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Yu GB, Kwon J, Chae S, Lee SY, Jung S. Evaluations of patient-specific bolus fabricated by mold-and-cast method using computer numerical control machine tools†. JOURNAL OF RADIATION RESEARCH 2023; 64:973-981. [PMID: 37839093 PMCID: PMC10665306 DOI: 10.1093/jrr/rrad075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 01/19/2023] [Indexed: 10/17/2023]
Abstract
The patient-specific bolus fabricated by a mold-and-cast method using a 3D printer (3DP) and silicon rubber has been adopted in clinical practices. Manufacturing a mold using 3DP, however, can cause time delays due to failures during the 3D printing process. Thereby, we investigated an alternative method of the mold fabrication using computer numerical control (CNC) machine tools. Treatment plans were conducted concerning a keloid scar formed on the ear and nose. The bolus structures were determined in a treatment planning system (TPS), and the molds were fabricated using the same structure file but with 3DP and CNC independently. Boluses were then manufactured using each mold with silicone rubbers. We compared the geometrical difference between the boluses and the planned structure using computed tomography (CT) images of the boluses. In addition, dosimetric differences between the two measurements using each bolus and the differences between the measured and calculated dose from TPS were evaluated using an anthropomorphic head phantom. Geometrically, the CT images of the boluses fabricated by the 3DP mold and the CNC mold showed differences compared to the planned structure within 2.6 mm of Hausdorff distance. The relative dose difference between the measurements using either bolus was within 2.3%. In conclusion, the bolus made by the CNC mold benefits from a stable fabricating process, retaining the performance of the bolus made by the 3DP mold.
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Affiliation(s)
- Geum Bong Yu
- Department of Radiation Oncology, Seoul National University Hospital, Seoul 03080, Republic of Korea
- Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul 03080, Republic of Korea
| | - Jimin Kwon
- Department of Radiation Oncology, Seoul National University Hospital, Seoul 03080, Republic of Korea
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto M5S 3G8, Ontario, Canada
| | - Seunghoon Chae
- Department of Radiation Oncology, Seoul National University Hospital, Seoul 03080, Republic of Korea
| | - Sung Young Lee
- Department of Radiation Oncology, Seoul National University Hospital, Seoul 03080, Republic of Korea
| | - Seongmoon Jung
- Department of Radiation Oncology, Seoul National University Hospital, Seoul 03080, Republic of Korea
- Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul 03080, Republic of Korea
- Biomedical Research Institute, Seoul National University Hospital, Seoul 03080, Republic of Korea
- Department of Nuclear Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
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Wang X, Zhao J, Xiang Z, Wang X, Zeng Y, Luo T, Yan X, Zhang Z, Wang F, Liu L. 3D-printed bolus ensures the precise postmastectomy chest wall radiation therapy for breast cancer. Front Oncol 2022; 12:964455. [PMID: 36119487 PMCID: PMC9478602 DOI: 10.3389/fonc.2022.964455] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 08/15/2022] [Indexed: 11/13/2022] Open
Abstract
Purpose To investigate the values of a 3D-printed bolus ensuring the precise postmastectomy chest wall radiation therapy for breast cancer. Methods and materials In the preclinical study on the anthropomorphic phantom, the 3D-printed bolus was used for dosimetry and fitness evaluation. The dosimetric parameters of planning target volume (PTV) were assessed, including Dmin, Dmax, Dmean, D95%, homogeneity index (HI), conformity index (CI), and organs at risk (OARs). The absolute percentage differences (|%diff|) between the theory and fact skin dose were also estimated, and the follow-up was conducted for potential skin side effects. Results In preclinical studies, a 3D-printed bolus can better ensure the radiation coverage of PTV (HI 0.05, CI 99.91%), the dose accuracy (|%diff| 0.99%), and skin fitness (mean air gap 1.01 mm). Of the 27 eligible patients, we evaluated the radiation dose parameter (median(min–max): Dmin 4967(4789–5099) cGy, Dmax 5447(5369–5589) cGy, Dmean 5236(5171–5323) cGy, D95% 5053(4936–5156) cGy, HI 0.07 (0.06–0.17), and CI 99.94% (97.41%–100%)) and assessed the dose of OARs (ipsilateral lung: Dmean 1341(1208–1385) cGy, V5 48.06%(39.75%–48.97%), V20 24.55%(21.58%–26.93%), V30 18.40%(15.96%–19.16%); heart: Dmean 339(138–640) cGy, V30 1.10%(0%–6.14%), V40 0.38%(0%–4.39%); spinal cord PRV: Dmax 639(389–898) cGy). The skin doses in vivo were Dtheory 208.85(203.16–212.53) cGy, Dfact 209.53(204.14–214.42) cGy, and |%diff| 1.77% (0.89–2.94%). Of the 360 patients enrolled in the skin side effect follow-up study (including the above 27 patients), grade 1 was the most common toxicity (321, 89.2%), some of which progressing to grade 2 or grade 3 (32, 8.9% or 7, 1.9%); the radiotherapy interruption rate was 1.1%. Conclusion A 3D-printed bolus can guarantee the precise radiation dose on skin surface, good fitness to skin, and controllable acute skin toxicity, which possesses a great clinical application value in postmastectomy chest call radiation therapy for breast cancer.
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Affiliation(s)
- Xiran Wang
- Department of Head and Neck and Mammary Oncology, West China Hospital, Sichuan University, Chengdu, China
| | - Jianling Zhao
- Department of Radiotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Zhongzheng Xiang
- Department of Head and Neck and Mammary Oncology, West China Hospital, Sichuan University, Chengdu, China
| | - Xuetao Wang
- Department of Radiotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Yuanyuan Zeng
- Department of Head and Neck and Mammary Oncology, West China Hospital, Sichuan University, Chengdu, China
| | - Ting Luo
- Department of Head and Neck and Mammary Oncology, West China Hospital, Sichuan University, Chengdu, China
- Clinical Research Center for Breast, West China Hospital, Sichuan University, Chengdu, China
| | - Xi Yan
- Department of Head and Neck and Mammary Oncology, West China Hospital, Sichuan University, Chengdu, China
- Clinical Research Center for Breast, West China Hospital, Sichuan University, Chengdu, China
| | - Zhuang Zhang
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Feng Wang
- Department of Head and Neck and Mammary Oncology, West China Hospital, Sichuan University, Chengdu, China
- Clinical Research Center for Breast, West China Hospital, Sichuan University, Chengdu, China
| | - Lei Liu
- Department of Head and Neck and Mammary Oncology, West China Hospital, Sichuan University, Chengdu, China
- Clinical Research Center for Breast, West China Hospital, Sichuan University, Chengdu, China
- *Correspondence: Lei Liu,
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Pollmann S, Toussaint A, Flentje M, Wegener S, Lewitzki V. Dosimetric Evaluation of Commercially Available Flat vs. Self-Produced 3D-Conformal Silicone Boluses for the Head and Neck Region. Front Oncol 2022; 12:881439. [PMID: 36033533 PMCID: PMC9399510 DOI: 10.3389/fonc.2022.881439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 06/21/2022] [Indexed: 11/25/2022] Open
Abstract
Background Boluses are routinely used in radiotherapy to modify surface doses. Nevertheless, considerable dose discrepancies may occur in some cases due to fit inaccuracy of commercially available standard flat boluses. Moreover, due to the simple geometric design of conventional boluses, also surrounding healthy skin areas may be unintentionally covered, resulting in the unwanted dose buildup. With the fused deposition modeling (FDM) technique, there is a simple and possibly cost-effective way to solve these problems in routine clinical practice. This paper presents a procedure of self-manufacturing bespoke patient-specific silicone boluses and the evaluation of buildup and fit accuracy in comparison to standard rectangular commercially available silicone boluses. Methods 3D-conformal silicone boluses were custom-built to cover the surgical scar region of 25 patients who received adjuvant radiotherapy of head and neck cancer at the University Hospital Würzburg. During a standard CT-based planning procedure, a 5-mm-thick 3D bolus contour was generated to cover the radiopaque marked surgical scar with an additional safety margin. From these digital contours, molds were 3D printed and poured with silicone. Dose measurements for both types of boluses were performed with radiochromic films (EBT3) at three points per patient—at least one aimed to be in the high-dose area (scar) and one in the lower-dose area (spared healthy skin). Surface–bolus distance, which ideally should not be present, was determined from cone-beam CT performed for positioning control. The dosimetric influence of surface–bolus distance was also determined on slab phantom for different field sizes. The trial was performed with hardware that may be routinely available in every radiotherapy department, with the exception of the 3D printer. The required number of patients was determined based on the results of preparatory measurements with the help of the statistical consultancy of the University of Würzburg. The number of measuring points represents the total number of patients. Results In the high-dose area of the scar, there was a significantly better intended dose buildup of 2.45% (95%CI 0.0014–0.0477, p = 0.038, N = 30) in favor of a 3D-conformal bolus. Median distances between the body surface and bolus differed significantly between 3D-conformal and commercially available boluses (3.5 vs. 7.9 mm, p = 0.001). The surface dose at the slab phantom did not differ between commercially available and 3D-conformal boluses. Increasing the surface–bolus distance from 5 to 10 mm decreased the surface dose by approximately 2% and 11% in the 6 × 6- and 3 × 3-cm2 fields, respectively. In comparison to the commercially available bolus, an unintended dose buildup in the healthy skin areas was reduced by 25.9% (95%CI 19.5–32.3, p < 0.01, N = 37) using the 3D-conformal bolus limited to the region surrounding the surgical scar. Conclusions Using 3D-conformal boluses allows a comparison to the commercially available boluses’ dose buildup in the covered areas. Smaller field size is prone to a larger surface–bolus distance effect. Higher conformity of 3D-conformal boluses reduces this effect. This may be especially relevant for volumetric modulated arc therapy (VMAT) and intensity-modulated radiotherapy (IMRT) techniques with a huge number of smaller fields. High conformity of 3D-conformal boluses reduces an unintended dose buildup in healthy skin. The limiting factor in the conformity of 3D-conformal boluses in our setting was the immobilization mask, which was produced primarily for the 3D boluses. The mask itself limited tight contact of subsequently produced 3D-conformal boluses to the mask-covered body areas. In this respect, bolus adjustment before mask fabrication will be done in the future setting.
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Buildup Factor Computation and Percentage Depth Dose Simulation of Tissue Mimicking Materials for an External Photon Beam (0.15–15 MeV). APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12094250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Nowadays, the use of tissue mimicking material (TMM) is widespread in both diagnostic and therapeutic medicine, as well as for quality assurance and control. For example, patient exposure evaluation during therapeutic tests has been commonly measured using TMMs. However, only a few materials have been developed for research use at the megavoltage photon energy encountered in medical radiology. In this paper, we extended our previous work to cover the photon energy range of 0.15–15 MeV for five human tissues (adipose, cortical bone, fat, lung and muscle). As a selection criterion for TMM, other than the attenuation coefficient, we introduced the computation of the buildup factor (BUF) for a given couple of energy and depth based on the geometric progression fitting method. Hence, we developed a C++ program able to compute BUF for depths up to 40 mean free path. Moreover, we simulated the percentage depth dose (PDD) of a 6 MV photon beam through each tissue and their equivalent materials using the Geant4 Monte Carlo toolkit (version 10.5). After the comparison of a set of parameters (mass attenuation and mass energy absorption coefficients, BUF, equivalent and effective atomic numbers, electron density, superficial and maximal dose and dose at 10 and 20 cm depths), we found that SB3 (a mixture of epoxy and calcium carbonate) and MS15 (a mixture of epoxy, phenol, polyethylene and aluminum oxide) accurately imitate cortical bone and muscle tissues, respectively. AP6 (a mixture of epoxy, phenol, polyethylene and teflon), glycerol trioleate and LN1 (a mixture of polyurethane and aluminum oxide) are also suitable TMMs for adipose, fat and lung tissues, respectively. Therefore, this work can be useful to physician researchers in dosimetry and radiological diagnosis.
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The optimal timing of radiotherapy in the combination treatment of limited-stage extranodal natural killer/T-cell lymphoma, nasal type: an updated meta-analysis. Ann Hematol 2021; 100:2889-2900. [PMID: 34708280 DOI: 10.1007/s00277-021-04700-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 10/10/2021] [Indexed: 11/27/2022]
Abstract
This study was designed to explore the relative efficacy and toxicity of upfront radiotherapy (RT) and late RT in combination treatments for patients with limited-stage extranodal natural killer/T-cell lymphoma nasal type (LS-ENKTL). We searched for clinical trials in the PubMed database that compared upfront RT with late RT in the combined treatment of patients with LS-ENKTL. We systematically evaluated the differences in survival, treatment response, and treatment-related adverse events (AEs) between these two groups. Ten retrospective studies with a total of 1752 patients were included. Upfront RT significantly prolonged the overall survival (OS) and progression-free survival (PFS) of patients compared to late RT in combination with chemotherapy (CT) (HR = 0.72, 95% CI 0.59-0.88, P = 0.001 for OS; HR = 0.57, 95% CI 0.41-0.79, P = 0.0007 for PFS). The complete remission (CR) rate in the upfront RT group was superior to that in the late RT group (HR = 1.61, 95% CI 1.09-2.37, P = 0.02). Patients experienced similar local recurrence-free survival (LRFS), objective response rates (ORR), and toxicity between these two arms (P > 0.05 for all) in the analysis of each subgroup. The survival benefit of upfront RT was not correlated with the RT dose, concurrent chemoradiotherapy (CCRT) (or not), or the CT regimen (P > 0.05 for all). Without compromises in terms of toxicity, RT dose, and treatment modality, upfront RT can significantly benefit OS, PFS, and CR compared to late RT in combination treatment. These findings verified that the upfront RT regimen is more suitable for patients with LS-ENKTL.
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Wang X, Wang X, Xiang Z, Zeng Y, Liu F, Shao B, He T, Ma J, Yu S, Liu L. The Clinical Application of 3D-Printed Boluses in Superficial Tumor Radiotherapy. Front Oncol 2021; 11:698773. [PMID: 34490095 PMCID: PMC8416990 DOI: 10.3389/fonc.2021.698773] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 06/23/2021] [Indexed: 02/05/2023] Open
Abstract
During the procedure of radiotherapy for superficial tumors, the key to treatment is to ensure that the skin surface receives an adequate radiation dose. However, due to the presence of the built-up effect of high-energy rays, equivalent tissue compensators (boluses) with appropriate thickness should be placed on the skin surface to increase the target radiation dose. Traditional boluses do not usually fit the skin perfectly. Wet gauze is variable in thickness day to day which results in air gaps between the skin and the bolus. These unwanted but avoidable air gaps lead to a decrease of the radiation dose in the target area and can have a poor effect on the outcome. Three-dimensional (3D) printing, a new rising technology named “additive manufacturing” (AM), could create physical models with specific shapes from digital information by using special materials. It has been favored in many fields because of its advantages, including less waste, low-cost, and individualized design. It is not an exception in the field of radiotherapy, personalized boluses made through 3D printing technology also make up for a number of shortcomings of the traditional commercial bolus. Therefore, an increasing number of researchers have tried to use 3D-printed boluses for clinical applications rather than commercial boluses. Here, we review the 3D-printed bolus’s material selection and production process, its clinical applications, and potential radioactive dermatitis. Finally, we discuss some of the challenges that still need to be addressed with the 3D-printed boluses.
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Affiliation(s)
- Xiran Wang
- Department of Head and Neck Oncology, West China Hospital, Sichuan University, Chengdu, China
| | - Xuetao Wang
- Department of Radiotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Zhongzheng Xiang
- Department of Head and Neck Oncology, West China Hospital, Sichuan University, Chengdu, China
| | - Yuanyuan Zeng
- Department of Head and Neck Oncology, West China Hospital, Sichuan University, Chengdu, China
| | - Fang Liu
- Department of Head and Neck Oncology, West China Hospital, Sichuan University, Chengdu, China
| | - Bianfei Shao
- Department of Head and Neck Oncology, West China Hospital, Sichuan University, Chengdu, China
| | - Tao He
- Department of Head and Neck Oncology, West China Hospital, Sichuan University, Chengdu, China
| | - Jiachun Ma
- Department of Head and Neck Oncology, West China Hospital, Sichuan University, Chengdu, China
| | - Siting Yu
- Department of Head and Neck Oncology, West China Hospital, Sichuan University, Chengdu, China
| | - Lei Liu
- Department of Head and Neck Oncology, West China Hospital, Sichuan University, Chengdu, China
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Zhang C, Hu W, Zhou Q, He J, Wang H, Qiu K, Wang L, Li X. The possibility of developing customized 3D-printed silicone hydrogel bolus for post-mastectomy radiotherapy. JOURNAL OF RADIATION RESEARCH AND APPLIED SCIENCES 2021. [DOI: 10.1080/16878507.2021.1962629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Caixun Zhang
- Department of Radiotherapy, Renmin Hospital of Wuhan University, Wuhan, P .R. China
| | - Weiguo Hu
- Department of Oncology Center, Renmin Hospital of Wuhan University, Wuhan, P .R. China
| | - Qing Zhou
- Department of Ultrasound, Renmin Hospital of Wuhan University, Wuhan, P .R. China
| | - Junxiang He
- Department of Radiotherapy, Renmin Hospital of Wuhan University, Wuhan, P .R. China
| | - Hao Wang
- Department of Ultrasound, Renmin Hospital of Wuhan University, Wuhan, P .R. China
| | - Kehu Qiu
- Department of Oncology Center, Renmin Hospital of Wuhan University, Wuhan, P .R. China
| | - Luzhou Wang
- Department of Radiotherapy, Renmin Hospital of Wuhan University, Wuhan, P .R. China
| | - Xiangpan Li
- Department of Radiotherapy, Renmin Hospital of Wuhan University, Wuhan, P .R. China
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