[Reality and expectation of machine learning in critically ill patients with acute kidney injury].

The prediction model constructed by machine learning can early predict acute kidney injury (AKI) in critically ill patients, which contributes to taking preventive measures to reduce incidence of AKI as soon as possible. Machine learning can also identify AKI subtypes in real time, so as to facilitate the implementation of precise treatments for their subtypes in the future, which may improve the prognosis of patients. In this article, the construction of forecasting model of AKI and identification of AKI subtypes in critically ill patients and it's precise treatment with machine learning, limitations and development trend of machine learning in the field of AKI in critically ill patients is addressed for clinical reference.

[3D printing non-coplanar template-assisted 125-iodine seed implantation for thorax movement tumor: individual template design method].

Objective: To compare the dosimetric data between preoperative plans and postoperative verification in computed tomography CT-guided and 3D printing template-assisted 125-iodine ((125)I) seed implantation for thorax movement tumor and to explore the feasibility and accuracy of the individualized template design method. Methods: A total of 35 patients, 20 males and 15 females with median age of 62 (17-87) years old, who registered from January 2016 to December 2017 applied with 3D printing guided template assisted radioactive seed implantations in Peking University Third Hospital were included in this study. (125)I seeds with a prescribed dose of 110-180 Gy were impanted. 3D printing templates were designed and produced for 35 cases. The dosimetric parameters: D(90), minimum peripheral dose (mPD), V(100), V(150), V(200), conformal index (CI), external index (EI), and homogeneity index (HI) were compared between pre-and post-plannings. Statistical method was two group of related non-parameters test. Results: The design and production of 35 cases' templates were in place well. Compared with the preoperative planning, the postoperative D(90), V(100), V(150), V(200), mPD, CI, EI and HI differences were 5.57%, 0.34%, 0.33%, -1.20%, 21%, 2.8%, -14.2%, 4.71%, -10.4%. All the included dosimetry parameters changed slightly after surgery compared with before surgery, but the difference was not statistically significant(all P>0.05). Conclusions: The dosimetric parameters of postoperative verification are consistent well with the preoperative planning and have good accuracy, the results could meet the clinical requirements.

[Comparison of preoperative planning of radioactive seed implantation for pelvic wall recurrent gynecological malignant tumors between 3D-printing non-coplanar template and 3D-printing coplanar template].

Objective: To compare the difference of preoperative planning parameters between 3D-printing non-coplanar template (3D-PNCT) and 3D-printing coplanar template (3D-PCT) in the treatment of pelvic wall recurrent gynecological malignant tumor with radioactive seeds implantation, and to guide the clinical application. Methods: From January 2016 to March 2018, 33 patients with pelvic wall recurrent gynecological malignant tumor were treated with radioactive seeds implantation assisted by 3D-printing template and in Peking University Third Hospital. All patients underwent 3D-PNCT and 3D-PCT preoperative planning. The D(90) of target remained similar for the same patient. The parameters were compared with Wilcoxon test or Kruskal-Wallis test. Results: D(90) was similar between the two groups (P>0.05). The number of inserting needles through intestine and bone in 3D-PNCT group was less than that in 3D-PCT group (0 (0-13), 0 (0-25), Z=-2.941, P<0.05;0 (0-3), 0 (0-25), Z=-2.232, P<0.05). Conclusion: For patients with gynecological malignancies with pelvic recurrence, both of the two peroperative plans could achieve prescription dose, but 3D-PNCT is more safer.

[CT-guidance interstitial Iodine-125 seed brachytherapy as a salvage therapy for recurrent head and neck carcinoma].

Objective: To investigate the efficacy of CT-guidance interstitial Iodine-125 seed brachytherapy as a salvage therapy for recurrent head and neck carcinoma. Methods: A total of 122 patients who had been treated for recurrent head and neck carcinoma with CT-guided Iodine-125 seed permanent implantation were conducted a retrospective analysis at Peking University Third Hospital from February 2003 to December 2015. The study included 78 male and 44 female patients. Of the 122 patients, 76 had undergone radical surgery, 106 had received EBRT. Among the patients who underwent EBRT, the total dose delivered to PTV ranged from 30 to 140 Gy (median, 68.4 Gy). The actuarial median number of the implanted Iodine-125 seeds was 38 (range, 5-158). The specific activity of Iodine-125 seeds ranged from 14.8 to 28.9 MBq/seed (median, 22.2 MBq). The evaluation of post plan showed the actuarial D90 ranged from 46 to 282 Gy (median, 121 Gy). The overall local control and survival times were determined by using the Kaplan-Meier method from SPSS 13.0.Univariate analysis was performed on the local control rate and overall survival rate. Results: Tumor responses rate was 75.4%. The median local control time was 10.0 months (95% CI 9.8-24.2 months), and the 1-, 2-, 3-, and 5-year local control were 41.9%, 21.2%, 3.7%, and 3.7%, respectively. Univariate analysis showed that the local control in D90≥120 Gy group had an increasing tendency, but no statistical difference were found. The effect of local control in the squamous cell carcinoma group was slightly worse than that in the non-squamous cell carcinoma group (P=0.032). Multi-factor analysis showed that the effect of local control in the squamous cell carcinoma group was slightly poor (P=0.03). The median survival time was 14 months (95% CI 14.4-35.8 months), and the 1-, 2-, 3- and 5-year survival rate were 51.5%, 34.2%, 19.4%, and 19.4%, respectively. The three factors, such as the tumor responses, KPS status before the seed implantation, and the D90 after the seed implantation, had a tendency to improve the total survival, but there was still no statistical differences. Multivariate analysis showed no clear influence factors. Conclusions: Interstitial permanent Iodine-125 seed implantation is an effective salvage re-irradiation modality for recurrent head and neck carcinoma after previous surgery and/or EBRT. CT image-guided method could yield the reliable seeds configuration and accurate dose distribution.

[Effect of image fusion technology of radioactive particles implantation before and after the planning target and dosimetry].

Objective: To compare the post-implant target volumes and dosimetric evaluation with pre-plan, the gross tumor volume(GTV) by CT image fusion-based and the manual delineation of target volume in CT guided radioactive seeds implantation. Methods: A total of 10 patients treated under CT-guidance (125)I seed implantation during March 2016 to April 2016 were analyzed in Peking University Third Hospital.All patients underwent pre-operative CT simulation, pre-operative planning, implantation seeds, CT scanning after seed implantation and dosimetric evaluation of GTV.In every patient, post-implant target volumes were delineated by both two methods, and were divided into two groups. Group 1: image fusion pre-implantation simulation and post-operative CT image, then the contours of GTV were automatically performed by brachytherapy treatment planning system; Group 2: the contouring of the GTV on post-operative CT image were performed manually by three senior radiation oncologists independently. The average of three data was sets. Statistical analyses were performed using SPSS software, version 3.2.0. The paired t-test was used to compare the target volumes and D(90) parameters in two modality. Results: In Group 1, average volume of GTV in post-operation group was 12-167(73±56) cm(3). D(90) was 101-153 (142±19)Gy. In Group 2, they were 14-186(80±58)cm(3) and 96-146(122±16) Gy respectively. In both target volumes and D(90), there was no statistical difference between pre-operation and post-operation in Group 1.The D(90) was slightly lower than that of pre-plan group, but there was no statistical difference (P=0.142); in Group 2, between pre-operation and post-operation group, there was a significant statistical difference in the GTV (P=0.002). The difference of D(90) was similarly (P<0.01). Conclusion: The method of delineation of post-implant GTV through fusion pre-implantation simulation and post-operative CT scan images, the contours of GTV are automatically performed by brachytherapy treatment planning system appears to have improved more accuracy, reproducibility and convenience than manual delineation of target volume by maximum reduce the interference from artificial factor and metal artifacts. Further work and more cases are required in the future.

[Dosimetry verification of radioactive seed implantation with 3D printing template and CT guidance for paravertebral/retroperitoneal malignant tumor].

Objective: To compare the dose distributions of postoperative plans with preoperative plans for seeds implantations of paravertebral/retroperitoneal tumors assisted by 3D printing guide template and CT guidance, explore the effects of the technology for seeds implantations in dosimetry level and provide data support for the optimization and standardization in seeds implantation. Methods: Between December 2015 and July 2016, a total of 10 patients with paravertebral/retroperitoneal tumors (12 lesions) received 3D printing template assist radioactive seeds implantations in department of radiation oncology of Peking University Third Hospital, and included in the study. The diseases included cervical cancer, kidney cancer, abdominal stromal tumor, leiomyosarcoma of kidney, esophageal cancer and carcinoma of ureter. The prescribed doses was 110-150 Gy. All patients received preoperative planning design, individual template design and production, and the dose distribution of postoperative plan was compared with preoperative plan. Dose parameters including D(90), MPD, V(100), V(150,)conformal index(CI), EI of target volume and D(2cc) of organs at risk (spinal cord, aorta, kidney). Statistical software was SPSS 19.0 and statistical method was non-parameters Wilcoxon symbols test. Results: A total of 10 3D printing templates were designed and produced which were including 12 treatment areas.The mean D(90) of postoperative target area (GTV) was 131.1 (97.8-167.4 Gy) Gy. The actual seeds number of post operation increased by 3 to 12 in 5 cases (42.0%). The needle was well distributed. For postoperative plans, the mean D(90,)MPD, V(100,)V(150) was 131.1 Gy, 69.3 Gy, 90.2% and 65.2%, respectively, and which was 140.2 Gy, 65.6 Gy, 91.7% and 26.8%, respectively, in preoperative plans. This meant that the actual dose of target volume was slightly lower than preplanned dose, and the high dose area of target volume was larger than preplanned range, but there was no statistical difference in P value between the two groups except V(150)(P=0.004). The actual dose conformity of target volume was worse than preplanned (CI was 0.58 and 0.62, respectively) and the difference was statistically significant(P=0.019). The actual dose of external target volume was higher than preplanned (EI was 55% and 45.9%, respectively) and the difference had no significance. For organs at risk, the actual mean D(2cc) of spinal cord, aorta and kidney was 24.7, 54.4 and 29.7 Gy, respectively, which was higher than preplanned(20.6, 51.6 and 28.6 Gy, respectively), and there was no significant difference in two groups. Conclusions: Most parameters of postoperative validations for 3D printing template assisted seeds implantation in paravertebral/retroperitoneal are closed to the expectations of preoperative plans which means the improvement of accuracy in treatment.

[A clinical study of antiviral therapy for patients with compensated hepatitis C cirrhosis].

Objective: To investigate the effect of antiviral therapy on the progression of liver cirrhosis and related predictive factors through a retrospective analysis of patients with compensated hepatitis C cirrhosis. Methods: The patients with compensated hepatitis C cirrhosis who were treated in our hospital from 2004 to 2015 were divided into sustained virologic response (SVR) group, non-SVR (NSVR) group, and untreated group. The baseline features of patients with or without liver cirrhosis were compared to identify the predictive factors for the progression of liver cirrhosis. The changes in platelet count, spleen sizes, Model for End-Stage Liver Disease (MELD) score, Sequential Organ Failure Assessment (SOFA) score, and Child-Turotte-Pugh (CTP) score were analyzed, and the incidence rate of liver cancer was compared between groups. A one-way analysis of variance, the Kruskal-wallis H test, the two-independent-sample t test, the chi-square test, and a multivariate logistic regression analysis were used for data analysis based on data type. Results: A total of 89 patients with compensated liver cirrhosis were enrolled, among whom 42 received the antiviral treatment with interferon and ribavirin (30 were treated with pegylated interferon-α and 12 were treated with ordinary interferon) and 47 did not receive any antiviral therapy. Among the patients who received the antiviral treatment with interferon and ribavirin, 20 achieved SVR and 22 did not achieve SVR. Compared with baseline values, platelet count in the SVR group and the NSVR group was increased by (44.93 ± 32.66)×10(9)/L and (9.73 ± 28.83)×10(9)/L, respectively, and platelet count in the untreated group was reduced by (19.76 ± 54.5)×10(9)/L; the three groups had a significant change in platelet count (F = 14.731, P < 0.001). Spleen size was reduced by 0.91 ± 1.09 cm in the SVR group and increased by 0.20±0.84 cm and 1.11 ± 1.69 cm in the NSVR group and the untreated group, respectively; the three groups had a significant change in spleen size (F = 14.943, P < 0.001). The three groups had no significant changes in MELD, SOFA, and CTP scores (P > 0.05). One patient (5.00%) in the SVR group, 5 (22.73%) in the NSVR group, and 6 (12.77%) in the untreated group progressed to liver cancer (χ (2) = 13.787, P = 0.001). The univariate analysis showed that SVR, HCV RNA, total bilirubin, and albumin were predictive factors for disease progression, and the multiple logistic regression analysis demonstrated that SVR and total bilirubin were predictive factors for disease progression. Conclusion: Interferon combined with ribavirin has a marked clinical effect in the treatment of compensated hepatitis C cirrhosis with good short- and long-term efficacy.

[CT guidance 125I seed implantation for pelvic recurrent rectal cancer assisted by 3D printing individual non-coplanar template].

Objective: To analyze the difference of dosimetric parameters between pre-plan and post-plan of 125I radioactive seed implantation assisted by 3D printing individual non-coplanar template (3D printing template) for locally recurrent rectal cancer (LRRC). Methods: From February 2016 to April 2016, a total of 10 patients with locally recurrent rectal cancer received 125I seeds implantation under CT guidance assisted by 3D printing template in Department of Radiation Oncology, Peking University Third Hospital.Each patient underwent CT simulation, three-dimentional treatment planning pre-implantation, 3D printing template design, radioactive seed implantation assisted by 3D printing template and dosimetric verification post implantation. The median activity of seed was 0.63 mCi (0.58 to 0.7 mCi) (2.15- 2.59×107 Bq), and the median number of seeds was 80 (19 to 192). D90, D100, V100, V150, CI, EI, HI, D5cc, D2cc of bladder and bowel of pre-plan and post-plan were calculated, respectively.Paired t test was used to evaluate the difference of dosimetric parameters between pre-plan and post-plan. Results: The median D90 of pre-plan and post-plan were 13 761.0 and 12 798.8 cGy, respectively.The median D100 of pre-plan and post-plan were 5 293.6 and 5 397.9 cGy, respectively.The median V100 of pre-plan and post-plan were 90.0% and 90.0%, respectively.The median V150 of pre-plan and post-plan were 63.8% and 62.4%, respectively.The median CI of pre-plan and post-plan were 0.73 and 0.67.The median EI of pre-plan and post-plan were 0.22 and 0.30, respectively. The median HI of pre-plan and post-plan were 0.29 and 0.31.The median bladder D2cc of pre-plan and post-plan were 3 088.8 and 4 240.4 cGy, respectively.The median bowel D2cc of pre-plan and post-plan were 7 051.6 and 7 903.9 cGy, respectively. Conclusions: 3D printing template might be helpful for locally recurrent rectal cancer patients who received 125I radioactive seed implantation assisted by 3D printing individual template.Seed implantation might have more chances to achieve prescription dose and dose limitation of organs at risk of pre-plan, which is important for precise implantation and quality control.

[Energy transfer between electric polymer PVK and terbium complex and its transmission electronmicroscope (TME) study].

A chloroform-soluble terbium complex, which is confirmed to be Tb(aspirin)3 phen using element analysis and FT-IR spectroscopy, was synthesized. Photoluminescent investigation on the terbium complex and PVK-terbium complex composite was conducted. Förster energy transfer occurred between the terbium complex and the PVK matrix. There are no overlap between UV spectrum of the complex and the emission spectrum of PVK, however, overlap is observed between the excitation spectrum of the complex and the emission spectrum of PVK. Therefore, we suggest that the necessary condition of Förster energy transfer should be overlap between the excitation (not UV) spectrum of one complex and the emission spectrum of polymer matrix. Further investigation indicates that the emission of PVK can be suppressed at different extents by doping various amount of Tb(aspirin)3 phen into PVK films. The ratio of Tb(aspirin)3 phen: PVK = 1:2 (wt%) are regarded as an optimized ratio for limiting the emission of PVK. TEM images of PVK/Tb(aspirin)3 phen films reveal that nanoparticles of the Tb complex are dispersed in the PVK matrix. The size of the aggregated complex in PVK matrix is 20-30 nm. The film is not homogeneous as dark regions co-exist with light region in the TEM images. This phenomenon may be related to the short lifetime of electroluminescent devices.