Objective To investigate the expression of vascular endothelial growth factor (VEGF) and platelet drived endothelial cell growth factor (PD-ECGF) and their influence on the clinicopathological characteristics and the prognosis in aged patients with gastric carcinoma. Methods The expression of VEGF and PD-ECGF were examined with immnunohistochemical technique through preoperative biopsied specimens in 92 cases. Results The expression of VEGF and PD-ECGF were significantly higher in gastric carinoma than in chronic atrophic gastritis. VEGF and PD-ECGF levels in advanced carcinoma were higher compared with early carcinoma( P

Objective: To compare the dosimetric data between the preoperative plans and postoperative verification in personalized 3D printed template-assisted and computed tomography (CT) image-guided 125-iodine seed implantation for supraclavicular metastatic tumor, and to evaluate the accuracy and feasibility at the dosimetry level.Methods: A total of 14 patients with supraclavicular metastatic tumor (including 15 lesions) who received 3D printed template assisted and CT image-guided 125-iodine seed implantation in Department of Radiation Oncology of Peking University Third Hospital from January to September 2016 were enrolled.There were 8 males and 6 females, aged from 46 to 79 years (mean age: 59.9 years).The Karnofsky performance score (KPS) was from 60 to 90 (median of 80).There were one patient who had not received radiotherapy before, and one patient had received radiotherapy, but the dose was unknown.The remaining 12 patients had received radiotherapy, with the median of 60 Gy (20-70 Gy), and one of them with the dose unknown.All the patients underwent preoperative enhanced CT scan, preoperative planning design, 3D printing template, puncture and particle implantation, the prescription dose from 110 Gy to 150 Gy.Comparisons of the dosimetric parameters between the postoperative verification and preoperative plans were made by paired t-test.The dose parameters inclu-ded D90, V100, V150, V200, matched peripheral dose (mPD), conformal index (CI), and external index (EI).The agreement was evaluated between the preoperative planning and postoperative actual dose parameters using Bland-Altman analysis.Bland-Altman plot showed the difference against the average of preoperative planning and postoperative actual dose parameters with limits of agreement (LoA) (broken lines).Results: The difference of all the data between pre-and postoperation, included D90, V100, V150, V200, mPD, and CI, which was not statistically significant (P>0.05).EI was statistically significant (P<0.05).There was poor consistency of D90, V100, V150, V200, and mPD, but better consistency of CI and EI.Conclusion: Personalized 3D printed template-assisted and CT image-guided 125-iodine seed implantation for supraclavicular metastatic tumor is accurate and feasible.

Objective To compare the pre-and post-operative tumor target volume and to examine the consistency in physical dosimetric parameters of organs at risk (OAR) following 3D-printed coplanar template (3D-PCT)-assisted and CT-guided radioactive seed implantation.Methods The 3D-printed coplanar template was designed using a computer software, and the coordinate system was established where the center was used as the basis for setting the x axis and y axis.Crosses defining the center of treatment were drawn on the patient''s body and matched with the corresponding central point, x axis, and y axis of the coplanar template.3D-PCT-assisted and CT-guided radioactive seed implantation was performed based on the pre-operative plan, and the pre-operative, operative, and post-operative plans were designed to evaluate the target tumor volume and the normal dose received by the tissues.In addition, dosimetric parameters, including D90(minimum dose received by 90% of the gross target volume), V100, V150, V200(percentage of GTV that received 100%, 150%, and 200% of the prescribed dose, respectively), minimum peripheral dose (MPD), conformal index (CI), external index (EI), and homogeneity index (HI) in the pre-operative and post-operative plans were also assessed and compared using the Wilcoxon test. Results Fourteen patients treated in our institution from August to October, 2016 were included in this study. The median age of the patients was 61.5 years, and the median Karnofsky Performance Scale score was 80. A total of 14 lesions from the 14 patients were treated by seed implantation in the neck (n=4), chest (n=3), abdomen (n=5), and pelvis (n=2). Of the 14 patients that underwent implantation, 8 had previously received radiation therapy, and 6 had not received radiation therapy. Dosage optimization was performed for all patients during the operation. The median activity of the implanted seeds was 0.625 mCi (0.55-0.75 mCi,1 Ci=3.7×1010 Bq), and the preoperatively planned median number of needling and implanted seeds were 9(4-34) and 45.5(10-162), respectively. However, the actual median number of needling and implanted seeds were 9.5(4-34) and 45.5(10-162), respectively. Dosimetric analysis showed that there were no significant changes in tumor volume (P=0.135), D90(P=0.208), MPD (P=0.104), V100(P=0.542), V150(P=0.754), V200(P=0.583), CI (P=0.426), EI (P=0.326), and HI (P=0.952) after implantation. Conclusions 3D-PCT guidance and dosage optimization can result in good consistency between pre-and post-operative plans for radioactive seed implantation. 3D-PCT is a convenient and cheap technique suitable for large-scale clinical application.

Objective To compare the preoperative and postoperative dosimetric results of radioactive seed implantation assisted by 3D printing template in the treatment of chest malignant tumor, and to examine the effect this technique on the precision of radioactive seed implantation.Methods A total of 21 patients who received 3D printing template-assisted CT-guided 125I seed implantation for chest tumors in 2016 were included in the study.The prescribed dose of the treatment was 110-180 Gy.Preoperative planning, individual template production, and puncture and seed implantation were performed in all patients, and the postoperative dosimetric results were then compared with the preoperative plan by assessing various dosimetric parameters including D90, MPD, V100, V150, CI, EI, and HI of gross tumor volume (GTV), D2cc of the spinal cord and aorta, and Dmean and V20 of the affected side of the lung.Statistical analysis was performed using the Wilcoxon non-parametric test.Results A total of 21 3D printing templates were designed and produced.The mean GTV volume (preoperative) of all patients was 77.1 cm3, and the mean number of implanted seeds was 68.In addition, the mean D90 of the postoperative GTV was 147.3 Gy.There were slight changes in the dosimetric parameters after treatment (P>0.05).Conclusions 3D printing template allows for accurate positioning and implantation of radioactive seeds during the treatment of chest tumor.Postoperative dosimetric parameters were consistent with those in the preoperative planning, indicating that the 3D printing template provides high precision for the treatment of chest tumor.

Objective To compare the dose distribution of postoperative plans with preoperative plans for 3D printing guide template assist radioactive seeds implantations,and explore the accuracy of treatment at dosimetry level.Methods A total of fourteen patients registered from Dec 2015 to Mar 2016 who were applied with 3D printing guide template assisted radioactive seed implantations in the hospital were included in this study.The preoperative planning design and 3D printing template production were performed for all patients.The dose related parameters including D90％,minimum peripheral dose (MPD),V100％,V150％,V200％,conformal index (CI),external index (EI),and homogeneity index (HI) were compared between pre-and post-operation.The paired t-test was used to perform the statistical analysis.Results A total of fourteen 3D printing individual templates were produced which included 16 treatment areas.Compared with preoperative plans,the mean value of V100％,Dg0％ and V150％ decreased while the mean value of V200％ and MPD increased in postoperative plans.However,there was no significant difference between the two groups except for V100％ (t =2.451,P ＜0.05).The differences of CI,EI,HI between two groups were not statistically significant (P ＞ 0.05).Conclusions The validation of actual dose distribution in postoperation assistied by 3D printing template in seed implantation shows that most of parameters could meet the expectation of preoperative plans,which indicates the improvement in accuracy for this new type of treatment.

Objective To establish a model for the calculation of biologically effective dose (BED) and EQD2 (Equivalent dose in 2 Gy fractions) in radioactive seed implantation brachytherapy.Methods The BED formula for EBRT(external beam radiotherapy) and for continuous low dose-rate irradiation established under the L-Q model were introduced.The EDQ2 formula for the continuous low dose-rate irradiation (radioactive seed implantation) was established according to the definition of EQD2 and the formula of BED.The α/β values of common tissues and the Tr 1/2 values reported in the literature were summarized.The EDQ2 formula were further simplified by using the actual values.The empirical formula of EDQ2 for early reaction tissues and late reaction tissues were proposed,named as Wang-Peng empirical formula.EDQ2≈ (10/12) D (Wang-Peng Formula 1) was fit for early response tissue,and EDQ2≈ D/2 (Wang-Peng Formula 2) for late reaction tissues.Further examples on the clinical applications of the proposed formula were given,including primary lung cancer,supraclavicular lymph node metastasis of esophageal cancer and celic lymph node metastasis of cervical carcinoma.Results According to the Wang-Peng empirical formula,the EDQ2 of the late reaction tissue adjacent to the tumor was only about half that of the tumor tissue,so the radioactive seed implantation brachytherapy naturally protected the late reaction tissue by the biological equivalent dose.The actual calculation,showed that the empirical formula of early reaction tissue was more accurate,but the empirical formula of late reaction orgtissue was less inaccurate and could only be roughly estimated.Conclusions The BED calculation formula introduced here and the set of EQD2 calculation formula and Wang-Peng empirical formula established here were theoretically feasible and could be used for the conversion and superposition between the physical dose of radioactive seed implantation brachytherapy and the external irradiation dose.But it should be careful to apply the formula,pay attention to the default conditions,and carefully interpret the calculated results.

Objective:To verify the accuracy and feasibility of radioactive 125I seed implantation assisted by an optical navigation system and a 3D-printing non-coplanar template in the treatment of recurrent head and neck cancers. Methods:A total of 12 patients with recurrent head and neck cancer treated with radioactive 125I seed implantation assisted by an optical navigation system and 3D-printing non-coplanar template were enrolled from Dec 2018 to Dec 2019.The pre-plan and post-implant implantation needle number and implanted seed number were recorded.Meanwhile, their dosimetric parameters were compared, including D90, minimum peripheral dose (MPD), V100, V150, V200, conformity index (CI), external index (EI), and the homogeneity index (HI) of the target volume. Results:The median lesion volume was 31.5 cm 3, the median number of seeds was 61.5, and the median prescription dose was 130 Gy.The means of the pre-plan D90, MPD, V100, V150 and V200 were 134.2, 64.6, 93.3, 75.3 and 39.3 Gy, respectively, while those of post-implant D90, MPD, V100, V150, and V200 were 146.7, 68.94, 97.47, 80.40 and 48.30 Gy, respectively, with no statistically significant difference ( P>0.05). Meanwhile, there was no statistically significant difference between the pre-plan and post-implantation needle number, implanted seed number, CI, HI, and EI ( P>0.05). In terms of postoperative dose quality assessment, eight cases were rated excellent (66.6%) and four cases were rated good (33.3%). Conclusions:Radioactive 125I seed implantation assisted by an optical navigation system and 3D-printing non-coplanar template can be accurately performed in the treatment of recurrent head and neck cancer, with good consistency between pre-plan and post-implant dosimetric parameters and thus of prospective potential in clinical application.

Objective:To compare preoperative planning parameters between non-coplanar and coplanar template-assisted radioactive seed implantation in the treatment of pancreatic cancers, in order to guide clinical application.Methods:Patients with pancreatic cancers who received external irradiation in the Peking University Third Hospital from Jan 2017 to May 2019 were selected.Their image information was imported into the brachytherapy planning system, and the non-coplanar plan and coplanar plan were designed individually.Each patient′s prescription dose was set to 110 Gy, and the activity of the radioactive seeds were 0.4 mCi(1 Ci=3.7×10 10Bq), respectively.For the two plans, the dose distribution was optimized and dosimetric parameters were compared, including the implantation needle number, the implanted seed number, the minimum prescription doses delivered to 90% and 100% of the target volume ( D90 and D100), mean percentages of volume receiving 100%, 150% and 200% of the prescription doses ( V100, V150 and V200), conformity index (CI), external index (EI), and homogeneity index (HI) of the target volume, as well as the doses of 2 cm 3 and 5 cm 3 ( D2 cm 3 and D5 cm 3) of the surrounding normal organs such as the small intestines, colon, duodenum, stomach, and spinal cord. Results:The implantation needle number in the coplanar plan was slightly higher than that in the non-coplanar plan, namely 18.63 vs. 16.45 ( t=-3.239, P <0.05). The implanted seed number was equivalent, namely 90.2 vs. 91.01, with no statistical difference ( P>0.05). There was no significant difference between D90, D100, V100, V150, V200, CI, EI, and HI in the target area of the two plans ( P>0.05). Meanwhile, there was no obvious difference in D2 cm 3 and D5 cm 3 of normal organs including the small intestines, colon, duodenum, stomach, and spinal cord ( P>0.05). Conclusions:With both the coplanar plan and the non-coplanar plan, the prescription doses can be achieved and meanwhile, there are very small differences in the doses of normal organs.Given that 3D-printing non-coplanar and coplanar templates have their own characteristics, it is necessary to choose them according to specific situations.

Objective:To explore the accuracy of CT-guided 125I seed implantation assisted by a navigation system and 3D-printing template in the treatment of recurrent malignant pelvic tumors by comparing pre-plan and intraoperative physical dosimetric parameters. Methods:This study involved 15 patients with recurrent malignant pelvic tumors who received CT-guided radioactive 125I seed implantation assisted by a navigation system and 3D-printing template in the Peking University Third Hospital from Dec 2018 to Feb 2020.Seven of the patients had cervical cancers, seven had rectal cancers, and one had prostate cancer.The median age was 55 years (34-84 years old). The prescription dose was 100-150 Gy.The pre-plan and post-implant data were compared, including the number of implanted seeds, implantation needle number, and some dosimetric parameters such as the minimum prescription doses delivered to 90% and 100% of target volume( D90, D100), mean percentages of volume receiving 100%, 150%, and 200% of the prescription doses( V100, V150, and V200), conformity index(CI), external index(EI), and homogeneity index(HI)of the target volume. Results:The median lesion volume was 29.20 cm 3, the median seed number was 54, and the median D90 was 150 Gy.The post-implant V150 was lower than pre-plan V150 (64.1% vs. 67.1%, t=2.937, P=0.011), and the post-implant mean HI was higher than pre-plan HI (32.01% vs. 26.68%, t=-2.950, P=0.011). There were no significant differences in other dosimetric parameters before and after seed implantation. Conclusions:With CT-guided radioactive seed implantation assisted by a navigation system and 3D-printing template in the treatment of recurrent malignant pelvic tumors, the actual postoperative dose could meet the preoperative plan requirement, ensuring the accuracy and consistency of the dose delivered.

Objective To investigate the acute side effect of 3D printing individual non-coplanar template for 125I seed implantation in head and neck recurrent/ metastatic carcinoma.Methods Between January 2016 and December 2016,42 patients of local recurrent malignant tumor of head and neck received 3D printing guide plate assist radioactive seeds implantations,and included in the study.The tumor volume ranged from 2.4 to 102.8 cm3 (median 28.6 cm3).The prescribed dose is 110-160 Gy,and the seeds activity were 0.34 to 0.70 mCi (1 Ci =3.7 × 1010 Bq).All patients carried out preoperative planning design,individual guide plate production,seed implantation,postoperative dose assessment,and followup.The side effects of skin,mucous membrane,blood and spinal cord were statistically analyzed.Results All patients were operated successfully.The follow-up time was 4-14 months (median 8.5 months).There were no adverse reactions at grade three or above.Three patients had grade one skin reaction.One patient experienced grade one mucosal reaction,two experienced grade two mucosal reactions.The skin response was correlated with the dose of the skin (x2 =7.067,P =0.032).No hematologic toxicity or radiation myelopathy was observed and no seed displacement was found.Conclusions 3D-printing guide plate can provide good accuracy for positioning and direction.For local recurrent malignant tumor of head and neck,there were no obvious adverse reactions and the operation was simple and the dosage was accurate.