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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 Subsequently, the needles were withdrawn by 10 mm, and the cold sources were implanted.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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BACKGROUND: Percutaneous lung biopsy is an important method to clarify the nature of lung nodules. However, the lungs are more active due to the presence of respiratory motion. Percutaneous lung biopsy, especially for small lung nodules, is difficult. OBJECTIVE: To introduce the application of 3D-printed coplanar template combined with fixed needle technique in percutaneous biopsy of small pulmonary nodules. METHODS: A total of 24 patients who had percutaneous lung biopsy in the Second Affiliated Hospital of Xuzhou Medical University from July 2018 to April 2019 were enrolled. Imaging examination indicated small pulmonary nodules with a nodule diameter of 8-30 mm in all the patients. According to the probability of malignancy, all tumors were of the middle and high risk grade, and there were indications for percutaneous lung biopsy. All the patients were randomized into two groups (n=12 per group): the control group underwent free hand biopsy, and the observation group underwent percutaneous lung biopsy guided by 3D printed coplanar template combined with fixed needle. The number of puncture needle adjustments, number of CT scans, positive rate of specimens, and incidence of complications were recorded and compared between the two groups. Approval for this trial was obtained from the Ethics Committee of the Second Affiliated Hospital of Xuzhou Medical University. RESULTS AND CONCLUSION: The number of puncture needle adjustments, the number of CT scans and the incidence of pneumothorax during the operation were significantly lower in the observation group than the control group (P 0.05). These findings indicate that the 3D-printed coplanar template combined with fixed needle technique can relatively fix the target lesion, reduce the number of needle adjustments and number of CT scans, reduce iatrogenic radiation, and reduce the incidence of complications, especially pneumothorax.
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Objective:To investigate the technical method and clinical efficacy of CT-guided radioactive 125I seed implantation (RISI) assisted by 3D-printed coplanar template(3D-PCT) in the treatment of metastatic tumors of chest wall, and analyze the influence of dosimetric parameters on the treatment efficacy. Methods:A retrospective analysis was conducted for 55 patients with metastatic tumors of chest wall treated with 3D-PCT-assisted 125I radioactive seed implantation in Tengzhou Central People′s Hospital from January 2014 to March 2021.Preoperative plans were made using a brachytherapy treatment planning system, and dosimetric parameters were assessed at 3d after surgery. During regular CT reexaminations after surgery, the local control rate and overall survival (OS) rate were calculated and the pain relief degree and complications were assessed. The Logrank test and Cox regression were used for univariate and multivariate analyses of local control time (LCT). Meanwhile, receiver operating characteristic (ROC) curves were plotted to analyze the critical values of dosimetric parameters and to predict the LCT. Results:The 1-, 2-, and 3-year OS rates ofthe 55 patients were 72.7% (40/55), 21.8% (12/55), and 16.4% (9/55), respectively.The local control rates of 3, 6, 12, and 24 months were 96.4%(53/55), 86.5%(45/52), 85.0%(34/40), and 91.7%(11/12), respectively. There was no statistically significant difference between postoperative and postoperative dosimetric parameters of GTV, particle number, D90, D100, V100, V150, V200, CI, EI, and HI ( P> 0.05). Compared with postoperative V90, the postoperative V90 decreased with a statistically significant difference( P=0.006). As indicated by the univariate Cox regression analysis, the pathological grade, D90, D100, V90, and V200had significant effects on the LCT( P<0.05). Among them, the pathological grade and D90 were independent influencing factors of the LCT, while the other factors showed no statistically significant difference according to the multivariate Cox regression analysis.The LCT of patients with D90≥127 Gy was significantly longer than that of patients with D90<127 Gy (χ 2=16.61, P=0.000). The pain relief rate was 80.8%(21/26) after three months. Five cases suffered from grade Ⅰ-Ⅱ radioactive dermatitis and one case experienced grade Ⅲ radioactive dermatitis. Conclusions:The 3D-PCT-assisted CT-guided 125I radioactive seed implementation can achieve precise and controllable dose and definite efficacy in the treatment of metastatic tumors of chest wall, with few complications.The LCT was remarkably prolonged in the case of D90≥127 Gy, and D90 is an independent influencing factor of the LCT.
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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 (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 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 preliminarily evaluate the safety of the coplanar template-assisted 192Ir hypofractionated stereotactic ablative brachytherapy (SABT) in patients with locally advanced non-small cell lung cancer (LA-NSCLC), and assess the effect of template-assisted technology upon the accuracy of SABT by comparing the consistency of dosimetric parameters between preoperative and operative plans.@*Methods@#Fifteen patients histologically confirmed with LA-NSCLC (stage ⅡB-ⅢA) were recruited and received the template-assisted SABT delivered in a risk-adapted fractionation (30 Gy/1F). Preoperative planning, template-assisted needle implantation, operative planning and implementation were performed in all patients. Dosimetric results of preoperative and operative plans were statistically compared by assessing the dosimetric parameters of gross tumor volume (HI, CI, D90, V100 and V150) and organ at risk(V5, V20 and mean dose of bilateral lung, D2cc of spinal cord. The incidence of perioperative complications of SABT was recorded. The safety and feasibility of SABT were evaluated.@*Results@#Slight changes were noted in terms of target dose and irradiated dose to the lung between preoperative and operative plans without statistical significance (both P>0.05). No severe adverse events, such as severe pneumothorax, hemothorax and hemoptysis were observed.@*Conclusions@#Application of the template-assisted SABT can enhance the accuracy of implantation, maintain the consistency of the dosimetric parameters between the preoperative and operative plans and guarantee the clinical efficacy.
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Objective To preliminarily evaluate the safety of the coplanar template-assisted 192Ir hypofractionated stereotactic ablative brachytherapy (SABT) in patients with locally advanced non-small cell lung cancer (LA-NSCLC),and assess the effect of template-assisted technology upon the accuracy of SABT by comparing the consistency of dosimetric parameters between preoperative and operative plans.Methods Fifteen patients histologically confirmed with LA-NSCLC (stage ⅡB-ⅢA) were recruited and received the template-assisted SABT delivered in a risk-adapted fractionation (30 Gy/1F).Preoperative planning,template-assisted needle implantation,operative planning and implementation were performed in all patients.Dosimetric results of preoperative and operative plans were statistically compared by assessing the dosimetric parameters of gross tumor volume (HI,CI,D90,V100 and V150) and organ at risk (V5,V20 and mean dose of bilateral lung,D2cc of spinal cord.The incidence of perioperative complications of SABT was recorded.The safety and feasibility of SABT were evaluated.Results Slight changes were noted in terms of target dose and irradiated dose to the lung between preoperative and operative plans without statistical significance (both P＞0.05).No severe adverse events,such as severe pneumothorax,hemothorax and hemoptysis were observed.Conclusions Application of the template-assisted SABT can enhance the accuracy of implantation,maintain the consistency of the dosimetric parameters between the preoperative and operative plans and guarantee the clinical efficacy.
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Objective To investigate the clinical application value of 3D printing coplanar template in treating pancreatic cancer with 125I seed implantation.Methods Clinical data of 10 patients with pancreatic cancer,who received 3D printing coplanar template-guided 125I seed implantation during the period from January 2016 to June 2017,were retrospectively analyzed.According to preoperative CT scan results and treatment planning system findings,a 3D coplanar template was designed and printed,guided by which percutaneous puncture and 125I seed implantation were conducted.Dosimetric verification was performed after 125I seed implantation.Both preoperative and postoperative 90％ dose of target volume (D90),90％ target volume of prescription dose (V90),100％ target volume of prescription dose (V100) and 150％ target volume of prescription dose (V150) were calculated.The success rate of puncture location of 3D printing coplanar template-guided 125I seed implantation was calculated.The coincidence between preoperative dosimetric plan and postoperative dosimetric parameter was assessed,and the complications were recorded.Results Under the guidance of 3D coplanar template,percutaneous puncture and 125I seed implantation were successfully accomplished in all 10 patients with pancreatic cancer.The postoperative dosimetric parameter D90 was consistent with preoperative planning.No statistically significant difference in D90 existed between preoperative value and postoperative one (P＞0.05).The postoperative V90,V100 and V150 were (94.3±2.4)％,(90.4±4.1)％ and (62.1±13.4)％ respectively,which were compliance with therapeutic dosimetry requirements.Local hematoma occurred in one patient after the treatment.Conclusion 3D printing coplanar template appears to be a safe and effective guiding tool,it is very helpful for precise implantation of 125I seeds in treating pancreatic cancer,and with the help of 3D printing coplanar template the postoperative dose parameters will be able to meet the preoperative planning requirements.
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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 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.
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Objective To compare the dose distribution of postoperative plans with preoperative plans for 3D printing coplanar template assisted radioactive seed implantation,and to explore the accuracy of the technique in seed implantation.Methods From November 2015 to December 2016 a total of 32 patients were selected and underwent 3D printing coplanar template assisted radioactive seed implantation in Tengzhou Central People's Hospital of Shandong province.There were 36 implanted lesions,including l0 in the lungs,5 in neck lymphs,3 in pelvic cavities,3 in vertebral body,2 in pancreas,2 in abdominal lymph nodes,2 in portal veins,and 9 in the other parts.All patients were given preoperative planning and guided by the coplanar templates.Compared with the preoperative plan,all levels needles inserted at the same time.According to preoperative planning the implantation surgery was completed accurately.The postoperative dosimetry was evaluated.The preoperative and postoperative dosimetry parameters were compared,including Dg0,D100,V90,V100.V150,V200 and conformal index (CI),external index (EI),and homogeneity index(HI).The paired t test was used to perform the statistical analysis.Result There was no significant differences in Dg0,D100,V90,V100,V150,V200,CI,EI and HI between before and after operation(P ＞ 0.05).Conclusions The dose parameters in postplan showed no difference compared with preplan in this study.For fixed and moving organ tumors,3D printing coplanar template assisted radioactive seed implantation has good therapeutic accuracy,and may be a standardized surgicalmethod for seed implantation in the future.
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Objective To explore the safety,effectivity and dosimetric continence of 3D-printing coplanar template(3D-PCT)combined with CT-guided 125I seed implantation in the treatment of non-small cell lung cancer(NSCLC).Methods From May 2014 to November 2016,a total of 20 NSCLC patients who were suitable for 125I seed implantation were recruited in this study.Of all the patients,10 received 125I seed implantation treatment by CT-guided combined with 3D-PCT (3D group),and the rest,by freehand puncture combined with CT-guided 125I seed implantation (free-hand group).During two days before the surgery,the patients received the CT scan.Then the digital imaging and communications in medicine (DICOM) was collected to input to the Brachytherapy Treatment Planning System (BTPS).The dose parameters including D90,D100,V100,V150,conformal index(CI),external index(EI),and homogneneity index(HI) were compared between pre-operation and post-operation.Pair t-test and single sample t-test were performed.Results V150 in 3D group between preoperation and postoperation showed statistically significant difference (t =-2.916,P ＜ 0.05),and there was no significant difference in the rest parameters(P ＞ 0.05).However,the number of seeds,V100,EI,HI in free-hand group between preoperation and postoperation showed statistically significant difference (t =-2.516,2.492,4.725,7.258,P ＜0.05),and there was no significant difference in the rest parameters(P ＞0.05).Comparison of indicuted that there was significant difference in V100,V150,CI,EI,HI and dose error rate between the 3D group and the free-hand group with single sample t test,the result showed V100,CI,EI,HI between two groups(t =2.598,2.278,4.637,4.616,-4.785,P ＜0.05),and there was no significant difference in V150 (P ＞ 0.05).Conclusions CT-guided 125I seed implantation brachytherapy combined with 3D-PCT for treatment of NSCLC safe is feasible,and dose controllable,and there is a certain advantage in the spatial distribution of seed compared with free-hand puncture.
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Objective To compare the planned radiation dose and the actual dose received after 125I radioactive seeds implantation supported by coplanar template (CPT) in lung cancer patients with mediastinal node metastases 4R,and to evaluate the clinical efficacy.Methods Totally 32 patients with lung cancer with mediastinal lymph node metastases 4R who had been diagnosed via cellular pathology studies were selected from January 2008 to December 2014.The mediastinal lymph node metastases were treated by CPT-assisted 125I radioactive seed implantation.Digital imaging and communications in medicine (DICOM) data were acquired by chest CT scan before implantation,brachytherapy radiation treatment planning system (BTPS) was introduced to carry out the plan,and the prescribed dose(PD) was 120 Gy.CPT was used to control the precision of needle penetration and implantation of radioactive seeds.Computer tomography (CT) was used to ensure the correct position of needles and radioactive seeds.Dose evaluation was performed immediately after implantation and was compared with planned dose using paired t-test.The 6-months postoperative chest CT was conducted to evaluate treatment efficacy according to response evaluation criteria in solid tumors(RECIST Version 1.1).Results All patients went through implantation procedure successfully.Dose evaluation after implantation was as followed.The average dose received (231.9 ±29.6)Gy,the dose received by 90％ of the target(D90) (150.8 ± 16.6) Gy,the dose received by 100％ of the target(D100) (100.4 ± 12.6)Gy,the volume of 100％PD covering the target(V100)(94.1 ± 2.6) ％,the volume of 200％ PD covering the target(V200) (33.0 ± 5.7) ％,the conformal index (CI) 0.75 ±0.06,the external index(EI) (22.7 ± 5.8)％,the average dose received by the superior vena cava (19.3 ± 7.2)Gy,and the average dose received by aorta (12.1 ± 5.1)Gy.Efficacy was followed for 6 months after implantation and the effective rate was 84.37％.There was no serious complications (such as radioactive lung injury,major vascular injury,bleeding,and et al.) occurred in follow-up period.Conclusions CPT assisted CT guided 125I radioactive seed imnplantation in treating mediastinal node metastases 4R can achieve preoperative BTPS,minimize major vascular or organ injury.It is an accurate,effective and safe treatment approach and may be of great value to standardize the procedure of radioactive seed implantation in mediastinal metastases.
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Objective To evaluate the dosimetry accuracy and clinical efficacy of 125I radioactive seed implantation using coplanar template (CPT) in the treatment of metastatic or recurrent chest wall tumor.Methods Thirty-one patients with metastasis or recurrence of chest wall tumor,who had been diagnosed with pathology between July 2005 and July 2015,were retrospectively studied.All patients underwent CPT-assisted 125I radioactive seed implantation.Brachytherapy radiation treatment planning system (BTPS) was used to make preoperative plans,and the prescribed dose (PD) was 110 Gy.CPT was used to assist CT guided 125I radioactive seeds implantation.Dose evaluation was performed immediately after implantation.The difference of dose parameters was compared between preoperation and postoperation,including Dg0,D100,V90,V100 and the numbers of seeds.Postoperative chest CT was conducted regularly to assess the treatment efficacy based on the response evaluation criteria in solid tumors (RECIST Version 1.1).The patients were followed up till July 2016.Results All patients went through implantation procedure successfully and there was no significant statistical difference between preoperative and postoperative dose parameters (P ＞ 0.05).The conformal index (CI) was 0.951 ± 0.13,external index(EI) was 6.5％ ±0.9％.Six months after implantation,CR,PR,SD and PD were 25.8％ (8/31),51.6％ (16/31),6.5％ (2/31) and 16.1％ (5/31),respectively.The effective rate was 77.4％,and local control rate was 83.9％ (26/31).Skin pigmentation occurred in 13 patients during the follow-up period,without any special treatment.Conclusions The auxiliary of CPT in the treatment of metastatic or recurrent chest wall tumor under the guiding of CT could achieve quality control,safety and effectiveness.
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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.