number of MUs (reduced by 275.4 MU and 134.2 MU) than IMRT (P=0.000 and 0.009;P=0.000 and 0.022).Conclusions VMAT can significantly reduce TT, MUs, irradiation dose to the lung, and the risk of radiation pneumonitis, and improve the utilization rate of equipment.Compared with IMRT, VMAT has no significant advantages in protection of the spinal cord and the heart and dosimetric parameters of target volumes except Dmean of PTV and Dmean and Dmax of GTV when the total dose was ≤50.4 Gy.

Objective To evaluate dynamic graciloplasty (DGP) for canine in situ anal reconstruction. Methods Seventeen dogs were randomly divided into experimental group and control group. In control group, on the stage 1, the gracilis muscle were dissected in situ, manometry performed intraoperatively; In experimental group, the gracilis muscle were dissected in situ and stimulated chronically starting 7 days postoperatively. On stage 2, abdominoperineal resection of anus and graciloplasty for anal reconstruction were performed in two groups. After 2 weeks recovery, manometry and muscular fatigue-resistant curve (MFRC) were observed while myostimulator is switched off and on. The muscle of neosphincter was biopsied. Results After chronic low frequency electrical stimulation (CLFS), the percentage of type Ⅰ fibers in the stimulation group was higher than the control group (P0.05), but functioning neosphincter pressure is different significantly (P