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Objective:To study the precision of 3D printing coplanar template (3D-PCT) assisted CT-guided radioactive particle implantation using two types of phantoms, and compare the differences between the phantoms, in order to provide reference for radioactive particle implantation.Methods:The needle inserting path was designed in the brachytherapy treatment planning system (BTPS) and the needle tip coordinates were obtained. Following the needle inserting path, the implant needles were inserted into the custom and the liver phantoms, respectively. Then gold markers were implanted through the needles. Subsequently, the needles were withdrawn by 10 mm, and the cold sources were implanted. The coordinates of needle tips, gold markers, and cold sources were recorded. The precision of implanted needles, first particles, and particles after needle withdrawal were obtained by calculating the distance between two points in the space. Finally, the differences between the two phantoms were compared through independent samples t-test. Results:In the 3D-PCT-assisted CT-guided radioactive particle implantation, the precision of implanted needles, first particles, and particles after needle withdrawal in the custom and the liver phantoms was (1.89±0.72) and (2.14±0.88 ) mm ( P>0.05), (2.03±1.14) and (2.42±1.12) mm ( P>0.05), and (-1.96±1.29) and (-2.82±0.91) mm ( t=2.09, P=0.046), respectively. Conclusions:The 3D-PCT-assisted CT-guided radioactive particle implantation is efficient, stable, and precise, showing slight precision differences between the two phantoms.
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Objective:To explore the effects of multimodal imaging on the performance of automatic segmentation of glioblastoma targets for radiotherapy based on a deep learning approach.Methods:The computed tomography (CT) images and the contrast-enhanced T1 weighted (T1C) sequence and the T2 fluid attenuated inversion recovery (T2- FLAIR) sequence of magnetic resonance imaging (MRI) of 30 patients with glioblastoma were collected. The gross tumor volumes (GTV) and their corresponding clinical target volumes CTV1 and CTV2 of the 30 patients were manually delineated according to the criteria of the Radiation Therapy Oncology Group (RTOG). Moreover, four different datasets were designed, namely a unimodal CT dataset (only containing the CT sequences of 30 cases), a multimodal CT-T1C dataset (containing the CT and T1C sequences of 30 cases), a multimodal CT-T2-FLAIR dataset (containing the CT and T2- FLAIR sequences of the 30 cases), and a trimodal CT-MRI dataset (containing the CT, T1C, and T2- FLAIR sequences of 30 cases). For each dataset, the data of 25 cases were used for training the modified 3D U-Net model, while the data of the rest five cases were used for testing. Furthermore, this study evaluated the segmentation performance of the GTV, CTV1, and CTV2 of the testing cases obtained using the 3D U-Net model according to the indices including Dice similarity coefficient (DSC), 95% Hausdorff distance (HD95), and relative volume error (RVE).Results:The best automatic segmentation result of GTV were achieved using the CT-MRI dataset. Compared with the segmentation result using the CT dataset (DSC: 0.94 vs. 0.79, HD95: 2.09 mm vs. 12.33 mm, and RVE: 1.16% vs. 20.14%), there were statistically significant differences in DSC ( t=3.78, P<0.05) and HD95 ( t=4.07, P<0.05) obtained using the CT-MRI dataset. Highly consistent automatic segmentation result of CTV1 and CTV2 were also achieved using the CT-MRI dataset (DSC: 0.90 vs. 0.91, HD95: 3.78 mm vs. 2.41 mm, RVE: 3.61% vs. 5.35%). However, compared to the CT dataset, there were no statistically significant differences in DSC and HD95 of CTV1 and CTV2 ( P>0.05). Additionally, the 3D U-Net model yielded some errors in predicting the upper and lower bounds of GTV and the adjacent organs (e.g., the brainstem and eyeball) of CTV2. Conclusions:The modified 3D U-Net model based on the multimodal CT-MRI dataset can achieve better segmentation result of glioblastoma targets and its application potentially benefits clinical practice.
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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.
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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.
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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.
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Interstitial permanent radioactive seed implantation delivers a high local dose to tumors and sharply drops off at surrounding normal tissues. Radioactive seeds implanted via ultrasound or computed tomography (CT) guidance are minimally invasive and facilitate quick recovery. Transrectal ultrasound-guided 125I seed implantation assisted by a transperineal plane template is standard for early-stage prostate carcinoma, with a highly consistent target volume dose distribution. The postplan dose evaluation is consistent with the preplan evaluation. Until now, there was no workflow for seed implantation elsewhere in the body, and it was difficult to effectively preplan for seed implantation because of patients' position changes, organ movement, and bone structure interference. Along with three-dimensional (3D) printing techniques and seed implantation planning systems for brachytherapy, coplanar and X Y axis coordinate templates were created, referred to as 3D-printed coplanar templates (3D-PCT). 125I seed implantation under CT guidance with 3D-PCT assistance has been very successful in some carcinomas. Preplanning was very consistent with postplanning of the gross tumor volume. All needles are kept parallel for 3D-PCT, with no coplanar needle rearrangement. No standard workflow for 3D-PCT-assisted seed implantation exists at present. The consensus topics for CT-assisted guidance compared to 3D-PCT-assisted guidance for seed implantation are as follows: Indications for seed implantation, preplanning, definition of radiation doses and dosimetry evaluation, 3D-PCT workflow, radiation protection, and quality of staff. Despite current data supporting 125I seed implantation for some solid carcinomas, there is a need for prospectively-randomized multicenter clinical trials to gather strong evidence for using 125I seed implantation in other solid carcinomas
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Objective@#To compare the preoperative and postoperative dosimetric parameters in the treatment of spinal metastasis, and to verify the accuracy of 3D-printing non-coplanar template (3D-PNCT) combined with CT-guided 125I seed implantation for the treatment of spinal metastasis.@*Methods@#The treatment plans of 7 patients with spinal metastasis (9 lesions) from 2016 to 2018 receiving 3D-PNCT in combination with CT-guided 125I seed implantation were retrospectively analyzed. The dosimetric parameters including homogeneity index (HI), conformal index (CI), external index (EI), dose of 90% target volume(D90), mPD, volume percent of 100%, 150%, and 200% prescribed dose V100、V150、V200 and D2cm3 of spinal cord were compared before and after operation. The british columbia cancer ageny particle implantation quality evaluation standard was applied to evaluate the quality of implantation.@*Results@#The HI, EI and CI, D90, mPD, V100, V150, V200 and D2cm3 of spinal cord did not significantly differ before and after the plan (all P>0.05). Five were evaluated as excellent and 4 were assessed as good.@*Conclusion@#The postoperative dosimetric parameters of 3D-PNCT combined with CT guided 125I seed implantation of spinal metastasis are basically consistent with preoperative dosimetric parameters. The postoperative plans are evaluated as excellent or good, suggesting that the technology has a good therapeutic accuracy in the treatment of spinal metastasis.
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Objective@#To compare the dosimetric data between preoperative plans and postoperative verification in computed tomography (CT)-guided and 3D-printing non-coplanar template-assisted 125I seed implantation for head and neck tumor, aiming to explore the safety, feasibility and accuracy of the individualized template design method.@*Methods@#A total of 42 patients with recurrent/metastatic malignant head and neck tumor admitted to Peking University Third Hospital from January to December 2016 were recruited in this study. A prescribed dose of 110-160Gy was adopted.3D-printing non-coplanar templates were designed for 42 cases. The dosimetric parameters including D90, minimum peripheral dose (mPD), V100, V150, V200, conformal index (CI), external index (EI) and homogeneity index (HI) were statistically compared before and after surgery.@*Results@#All templates were properly implanted intraoperatively. Compared with preoperative planning, postoperative D90, V100, CI, EI and HI did not significantly differ (P=0.490, 0.407, 0.893, 0.143 and 0.079), whereas mPD, V150 and V200 significantly differed (P=0.036, 0.007 and 0.000).@*Conclusion@#After postoperative verification, the main dosimetric parameters have high therapeutic accuracy and properly match with preoperative planning, which can meet clinical requirements.
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Objective:To compare the difference of preoperative and postoperative plans of navigation-assisted three-dimensional (3D)-printing template combined with CT-guided radioactive 125I seeds implantation for malignant tumors, and verify preliminarily the plan quality of optical navigation-assisted seeds implantation. Methods:From December 2018 to November 2019, a total of 20 patients (10 males, 10 females, median age: 60.5 years) with malignant tumors received navigation-assisted 3D-printing template combined with CT-guided radioactive 125I seeds implantation in Peking University Third Hospital. Eight cases were implanted in the head and neck, 1 case in the chest wall, 9 cases in the pelvis and 2 cases in the paravertebral and/or retroperitoneal region. The median prescription dose was 150 Gy. The data in the preoperative and postoperative plans was compared, including seeds number, needles number, and some dosimetry parameters. Dosimetry parameters including dose delivered to 90% gross tumor volume (GTV) ( D90), percentage of GTV received 100%, 150%, and 200% of the prescribed dose ( V100, V150, V200), minimum peripheral dose (MPD), conformal index (CI), external index (EI), homogeneity index (HI) of target volume, and 2 cm 3 range of spinal cord receiving dose ( D2 cm 3). Paired t test and Wilcoxon signed rank test were used to analyze the data. Results:The needles number of preoperative and postoperative plans was the same (both 12 (9, 19)), and the seeds number of postoperative plan was more than preoperative plan with no significant difference (51(35, 68) vs 49(35, 63); z=1.859, P>0.05). The MPD of postoperative plans was higher than preoperative plans ((80.52±14.89) vs (67.22±20.56) Gy, t=-3.769, P=0.001). There were no significant differences in other dosimetry parameters between the two plans ( t values: -0.533, -0.423, z values: from -0.849 to 1.416, all P>0.05). Postoperative dose quality assessment was excellent in 17 cases (17/20), good in 2 cases (2/20) and middle in 1 case (1/20). Conclusions:The quality of the implantation is good under the guidance of combined mode. The actual target dose after operation can meet the requirements of preoperative planning.
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Objective To compare the preoperative and postoperative dosimetric parameters in the treatment of spinal metastasis,and to verify the accuracy of 3D-printing non-coplanar template (3D-PNCT)combined with CT-guided 125I seed implantation for the treatment of spinal metastasis.Methods The treatment plans of 7 patients with spinal metastasis (9 lesions) from 2016 to 2018 receiving 3D-PNCT in combination with CT-guided 125I seed implantation were retrospectively analyzed.The dosimetric parameters including homogeneity index (HI),conformal index (CI),external index (EI),dose of 90％ target volume (Dg0),mPD,volume percent of 100％,150％,and 200％ prescribed dose V100、V150、V200 and D2cm3 of spinal cord were compared before and after operation.The british columbia cancer ageny particle implantation quality evaluation standard was applied to evaluate the quality of implantation.Results The HI,EI and CI,Dg0,mPD,V100,V150,V200 and D2cm3 of spinal cord did not significantly differ before and after the plan (all P＞0.05).Five were evaluated as excellent and 4 were assessed as good.Conclusion The postoperative dosimetric parameters of 3D-PNCT combined with CT guided 125I seed implantation of spinal metastasis are basically consistent with preoperative dosimetric parameters.The postoperative plans are evaluated as excellent or good,suggesting that the technology has a good therapeutic accuracy in the treatment of spinal metastasis.
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Objective To compare the dosimetric data between preoperative plans and postoperative verification in computed tomography (CT)-guided and 3D-printing non-coplanar template-assisted 125I seed implantation for head and neck tumor,aiming to explore the safety,feasibility and accuracy of the individualized template design method.Methods A total of 42 patients with recurrent/metastatic malignant head and neck tumor admitted to Peking University Third Hospital from January to December 2016 were recruited in this study.A prescribed dose of l10-160Gy was adopted.3D-printing non-coplanar templates were designed for 42 cases.The dosimetric parameters including D90,minimum peripheral dose (mPD),V100,V150,V200,conformal index (CI),external index (EI) and homogeneity index (HI) were statistically compared before and after surgery.Results All templates were properly implanted intraoperatively.Compared with preoperative planning,postoperative D90,V100,CI,EI and HI did not significantly differ (P=0.490,0.407,0.893,0.143 and 0.079),whereas mPD,V150 and V200 significantly differed (P=0.036,0.007 and 0.000).Conclusion After postoperative verification,the main dosimetric parameters have high therapeutic accuracy and properly match with preoperative planning,which can meet clinical requirements.
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OBJECTIVE@#To screen for pathogenic variants in the coding regions of STK11 gene among Chinese patients with Peutz-Jeghers syndrome (PJS).@*METHODS@#Peripheral blood samples were collected from 64 patients. The coding regions of the STK11 gene were detected by PCR and Sanger sequencing.@*RESULTS@#Fourty-eight patients were found to harbor STK11 gene variants, which included 39 types of variants consisting of missense, nonsense, insertional, deletional and splice site variants. Among 64 PJS patients, the detection rate of point variants was 75.00% (48/64), of which missense variants accounted for 29.17% (14/48), nonsense variants accounted for 29.17%(14/48), insertion variants accounted for 2.08% (1/48), deletional variants accounted for 10.42% (5/48), and splice site variants accounted for 29.17% (14/48). The detection rates of sporadic cases and those with a family history were 71.8% (28/39) and 80.0% (20/25), respectively. Two variants (c.250A>T, c.580G>A) occurred in 3 PJS probands. Thirteen variants were unreported previously and were considered to be pathogenic.@*CONCLUSION@#The detection rate of variants among Chinese PJS patients is similar to that of other countries. A number of novel common variant sites were discovered, which enriched the spectrum of PJS-related variants.
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Humans , Asian People , China , DNA Mutational Analysis , Peutz-Jeghers Syndrome , Genetics , Protein Serine-Threonine Kinases , GeneticsABSTRACT
Objective@#To screen for pathogenic variants in the coding regions of STK11 gene among Chinese patients with Peutz-Jeghers syndrome (PJS).@*Methods@#Peripheral blood samples were collected from 64 patients. The coding regions of the STK11 gene were detected by PCR and Sanger sequencing.@*Results@#Fourty-eight patients were found to harbor STK11 gene variants, which included 39 types of variants consisting of missense, nonsense, insertional, deletional and splice site variants. Among 64 PJS patients, the detection rate of point variants was 75.00% (48/64), of which missense variants accounted for 29.17% (14/48), nonsense variants accounted for 29.17%(14/48), insertion variants accounted for 2.08% (1/48), deletional variants accounted for 10.42% (5/48), and splice site variants accounted for 29.17% (14/48). The detection rates of sporadic cases and those with a family history were 71.8% (28/39) and 80.0% (20/25), respectively. Two variants (c.250A>T, c. 580G>A) occurred in 3 PJS probands. Thirteen variants were unreported previously and were considered to be pathogenic.@*Conclusion@#The detection rate of variants among Chinese PJS patients is similar to that of other countries. A number of novel common variant sites were discovered, which enriched the spectrum of PJS-related variants.
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OBJECTIVE: To investigate the efficacy of image-guided radioactive 125I seed (IGRIS) implantation for pelvic recurrent cervical cancer (PRCC) after external beam radiotherapy (EBRT), and analyze the influence of clinical and dosimetric factors on efficacy. METHODS: From July 2005 to October 2015, 36 patients with PRCC received IGRIS. We evaluated local progression-free survival (LPFS) and overall survival (OS). RESULTS: The median follow up was 11.5 months. The 1- and 2-year LPFS rate was 34.9% and 20%, respectively. The multivariate analysis indicated recurrence site (central or pelvic wall) (hazard ratio [HR]=0.294; 95% confidence interval [CI]=0.121–0.718), lesion volume (HR=2.898; 95% CI=1.139–7.372), D 90 (HR=0.332; 95% CI=0.130–0.850) were the independent factors affecting LPFS. The 1- and 2-year OS rate was 52.0% and 19.6%, respectively. The multivariate analysis suggested pathological type (HR=9.713; 95% CI=2.136–44.176) and recurrence site (HR=0.358; 95% CI=0.136–0.940) were the independent factors affecting OS. The dosimetric parameters of 33 patients mainly included D 90 (128.5±47.4 Gy), D 100 (50.4±23.7 Gy) and V 100 (86.7%±12.9%). When D 90 ≥105 Gy or D 100 ≥55 Gy or V 100 ≥91%, LPFS was extended significantly, but no significant difference for OS. The 79.2% of 24 patients with local pain were suffering from pain downgraded after radioactive 125I seed implantation. CONCLUSION: IGRIS implantation could be a safe and effective salvage treatment for PRCC after EBRT, which could markedly release the pain. Recurrence site, tumor volume and dose were the main factors affected efficacy. Compared with central recurrence, it was more suitable for patients with pelvic wall recurrent cervical cancer after EBRT.
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Humans , Brachytherapy , Disease-Free Survival , Follow-Up Studies , Multivariate Analysis , Radiometry , Radiotherapy , Radiotherapy, Image-Guided , Recurrence , Salvage Therapy , Tumor Burden , Uterine Cervical NeoplasmsABSTRACT
Objective To evaluate the clinical efficacy and safety of CT-guided 125 I seed implantation in the treatment of recurrent head and neck tumors after radiotherapy. Methods Clinical data of 101 patients who received CT-guided radioactive 125 I seed implantation for recurrent head and neck cancer after radiotherapy from 2007 to 2015 were retrospectively analyzed. The median accumulated dose of external radiotherapy was 66 Gy and the median dose after seed implantation (D90) was 117 Gy. The local progression-free survival and overall survival were analyzed by Kaplan-Meier method. Univariate analysis was performed by log-rank test and multivariate analysis was conducted by using Cox regression model. Results The median follow-up time was 12. 2 months. The 5-year local progression-free survival rate was 26. 6％.The 5-year overall survival rate was 15. 5％. Univariate analysis demonstrated that age,pathological type,implantation site,lesion volume,D90 and short-term efficacy were correlated with local control,and KPS score,lesion volume ,D90,and short-term efficacy were associated with survival (all P<0. 05). Multivariate analysis revealed that pathological type,lesion volume ,D90 and short-term efficacy were independent factors related to local control (P= 0. 000, 0. 002,0. 003 and 0. 014).In terms of the adverse events,skin/ mucosal ulceration was observed in 25. 7％ and pain occurred in 13. 9％ of all patients. No correlation was noted between the adverse events and dose.Conclusions CT-guided radioactive 125 I seed implantation is an efficacious and safe treatment of recurrent head and neck tumors after radiotherapy. Non-squamous carcinoma,small lesion volume and high dose (D90) indicate excellent local control.
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Objective To investigate the utilization rate of gold fiducial markers and reasons for abandonment of gold fiducial markers in the CyberKnife VSI System, and to provide reference data for implantation of gold fiducial markers and radiotherapy planning. Methods From March to August,2017,a total of 47 patients had gold fiducial markers implanted or pasted. In those patients, 42 patients had gold fiducial markers implanted,including 32 receiving computed tomography(CT)-guided 3D-printing coplanar template assisted implantation, 1 receiving CT-guided 3D-printing non-coplanar template assisted implantation,1 receiving CT-guided implantation,and 8 receiving ultrasound-guided implantation. A total of 44 patients received the CyberKnife treatment, including 2 patients who failed to use gold fiducial markers and were treated with spine tracking instead and 3 patients missing the treatment for other reasons. The numbers of utilized and abandoned gold fiducial markers were recorded for calculation of the utilization and abandonment rates. The reasons for abandonment of gold fiducial markers were analyzed and classified. Results A total of 134 gold fiducial markers were implanted into or pasted to the 44 patients.In all the gold fiducial markers, 111 were utilized and 23 abandoned, yielding a utilization rate of 82.8% and an abandonment rate of 17.2%.The reasons for abandonment of gold fiducial markers included large rigidity error(26.1%), unqualified implanted fold fiducial markers(17.4%), displacement of gold fiducial markers(26.1%), and others(30.4%). Conclusions Compared with the CT-guided or ultrasound-guided implantation of gold fiducial markers, the CT-guided 3D-printing coplanar or non-coplanar template assisted implantation of gold fiducial markers requires only two puncture needles for each implantation and implants two gold fiducial markers by a single needle,which reduces the number of puncture needles,risk of puncture-induced injury,and incidence of complications after implantation. Not all the gold fiducial markers implanted by a variety of ways will be utilized. Some gold fiducial markers will be abandoned for different reasons,which should be taken into account during implantation of gold fiducial markers.
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Objective To compare the dose distributions of postoperative plans with preoperative plans for 3D printing guide plate assist radioactive seeds implantations, explore the effects of the technology for seeds implantations in dosimetry level. Methods From January 2016 to December 2016, a total of 42 patients of local recurrent malignant tumor of head and neck received 3D printing guide plate assist radioactive seeds implantations in in Peking University Third Hospital, and included in the retrospective study. The prescribed dose was 110 -160 Gy. All patients carried out preoperative planning design, individual guide plate production, and compared the dose distribution of postoperative plan with preoperative plan. Dose parameters include D90 , mPD, V100 , V150 , V200 , CI, EI and HI. Statistical method was paired t-test. Results A total of 423D printing individual templates were produced. The mean GTV volume of all patients was 28. 6 cm3 , and mean D90 of postoperative target area ( GTV) was 142. 6 Gy. For postoperative plans, the mean D90 , mPD, V100 , V150, V200 was 142. 6 Gy, 77. 3 Gy, 92. 48％, 68. 40％and 42. 98％, respectively, and 144. 5 Gy, 70. 2 Gy, 91. 45％, 63. 12％ and 34. 74％, respectively, in preoperative plans. Except mPD, V150, V200(t= -2. 166, -2. 863, -4. 778, P<0. 05), there was no significant difference between the two groups. Conclusions 3D printing guide plate could provide good accuracy for positioning and direction. For local recurrent malignant tumor of head and neck, the actual dose distributions in postoperative validations were close to the expectations of preoperative plans which mean the improvement of accuracy in treatment.
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Objective To investigate the feasibility of 3D-printing coplanar coordinate template (3D-PCT) for guiding 125I radioactive seed implantation in the treatment of pelvic wall recurrence of cervical cancer on ensuring the accuracy of dose.Methods From Oct 2016 to Dec 2017 in Peking University Third Hospital,totally 10 patients with pelvic wall recurrent cervical cancer after radiotherapy were treated with 125I radioactive seed implantation assisted by 3D-PCT.The median age was 53.5 years old (37-71 years old).KPS score of the cohort were more than 70.All patients had received pelvic radiation therapy previously.The median volume of the lesion was 31.9 cm3 (3.5-58.0 cm3).The prescription dose was 120-180 Gy.The activity of seeds was 0.55-0.67 mCi(1 Ci =3.7 × 1010Bq),while the number of seeds was 12-81 (median 50) on preoperative plan.Radioactive seeds implantation was performed under 3D-PCT guidance according to the preoperative plan.The actual number of implanted seeds was 53 (10-82).Dosimetry parameters of preoperative plan and postoperative plan including D90,D100,V100,V150,V200,external index (EI),conformal index (CI),heterogeneity index (HI),and organat-risk doses of D2 cm3,D1 cm3 and D0.1 cm3 were compared using the nonparametric test.Results The seed number of postoperative plan was more than that of preoperative plan (Z =-2.255,P ＜ 0.05),but all of the dosimetric parameters showed no significant difference (P ＞ 0.05).D2 cm3 and D1 cm3 of rectum for postoperative plan were lower than that of preoperative plan (Z =-2.100,-2.240,P ＜ 0.05),while other dose parameters of normal tisssues showed no statistically significant difference (P ＞ 0.05).Conclusions Assisted by 3D-PCT for 125I radioactive seed implantation in pelvic wall recurrence of cervical cancer,the actual postoperative dose could meet the requirement of the preoperatie plan through the intraoperative optimization of dose.3D-PCT could ensure the precise of delivered dose of 125I radioactive seed implantation.
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Objective To evaluate the outcomes and prognostic factors of image-guided 125I seed implantation for locally recurrent soft tissue sarcoma(RSTS).Methods A total of 60 patients with RSTS who received image-guided 125I seed implantation in Peking University Third Hospital,from September 2002 to December 2015,were retrospectively analyzed.The enrollment criteria: KPS ＞60 points,refused or could not tolerate surgery or radiotherapy,the expecting survival time ＞3 months,relapsed after multiple treatment of soft tissue sarcoma,and underwent CT or ultrasound guided 125 I seed implantation treatment.In all,the median activity of seeds was 25.9×106Bq(range,11.1×106-29.6×106Bq),median number of implanted seeds was 58(range,3-133),and the median D90was 120 Gy(range,36.50-460.97 Gy).The local progression-free survival(LPFS)and overall survival(OS)were calculated using the Kaplan-Meier method.The log-rank test and Cox regression model were used for the univariate and multivariate analyses.Results The median follow-up was 18.75 months(range,1-146).The median OS was 18.5 months(95％CI 13.1-23.9).The 1-,3-and 5-year OS rate were 63.3％,33.0％and 29.5％,respectively.The 1-,3-and 5-year LPFS rate were 72.5％,63.7％and 59.7％,respectively.The general rate of pain relieving was 100％(6/6).8.3％(5/60)presented grade Ⅳskin toxicity.No fatal complications ocurred.The univariate analysis suggested that tumor size,tumor volume,KPS score,D90were prognostic factors of OS and LPFS.The multivariate analysis demonstrated that previous chemotherapy history and distant metastases were independent prognostic factors of survival.Conclusions Image-guided 125I seed implantation for recurrent soft tissue sarcoma is a safe treatment option with high efficacy and low morbidity.Tumor size and D90were the prognostic factors of OS and LPFS.
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Objective To compare the dose distribution of postoperative plans with preoperative plans of 3D-printing template (coplanar and non-coplanar) assisted and CT-guided 125I seed implantation for the treatment of soft tissue sarcoma,and to explore the accuracy of treatment at dosimetry level.Methods From December 2015 to July 2017,19 patients with soft tissue sarcoma (a total of 25 lesions)were treated with 3D printing template assisted and CT-guided 125I seed implantation in Peking University Third Hospital.All patients underwent preoperative assessment,CT simulation orientation,preoperative planning,3D-template printing,3D-template reduction,needle and seed implantation,postoperative dosimetry assessment,postoperative care and follow-up.The preoperative and postoperative dosimetric parameters were conpared.Ten cases of soft tissue sarcoma in superficial trunk or limbs were screened.Preoperative planning of coplanar template and non-coplanar template were designed respectively.The dosimetric parameters of preoperative planning guided of two templates were compared.Results Twentyfive 3D-printing templates were designed and constructed,and 25 lesions were totalled.There was no statistical difference between preoperative and postoperative dosimetric parameters.There was no statistical difference of the preoperative plan's dosimetric parameters between coplanar and non-coplanar in soft tissue sarcoma of superficial trunk/limbs.Conclusions The validation of actual dose distribution in postoperative plans assisted by 3D-printing template in 125I seed implantation showed that most of parameters could meet the expectation of preoperative plans,which indicated the improvement in accuracy for this new modality.For soft tissue sarcoma located in the superficial trunk/limbs,it was recommended to select the 3D-printing coplanar template firstly.