Three-Dimensional-Printed Template-Guided Radioactive Seed Brachytherapy via a Submental Approach for Recurrent Base of Tongue and Floor of Mouth Cancer.

Background: This study assessed clinical outcomes of three-dimensional-printed template (3DPT)-guided radioactive seed brachytherapy (RSBT) via a submental approach for recurrent base of tongue and floor of mouth cancer. Methods: Thirty-one patients with recurrent lingual and floor of mouth squamous cell carcinoma after surgery and radiotherapy were treated with 3DPT-guided RSBT from 2015 to 2022. Seeds were implanted through a submental approach guided by 3DPTs. Local control (LC), overall survival (OS), disease control (DC) and quality of life (QOL) were evaluated. Results: The median follow-up was 13.7 months. The 1-, 3- and 5-year LC rates were 66.1%, 66.1%, and 55.1% respectively. The 1-, 3- and 5-year OS rates were 63.4%, 33.4%, and 8.3%. The 1-, 3- and 5-year DC rates were 37.8%, 26.5%, and 21.2%. Univariate analysis showed tumor size significantly affected LC (P = 0.031). The presence of extraterritorial lesions affected DC and OS on multivariate analysis (P < 0.01). QOL improved significantly in domains of pain, swallowing, chewing, taste, and emotion after treatment compared to baseline. Four patients (13%) developed necrosis and osteoradionecrosis. Conclusions: 3DPT-guided submental RSBT provided favorable LC and QOL for recurrent tongue/floor of mouth cancer with minimal toxicity; moreover, severe toxicity should be noted.

Digital partition bonding for porcelain veneers guided by sequence 3D printing templates.

Obtaining optimal enamel bonding is a common recommendation to ensure the retention, edge closure, and clinical service life of porcelain veneers. Bonding surface is determined after tooth preparation. More or less dentin exposure often occurs due to the uneven thickness of the enamel. Identifying the enamel or dentin on the bonding surface and adopting the "selective etching" technique are useful to obtain the maximal bonding strength. Naked eye recognition in "selective etching" has uncertain results and is experience-based, whereas the proposed technique controls the preparation depth through the first target restoration space template to obtain the accurate enamel and dentin subarea. It is mapped to the second bonding template, depending on the treatment carried out on the enamel and dentin surface, to accurately predict the adhesion of porcelain veneers.

Radioactive Iodine-125 in Tumor Therapy: Advances and Future Directions.

Radioactive iodine-125 (I-125) is the most widely used radioactive sealed source for interstitial permanent brachytherapy (BT). BT has the exceptional ability to deliver extremely high doses that external beam radiotherapy (EBRT) could never achieve within treated lesions, with the added benefit that doses drop off rapidly outside the target lesion by minimizing the exposure of uninvolved surrounding normal tissue. Spurred by multiple biological and technological advances, BT application has experienced substantial alteration over the past few decades. The procedure of I-125 radioactive seed implantation evolved from ultrasound guidance to computed tomography guidance. Compellingly, the creative introduction of 3D-printed individual templates, BT treatment planning systems, and artificial intelligence navigator systems remarkably increased the accuracy of I-125 BT and individualized I-125 ablative radiotherapy. Of note, utilizing I-125 to treat carcinoma in hollow cavity organs was enabled by the utility of self-expandable metal stents (SEMSs). Initially, I-125 BT was only used in the treatment of rare tumors. However, an increasing number of clinical trials upheld the efficacy and safety of I-125 BT in almost all tumors. Therefore, this study aims to summarize the recent advances of I-125 BT in cancer therapy, which cover experimental research to clinical investigations, including the development of novel techniques. This review also raises unanswered questions that may prompt future clinical trials and experimental work.

Analysis on the accuracy of CT-guided radioactive I-125 seed implantation with 3D printing template assistance in the treatment of thoracic malignant tumors.

This article analyzes the accuracy of needle track and dose of a 3-dimensional printing template (3DPT) in the treatment of thoracic tumor with radioactive I-125 seed implantation (RISI). A total of 28 patients were included. The technical process included: (i) preoperative CT positioning, (ii) preoperative planning design, (iii) 3DPT design and printing, (iv) 3DPT alignment, (v) puncture and seed implantation. The errors of needle position and dosimetric parameters were analyzed. A total of 318 needles were used. The mean errors in needle depth, needle insertion point, needle tip and needle angle were 0.52 ± 0.48 cm, 3.4 ± 1.7 mm, 4.4 ± 2.9 mm and 2.8 ± 1.7°, respectively. The differences between actual needle insertion angle and needle depth and those designed in the preoperative were statistically significant (p < 0.05). The mean values of all the errors of the chest wall cases were smaller than those of the lungs, and the differences were statistically significant (p < 0.05). There was no significant difference between the D90 calculated in the postoperative plan and those designed in the preoperative and intraoperative plans (p > 0.05). Some dosimetric parameters of preoperative plans such as V100, V200, CI and HI were not consistent with that of preoperative plans, and the difference was statistically significant (p < 0.05). However, there were no statistical difference in the dosimetric parameters between the postoperative plans and intraoperative plans (p > 0.05). We conclude that for thoracic tumors, even under the guidance of 3DPT, there will be errors. The plan should be optimized in real time during the operation.

Dosimetric comparison of computed tomography-guided iodine-125 seed implantation assisted with and without three-dimensional printing non-coplanar template in locally recurrent rectal cancer: a propensity score matching study.

PURPOSE: To compare post-implant dosimetric parameters of computed tomography (CT)-guided radioactive iodine-125 (125I) seed (RIS) implantation assisted with and without three-dimensional printing non-coplanar template (3D-PNCT) in locally recurrent rectal cancer (LRRC). MATERIAL AND METHODS: One hundred and fifty-five LRRC patients treated by CT-guided RIS implantation assisted with or without 3D-PNCT from October 2003 to May 2019 were included in this study. Propensity score matching (PSM) method (1 : 1) was used to adjust for differences between the 3D-group (with 3D-PNCT) and the CT-group (without 3D-PNCT). After PSM, dosimetric parameters [D90 (dose that covered 90% of target volume), D100 (dose that covered 100% of target volume), V100 (percentage of gross tumor volume (GTV) receiving 100% of prescription dose), V150 (percentage of GTV receiving 150% of prescription dose), HI (homogeneity index), CI (conformity index), and EI (external index)] of the two groups were compared. RESULTS: After PSM, 45 pairs of matched cases were selected for analysis and differences in variables between the two groups were balanced. For the 3D-group, median values of D90, D100, V100, V150, EI, and HI were 142.6 Gy (73.7-218.2 Gy), 73.7 Gy (26.2-169.3 Gy), 94.1% (74.3-100%), 71.8% (35.4-98.3%), 0.7 (0.1-30.7), and 0.20 (0-0.60), respectively, and corresponding values were 119.9 Gy (39.8-159.3 Gy), 47.0 Gy (13.0-200.9 Gy), 89.9% (38.6-100%), 62.8% (14.8-100%), 0.39 (0-11.01), and 0.30 (0-0.95), respectively, for the CT-group. Parameters including D90, D100, V100, V150, and EI in the 3D-group were significantly higher than those in the CT-group (p < 0.001, p < 0.001, p < 0.001, p < 0.001, and p = 0.006, respectively). CONCLUSIONS: 3D-PNCT can improve the accuracy of radioactive seed implantation by increasing the dose delivered to the tumor and reducing the number of "cold" spots of dose.

Accuracy and dosimetric parameters comparison of 3D-printed non-coplanar template-assisted computed tomography-guided iodine-125 seed ablative brachytherapy in pelvic lateral recurrence of gynecological carcinomas.

PURPOSE: To investigate the accuracy of needle distribution and dosimetric parameter differences of 3D-printing non-coplanar template (3D-PNCT)-assisted computed tomography (CT)-guided iodine-125 seed ablative brachytherapy (125I-SAB) in gynecological cancer patients with non-central pelvic recurrence between pre-operative plan and post-operative plan. MATERIAL AND METHODS: Thirty-eight patients with forty-one non-central pelvic recurrent gynecological carcinomas after radiotherapy were enrolled in this study. All patients received 3D-PNCT-assisted CT-guided 125I-SAB from January 2016 to January 2019. The position, angle, and depth of seed needles were measured in both pre-operative plan and intra-operative real-time plan in brachytherapy treatment planning system (B-TPS). Dosimetric parameters of D90, D100, V100, V150, and V200 as well as quality parameters of conformal index (CI), external index (EI), and homogeneity index (HI) were compared between pre-operative plan and post-operative plan. Peri-operation complications and radiation-related toxicity were assessed. RESULTS: Median follow-up time was 12 months (range, 5-34 months). Prescribed dose was 100-170 Gy (median, 120 Gy). Radioactivity of 125I seed was 0.4-0.7 mCi (median, 0.55 mCi). Mean depth deviation for 499 needles was 0.8 ±1.0 cm. Mean angular deviation was 2.2 ±2.1 degrees. Mean tip distance deviation of needles was 0.4 ±0.3 cm. There were significant differences between pre-operative and post-operative plans in CI (p = 0.001) and EI (p = 0.005). No significant differences were shown in D90, D100, V100, V150, V200, and HI between pre-operative and post-operative plans. Only few patients suffered from ≤ grade 2 toxicities. CONCLUSIONS: 3D-PNCT-assisted CT-guided 125I-SAB is safe and feasible for non-central pelvic recurrence of gynecological cancer. All complications are tolerable and mild.

Clinical application of 3D template-assisted brachytherapy in para-iliac lymph node metastasis / 中华放射肿瘤学杂志

Objective:To preliminarily evaluate the safety and efficacy of 3D printing template-assisted brachytherapy in the treatment of solitary metastatic lymph nodes adjacent to iliac vessels.Methods:Clinical data of 12 cases of para-iliac lymph node metastasis after radiotherapy admitted to our hospital from October 2018 to April 2020 were retrospectively analyzed. All patients received 3D printing template-assisted brachytherapy at a prescription dose of 20-30 Gy/fraction. CT scan was reviewed every 1 month in the first 3 months after treatment and every 3 months at 3 months after treatment.Local control rate, symptom relief rate and adverse events were evaluated.Results:All the 12 patients successfully completed the treatment and follow-up. At 1, 3 and 6 months after 3D printing template-assisted brachytherapy, 2, 2 and 3 patients obtained complete remission of lymph nodes, 9, 8 and 8 cases of partial remission, 1 case of stable disease and no case of disease progression. The symptoms were relieved in 10 patients. Acute radiation enteritis occurred in 2 patients and myelosuppression in 2 patients, which were mitigated after symptomatic treatment.Conclusion:3D printing template-assisted brachytherapy may be an efficacious and safe treatment of para-iliac lymph node metastasis, which yields tolerable adverse events.

Dosimetry verfication between pre and post operation of 3D-printing template assisted by CT-guided 125I seed implantation in the treatment of bone metastases / 中华放射医学与防护杂志

Objective:To compare and analyze the differences of common dose indicators before and after operation of 3D-printing template assisted by CT-guided 125I seed implantation in the treatment of bone metastases to guide clinical application. Methods:A retrospective analysis of 12 lesions in the 10 patients (9 males and 1 female, median age 65 years), who underwent seed implantation surgery for bone metastases in the Tianjin Third Central Hospital from June 2019 to January 2021, was conducted. All the lesions were adopted for 3D-printing template to guide seed implantation and the prescribed dose was 120-140 Gy. The differences of common dose indicators between preoperative treatment plan and postoperative verification plan were compared, including D90 (dose received by 90% of the target volume), D100 (dose received by 100% of the target volume), V90 (the volume percent for tumor target volume receiving 90% of the prescribed dose), V100 (the volume percent for tumor target volume receiving 100% of the prescribed dose), V150 (the volume percent for tumor target volume receiving 150 % of the prescribed dose), as well as the quantity of seeds planned and actually used. The paired t-test was performed to compare and analyze those parameters. Results:There was no statistically significant difference in pre- and postoperative D90, D100, V90, V100, V150 ( P > 0.05). The actual quantity of seeds used after operation was more than that of the preoperative planned quantity and the difference was statistically significant ( t=-2.930, P < 0.05). Conclusions:The clinical use of 3D-printing template assisted by CT-guided 125I seed implantation for bone metastasis should be promoted since the dose is accurate and the requirements of preoperative plan can be achieved.

Safety and efficacy of CT-guided radioactive iodine-125 seed implantation assisted by a 3D printing template for the treatment of thoracic malignancies.

OBJECTIVE: To ascertain the safety and efficacy of radioactive iodine-125 seed implantation (RISI) for the treatment of thoracic tumors. METHODS: Clinical patients with primary or metastatic tumors in the chest treated with RISI were analyzed. The RISI process included the following stages: preoperative planning, template design and 3D printing, CT-guided RISI assisted by a template, and postoperative dosimetric verification. The prescribed dose was ≥ 80 Gy. The main analytic measures were the local control (LC) rate and toxicity. RESULTS: From April 2015 to July 2018, a total of 92 patients, including 41 with lung cancer and 51 with lung metastases, were analyzed. The median lesion diameter was 5 cm. The median postoperative D90 was 142.6 Gy. The median follow-up was 10.7 months. The overall survival rates at 1 year and 3 years were 59.7% and 22.2%, respectively. The LC rates at 1 year and 3 years were 64.9% and 32.8%, respectively. The LC rates at 3 years for patients with D90 < 140 Gy and D90 > 140 Gy were 23.1% and 54.3%, respectively (P = 0.014). The LC rate of metastatic lung cancer was more favorable than that of primary lung cancer. The multivariate analyses showed that the dose and lesion type were independent factors for LC (P < 0.05). No factors were related to OS. The incidence of pneumothorax and hemoptysis was 35.8% and 3.2%, respectively. Few cases of radiotherapy-related toxicity effects were observed. CONCLUSIONS: RISI may be safe and efficacious and is associated with few complications during the treatment of thoracic tumors. If patients need local treatment and surgery or radiotherapy is not available, RISI could be considered.

Dosimetry verification of 3D-printed individual template based on CT-MRI fusion for radioactive 125I seed implantation in recurrent high-grade gliomas.

PURPOSE: To verify the accuracy and efficacy of three-dimensional printing individual template (3D-PIT) with computed tomography-magnetic resonance imaging (CT-MRI) fusion for radioactive iodine-125 (125I) seed implantation in high-grade brain gliomas. MATERIAL AND METHODS: Between June 2017 and June 2018, 16 patients with recurrent high-grade gliomas (rHGG) underwent radioactive seed implantation with 3D-PIT. The prescribed dose was 120-140 Gy. We compared the dose distribution of the postoperative plan with the preoperative plan. Dose parameters included D90, V100, V200, conformity index (CI), and external index of the target volume (EI). Local control and early complications were also analyzed. RESULTS: Sixteen treatment areas were reported in our study. Median gross tumor volume (preoperative) of patients was 64.2 cm3, median needle number was 8, and median number of implanted 125I seeds was 60. For postoperative plans, the median D90, V100, and V200 was 152.1 Gy, 96.8%, and 49.1%, respectively, and 151.7 Gy, 97.0%, and 48.9%, respectively, in preoperative plans. Comparing with the preplanned cases, the dose of the target volume was slightly higher; the high-dose area of the target volume was larger in postoperative cases, but the difference was not statistically significant (p > 0.05). Actual dose conformity of the target volume was greater than preplanned, and the difference was not statistically significant (p > 0.05). Local control was 81.25% and 75% at 3 and 6 months after implantation, respectively. No serious early toxicities were observed. CONCLUSIONS: 3D-PIT based on the CT-MRI fusion images can result in good accuracy for positioning and dose distribution in radioactive seed implantation for treatment of rHGG.

Comparative study for CT-guided 125I seed implantation assisted by 3D printing coplanar and non-coplanar template in peripheral lung cancer.

PURPOSE: We compared the three-dimensional printed non-coplanar template (3DPNCT) plans with 3D-printed coplanar template (3DPCT) plans for radioactive seed implantation (RSI) in lung cancer and explored the differences between the two technologies. MATERIAL AND METHODS: 33 patients with peripheral lung cancer that received 3DPCT-assisted RSI in our department between June 2017 and February 2018 were analyzed. A 3DPNCT plan was re-designed for all patients. The prescribed dose and seed activity in the new plan were the same as the 3DPCT plan. The data in the two plans were compared, including seed number, needle number, number of needles needed to cross the ribs, and dosimetry parameters. Dosimetry parameters included D90, Dmean, MPD (minimum peripheral dose), V100, V150, CI (conformity index), EI (external index), HI (homogeneity index) of target volume, D2cc of spinal cord and aorta, and V20 of affected side lung. We used a paired t-test and two groups of related non-parameters tests to examine statistical significance. A p value < 0.05 was considered statistically significant. RESULTS: We found no significant difference in dosimetry parameters (p > 0.05), except MPD. The mean MPD of the 3DPNCT plan was significantly higher than the 3DPCT plan (88.5 Gy and 81.8 Gy, respectively, p = 0.017). The number of needles used in the 3DPNCT plan and the number of needles needed to cross the ribs were significantly less compared with the 3DPCT plan (p = 0.000). CONCLUSIONS: The dose distributions of the two 3DPCT plans were similar. 3DPNCT plan had a higher dose in target volume margin, with fewer needles and fewer breaks to the ribs.

A nursing case of ct-guided 3D printed template assisted seed implantation of rhabdomyosarcoma in children with orbital embryos / 中国实用护理杂志

Objective@#To explore the nursing countermeasures of children with facial rhabdomyosarcoma treated by radioactive seed implantation.@*Methods@#Retrospective analysis was performed on the diagnosis, treatment and nursing process of a child orbital embryonal rhabdomyosarcoma admitted to the department of tumor radiotherapy, Peking University Third Hospital in February 2018.@*Results@#Mild wound swelling and pain occurred after treatment, and no acute complications such as increased intracranial pressure, particle displacement, wound bleeding and infection, or visual acuity change occurred.@*Conclusions@#Disease evaluation and preoperative preparation should be done strictly before the implantation of radioactive particles; changes of the disease should be monitored strictly during the operation to ensure the safety of treatment posture; postoperative complications observation and radiation protection guidance are the basis to ensure the smooth completion of the stage treatment of children.

A nursing case of ct-guided 3D printed template assisted seed implantation of rhabdomyosarcoma in children with orbital embryos / 中国实用护理杂志

Objective To explore the nursing countermeasures of children with facial rhabdomyosarcoma treated by radioactive seed implantation. Methods Retrospective analysis was performed on the diagnosis, treatment and nursing process of a child orbital embryonal rhabdomyosarcoma admitted to the department of tumor radiotherapy, Peking University Third Hospital in February 2018. Results Mild wound swelling and pain occurred after treatment, and no acute complications such as increased intracranial pressure, particle displacement, wound bleeding and infection, or visual acuity change occurred. Conclusions Disease evaluation and preoperative preparation should be done strictly before the implantation of radioactive particles; changes of the disease should be monitored strictly during the operation to ensure the safety of treatment posture; postoperative complications observation and radiation protection guidance are the basis to ensure the smooth completion of the stage treatment of children.

Dosimetry Verification of 125I Seeds Implantation With Three-Dimensional Printing Noncoplanar Templates and CT Guidance for Paravertebral/Retroperitoneal Malignant Tumors.

OBJECTIVE: To compare dose distributions of postoperative plans with preoperative plans for radioactive seed implantation of paravertebral/retroperitoneal tumors assisted by 3-dimensional printing noncoplanar templates and computed tomography. METHODS: Sixteen patients with paravertebral/retroperitoneal tumors (21 lesions) underwent radioactive seed implantation with 3-dimensional printing noncoplanar templates. Prescribed dose was 110 to 160 Gy. We compared the dose distribution of the postoperative plan with the preoperative plan. Dose parameters were D90, minimum peripheral dose, V100, V150, conformal index and external index of the target volume, and the dose received by 2 cm3 of normal tissue of organs at risk (spinal cord, aorta, and kidney). RESULTS: Sixteen 3-dimensional printing noncoplanar templates were produced for 21 treatment areas. Mean gross tumor volume (preoperative) of patients was 61.1 cm3, mean needle number was 17, mean number of implanted 125I seeds was 65, and mean D90 of postoperative target area (gross tumor volume) was 131.1 Gy. Actual number of seeds postbrachytherapy increased by 1 to 12 in 8 cases. For postoperative plans, the mean D90, minimum peripheral dose, V100, V150 was 131.1 Gy, 67.1 Gy, 90.2%, and 64.1%, respectively, and 135.0 Gy, 64.7 Gy, 90.9%, and 64.1%, respectively, in preoperative plans. Comparing with the preplanned cases, the dose of the target volume was slightly lower and the high-dose area of the target volume was larger in postoperative cases, but the difference was not statistically significant (P > .05). Actual dose conformity of the target volume was lower than preplanned, and the difference was statistically significant (P = .005). CONCLUSION: Three-dimensional printing noncoplanar templates can provide good accuracy for positioning and direction in radioactive seed implantation.

Dosimetric assessment of CT-guided radioactive seed implantation assisted by 3D printing non-coplanar template in treatment of chest malignant tumor / 中华放射肿瘤学杂志

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.

Expert consensus on 3D-printing template assisted CT-guided radioactive 125I seed implantation brachytherapy / 中华放射医学与防护杂志

As an interstitial brachytherapy,radioactive seed implantation could provide high doses in the local site and minimal doses at surrounding normal tissues.It has become one of the best choice for early stage prostate carcinoma.Radioactive seeds were implanted under the guidance by ultrasound,CT and MRI,featured with surgical and interventional treatment.Based on dosimetry for target and organs at risk,radioactive seed implantation is multiple disciplinary.In order to acquire the accurate and high quality seed implantation,it is necessary to set up a team including surgeons,radiation oncologists,interventional doctors and nuclear medicine doctors.The content of the consensus is as follows:radiation physics and dosimetry,indications,side-effects and 3 D-printing template work-follow.Despite the benefit of radioactive seed implantation for solid carcinoma,there still a compelling need for prospective randomized and stage Ⅲ clinical trials from multiple centers,so as to upgrade the evidencebased level,above all confirm the role of radioactive seed implantation in the comprehensive treatment of tumors.