objective: To produce titanium dioxide hydrogel layer on the pure rough titanium(Ti) surface. Methods: Pure Ti discs( d =15mm) were polished to 600 grind, sandblasted and etched with acid, socked in 60 ℃ 5 mol/L NaOH solution for 24 h and then heated to 600℃ for an hour to get goughening, alkaline and heat treated Ti(RAH). The smooth, rough and RAH surfaces were analyzed with scanning electron microscope(SEM) and energy despersive X ray analysis(EDXA). Results: On smooth surfaces only regular polished grooves could be seen, while holes in different diameters formed on rough surfaces. A porous framework was found on the surfaces of the RAH observed by SEM. EDXA showed that the smooth and rough surfaces were consisted of 100% Ti, while there were a lot ofoxygen and sodium in RAH discs. Apatite formed on the RAH Ti surfaces when it is soaked in simulated body fluid for two weeks. Conclusion: A porous Ti dioxide hydrogel layer forms on the rough titanium substrate during alkaline and heat treatment.

Linolenic acid containing selenium was synthesized and brought into emul- sion(82). Its aatitumor effects were tested in vitro and in vivo. As a result, when 82 was injected peritoneally into mice(200mg?kg-1?d-1), its inhibitory rate on mouse S180 was 42.6%(P

70%, P143%, p

Objective To investigate the plan quality between two treatment planning systems (TPSs) for volumetric modulated arc therapy (VMAT). Methods VMAT plans based on Varian Eclipse and Philips Pinnacle TPS were designed for 10 cervical cancer patients (2, 3 Arcs) and 10 prostate cancer patients ( 1, 2 Arcs) . The delivery system of VMAT was Varian ClinaciX machine, and RapidArc was used. The treatment plan quality between the two TPSs was evaluated based on dose distribution, delivery efficiency, and parameter settings. The differences between the two TPSs were compared using paired t-test. Results For cervical cancer patients, the 2-Arc VMAT plans based on the Pinnacle was slightly better than those based on the Eclipse in terms of the conformal index ( CI) of planning target volume ( PTV) , rectum V30 and V40 , and bladder V30 and V40 , and the homogeneity index ( HI) of PTV and PTV1 as well as CI of PTV1 in the Eclips were slightly better than those in the Pinnacle( P<005) Pinnacle were slightly worse than those in the Eclipse ( P>005) . The number of monitor units with 2-Arcs and 3-Arcs plans of the Eclipse was significantly smaller than those in the Pinnacle (P<005). For prostate cancer patients, The 1-arc VMAT plans of the Pinnacle TPS were slightly superior to those of the Eclipse TPS in terms of the HI of PTV, rectumV30 and V40 , and bladderV30 and V40 , but the former was slight inferior to the latter in terms of the CI of PTV (P<005). The number of monitor units of 1-arc and 2-Arcs plans showed no significant difference between the two TPSs (P>005). Conclusions For patients with cervical cancer and prostate cancer, the VMAT plans based on Varian Eclipse and Philips Pinnacle TPS can achieve a clinically acceptable dose distribution and show a little difference in the treatment plan quality. However, we will still need more cases to further study and determine the performance characteristics of the commercial TPSs for optimizing VMAT.

Objective To discuss and evaluate the dosimetric characteristics of different plans implementing stereotactic radiotherapy(SRT)for intracranial tumors using Fixed and Iris collimators of CyberKnife VSI.Methods Twenty patients with intracranial tumors were selected and divided into group A with a small target volume(≤30 cm3)and group B with a large target volume(≥30 cm3). There were 10 patients in each group,and the prescribed dose to the target was 21 Gy in 3 fractions. For each patient, two treatment plans were designed using Fixed and Iris collimators. By analyzing the dosimetric parameters such as conformity index(CI),homogeneity index(HI), gradient index(GI), gradient score index(GSI), and organs at risk (OAR),the quality and efficiency of the plans were evaluated in order to discuss the beam characteristics for two sets of collimators. The difference was analyzed with the paired t-test. Results The mean time of Iris plan for delivering was significantly less than that of Fixed plan(group A:P=0.001;group B:P=0.000). In group B,the peripheral dose(20% and 10% of the prescribed dose)volumes of Fixed plan were significantly less than those of Iris plan(P=0.001 and 0.009). For OAR,D minof the visual pathway and D meanor D minof the eyeball in group B were significantly different between Fixed and Iris plans(all P<0.05), while in group A, only D minof the optic chiasm was significantly different between the two plans(P=0.043). For the other parameters of targets,there were no significant differences between Fixed and Iris plans in both groups(all P>0.05). Conclusions Apart from less treatment time in the Iris plan, there are no significant dosimetric differences between the two collimator plans of CyberKnife VSI in treating small intracranial tumor. For the large and complex tumor,although Iris plan meets the requirement for OAR dose constraints,its low-dose volumes are larger than those of Fixed plan. Further studies of the dosimetric characteristics in CyberKnife should be done.

Objective To explore the feasibility of the volume modulated arc therapy ( VMAT) auto-planning based on template library ( TL). Methods VMAT plans of 68 patients diagnosed with postoperative rectal cancer in Eclipse system were retrospectively selected. The prescription dose was 50 Gy/25F. In 19 patients, the feature values of target and organs at risk were extracted as the vectors. The final optimized restricted conditions were saved as the TL. Then, the plans of 15 rectal cancer patients (10 cases from TL and 5 outside TL) were automatically optimized. According to the multi-dimensional vector similarity principle, the similarity parameter αwas defined. The designed program automatically selected the optimal-object template in an in-house software developed with Matlab. The dosimetric parameters of the auto-optimized plans with the optimal-object template (ATP) and the clinical plan (CP) were compared by the paired t-test. The changes in the dosimetric parameters and similarity parameter α were statistically compared by Pearson′s correlation analysis. The linear fitting of the dosimetric parameters with α was used by least squares method to explore the tendency of the ATP dosimetric parameters relative to CP. Results The dosimetric parameters of ATP for 13 cases were slightly worse than those of CP. The conformal index (P=0. 004), heterogeneous index (P= 0. 015),V40(P= 0. 003) and mean dose (P= 0. 022) of the intestine significantly differed. The α values of these 13 cases were 2. 67,2. 60,2. 60,2. 49,2. 67,2. 74,2. 72,2. 48, 2. 53,2. 86,2. 68,2. 56 and 2. 63. The α value was significantly correlated with the V40 or mean dose of the bladder (r= 0. 649 and 0. 603,P= 0. 016 and 0. 029).Along with the increase of α value ,V40 and mean dose of the intestine for ATP were gradually deteriorated than those of CP . The remaining dosimetric para-meters of ATP were close to or superior to those of CP. Conclusions The results of ATP are slightly worse than those of CP, whereas can satisfy the clinical requirements. The TL, the quality of TL and ATP remain to be further optimized.

Objective To study the curative efficacy and safety of single-unit umbilical cord blood transplantation (sUCBT) for malignant hematologic diseases,which is provided by China's public cord blood bank.Methods We retrospectively analyzed 409 cases of malignant hematologic diseases who accepted myeloablative single-unit unrelated donor UCBT without ATG at our center between May 2008 and December 2016.A comparative analysis was made on the total nuclear cells (TNC) of the umbilical cord blood before freezing and after thawing,the cells of CD34+,the recovery rate of cells and the clinical effect of UCBT.Result 409 units of umbilical cord blood used in UCBT respectively came from eight China's public cord blood banks.The average TNC of 409 units of umbilical cord blood before freezing and after the tubular recovery were respectively 18.5 × 108 and 16.34 × 108 (p =0.000).The average recovery rate of the tubular recovery was 88.5％,and there was significant difference among cord blood banks (P =0.000).The average TNC of umbilical cord blood before freezing and transfusion were respectively 18.5 × 108 and 15.86 × 108 (p =0.000).The average recovery rate of umbilical cord blood transfusion was 85.9％,with the difference being significant among cord blood banks (P =0.000).The average number of CD34+ cells before freezing and after the tubular recovery was 11.18 × 106and 8.68 × 106 (p =0.000).The average recovery rate of CD34+ cells after the tubular recovery was 80.75 ％,with the difference being significant among the cord blood banks (P =0.000).At 42nd day after UCBT,the cumulative incidence of neutrophil engraftment was 95.4％,and the median time of the engraftment was 17 days (11-38 days).The cumulative incidence of platelet engraftment at 120th day was 84.6％,and the median time of the engraftment was 36 days (14-93 days).The cumulative incidence of erythrocyte engraftment at 60th day was 92％,and the median time of engraftment was 22 days (9d-60 days).After the umbilical cord blood provided by each bank was used in UCBT,it got the difference in cumulative incidence of engraftment.The P values for cumulative incidence of neutrophil,platelet and erythrocyte engraftment were respectively 0.004,0.01 and 0.000 2,with the differences being statistically significant.At 100th day after UCBT,the cumulative incidence of Ⅱ-Ⅳ and Ⅲ-Ⅳ degrees of acute graft-versus-host disease (aGVHD) was respectively 28.63％ and 15.7％.After umbilical cord blood provided by each bank was used in UCBT,it got the difference in cumulative incidence of aGVHD.There was no significant difference between Ⅱ-Ⅳ and Ⅲ-Ⅳ degrees (P =0.809 and 0.68 respectively).At 3rd year after UCBT,the cumulative incidence of relapse was 15.89％.After umbilical cord blood provided by each bank was used in UCBT,there was no significant difference in the cumulative incidence of relapse (P =0.898).At 3rd year after UCBT,the overall survival (OS) rate and disease free survival (DFS) rate were respectively 66.7％ and 59％.After umbilical cord blood provided by each bank was used in UCBT,it got the difference in OS and DFS.There was no significant difference in OS and DFS (P =0.566 and 0.703 respectively).At 3rd year after sUCBT,the rate of graft-versus-host diseases/relapse-free survival (GRFS) was 54.3％.After umbilical cord blood provided by each bank was used in UCBT,there was no significant difference in the rate of GRFS (P =0.449).Conclusion The umbilical cord blood provided by China's public cord blood bank was used in UCBT.It has a high safety and good efficacy in treating malignant hematologic diseases.But it needs to set up the standardized and normalized quality-control system of umbilical cord blood for China's public cord blood bank.

Objective:To explore the beam performance of GTR 360° PBS dedicated nozzle for IBA Proteus Plus proton system and evaluate the beam characteristics of PBS during acceptance test procedure (ATP) to meet the precision and safety requirements of clinical treatment.Methods:According to the requirements of acceptance tests, the beam tests of PBS mainly included: test of integrated depth dose (IDD), test of maximum field size at the maximum and minimum ranges, field uniformity and informative PBS tests for the GTR 360°, test of lateral dose uniformity in a single field uniform dose in a cube, test of longitudinal dose uniformity in a single field uniform dose in a cube, and test of monitor unit reproducibility and proportionality.Results:The maximum deviation measured of range, fall back accuracy and distal fall-off was 0.03 g/m 2, 0.01 g/m 2 and 0.078 g/m 2, respectively. Maximum field size at the maximum and minimum ranges was 30.2 cm×40.2 cm and 30.1 cm×40.1 cm, respectively. During the different gantry angles and ranges, the lowest γ passing rate of a pattern plan was 97%, the maximum deviation of the centrical beam spot size at the X and Y axes was -0.16 mm and -0.21 mm, and the worst symmetry was 0.80%. Compared with the centrical beam spot, the maximum size deviation of the other beam spots was 0.11 mm and 0.14 mm at the X and Y axes, and the maximum position accuracy deviation of the beam spot was 0.60 mm and 0.43 mm at the X and Y axes. The maximum deviation of lateral dose uniformity at at the X and Y axes was 0.55% and 0.80% in the high energy region, and 0.6% and 0.75% in the low energy region. The maximum deviation of longitudinal dose uniformity was 0.79% in the high energy region, and 2.22% in the low energy region. The monitor unit (MU) reproducibility factor was 0.106% and the maximum proportionality deviation was 0.67%. Conclusion:The dedicated nozzle of PBS has passed all the beam performance acceptance tests, which meet the requirements of all parameters, and the whole system yields relatively high accuracy, repeatability and good stability.

Objective:To explore the feasibility of the clinical implementation of intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) plans with 6MV photon on two Elekta Linacs (Versa HD and Synergy) after beam matching.Methods:The images of 12 patients with nasopharyngeal carcinoma, central lung cancer and prostate cancer were randomly selected, and the IMRT and VMAT plans were designed. Two different dose tools of ionization chamber and three-dimensional detector ArcCheck were used to verify the individualized radiation treatment of 6MV photon beams on two Linacs and compare the differences.Results:The deviations between the doses of two Linacs (Versa HD and Synergy) measured by the ion chamber and treatment planning system were (0.32±1.32)% and (0.54±1.29)%. The differences of all plans were within the range of ±3%, and the deviations of the point dose between two Linacs were within the range of ±2% with no statistical significance (both P>0.05). The γ analysis of verification using ArcCheck showed that the passing rates of all plans under the 2mm/3% and 3mm/3% with 10% threshold conditions were over 95%, respectively. The average differences between two Linacs were 0.19%(2mm/3%) and 0.09%(3mm/3%). Conclusions:The results of performing IMRT/VMAT plans on two Linacs meet the clinical requirements and the differences between two Linacs are small. Hence, the same plans can be implemented interchangeably on different Linacs.

Objective: To study the dosimetric characteristics and plan quality of PTV-based intensity modulated proton radiotherapy (IMPT) and volumetric-modulated arc therapy (VMAT) plans for prostate cancer, so as to provide a reference for clinical application. Methods: A total of 10 prostate cancer cases were included in this retrospective study. IMPT and RapidArc plans were designed by RayStation and Eclipse TPS based on PTV, respectively. For each case, IMPT plans were generated using multiple field optimization (MFO) technique with two parallel-opposed lateral fields, whereas RapidArc plans were generated using double-arc technique (two full arcs). Final dose calculation of IMPT was conducted by pencil beam(PB) and Monte Carlo (MC) algorithm, respectively, with adopted data model from the pencil beam scanning (PBS) proton therapy system of IBA Protues Plus(IBA Group, Belgium); The data model originated from the linear accelerator of Varian Clinac iX (Varian Medical Systems, America) was used for RapidArc plans. Dosimetric parameters of DVH and dose distribution were used to compare the dose differences in targets and organs at risk (OARs) between these two treatment techniques. Results: For targets, HIs of PB-IMPT and MC-IMPT were slightly better than that of RapidArc , but CI of IMPT was slightly lower than that of RapidArc; D_1% of PB-IMPT was significantly better than those of MC-IMPT and RapidArc (Z=-2.805, -2.803, P<0.05). PB-IMPT and MC-IMPT achieved better protection than RapidArc on rectum V₃₀(Z=-2.191, -1.988, P<0.05)and D_mean(Z=-2.599, -2.497, P<0.05), bladder V₃₀(Z=-2.701, -2.701, P<0.05), V₄₀(Z=-2.395, -2.395, P<0.05)and D_mean(Z=-2.701, -2.701, P<0.05). There was no significant difference between PB-IMPT and MC-IMPT plans for prostate cancer, except for the D_1% [(73.86±67.34) Gy vs.(75.45±2.01) Gy] (RBE) and HI [(0.040±0.010) vs. (0.058±0.020)] of the target. Conclusions Both techniques can meet the clinical requirements, but IMPT showed significant dosimetric advantages compared with RapidArch by reducing the dose to OARs and improving the plan quality.