Objective To investigate the technological feasibility and short-term efficacy of 125I seeds implantation in head and neck cancer. Methods Thirty patients with head and neck recurrent cancer were treated with 125I seeds interstitial brachytherapy. The operation was performed under local anesthesia and the 125I seeds were implanted under the guidance of ultrasonography. The seed needles were implanted parallelly to each other, at 1～1.5 cm apart. The Mick applicator was used to implant seed at 1 cm interval. The radioactive activity per seed ranged 0.40～0.70 mCi, and the matched peripheral dose (MPD) was 90～160 Gy. The number of 125I seed implanted per lesion was 3～84 (median, 24). Ten patients with a seed radioactive dose

Objective　To evaluate the expression of MAGE-1 gene in esophageal carcinoma and determine whether esophageal carcinoma patients should be eligible for MAGE-1 antigen-based vaccine therapies． Methods　 MAGE-1 mRNA expression in esophageal carcinoma was assessed by reverse transcription and polymerase chain reaction amplification． The PCR products were then digested by restriction endonucleases and inserted into the pET-30a(+) vector． The sequence of the inserted gene fragment was confirmed by DNA sequence analysis． Results　Out of the 30 esophageal carcinomas studied, 43% of the esophageal carcinomas tissues expressed MAGE-1 gene and no expression was found in matched adjacent normal esophageal mucosae． The entire cDNA of the gene was cloned． Conclusion　Owing to the high frequency of MAGE-1 gene expression in esophageal carcinoma and MAGE-1 antigen can be recognized by cytolytic T lymphocytes when presented by class-I HLA molecular, a large proportion of these patients might be suitable candidates for immune therapy involving tumor specific antigens encoded by MAGE-1 gene．

Objective To identify-and study a monoclonal antibody (McAb) against pancreatic cancer stem cell in vitro,as well as to provide candidate antibody-drug for cancer stem cell-targeted therapy of pancreatic cancer.Methods Cell culture in serum-free medium and PKH26 staining were used to determine the existence of cancer stem cell in PANC-1 cell line.Flow cytometry was used to detect the expression of CD24 and CD44 in PANC-1 cells and sphere cells,Immunofluorescence was used to detect the expression of CD24 and antigen recognized by 15D2.The effects of 15D2 on self-renewal,proliferation and chemosensitivity to gemcitabine of PANC-1 parent or sphere cells were identified by serum-free suspension culture and CCK-8 assay,Immunohistochemistry was applied to detect the level of antigen recognized by 15D2 in cancer and adjacent tissues.Results PANC-1 cells could survive,proliferate and form sphere cells in serum-free medium.The sphere-forming rate was (2.5±0.5) ％.The percentage of CD44+ CD24+ cells population in sphere cells increased by 11.4 folds compared to PANC-1 cells,in which single nearly 97 ％ CD24+ cells was CD44+ CD24+ cells.Therefore,CD24+ was selected for cancer stem cell marker in PANC-1 in this study.The two-color immunofluorescence assay showed that 15D2 could recognize cells which was also stained by CD24.In vitro functional experiments demonstrated that 15D2 significantly suppressed the sphere formation of PANC-1 cells,with the inhibitory rate being 30.4 ％.Meanwhile,the combination of 15D2 and gemcitabine can significantly attenuate the growth of PANC-1 sphere cells.The IC50 was 0.10 μmol/L in 15D2+gemeitabine group,and 0.39 μmol/L in mlgM+gemcitabine group,Immunohistochemical results showed that the antigen recognized by 15D2 was greatly expressed in about 76.9 ％ (11/13) human pancreatic cancer tissues and hardly detected in adjacent normal tissues (10.0 ％,1/10).Conclusion McAb 15D2 can inhibit self-renewal and drug-resistance of pancreatic cancer stem cell in PANC-1 cell line,and it might become a candidate drug for target pancreatic cancer stem cell 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 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 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 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.

Objective To investigate the accuracy of 3D-printing non-coplanar template (3D-PNCT) assisted 125I seed implantation with CT guidance in the pelvic recurrent cervical between the preplan and post-plan dosimetric parameters.Methods Nine patients with pelvic recurrent cervical cancer received 125I seed implantation under CT guidance assisted with 3D-PNCT.A pre-plan based brachytherapy treatment planning system (B-TPS) assisted with 3D-PNCT for seed needle depth,direction and angle was designed.The dosimetry parameters including homogeneity index (HI),dose of 90％ target volume (Dg0),mPD,volume percent of 100％,150％ and 200％ prescribed dose V100,V150 and V200 and organ at risk between the pre-plan and post-plan were compared.Results Total seeds number was 675 (median 44,25-114) according to pre-plan,and 669 (median 47,25-113) seeds were implanted actually.138 needles need implant according to preplan,and 132 needles was implanted actually.The median angle deviation was 1.99 ° ± 2.94°(0 °-13 °).There was no significant difference of HI,EI and CI between perand post-plan.The differences of D90,MPD,V100,V150 and V200 between pre-and post-plan were not significant.Conclusions The confidence of pre-plan and post-plan for 3D-PNCT assisted 125I seed implantation in the pelvic recurrent cervical cancer could be accurately performed under CT guidance.

Objective To compare the dosimetric data between preoperative plans and postoperative verification in computed tomography (CT)-guided and 3D-printing non-coplanar templateassisted 125I seed implantation for pelvic tumor,and to explore the feasibility and accuracy of the personalized template designmethod.Methods A total of 51 patients registered from Dec 2015 to Dec 2016 who were applied with 3D-printing guided template assisted radioactive seed implantations in the hospital were included in this study.A prescribed dose of 110-160 Gy was adopted.3D-printing templates were designed and produced for 51 cases.The dosimetric parameters:Dg0,minimum peripheral dose (mPD),V100,V150,V200,conformal index (CI),external index (EI),and homogeneity index (HI) were compared between pre-and post-plans.Results 51 cases' templates were in place well during the operations.Compared with the preoperative planning,the postoperative D90,V100,V150,V200,CI,EI and HI differences had no statistical difference (P ＞ 0.05);mPD is larger than before (t =-2.96,P ＜ 0.05).Conclusions The main dosimetric parameters of postoperative verification were consistent well with the preoperative planning and have good accuracy,which could meet the clinical requirements.