1
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Morén B, Antaki M, Famulari G, Morcos M, Larsson T, Enger SA, Tedgren ÅC. Dosimetric impact of a robust optimization approach to mitigate effects from rotational uncertainty in prostate intensity-modulated brachytherapy. Med Phys 2023; 50:1029-1043. [PMID: 36478226 DOI: 10.1002/mp.16134] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 10/17/2022] [Accepted: 11/01/2022] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Intensity-modulated brachytherapy (IMBT) is an emerging technology for cancer treatment, in which radiation sources are shielded to shape the dose distribution. The rotatable shields provide an additional degree of freedom, but also introduce an additional, directional, type of uncertainty, compared to conventional high-dose-rate brachytherapy (HDR BT). PURPOSE We propose and evaluate a robust optimization approach to mitigate the effects of rotational uncertainty in the shields with respect to planning criteria. METHODS A previously suggested prototype for platinum-shielded prostate 169 Yb-based dynamic IMBT is considered. We study a retrospective patient data set (anatomical contours and catheter placement) from two clinics, consisting of six patients that had previously undergone conventional 192 Ir HDR BT treatment. The Monte Carlo-based treatment planning software RapidBrachyMCTPS is used for dose calculations. In our computational experiments, we investigate systematic rotational shield errors of ±10° and ±20°, and the same systematic error is applied to all dwell positions in each scenario. This gives us three scenarios, one nominal and two with errors. The robust optimization approach finds a compromise between the average and worst-case scenario outcomes. RESULTS We compare dose plans obtained from standard models and their robust counterparts. With dwell times obtained from a linear penalty model (LPM), for 10° errors, the dose to urethra ( D 0.1 c c $D_{0.1cc}$ ) and rectum ( D 0.1 c c $D_{0.1cc}$ and D 1 c c $D_{1cc}$ ) increase with up to 5% and 7%, respectively, in the worst-case scenario, while with the robust counterpart, the corresponding increases were 3% and 3%. For all patients and all evaluated criteria, the worst-case scenario outcome with the robust approach had lower deviation compared to the standard model, without compromising target coverage. We also evaluated shield errors up to 20° and while the deviations increased to a large extent with the standard models, the robust models were capable of handling even such large errors. CONCLUSIONS We conclude that robust optimization can be used to mitigate the effects from rotational uncertainty and to ensure the treatment plan quality of IMBT.
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Affiliation(s)
- Björn Morén
- Department of Mathematics, Linköping University, Linköping, Sweden
| | - Majd Antaki
- Department of Oncology, Medical Physics Unit, McGill University, Montreal, QC, Canada
| | - Gabriel Famulari
- Department of Oncology, Medical Physics Unit, McGill University, Montreal, QC, Canada.,Département de Radio-oncologie, Centre Hospitalier de l'Université de Montréal, Montreal, QC, Canada
| | - Marc Morcos
- Department of Oncology, Medical Physics Unit, McGill University, Montreal, QC, Canada
| | - Torbjörn Larsson
- Department of Mathematics, Linköping University, Linköping, Sweden
| | - Shirin A Enger
- Department of Oncology, Medical Physics Unit, McGill University, Montreal, QC, Canada.,Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, QC, Canada
| | - Åsa Carlsson Tedgren
- Radiation Physics, Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden.,Medical Radiation Physics and Nuclear Medicine, Karolinska University Hospital, Stockholm, Sweden.,Department of Oncology Pathology, Karolinska Institute, Stockholm, Sweden
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2
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Kim H, Goh Y, Kim DW, Kim JS, Lim YK. Integration of rotatable tandem applicator to conventional ovoid applicator toward complete framework of intensity modulated brachytherapy (IMBT) for cervical cancer. Phys Med 2021; 91:131-139. [PMID: 34800907 DOI: 10.1016/j.ejmp.2021.10.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 10/29/2021] [Accepted: 10/31/2021] [Indexed: 10/19/2022] Open
Abstract
A new tandem applicator with tungsten shield for Ir-192 radiation source used in intra-cavitary brachytherapy (ICBT) enabled intensity modulated brachytherapy (IMBT) in cervical cancer treatment through fluence-modulation by rotating shield. Our previous work employed group-wise and element-wise sparsity constraints for plan optimization of tandem applicator to minimizes the number of activated angles and source dwell points for delivery efficiency. It, however, did not incorporate the ovoid applicators into the optimizing process, which is generally used to prevent cancer recurrence. To integrate ovoid applicators to the new tandem applicator, this work proposed a comprehensive framework that modifies 1) dose deposition matrix for inverse planning, and 2) plan optimizing algorithm. The dose deposition matrix was newly formulated by the Monte-Carlo simulated dose distribution for 10 positions of ovoid applicators, followed by combining those with tandem-associated dose deposition matrix. The plan optimizing algorithm decomposed entire elements into tandem and ovoid applicators, which were governed by different constraints adaptive to specified plan objectives. The integrated framework was compared against conventional ICBT, and IMBT with tandem only for three patients with asymmetric dose distributions. Integrated IMBT framework resulted in the most optimal plans. Including fluence-modulation by rotating-shield outperformed conventional ICBT in dose sparing to critical organs. Adopting ovoid applicators to the optimization yielded more conformal dose distribution around inferior, laterally expanded region of target volume. The resulting plans reduced D5cc and D2cc by 30.9% and 27.8% for critical organs over conventional ICBT, and by 20.6% and 21.5% for target volume over IMBT with tandem only.
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Affiliation(s)
- Hojin Kim
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, South Korea
| | - Youngmoon Goh
- Department of Radiation Oncology, Asan Medical Center, Seoul, South Korea
| | - Dong Wook Kim
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, South Korea
| | - Jin Sung Kim
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, South Korea.
| | - Young Kyung Lim
- Proton Therapy Center, National Cancer Center, Goyang, South Korea.
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3
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Major T, Fröhlich G, Ágoston P, Polgár C, Takácsi-Nagy Z. The value of brachytherapy in the age of advanced external beam radiotherapy: a review of the literature in terms of dosimetry. Strahlenther Onkol 2021; 198:93-109. [PMID: 34724086 PMCID: PMC8789711 DOI: 10.1007/s00066-021-01867-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 10/03/2021] [Indexed: 12/29/2022]
Abstract
Brachytherapy (BT) has long been used for successful treatment of various tumour entities, including prostate, breast and gynaecological cancer. However, particularly due to advances in modern external beam techniques such as intensity-modulated radiotherapy (IMRT), volume modulated arc therapy (VMAT) and stereotactic body radiotherapy (SBRT), there are concerns about its future. Based on a comprehensive literature review, this article aims to summarize the role of BT in cancer treatment and highlight its particular dosimetric advantages. The authors conclude that image-guided BT supported by inverse dose planning will successfully compete with high-tech EBRT in the future and continue to serve as a valuable modality for cancer treatment.
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Affiliation(s)
- Tibor Major
- Radiotherapy Centre, National Institute of Oncology, Budapest, Hungary. .,Department of Oncology, Semmelweis University, Budapest, Hungary.
| | - Georgina Fröhlich
- Radiotherapy Centre, National Institute of Oncology, Budapest, Hungary.,Faculty of Science, Eötvös Loránd University, Budapest, Hungary
| | - Péter Ágoston
- Radiotherapy Centre, National Institute of Oncology, Budapest, Hungary.,Department of Oncology, Semmelweis University, Budapest, Hungary
| | - Csaba Polgár
- Radiotherapy Centre, National Institute of Oncology, Budapest, Hungary.,Department of Oncology, Semmelweis University, Budapest, Hungary
| | - Zoltán Takácsi-Nagy
- Radiotherapy Centre, National Institute of Oncology, Budapest, Hungary.,Department of Oncology, Semmelweis University, Budapest, Hungary
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4
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Morén B, Larsson T, Tedgren ÅC. Optimization in treatment planning of high dose-rate brachytherapy - Review and analysis of mathematical models. Med Phys 2021; 48:2057-2082. [PMID: 33576027 DOI: 10.1002/mp.14762] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 11/12/2020] [Accepted: 01/22/2021] [Indexed: 12/12/2022] Open
Abstract
Treatment planning in high dose-rate brachytherapy has traditionally been conducted with manual forward planning, but inverse planning is today increasingly used in clinical practice. There is a large variety of proposed optimization models and algorithms to model and solve the treatment planning problem. Two major parts of inverse treatment planning for which mathematical optimization can be used are the decisions about catheter placement and dwell time distributions. Both these problems as well as integrated approaches are included in this review. The proposed models include linear penalty models, dose-volume models, mean-tail dose models, quadratic penalty models, radiobiological models, and multiobjective models. The aim of this survey is twofold: (i) to give a broad overview over mathematical optimization models used for treatment planning of brachytherapy and (ii) to provide mathematical analyses and comparisons between models. New technologies for brachytherapy treatments and methods for treatment planning are also discussed. Of particular interest for future research is a thorough comparison between optimization models and algorithms on the same dataset, and clinical validation of proposed optimization approaches with respect to patient outcome.
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Affiliation(s)
- Björn Morén
- Department of Mathematics, Linköping University, Linköping, Sweden
| | - Torbjörn Larsson
- Department of Mathematics, Linköping University, Linköping, Sweden
| | - Åsa Carlsson Tedgren
- Radiation Physics, Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden.,Medical Radiation Physics and Nuclear Medicine, Karolinska University Hospital, Stockholm, Sweden.,Department of Oncology Pathology, Karolinska Institute, Stockholm, Sweden
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Badali DS, Vainer Y, Ellenor CW, Mitchell CR, Fishman K, Soro N, Price R, Funk T. Inverse treatment planning for an electronic brachytherapy system delivering anisotropic radiation therapy. Phys Med Biol 2021; 66:055004. [PMID: 33429370 DOI: 10.1088/1361-6560/abda9a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
An inverse radiation treatment planning algorithm for Sensus Healthcare's SculpturaTM electronic brachytherapy system has been designed. The algorithm makes use of simulated annealing to optimize the conformation number (CN) of the treatment plan. The highly anisotropic dose distributions produced by the SculpturaTM x-ray source empower the inverse treatment planning algorithm to achieve highly conformal treatment plans for a wide range of prescribed planning target volumes. Over a set of 10 datasets the algorithm achieved an average CN of 0.79 ± 0.08 and an average gamma passing rate of 0.90 ± 0.10 at 5%/5 mm. A regularization term that encouraged short treatment plans was used, and it was found that the total treatment time could be reduced by 20% with only a nominal reduction in the CN and gamma passing rate. It was also found that downsampling the voxelized volume (from 3203 to 643 voxels) prior to optimization resulted in a 150× speedup in the optimization time (from 2 + minutes to < 1 s) without affecting the quality of the treatment plan.
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6
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Plan optimization with L0-norm and group sparsity constraints for a new rotational, intensity-modulated brachytherapy for cervical cancer. PLoS One 2020; 15:e0236585. [PMID: 32722692 PMCID: PMC7386578 DOI: 10.1371/journal.pone.0236585] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 07/08/2020] [Indexed: 11/19/2022] Open
Abstract
The aim of this work is to build a framework that comprehends inverse planning procedure and plan optimization algorithm tailored to a novel directional beam intensity-modulated brachytherapy (IMBT) of cervical cancer using a rotatable, single-channel radiation shield. Inverse planning is required for finding optimal beam emitting direction, source dwell position and dwell time, which begin with creating a kernel matrix for each structure based on Monte-Carlo simulated dose distribution in the rotatable shield. For efficient beam delivery and less transit dose, the number of source dwell positions and angles needs to be minimized. It can be solved by L0-norm regularization for fewest possible dwell points, and by group sparsity constraint in L2,p-norm (0≤p<1) besides L0-norm for fewest active applicator rotating angles. The dose distributions from our proposed algorithms were compared to those of conventional tandem-based intracavitary brachytherapy (ICR) plans for six cervical cancer patients. The algorithmic performance was evaluated in delivery efficiency and plan quality relative to the unconstrained algorithm. The proposed framework yielded substantially enhanced plan quality over the conventional ICR plans. The L0-norm and (group sparsity+L0-norm) constrained algorithms reduced the number of source dwell points by 60 and 70% and saved 5 and 8 rotational angles on average (7 and 11 angles for highly modulated cases), relative to the unconstrained algorithm, respectively. Though both algorithms reduced the optimal source dwell positions and angles, the group sparsity constrained optimization with L0-norm was more effective than the L0-norm constraint only, mainly because of considering physical constraints of the new IMBT applicator. With much fewer dwell points compared to the unconstrained, the proposed algorithms led to statistically similar plan quality in dose volume histograms and iso-dose lines. It also demonstrated that the plan optimized by rotating the applicator resulted in much better plan quality than that of conventional applicator-based plans.
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7
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Cunha JAM, Flynn R, Bélanger C, Callaghan C, Kim Y, Jia X, Chen Z, Beaulieu L. Brachytherapy Future Directions. Semin Radiat Oncol 2020; 30:94-106. [DOI: 10.1016/j.semradonc.2019.09.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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8
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Famulari G, Duclos M, Enger SA. A novel
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Yb‐based dynamic‐shield intensity modulated brachytherapy delivery system for prostate cancer. Med Phys 2019; 47:859-868. [DOI: 10.1002/mp.13959] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 11/04/2019] [Accepted: 12/06/2019] [Indexed: 12/17/2022] Open
Affiliation(s)
- Gabriel Famulari
- Medical Physics Unit McGill University Montréal Québec H4A 3J1Canada
| | - Marie Duclos
- Department of Oncology McGill University Montréal Québec H4A 3J1Canada
| | - Shirin A. Enger
- Medical Physics Unit McGill University Montréal Québec H4A 3J1Canada
- Department of Oncology McGill University Montréal Québec H4A 3J1Canada
- Research Institute of the McGill University Health Centre Montréal Québec H3H 2R9Canada
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9
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Badali DS, Plateau GR, Ellenor CW, Ku CY, Vatahov P, Esterline J, Wilfley BP, Mitchell CR, Fishman K, Funk T. Characterization of an x-ray source with a partitioned diamond-tungsten target for electronic brachytherapy with 3D beam directionality. ACTA ACUST UNITED AC 2019; 64:245007. [DOI: 10.1088/1361-6560/ab5130] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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10
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Callaghan CM, Adams Q, Flynn RT, Wu X, Xu W, Kim Y. Systematic Review of Intensity-Modulated Brachytherapy (IMBT): Static and Dynamic Techniques. Int J Radiat Oncol Biol Phys 2019; 105:206-221. [DOI: 10.1016/j.ijrobp.2019.04.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 03/27/2019] [Accepted: 04/11/2019] [Indexed: 02/06/2023]
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11
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Safigholi H, Han DY, Soliman A, Song WY. Direction modulated brachytherapy (DMBT) tandem applicator for cervical cancer treatment: Choosing the optimal shielding material. Med Phys 2018; 45:3524-3533. [PMID: 29858499 DOI: 10.1002/mp.13030] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 05/28/2018] [Accepted: 05/29/2018] [Indexed: 01/14/2023] Open
Abstract
PURPOSE To investigate the dose modulation capability of a novel MRI-compatible direction modulated brachytherapy (DMBT) tandem applicator design with various high-density shielding materials for brachytherapy treatment of cervical cancer. The shield materials that have been evaluated are tantalum (Ta), pure tungsten (W), gold (Au), rhenium (Re), osmium (Os), platinum (Pt), iridium (Ir), and W' tungsten alloy (95%W, 3.5%Ni, 1.5%Cu). MATERIALS AND METHODS The recently proposed six-channel DMBT tandem is composed of nonmagnetic tungsten alloy (W') rod with diameter of 5.4 mm and coated with 0.3-mm thick bio-safe plastic sheath. The tandem shielding material can, however, be individually replaced with various other shields to create directional radiation. Monte Carlo N-Particle (MCNP) code was used to calculate the three-dimensional (3D) dose distributions in a water phantom for an HDR 192 Ir (mHDR-v2) source inside each DMBT tandem with various shields and a plastic conventional tandem (Con.T). Then, the 3D dose distributions were imported into an in-house-coded inverse planning optimization algorithm to obtain optimal plans for 12 clinical cases chosen at random from the international RetroEMBRACE dataset involving conventional tandem and ring (Con.T&R) applicators. All plans generated by the DMBT tandem and ring (DMBT&R) with the tungsten alloy [DMBT(W')&R] were compared with the corresponding Con.T&R plans, to generate benchmark results. These benchmark results were then considered as reference plans for other shields performances. Plans were normalized to receive the same high-risk clinical target volume (CTVHR ) D90 . The D100 , D10 , and V100 for CTVHR , and D2cm3 for organs at risk (OARs) of bladder, sigmoid, and rectum were calculated and compared. RESULTS Transmission factor (TF), that is, the dose in the backside of the DMBT shield over that in the front opening, at a 5 cm distance, were 36.6%, 34.8%, 31.9%, 28.9%, 27.9%, 26.2%, 26.2%, and 25.5%, for Ta, W', W, Re, Au, Os, Pt, and Ir shields, respectively. On average, the CTVHR values for D100 , V100 , D10 were not significantly different across all DMBT&R shields and the Con.T&R plans (P > 0.219). For the D2cm3 , the benchmark results showed significant reductions (P < 0.03), that is, on average, -8.3% for bladder, -10.7% for rectum, and -10.1% for sigmoid, compared to the Con.T&R plans. However, the various shields showed little improvement from the tungsten alloy (W'), where on average, rectum (bladder) [sigmoid] D2cm3 were reduced by -1.32% (-0.85%) [-1.01%], -1.25% (-0.78%) [-0.91%], -1.22% (-0.75%) [-0.86%], -0.94% (-0.60%) [-0.70%], -0.84% (-0.51%) [-0.59%], and -0.38% (-0.24%) [-0.23%] for Ir, Pt, Os, Au, Re, and W shields, relative to the benchmark W' DMBT plans, respectively. These corresponding values for Ta increased by +0.28% (+0.08%) [+0.25%], respectively. CONCLUSION The Ir, Pt, Os, Au, Re, and W shielding materials, respectively, in descending order, lead to better OAR sparing than the DMBT(W')&R plans. However, the amount of improvement is limited and clinically insignificant. This finding suggests that the initial W' shield remains a suitable choice given the proven MR compatibility, for use in MR-guided adaptive brachytherapy of cervical cancer.
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Affiliation(s)
- Habib Safigholi
- Department of Electrical Engineering, Shiraz Branch, Islamic Azad University, Shiraz, Iran
| | - Dae Yup Han
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT, USA
| | - Abraam Soliman
- R&D Clinical Excellence (MRI), Philips Healthcare, Best, The Netherlands
| | - William Y Song
- Department of Radiation Oncology, Virginia Commonwealth University, Richmond, VA, USA
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Cho M, Wu X, Dadkhah H, Yi J, Flynn RT, Kim Y, Xu W. Fast dose optimization for rotating shield brachytherapy. Med Phys 2017; 44:5384-5392. [PMID: 28744870 DOI: 10.1002/mp.12486] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Revised: 06/25/2017] [Accepted: 07/17/2017] [Indexed: 02/05/2023] Open
Abstract
PURPOSE To provide a fast computational method, based on the proximal graph solver (POGS) - A convex optimization solver using the alternating direction method of multipliers (ADMM), for calculating an optimal treatment plan in rotating shield brachytherapy (RSBT). RSBT treatment planning has more degrees of freedom than conventional high-dose-rate brachytherapy due to the addition of emission direction, and this necessitates a fast optimization technique to enable clinical usage. METHODS The multi-helix RSBT (H-RSBT) delivery technique was investigated for five representative cervical cancer patients. Treatment plans were generated for all patients using the POGS method and the commercially available solver IBM ILOG CPLEX. The rectum, bladder, sigmoid colon, high-risk clinical target volume (HR-CTV), and HR-CTV boundary were the structures included in our optimization, which applied an asymmetric dose-volume optimization with smoothness control. Dose calculation resolution was 1 × 1 × 3 mm3 for all cases. The H-RSBT applicator had 6 helices, with 33.3 mm of translation along the applicator per helical rotation and 1.7 mm spacing between dwell positions, yielding 17.5° emission angle spacing per 5 mm along the applicator. RESULTS For each patient, HR-CTV D90 , HR-CTV D100 , rectum D2cc , sigmoid D2cc , and bladder D2cc matched within 1% for CPLEX and POGS methods. Also, similar EQD2 values between CPLEX and POGS methods were obtained. POGS was around 18 times faster than CPLEX. For all patients, total optimization times were 32.1-65.4 s for CPLEX and 2.1-3.9 s for POGS. CONCLUSIONS POGS reduced treatment plan optimization time approximately 18 times for RSBT with similar HR-CTV D90 , organ at risk (OAR) D2cc values, and EQD2 values compared to CPLEX, which is significant progress toward clinical translation of RSBT.
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Affiliation(s)
- Myung Cho
- Department of Electrical and Computer Engineering, University of Iowa, 4016 Seamans Center, Iowa City, IA, 52242, USA
| | - Xiaodong Wu
- Department of Electrical and Computer Engineering, University of Iowa, 4016 Seamans Center, Iowa City, IA, 52242, USA.,Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, IA, 52242, USA
| | - Hossein Dadkhah
- Department of Biomedical Engineering, University of Iowa, 1402 Seamans Center, Iowa City, IA, 52242, USA
| | - Jirong Yi
- Department of Electrical and Computer Engineering, University of Iowa, 4016 Seamans Center, Iowa City, IA, 52242, USA
| | - Ryan T Flynn
- Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, IA, 52242, USA
| | - Yusung Kim
- Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, IA, 52242, USA
| | - Weiyu Xu
- Department of Electrical and Computer Engineering, University of Iowa, 4016 Seamans Center, Iowa City, IA, 52242, USA
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Shi C, Wang B. Preliminary Monte Carlo Investigation of Using Ir-192 as the Source for Real Time Imaging Purpose. INTERNATIONAL JOURNAL OF MEDICAL PHYSICS, CLINICAL ENGINEERING AND RADIATION ONCOLOGY 2017; 6:21-30. [PMID: 28824832 PMCID: PMC5562365 DOI: 10.4236/ijmpcero.2017.61003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The purpose of this study is to investigate the potential use of Ir-192 as the source for real time imaging during HDR (High Dose Rate) brachytherapy treatment. Phantom measurement was performed to determine outside of the body dose. Monte Carlo code, EGSnrcMP egs_inprz, was used for the simulation to calculate the outside of the body x-ray signal for CT reconstruction. Matlab code was developed to reconstruct the Ir-192 source and for 3D visualization in order to assess reconstructed CT resolution, signal-to-noise ratio, and imaging dose information. The measured dose was 0.67 ± 0.04 cGy, which was comparable to the Monte Carlo simulation result 0.71 ± 0.20 cGy. The reconstructed source diameter dimension was 1.3 mm compared with 1.1 mm for the real source dimension. The signal-to-noise ratio was 19.91 db following de-noising. Source position was within a 1 mm difference between programmed and simulated results. Although the Ir-192 signal is weak for CT imaging, it is possible to use it as a CT imaging x-ray source for HDR treatment localization, verification and dosimetry purposes. Further study is needed for the detailed design of an outside of the body CT-like device for use in brachytherapy imaging.
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Affiliation(s)
- Chengyu Shi
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Brian Wang
- Department of Radiation Oncology, James Brown Cancer Center, The University of Louisville, Louisville, KY, USA
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Liu Y, Flynn RT, Kim Y, Wu X. Asymmetric dose–volume optimization with smoothness control for rotating‐shield brachytherapy. Med Phys 2016; 41:111709. [DOI: 10.1118/1.4897617] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Affiliation(s)
- Yunlong Liu
- Department of Electrical and Computer Engineering, University of Iowa, 4016 Seamans Center, Iowa City, Iowa 52242
| | - Ryan T. Flynn
- Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242
| | - Yusung Kim
- Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242
| | - Xiaodong Wu
- Department of Electrical and Computer Engineering, University of Iowa, 4016 Seamans Center, Iowa City, Iowa 52242 and Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242
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Karimi Jashni H, Safigholi H, Meigooni AS. Influences of spherical phantom heterogeneities on dosimetric charactristics of miniature electronic brachytherapy X-ray sources: Monte Carlo study. Appl Radiat Isot 2015; 95:108-113. [DOI: 10.1016/j.apradiso.2014.10.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Revised: 07/16/2014] [Accepted: 10/15/2014] [Indexed: 10/24/2022]
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Abstract
PURPOSE To present dynamic rotating shield brachytherapy (D-RSBT), a novel form of high-dose-rate brachytherapy (HDR-BT) with electronic brachytherapy source, where the radiation shield is capable of changing emission angles during the radiation delivery process. METHODS A D-RSBT system uses two layers of independently rotating tungsten alloy shields, each with a 180° azimuthal emission angle. The D-RSBT planning is separated into two stages: anchor plan optimization and optimal sequencing. In the anchor plan optimization, anchor plans are generated by maximizing the D90 for the high-risk clinical-tumor-volume (HR-CTV) assuming a fixed azimuthal emission angle of 11.25°. In the optimal sequencing, treatment plans that most closely approximate the anchor plans under the delivery-time constraint will be efficiently computed. Treatment plans for five cervical cancer patients were generated for D-RSBT, single-shield RSBT (S-RSBT), and (192)Ir-based intracavitary brachytherapy with supplementary interstitial brachytherapy (IS + ICBT) assuming five treatment fractions. External beam radiotherapy doses of 45 Gy in 25 fractions of 1.8 Gy each were accounted for. The high-risk clinical target volume (HR-CTV) doses were escalated such that the D2cc of the rectum, sigmoid colon, or bladder reached its tolerance equivalent dose in 2 Gy fractions (EQD2 with α∕β = 3 Gy) of 75 Gy, 75 Gy, or 90 Gy, respectively. RESULTS For the patients considered, IS + ICBT had an average total dwell time of 5.7 minutes∕fraction (min∕fx) assuming a 10 Ci(192)Ir source, and the average HR-CTV D90 was 78.9 Gy. In order to match the HR-CTV D90 of IS + ICBT, D-RSBT required an average of 10.1 min∕fx more delivery time, and S-RSBT required 6.7 min∕fx more. If an additional 20 min∕fx of delivery time is allowed beyond that of the IS + ICBT case, D-RSBT and S-RSBT increased the HR-CTV D90 above IS + ICBT by an average of 16.3 Gy and 9.1 Gy, respectively. CONCLUSIONS For cervical cancer patients, D-RSBT can boost HR-CTV D90 over IS + ICBT and S-RSBT without violating the tolerance doses to the bladder, rectum, or sigmoid. The D90 improvements from D-RSBT depend on the patient, the delivery time budget, and the applicator structure.
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Affiliation(s)
- Yunlong Liu
- Department of Electrical and Computer Engineering, University of Iowa, 4016 Seamans Center, Iowa City, Iowa 52242
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Wan XB, Jiang R, Xie FY, Qi ZY, Li AJ, Ye WJ, Hua YJ, Zhu YL, Zou X, Guo L, Mai HQ, Guo X, Hong MH, Chen MY. Endoscope-guided interstitial intensity-modulated brachytherapy and intracavitary brachytherapy as boost radiation for primary early T stage nasopharyngeal carcinoma. PLoS One 2014; 9:e90048. [PMID: 24595299 PMCID: PMC3940723 DOI: 10.1371/journal.pone.0090048] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Accepted: 01/27/2014] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Intracavitary brachytherapy (ICBT) is usually applied as boost radiotherapy for superficial residual of nasopharyngeal carcinoma (NPC) after primary extern-beam radiptherapy (ERT). Here, we evaluated the outcome of endoscope-guided interstitial intensity-modulated brachytherapy (IMBT) boost radiation for deep-seated residual NPC. METHODOLOGY/PRINCIPAL FINDINGS Two hundred and thirteen patients with residual NPC who were salvaged with brachytherapy boost radiation during 2005-2009 were analyzed retrospectively. Among these patients, 171 patients had superficial residual NPC (≤1 cm below the nasopharyngeal epithelium) were treated with ICBT boost radiation, and interstitial IMBT boost radiation was delivered to 42 patients with deep-seated residual NPC (>1 cm below the nasopharyngeal epithelium). We found that IMBT boost subgroup had a higher ratio of T2b (81.0% VS 34.5%, P<0.001) and stage II (90.5% VS 61.4%, P = 0.001) than that of ICBT boost subgroup. The dosage of external-beam radiotherapy in the nasopharyngeal (63.0±3.8 VS 62.6±4.3 Gray (Gy), P = 0.67) and regional lymph nodes (55.8±5.0 VS 57.5±5.7 Gy, P = 0.11) was comparable in both groups. For brachytherapy, IMBT subgroup had a lower boost radiation dosage than ICBT subgroup (11.0±2.9 VS 14.8±3.2 Gy, P<0.01). Though the IMBT group had deeper residual tumors and received lower boost radiation dosages, both subgroups had the similar 5-year actuarial overall survival rate (IMBT VS ICBT group: 96.8% VS 93.6%, P = 0.87), progression-free survival rate (92.4% VS 86.5%, P = 0.41) and distant metastasis-free survival rate (94.9% VS 92.7%, P = 0.64). Moreover, IMBT boost radiation subgroup had a similar local (97.4% VS 94.4%, P = 0.57) and regional (95.0% VS 97.2%, P = 0.34) control to ICBT subgroup. The acute and late toxicities rates were comparable between the both subgroups. CONCLUSIONS/SIGNIFICANCE IMBT boost radiation may be a promising therapeutic selection for deep-seated residual NPC.
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Affiliation(s)
- Xiang-Bo Wan
- Department of Nasopharyngeal Carcinoma, Sun Yat-sen University Cancer Center, Guangzhou, P. R. China
- State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, P. R. China
- Department of Radiation Oncology, the Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, P. R. China
- Collaborative Innovation Center for Cancer Medicine, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center; Guangzhou, P. R. China
| | - Rou Jiang
- Department of Nasopharyngeal Carcinoma, Sun Yat-sen University Cancer Center, Guangzhou, P. R. China
- State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, P. R. China
- Collaborative Innovation Center for Cancer Medicine, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center; Guangzhou, P. R. China
| | - Fang-Yun Xie
- State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, P. R. China
- Department of Radiation Oncology, Sun Yat-sen University Cancer Center, Guangzhou, P. R. China
- Collaborative Innovation Center for Cancer Medicine, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center; Guangzhou, P. R. China
| | - Zhen-Yu Qi
- Department of Radiation Oncology, Sun Yat-sen University Cancer Center, Guangzhou, P. R. China
- Collaborative Innovation Center for Cancer Medicine, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center; Guangzhou, P. R. China
| | - Ai-Ju Li
- State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, P. R. China
- Department of Radiation Oncology, Sun Yat-sen University Cancer Center, Guangzhou, P. R. China
- Collaborative Innovation Center for Cancer Medicine, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center; Guangzhou, P. R. China
| | - Wei-Jun Ye
- State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, P. R. China
- Department of Radiation Oncology, Sun Yat-sen University Cancer Center, Guangzhou, P. R. China
- Collaborative Innovation Center for Cancer Medicine, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center; Guangzhou, P. R. China
| | - Yi-Jun Hua
- Department of Nasopharyngeal Carcinoma, Sun Yat-sen University Cancer Center, Guangzhou, P. R. China
- State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, P. R. China
- Collaborative Innovation Center for Cancer Medicine, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center; Guangzhou, P. R. China
| | - Yu-Liang Zhu
- Department of Nasopharyngeal Carcinoma, Sun Yat-sen University Cancer Center, Guangzhou, P. R. China
- State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, P. R. China
- Collaborative Innovation Center for Cancer Medicine, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center; Guangzhou, P. R. China
| | - Xiong Zou
- Department of Nasopharyngeal Carcinoma, Sun Yat-sen University Cancer Center, Guangzhou, P. R. China
- State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, P. R. China
- Collaborative Innovation Center for Cancer Medicine, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center; Guangzhou, P. R. China
| | - Ling Guo
- Department of Nasopharyngeal Carcinoma, Sun Yat-sen University Cancer Center, Guangzhou, P. R. China
- State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, P. R. China
- Collaborative Innovation Center for Cancer Medicine, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center; Guangzhou, P. R. China
| | - Hai-Qiang Mai
- Department of Nasopharyngeal Carcinoma, Sun Yat-sen University Cancer Center, Guangzhou, P. R. China
- State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, P. R. China
- Collaborative Innovation Center for Cancer Medicine, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center; Guangzhou, P. R. China
| | - Xiang Guo
- Department of Nasopharyngeal Carcinoma, Sun Yat-sen University Cancer Center, Guangzhou, P. R. China
- State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, P. R. China
- Collaborative Innovation Center for Cancer Medicine, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center; Guangzhou, P. R. China
| | - Ming-Huang Hong
- Department of Nasopharyngeal Carcinoma, Sun Yat-sen University Cancer Center, Guangzhou, P. R. China
- State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, P. R. China
- Collaborative Innovation Center for Cancer Medicine, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center; Guangzhou, P. R. China
| | - Ming-Yuan Chen
- Department of Nasopharyngeal Carcinoma, Sun Yat-sen University Cancer Center, Guangzhou, P. R. China
- State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, P. R. China
- Collaborative Innovation Center for Cancer Medicine, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center; Guangzhou, P. R. China
- * E-mail:
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Liu Y, Flynn RT, Yang W, Kim Y, Bhatia SK, Sun W, Wu X. Rapid emission angle selection for rotating-shield brachytherapy. Med Phys 2013; 40:051720. [PMID: 23635268 DOI: 10.1118/1.4802750] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE The authors present a rapid emission angle selection (REAS) method that enables the efficient selection of the azimuthal shield angle for rotating shield brachytherapy (RSBT). The REAS method produces a Pareto curve from which a potential RSBT user can select a treatment plan that balances the tradeoff between delivery time and tumor dose conformity. METHODS Two cervical cancer patients were considered as test cases for the REAS method. The RSBT source considered was a Xoft Axxent(TM) electronic brachytherapy source, partially shielded with 0.5 mm of tungsten, which traveled inside a tandem intrauterine applicator. Three anchor RSBT plans were generated for each case using dose-volume optimization, with azimuthal shield emission angles of 90°, 180°, and 270°. The REAS method converts the anchor plans to treatment plans for all possible emission angles by combining neighboring beamlets to form beamlets for larger emission angles. Treatment plans based on exhaustive dose-volume optimization (ERVO) and exhaustive surface optimization (ERSO) were also generated for both cases. Uniform dwell-time scaling was applied to all plans such that that high-risk clinical target volume D90 was maximized without violating the D2cc tolerances of the rectum, bladder, and sigmoid colon. RESULTS By choosing three azimuthal emission angles out of 32 potential angles, the REAS method performs about 10 times faster than the ERVO method. By setting D90 to 85-100 Gy10, the delivery times used by REAS generated plans are 21.0% and 19.5% less than exhaustive surface optimized plans used by the two clinical cases. By setting the delivery time budget to 5-25 and 10-30 min∕fx, respectively, for two the cases, the D90 contributions for REAS are improved by 5.8% and 5.1% compared to the ERSO plans. The ranges used in this comparison were selected in order to keep both D90 and the delivery time within acceptable limits. CONCLUSIONS The REAS method enables efficient RSBT treatment planning and delivery and provides treatment plans with comparable quality to those generated by exhaustive replanning with dose-volume optimization.
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Affiliation(s)
- Yunlong Liu
- Department of Electrical and Computer Engineering, University of Iowa, 4016 Seamans Center, Iowa City, Iowa 52242, USA
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Webster MJ, Devic S, Vuong T, Yup Han D, Park JC, Scanderbeg D, Lawson J, Song B, Tyler Watkins W, Pawlicki T, Song WY. Dynamic modulated brachytherapy (DMBT) for rectal cancer. Med Phys 2012; 40:011718. [DOI: 10.1118/1.4769416] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
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Safigholi H, Faghihi R, Jashni SK, Meigooni AS. Characteristics of miniature electronic brachytherapy x-ray sources based on TG-43U1 formalism using Monte Carlo simulation techniques. Med Phys 2012; 39:1971-9. [DOI: 10.1118/1.3693046] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Shi C, Guo B, Cheng CY, Eng T, Papanikolaou N. Applications of tissue heterogeneity corrections and biologically effective dose volume histograms in assessing the doses for accelerated partial breast irradiation using an electronic brachytherapy source. Phys Med Biol 2010; 55:5283-97. [DOI: 10.1088/0031-9155/55/18/003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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