Objective To analyze the clinical efficacy of gamma-ray fractionated stereotactic radiotherapy (FSRT) in the treatment of intracranial metastatic polycystic tumors.Methods Forty cases with 61 metastatic polycystic tumors were selected from 189 patients with 373 intracranial metastatic tumors admitted to our hospital from 2013 to 2015.All cases received gamma-ray FSRT.The isodose line at 50％ was defined as the prescription dose.The prescription dose was ranged from 40 to 48 Gy/10-12f.The survival rate was calculated by Kaplan-Meier method.The single factor analysis was performed by Log-rank method.Results The median follow-up time was 21months (range:6-39 months).The median survival time was 15.3 months.The 6-month,1-and 2-year local control rate was 93％,82％ and 79％,respectively.The 1-and 2-year survival rate was 63％ and 30％.Single factor analysis demonstrated that the volume of cysts and the volume of lesions were not significantly correlated with local control rate (P=0.17 and 0.48).Conclusion Gamma-ray FSRT can be adopted to treat intracranial metastatic polycystic tumors,which yields similar clinical efficacy to metastatic solid tumors.It deserves wide application in clinical practice due to high local control rate and safety.

Objective:To explore the feasibility and effectiveness of 3D printing aortic model for preoperative evaluation and surgical simulation, and to assist interventional treatment of coarctation of the aorta(CoA).Methods:From December 2017 to January 2019, 8 patients with congenital coarctation of the aorta who underwent percutaneous balloon dilatation and covered stent placement in Xijing Hospital of Air Force Military Medical University were analyzed retrospectively. Among them, 7 cases were male and 1 case was female. The age was(32.00±14.93) years old. Before operation, CT data of patients' heart and aorta were collected, reconstructed with Mimics software, and 3D printing technology was used to make the model of patients' aortic lesions. Before operation, the operation simulation was carried out to determine the best operation scheme and estimate the possible situation, and the relevant clinical data of patients during hospitalization and follow-up were collected.Results:One stent graft was successfully implanted into CoA through femoral artery in all 8 patients. The mean diameter of CoA increased from(3.70±2.94) mm before operation to(18.01±1.51) mm immediately after operation( P<0.05), and the mean systolic pressure difference decreased from(83.75±25.44) mmHg before operation to(14.63±8.09) mmHg after operation( P<0.05). The mean systolic blood pressure of the right upper extremity decreased from(204.13±22.31) mmHg before operation to(145.63±32.08) mmHg after operation( P<0.05), and there was no significant difference between the two groups. During the period of hospitalization and follow-up, no corresponding cardiovascular complications were found. Conclusion:The short-term effect of percutaneous balloon dilatation covered stent implantation on CoA in adolescents and adults is obvious. 3D printing model can reproduce the anatomical model of CoA site of patients individually, which is feasible and effective for the preoperative evaluation of CoA and the preparation of operation plan.