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Zahir NSM, Saad M, Alip A, Rejab M, Jamalludin Z, Hizam NDA, Liew YM, Ung NM. Evaluation of intrafractional prostate displacement during prostate radiotherapy using real-time ultrasound system. Phys Eng Sci Med 2023; 46:405-412. [PMID: 36806157 DOI: 10.1007/s13246-023-01230-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 01/30/2023] [Indexed: 02/23/2023]
Abstract
Transperineal ultrasound (TPUS) is an image-guided radiotherapy system used for tracking intrafraction prostate displacements in real time. The objectives of this study are to evaluate intrafraction prostate displacements and derive planning target volume (PTV) margins for prostate radiotherapy at our institution. The ultrasound (US) data of nine prostate cancer patients referred for VMAT radiotherapy was retrieved. Prior to beam on, patient position was set up with the US probe positioned transperineally with the aid of reference images (fused US and computed tomography images). In each fraction, prostate displacements in three directions [superior/inferior (SI), left/right (LR) and anterior/posterior (AP)] were recorded. PTV margins were determined using Van Herk's formula. To assess the prostate displacement time trend, continuous displacement data were plotted in 30-s intervals for eight minutes. The intrafraction prostate monitoring found a population mean setup error (Mp) of 0.8, 0.1, - 1.7 mm, a systematic error of (∑p) 0.7, 0.4, 0.9 mm and random error (σp) of 0.2, 0.1, 0.3 mm in SI, LR and AP directions, respectively. The PTV margin was found to be the largest in the AP direction at 2.5 mm compared with 1.9 mm and 1.1 mm for SI and LR directions, respectively. The PTV margin allowed for prostate radiotherapy at our institution was 2.5 mm in all directions. The prostate displacement time trend showed an increase in intrafraction displacements, with most patients were observed to have strong positive correlation between time and intrafraction prostate displacements in SI direction. TPUS is feasible for monitoring intrafraction displacement of the prostate and may facilitate PTV margin generation to account for such displacements during radiotherapy.
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Affiliation(s)
| | - Marniza Saad
- Clinical Oncology Unit, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Adlinda Alip
- Clinical Oncology Unit, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Munira Rejab
- Clinical Oncology Unit, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
- Medical Physics Unit, Universiti Malaya Medical Centre, Kuala Lumpur, Malaysia
| | - Zulaikha Jamalludin
- Clinical Oncology Unit, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | | | - Yih Miin Liew
- Department of Biomedical Engineering, Faculty of Engineering, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Ngie Min Ung
- Clinical Oncology Unit, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia.
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Bednarz BP, Jupitz S, Lee W, Mills D, Chan H, Fiorillo T, Sabitini J, Shoudy D, Patel A, Mitra J, Sarcar S, Wang B, Shepard A, Matrosic C, Holmes J, Culberson W, Bassetti M, Hill P, McMillan A, Zagzebski J, Smith LS, Foo TK. First-in-human imaging using a MR-compatible e4D ultrasound probe for motion management of radiotherapy. Phys Med 2021; 88:104-110. [PMID: 34218199 DOI: 10.1016/j.ejmp.2021.06.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Revised: 06/08/2021] [Accepted: 06/21/2021] [Indexed: 12/25/2022] Open
Abstract
PURPOSE Respiration-induced tumor or organ positional changes can impact the accuracy of external beam radiotherapy. Motion management strategies are used to account for these changes during treatment. The authors report on the development, testing, and first-in-human evaluation of an electronic 4D (e4D) MR-compatible ultrasound probe that was designed for hands-free operation in a MR and linear accelerator (LINAC) environment. METHODS Ultrasound components were evaluated for MR compatibility. Electromagnetic interference (EMI) shielding was used to enclose the entire probe and a factory-fabricated cable shielded with copper braids was integrated into the probe. A series of simultaneous ultrasound and MR scans were acquired and analyzed in five healthy volunteers. RESULTS The ultrasound probe led to minor susceptibility artifacts in the MR images immediately proximal to the ultrasound probe at a depth of <10 mm. Ultrasound and MR-based motion traces that were derived by tracking the salient motion of endogenous target structures in the superior-inferior (SI) direction demonstrated good concordance (Pearson correlation coefficients of 0.95-0.98) between the ultrasound and MRI datasets. CONCLUSION We have demonstrated that our hands-free, e4D probe can acquire ultrasound images during a MR acquisition at frame rates of approximately 4 frames per second (fps) without impacting either the MR or ultrasound image quality. This use of this technology for interventional procedures (e.g. biopsies and drug delivery) and motion compensation during imaging are also being explored.
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Affiliation(s)
- Bryan P Bednarz
- Medical Physics, University of Wisconsin-Madison, Madison, WI 53705, United States.
| | - Sydney Jupitz
- Medical Physics, University of Wisconsin-Madison, Madison, WI 53705, United States
| | - Warren Lee
- GE Global Research, Niskayuna, NY 12309, United States
| | - David Mills
- GE Global Research, Niskayuna, NY 12309, United States
| | - Heather Chan
- GE Global Research, Niskayuna, NY 12309, United States
| | | | | | - David Shoudy
- GE Global Research, Niskayuna, NY 12309, United States
| | - Aqsa Patel
- GE Global Research, Niskayuna, NY 12309, United States
| | - Jhimli Mitra
- GE Global Research, Niskayuna, NY 12309, United States
| | | | - Bo Wang
- GE Global Research, Niskayuna, NY 12309, United States
| | - Andrew Shepard
- Medical Physics, University of Wisconsin-Madison, Madison, WI 53705, United States; Department of Radiation Oncology, University of Iowa, Iowa City, IA 52242, United States
| | - Charles Matrosic
- Medical Physics, University of Wisconsin-Madison, Madison, WI 53705, United States; Department of Radiation Oncology, University of Michigan, Ann Arbor, MI 48109, United States
| | - James Holmes
- Department of Radiology, University of Wisconsin-Madison, Madison, WI 53705, United States
| | - Wesley Culberson
- Medical Physics, University of Wisconsin-Madison, Madison, WI 53705, United States
| | - Michael Bassetti
- Department of Human Oncology, University of Wisconsin-Madison, Madison, WI 53705, United States
| | - Patrick Hill
- Department of Human Oncology, University of Wisconsin-Madison, Madison, WI 53705, United States
| | - Alan McMillan
- Department of Radiology, University of Wisconsin-Madison, Madison, WI 53705, United States
| | - James Zagzebski
- Medical Physics, University of Wisconsin-Madison, Madison, WI 53705, United States
| | - L Scott Smith
- GE Global Research, Niskayuna, NY 12309, United States
| | - Thomas K Foo
- GE Global Research, Niskayuna, NY 12309, United States
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Grimwood A, Thomas K, Kember S, Aldis G, Lawes R, Brigden B, Francis J, Henegan E, Kerner M, Delacroix L, Gordon A, Tree A, Harris EJ, McNair HA. Factors affecting accuracy and precision in ultrasound guided radiotherapy. Phys Imaging Radiat Oncol 2021; 18:68-77. [PMID: 34258411 PMCID: PMC8254201 DOI: 10.1016/j.phro.2021.05.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 05/04/2021] [Accepted: 05/11/2021] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND AND PURPOSE Transperineal ultrasound (TPUS) is used clinically for directly assessing prostate motion. Factors affecting accuracy and precision in TPUS motion estimation must be assessed to realise its full potential. METHODS AND MATERIALS Patients were imaged using volumetric TPUS during the Clarity-Pro trial (NCT02388308). Prostate motion was measured online at patient set-up and offline by experienced observers. Cone beam CT with markers was used as a comparator and observer performance was also quantified. The influence of different clinical factors was examined to establish specific recommendations towards efficacious ultrasound guided radiotherapy. RESULTS From 330 fractions in 22 patients, offline observer random errors were 1.5 mm, 1.3 mm, 1.9 mm (left-right, superior-inferior, anteroposterior respectively). Errors increased in fractions exhibiting poor image quality to 3.3 mm, 3.3 mm and 6.8 mm. Poor image quality was associated with inconsistent probe placement, large anatomical changes and unfavourable imaging conditions within the patient. Online matching exhibited increased observer errors of: 3.2 mm, 2.9 mm and 4.7 mm. Four patients exhibited large systematic residual errors, of which three had poor quality images. Patient habitus showed no correlation with observer error, residual error, or image quality. CONCLUSIONS TPUS offers the unique potential to directly assess inter- and intra-fraction motion on conventional linacs. Inconsistent image quality, inexperienced operators and the pressures of the clinical environment may degrade precision and accuracy. Experienced operators are essential and cross-centre standards for training and QA should be established that build upon current guidance. Greater use of automation technologies may further minimise uncertainties.
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Affiliation(s)
- Alexander Grimwood
- Department of Radiotherapy, Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Radiotherapy Department, Royal Marsden NHS Foundation Trust, Sutton SM2 5PT, United Kingdom
- Joint Department of Physics, Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Radiotherapy Department, Royal Marsden NHS Foundation Trust, Sutton SM2 5PT, United Kingdom
| | - Karen Thomas
- Department of Statistics and Computing, Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Radiotherapy Department, Royal Marsden NHS Foundation Trust, Sutton SM2 5PT, United Kingdom
| | - Sally Kember
- Department of Radiotherapy, Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Radiotherapy Department, Royal Marsden NHS Foundation Trust, Sutton SM2 5PT, United Kingdom
| | - Georgina Aldis
- Department of Radiotherapy, Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Radiotherapy Department, Royal Marsden NHS Foundation Trust, Sutton SM2 5PT, United Kingdom
| | - Rebekah Lawes
- Department of Radiotherapy, Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Radiotherapy Department, Royal Marsden NHS Foundation Trust, Sutton SM2 5PT, United Kingdom
| | - Beverley Brigden
- Department of Radiotherapy, Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Radiotherapy Department, Royal Marsden NHS Foundation Trust, Sutton SM2 5PT, United Kingdom
| | - Jane Francis
- Department of Radiotherapy, Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Radiotherapy Department, Royal Marsden NHS Foundation Trust, Sutton SM2 5PT, United Kingdom
| | - Emer Henegan
- Department of Radiotherapy, Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Radiotherapy Department, Royal Marsden NHS Foundation Trust, Sutton SM2 5PT, United Kingdom
| | - Melanie Kerner
- Department of Radiotherapy, Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Radiotherapy Department, Royal Marsden NHS Foundation Trust, Sutton SM2 5PT, United Kingdom
| | - Louise Delacroix
- Department of Radiotherapy, Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Radiotherapy Department, Royal Marsden NHS Foundation Trust, Sutton SM2 5PT, United Kingdom
| | - Alexandra Gordon
- Department of Radiotherapy, Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Radiotherapy Department, Royal Marsden NHS Foundation Trust, Sutton SM2 5PT, United Kingdom
| | - Alison Tree
- Department of Radiotherapy, Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Radiotherapy Department, Royal Marsden NHS Foundation Trust, Sutton SM2 5PT, United Kingdom
| | - Emma J. Harris
- Department of Radiotherapy, Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Radiotherapy Department, Royal Marsden NHS Foundation Trust, Sutton SM2 5PT, United Kingdom
- Joint Department of Physics, Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Radiotherapy Department, Royal Marsden NHS Foundation Trust, Sutton SM2 5PT, United Kingdom
| | - Helen A. McNair
- Department of Radiotherapy, Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Radiotherapy Department, Royal Marsden NHS Foundation Trust, Sutton SM2 5PT, United Kingdom
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Mason SA, White IM, O'Shea T, McNair HA, Alexander S, Kalaitzaki E, Bamber JC, Harris EJ, Lalondrelle S. Combined Ultrasound and Cone Beam CT Improves Target Segmentation for Image Guided Radiation Therapy in Uterine Cervix Cancer. Int J Radiat Oncol Biol Phys 2019; 104:685-693. [PMID: 30872145 PMCID: PMC6542416 DOI: 10.1016/j.ijrobp.2019.03.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 02/07/2019] [Accepted: 03/03/2019] [Indexed: 12/14/2022]
Abstract
PURPOSE Adaptive radiation therapy strategies could account for interfractional uterine motion observed in patients with cervix cancer, but the current cone beam computed tomography (CBCT)-based treatment workflow is limited by poor soft-tissue contrast. The goal of the present study was to determine if ultrasound (US) could be used to improve visualization of the uterus, either as a single modality or in combination with CBCT. METHODS AND MATERIALS Interobserver uterine contour agreement and confidence were compared on 40 corresponding CBCT, US, and CBCT-US-fused images from 11 patients with cervix cancer. Contour agreement was measured using the Dice similarity coefficient (DSC) and mean contour-to-contour distance (MCCD). Observers rated their contour confidence on a scale from 1 to 10. Pairwise Wilcoxon signed-rank tests were used to measure differences in contour agreement and confidence. RESULTS CBCT-US fused images had significantly better contour agreement and confidence than either individual modality (P < .05), with median (interquartile range [IQR]) values of 0.84 (0.11), 1.26 (0.23) mm, and 7 (2) for the DSC, MCCD, and observer confidence ratings, respectively. Contour agreement was similar between US and CBCT, with median (IQR) DSCs of 0.81 (0.17) and 0.82 (0.14) and MCCDs of 1.75 (1.15) mm and 1.62 (0.74) mm. Observers were significantly more confident in their US-based contours than in their CBCT-based contours (P < .05), with median (IQR) confidence ratings of 7 (2.75) versus 5 (4). CONCLUSIONS CBCT and US are complementary and improve uterine segmentation precision when combined. Observers could localize the uterus with a similar precision on independent US and CBCT images.
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Affiliation(s)
- Sarah A Mason
- Institute of Cancer Research, Radiotherapy and Imaging, London, United Kingdom
| | - Ingrid M White
- Radiotherapy Department, Royal Marsden NHS Foundation Trust, London, United Kingdom
| | - Tuathan O'Shea
- Radiotherapy Physics Department, Royal Marsden NHS Foundation Trust, London, United Kingdom
| | - Helen A McNair
- Radiotherapy Department, Royal Marsden NHS Foundation Trust, London, United Kingdom
| | - Sophie Alexander
- Radiotherapy Department, Royal Marsden NHS Foundation Trust, London, United Kingdom
| | | | - Jeffrey C Bamber
- Institute of Cancer Research, Radiotherapy and Imaging, London, United Kingdom
| | - Emma J Harris
- Institute of Cancer Research, Radiotherapy and Imaging, London, United Kingdom.
| | - Susan Lalondrelle
- Radiotherapy Department, Royal Marsden NHS Foundation Trust, London, United Kingdom
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Liu X, Li J, Schild SE, Schild MH, Wong W, Vora S, Herman MG, Fatyga M. Modeling of Acute Rectal Toxicity to Compare Two Patient Positioning Methods for Prostate Cancer Radiotherapy: Can Toxicity Modeling be Used for Quality Assurance? ACTA ACUST UNITED AC 2019; 7. [PMID: 30775161 PMCID: PMC6376967 DOI: 10.4172/2167-7964.1000302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Purpose: Intensity Modulated Radiation Therapy (IMRT) allows for significant dose reductions to organs at risk in prostate cancer patients. However, the accurate delivery of IMRT plans can be compromised by patient positioning errors. The purpose of this study was to determine if the modeling of grade ≥ 2 acute rectal toxicity could be used to monitor the quality of IMRT protocols. Materials and Methods: 79 patients treated with Image and Fiducial Markers Guided IMRT (FMIGRT) and 302 patients treated with trans-abdominal ultrasound guided IMRT (USGRT) was selected for this study. Treatment plans were available for the FMIGRT group, and hand recorded dosimetric indices were available for both groups. We modeled toxicity in the FMIGRT group using the Lyman Kutcher Burman (LKB) and Univariate Logistic Regression (ULR) models, and we modeled toxicity in USGRT group using the ULR model. We performed Receiver Operating Characteristics (ROC) analysis on all of the models and compared the Area under the ROC curve (AUC) for the FMIGRT and the USGRT groups. Results: The observed Incidence of grade ≥ 2 rectal toxicity was 20% in FMIGRT patients and 54% in USGRT patients. LKB model parameters in the FMIGRT group were TD50=56.8 Gy, slope m=0.093, and exponent n=0.131. The most predictive indices in the ULR model for the FMIGRT group were D25% and V50 Gy. AUC for both models in the FMIGRT group was similar (AUC=0.67). The FMIGRT URL model predicted less than a 37% incidence of grade ≥ 2 acute rectal toxicity in the USGRT group. A fit of the ULR model to USGRT data did not yield a predictive model (AUC=0.5). Conclusion: Modeling of acute rectal toxicity provided a quantitative measure of the correlation between planning dosimetry and this clinical endpoint. Our study suggests that an unusually weak correlation may indicate a persistent patient positioning error.
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Affiliation(s)
- X Liu
- School of Computing, Informatics and Decision Systems Engineering, Arizona State University, USA
| | - J Li
- School of Computing, Informatics and Decision Systems Engineering, Arizona State University, USA
| | - S E Schild
- Department of Radiation Oncology, Mayo Clinic Arizona, USA
| | - M H Schild
- Department of Pathology, Duke University School of Medicine, USA
| | - W Wong
- Department of Radiation Oncology, Mayo Clinic Arizona, USA
| | - S Vora
- Department of Radiation Oncology, Mayo Clinic Arizona, USA
| | - M G Herman
- Department of Radiation Oncology, Mayo Clinic Arizona, USA
| | - M Fatyga
- Department of Radiation Oncology, Mayo Clinic Arizona, USA
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Zhou S, Luo L, Li J, Lin M, Chen L, Shao J, Lu S, Ma Y, Zhang Y, Chen W, Liu M, Liu S, He L. Analyses of the factors influencing the accuracy of three-dimensional ultrasound in comparison with cone-beam CT in image-guided radiotherapy for prostate cancer with or without pelvic lymph node irradiation. Radiat Oncol 2019; 14:22. [PMID: 30696488 PMCID: PMC6352439 DOI: 10.1186/s13014-019-1217-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 01/08/2019] [Indexed: 11/16/2022] Open
Abstract
Background Three-dimensional ultrasound (3DUS) is an attractive option in image-guided radiotherapy (IGRT) for prostate cancer (PCa) patients. However, the potential factors influencing the accuracy of 3DUS in comparison with cone-beam CT (CBCT) in IGRT for PCa patients haven’t been clearly identified. Methods The differences between US/US and CBCT/CT registrations were analyzed over 586 and 580 sessions for 24 and 25 PCa patients treated with or without pelvic lymph node irradiation, respectively. The clinical factors that may influence registration differences were also evaluated. Results The average discrepancies between US/US and CBCT/CT registrations were − 0.28 ± 5.28 mm, − 0.16 ± 3.48 mm, and − 0.47 ± 4.31 mm in the superior-inferior (SI), left-right (LR), and anterior-posterior (AP) directions, respectively. The discrepancies were respectively less than 5 mm longitudinally, laterally, and vertically in 64.4 and 70.1%, 84.9 and 89.2%, and 75.9 and 79.1% of the patients treated with or without pelvic lymph node irradiation, respectively. The registration differences were significantly smaller at least in one direction in patients younger than 70 years, without pelvic lymph node irradiation, guided by transperineal ultrasonography and had a bladder volume smaller than 300 mL. Conclusions Age, irradiated regions, 3DUS modality, and bladder volume are important factors that may influence the differences between US/US and CBCT/CT registrations. 3DUS guidance is more feasible for younger PCa patients with a better control of bladder volume during the treatment and those who did not undergo pelvic lymph node irradiation. Electronic supplementary material The online version of this article (10.1186/s13014-019-1217-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sha Zhou
- Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, No. 651, Dongfeng Road East, Guangzhou, 510060, China
| | - Liling Luo
- Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, No. 651, Dongfeng Road East, Guangzhou, 510060, China
| | - Jibin Li
- Department of Clinical Research, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
| | - Maosheng Lin
- Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, No. 651, Dongfeng Road East, Guangzhou, 510060, China
| | - Li Chen
- Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, No. 651, Dongfeng Road East, Guangzhou, 510060, China
| | - Jianhui Shao
- Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, No. 651, Dongfeng Road East, Guangzhou, 510060, China
| | - Shipei Lu
- Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, No. 651, Dongfeng Road East, Guangzhou, 510060, China
| | - Yaru Ma
- Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, No. 651, Dongfeng Road East, Guangzhou, 510060, China
| | - Yingting Zhang
- Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, No. 651, Dongfeng Road East, Guangzhou, 510060, China
| | - Wenfen Chen
- Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, No. 651, Dongfeng Road East, Guangzhou, 510060, China
| | - Mengzhong Liu
- Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, No. 651, Dongfeng Road East, Guangzhou, 510060, China
| | - Shiliang Liu
- Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, No. 651, Dongfeng Road East, Guangzhou, 510060, China.
| | - Liru He
- Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, No. 651, Dongfeng Road East, Guangzhou, 510060, China.
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Kim H, Chang AR, Cho S, Ye SJ. A patient-specific three-dimensional couplant pad for ultrasound image-guided radiation therapy: a feasibility study. Radiat Oncol 2018; 13:164. [PMID: 30176924 PMCID: PMC6122664 DOI: 10.1186/s13014-018-1098-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2017] [Accepted: 08/13/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND A wide application of ultrasound for radiation therapy has been hindered by a few issues such as skin and target deformations due to probe pressure, optical tracking disabilities caused by irregular surfaces and inter-user variations. The purpose of this study was to overcome these barriers by using a patient-specific three-dimensional (3D) couplant pad (CP). METHODS A patient skin mold was designed using a skin contour of simulation CT images and fabricated by a 3D printer. A CP was then casted by pouring gelatin solution into a container accommodating the mold. To validate the use of the CP in positioning accuracy and imaging quality, phantom tests were carried out in our ultrasound-based localization system and then daily ultrasound images of four patients were acquired with and without the CP before treatment. RESULTS In the phantom study, the use of CP increased a contrast-to-noise ratio from 2.4 to 4.0. The positioning accuracies in the US scans with and without the CP were less than 1 mm in all directions. In the patient study, the use of CP decreased the centroid offset of the target volume after target position alignment from 4.4 mm to 2.9 mm. One patient with a small volume of target showed a substantial increase in the inter-fractional target contour agreement (from 0.07 (poor agreement) to 0.31 (fair agreement) in Kappa values) by using the CP. CONCLUSIONS Our patient-specific 3D CP based on a 3D mold printing technique not only maintained the tracking accuracy but also reduced the inter-user variation, as well as that could potentially improve detectability of optical markers and target visibility for ultrasound image-guided radiotherapy.
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Affiliation(s)
- Heejung Kim
- Department of Biomedical Engineering, Seoul National University, Seoul, Korea.,Department of Radiation Oncology, Soonchunhyang University Hospital, Seoul, Korea
| | - Ah Ram Chang
- Department of Radiation Oncology, Soonchunhyang University Hospital, Seoul, Korea
| | - Sungwoo Cho
- Department of Surgery, Soonchunhyang University Hospital, Seoul, Korea
| | - Sung-Joon Ye
- Department of Transdisciplinary Studies, Seoul National University, Seoul, Korea. .,Advanced Institutes of Convergence Technology, Seoul National University, Suwon, Korea. .,Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea.
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The Use of Ultrasound Imaging in the External Beam Radiotherapy Workflow of Prostate Cancer Patients. BIOMED RESEARCH INTERNATIONAL 2018; 2018:7569590. [PMID: 29619375 PMCID: PMC5829356 DOI: 10.1155/2018/7569590] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 12/13/2017] [Accepted: 12/28/2017] [Indexed: 12/16/2022]
Abstract
External beam radiotherapy (EBRT) is one of the curative treatment options for prostate cancer patients. The aim of this treatment option is to irradiate tumor tissue, while sparing normal tissue as much as possible. Frequent imaging during the course of the treatment (image guided radiotherapy) allows for determination of the location and shape of the prostate (target) and of the organs at risk. This information is used to increase accuracy in radiation dose delivery resulting in better tumor control and lower toxicity. Ultrasound imaging is harmless for the patient, it is cost-effective, and it allows for real-time volumetric organ tracking. For these reasons, it is an ideal technique for image guidance during EBRT workflows. Review papers have been published in which the use of ultrasound imaging in EBRT workflows for different cancer sites (prostate, breast, etc.) was extensively covered. This new review paper aims at providing the readers with an update on the current status for prostate cancer ultrasound guided EBRT treatments.
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Yu AS, Najafi M, Hristov DH, Phillips T. Intrafractional Tracking Accuracy of a Transperineal Ultrasound Image Guidance System for Prostate Radiotherapy. Technol Cancer Res Treat 2017; 16:1067-1078. [PMID: 29332454 PMCID: PMC5762073 DOI: 10.1177/1533034617728643] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
PURPOSE The aim of this study is to evaluate the tracking accuracy of a commercial ultrasound system under relevant treatment conditions and demonstrate its clinical utility for detecting significant treatment deviations arising from inadvertent intrafractional target motion. METHODS A multimodality male pelvic phantom was used to simulate prostate image-guided radiotherapy with the system under evaluation. Target motion was simulated by placing the phantom on a motion platform. The tracking accuracy of the ultrasound system was evaluated using an independent optical tracking system under the conditions of beam-on, beam-off, poor image quality with an acoustic shadow introduced, and different phantom motion cycles. The time delay between the ultrasound-detected and actual phantom motion was investigated. A clinical case example of prostate treatment is presented as a demonstration of the utility of the system in practice. RESULTS Time delay between the motion phantom and ultrasound tracking system is 223 ± 45.2 milliseconds including video and optical tracking system frame rates. The tracking accuracy and precision were better with a longer period. The precision of ultrasound tracking performance in the axial (superior-inferior) direction was better than that in the lateral (left-right) direction (root mean square errors are 0.18 and 0.25 mm, respectively). The accuracy of ultrasound tracking performance in the lateral direction was better than that in the axial direction (the mean position errors are 0.23 and 0.45 mm, respectively). Interference by radiation and image quality do not affect tracking ability significantly. Further, utilizing the tracking system as part of a clinical study for prostate treatment further verified the accuracy and clinical appropriateness. CONCLUSIONS It is feasible to use transperineal ultrasound daily to monitor prostate motion during treatment. Our results verify the accuracy and precision of an ultrasound system under typical external beam treatment conditions and further demonstrate that the tracking system was able to identify important prostate shifts in a clinical case.
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Affiliation(s)
- Amy S Yu
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford University, Stanford, CA, USA
| | - Mohammad Najafi
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford University, Stanford, CA, USA
| | - Dimitre H Hristov
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford University, Stanford, CA, USA
| | - Tiffany Phillips
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford University, Stanford, CA, USA
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Mason SA, O’Shea TP, White IM, Lalondrelle S, Downey K, Baker M, Behrens CF, Bamber JC, Harris EJ. Towards ultrasound-guided adaptive radiotherapy for cervical cancer: Evaluation of Elekta's semiautomated uterine segmentation method on 3D ultrasound images. Med Phys 2017; 44:3630-3638. [PMID: 28493295 PMCID: PMC5575494 DOI: 10.1002/mp.12325] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 02/10/2017] [Accepted: 03/29/2017] [Indexed: 11/06/2022] Open
Abstract
PURPOSE 3D ultrasound (US) images of the uterus may be used to adapt radiotherapy (RT) for cervical cancer patients based on changes in daily anatomy. This requires accurate on-line segmentation of the uterus. The aim of this work was to assess the accuracy of Elekta's "Assisted Gyne Segmentation" (AGS) algorithm in semi-automatically segmenting the uterus on 3D transabdominal ultrasound images by comparison with manual contours. MATERIALS & METHODS Nine patients receiving RT for cervical cancer were imaged with the 3D Clarity® transabdominal probe at RT planning, and 1 to 7 times during treatment. Image quality was rated from unusable (0)-excellent (3). Four experts segmented the uterus (defined as the uterine body and cervix) manually and using AGS on images with a ranking > 0. Pairwise analysis between manual contours was evaluated to determine interobserver variability. The accuracy of the AGS method was assessed by measuring its agreement with manual contours via pairwise analysis. RESULTS 35/44 images acquired (79.5%) received a ranking > 0. For the manual contour variation, the median [interquartile range (IQR)] distance between centroids (DC) was 5.41 [5.0] mm, the Dice similarity coefficient (DSC) was 0.78 [0.11], the mean surface-to-surface distance (MSSD) was 3.20 [1.8] mm, and the uniform margin of 95% (UM95) was 4.04 [5.8] mm. There was no correlation between image quality and manual contour agreement. AGS failed to give a result in 19.3% of cases. For the remaining cases, the level of agreement between AGS contours and manual contours depended on image quality. There were no significant differences between the AGS segmentations and the manual segmentations on the images that received a quality rating of 3. However, the AGS algorithm had significantly worse agreement with manual contours on images with quality ratings of 1 and 2 compared with the corresponding interobserver manual variation. The overall median [IQR] DC, DSC, MSSD, and UM95 between AGS and manual contours was 5.48 [5.45] mm, 0.77 [0.14], 3.62 [2.7] mm, and 5.19 [8.1] mm, respectively. CONCLUSIONS The AGS tool was able to represent uterine shape of cervical cancer patients in agreement with manual contouring in cases where the image quality was excellent, but not in cases where image quality was degraded by common artifacts such as shadowing and signal attenuation. The AGS tool should be used with caution for adaptive RT purposes, as it is not reliable in accurately segmenting the uterus on 'good' or 'poor' quality images. The interobserver agreement between manual contours of the uterus drawn on 3D US was consistent with results of similar studies performed on CT and MRI images.
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Affiliation(s)
- Sarah A. Mason
- Joint Department of Physics at the Institute of Cancer Research and Royal Marsden NHS Foundation TrustSutton and LondonUK
| | - Tuathan P. O’Shea
- Joint Department of Physics at the Institute of Cancer Research and Royal Marsden NHS Foundation TrustSutton and LondonUK
| | - Ingrid M. White
- Joint Department of Physics at the Institute of Cancer Research and Royal Marsden NHS Foundation TrustSutton and LondonUK
| | - Susan Lalondrelle
- Joint Department of Physics at the Institute of Cancer Research and Royal Marsden NHS Foundation TrustSutton and LondonUK
| | - Kate Downey
- Joint Department of Physics at the Institute of Cancer Research and Royal Marsden NHS Foundation TrustSutton and LondonUK
| | - Mariwan Baker
- Department of OncologyHerlev Hospital, University of CopenhagenHerlevDenmark
| | - Claus F. Behrens
- Department of OncologyHerlev Hospital, University of CopenhagenHerlevDenmark
| | - Jeffrey C. Bamber
- Joint Department of Physics at the Institute of Cancer Research and Royal Marsden NHS Foundation TrustSutton and LondonUK
| | - Emma J. Harris
- Joint Department of Physics at the Institute of Cancer Research and Royal Marsden NHS Foundation TrustSutton and LondonUK
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Li M, Hegemann NS, Manapov F, Kolberg A, Thum PD, Ganswindt U, Belka C, Ballhausen H. Prefraction displacement and intrafraction drift of the prostate due to perineal ultrasound probe pressure. Strahlenther Onkol 2017; 193:459-465. [DOI: 10.1007/s00066-017-1105-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 01/24/2017] [Indexed: 11/30/2022]
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12
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Comparison of prostate positioning guided by three-dimensional transperineal ultrasound and cone beam CT. Strahlenther Onkol 2016; 193:221-228. [PMID: 27928626 DOI: 10.1007/s00066-016-1084-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 11/09/2016] [Indexed: 12/25/2022]
Abstract
OBJECTIVE The accuracy of a transperineal three-dimensional ultrasound system (3DUS) was assessed for prostate positioning and compared to fiducial- and bone-based positioning in kV cone beam computed tomography (CBCT) during definitive radiotherapy of prostate cancer. METHODS Each of the 7 patients had three fiducial markers implanted into the prostate before treatment. Prostate positioning was simultaneously measured by 3DUS and CBCT before each fraction. In total, 177 pairs of 3DUS and CBCT scans were collected. Bone-match and seed-match were performed for each CBCT. Using seed-match as a reference, the accuracy of 3DUS and bone-match was evaluated. Systematic and random errors as well as optimal setup margins were calculated for 3DUS and bone-match. RESULTS The discrepancy between 3DUS and seed-match in CBCT (average ± standard deviation) was 0.0 ± 1.7 mm laterally, 0.2 ± 2.0 mm longitudinally, and 0.3 ± 1.7 mm vertically. Using seed-match as a reference, systematic errors for 3DUS were 1.2 mm, 1.1 mm, and 0.9 mm; and random errors were 1.4 mm, 1.8 mm, and 1.6 mm, on lateral, longitudinal, and vertical axes, respectively. By analogy, the difference of bone-match to seed-match was 0.1 ± 1.1 mm laterally, 1.3 ± 3.8 mm longitudinally, and 1.3 ± 4.5 mm vertically. Systematic errors were 0.5 mm, 2.2 mm, and 2.6 mm; and random errors were 1.0 mm, 3.1 mm, and 3.9 mm on lateral, longitudinal, and vertical axes, respectively. The accuracy of 3DUS was significantly higher than that of bone-match on longitudinal and vertical axes, but not on the lateral axis. CONCLUSION Image-guided radiotherapy of prostate cancer based on transperineal 3DUS was feasible, with overall small discrepancy to seed-match in CBCT in this retrospective study. Compared to bone-match, transperineal 3DUS achieved higher accuracy on longitudinal and vertical axes.
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Schlosser J, Hristov D. Radiolucent 4D Ultrasound Imaging: System Design and Application to Radiotherapy Guidance. IEEE TRANSACTIONS ON MEDICAL IMAGING 2016; 35:2292-2300. [PMID: 27164579 DOI: 10.1109/tmi.2016.2559499] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Four-dimensional (4D) ultrasound (US) is an attractive modality for image guidance due to its real-time, non-ionizing, volumetric imaging capability with high soft tissue contrast. However, existing 4D US imaging systems contain large volumes of metal which interfere with diagnostic and therapeutic ionizing radiation in procedures such as CT imaging and radiation therapy. This study aimed to design and characterize a novel 4D Radiolucent Remotely-Actuated UltraSound Scanning (RRUSS) device that overcomes this limitation. In a phantom, we evaluated the imaging performance of the RRUSS device including frame rate, resolution, spatial integrity, and motion tracking accuracy. To evaluate compatibility with radiation therapy workflow, we evaluated device-induced CT imaging artifacts, US tracking performance during beam delivery, and device compatibility with commercial radiotherapy planning software. The RRUSS device produced 4D volumes at 0.1-3.0 Hz with 60° lateral field of view (FOV), 50° maximum elevational FOV, and 200 mm maximum depth. Imaging resolution (-3 dB point spread width) was 1.2-7.9 mm at depths up to 100 mm and motion tracking accuracy was ≤ 0.3±0.5 mm. No significant effect of the RRUSS device on CT image integrity was found, and RRUSS device performance was not affected by radiotherapy beam exposure. Agreement within ±3.0% / 2.0 mm was achieved between computed and measured radiotherapy dose delivered directly through the RRUSS device at 6 MV and 15 MV. In vivo liver, kidney, and prostate images were successfully acquired. Our investigations suggest that a RRUSS device can offer non-interfering 4D guidance for radiation therapy and other diagnostic and therapeutic procedures.
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Trivedi A, Ashikaga T, Hard D, Archambault J, Lachaine M, Cooper DT, Wallace HJ. Development of 3-dimensional transperineal ultrasound for image guided radiation therapy of the prostate: Early evaluations of feasibility and use for inter- and intrafractional prostate localization. Pract Radiat Oncol 2016; 7:e27-e33. [PMID: 27742558 DOI: 10.1016/j.prro.2016.08.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 08/05/2016] [Accepted: 08/30/2016] [Indexed: 10/21/2022]
Abstract
PURPOSE Transperineal ultrasound (TPUS) allows for continuous imaging of the prostate gland, but the accuracy of TPUS has not been rigorously studied. We determined the feasibility of prostate imaging with TPUS and subsequently compared prostate localization with TPUS and computed tomography (CT). METHODS AND MATERIALS We completed 2 sequential evaluations of TPUS. The feasibility study included 15 men with localized prostate cancer and tested if TPUS adequately imaged the prostate. Image qualities of the prostate and adjacent normal structures were measured. The subsequent study included 17 men who at the time of initial radiation treatment planning and in 3 subsequent sessions had CT and TPUS imaging performed and compared. RESULTS Feasibility of TPUS was confirmed in the first trial. After expected hardware and software modifications were completed, TPUS provided near complete edge definition of the prostate in the final 5 patients in the feasibility trial. The second study allowed for the comparison of 30 image sets. The differences between TPUS and CT in each direction (mean + standard deviation) were found to be 0.06 ± 2.86 mm (anteroposterior), 0.49 ± 3.49 mm (superoinferior), and 0.63 ± 3.27 mm (left-right), with no significant difference between the 2 modalities (all P > .32). The Euclidean distance variance using the 2 techniques was 5.25 ± 1.79 mm, which was significantly different. CONCLUSIONS TPUS provides good imaging of the prostate gland. We noted excellent correlation in gland localization when TPUS is compared with CT scans when comparing routine 3-dimensional positional data. Euclidean distance variation suggests the potential that summation of small errors may in fact lead to significant differences in actual gland positional certainty. The reported difference is within the range of standard planning target volume expansion however requires additional evaluation.
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Affiliation(s)
- Apoorva Trivedi
- Medical student, University of Vermont College of Medicine, Burlington, Vermont
| | - Takamura Ashikaga
- Medical Biostatistics, University of Vermont College of Medicine, Burlington, Vermont
| | - Daphne Hard
- Radiation Oncology, University of Vermont Medical Center, Burlington, Vermont
| | - Jessica Archambault
- Radiation Oncology, University of Vermont Medical Center, Burlington, Vermont
| | | | | | - Harold James Wallace
- Medical Biostatistics, University of Vermont College of Medicine, Burlington, Vermont; University of Vermont Cancer Center, Burlington, Vermont.
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Baker M, Cooper DT, Behrens CF. Evaluation of uterine ultrasound imaging in cervical radiotherapy; a comparison of autoscan and conventional probe. Br J Radiol 2016; 89:20160510. [PMID: 27452268 DOI: 10.1259/bjr.20160510] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE In cervical radiotherapy, it is essential that the uterine position is correctly determined prior to treatment delivery. The aim of this study was to evaluate an autoscan ultrasound (A-US) probe, a motorized transducer creating three-dimensional (3D) images by sweeping, by comparing it with a conventional ultrasound (C-US) probe, where manual scanning is required to acquire 3D images. METHODS Nine healthy volunteers were scanned by seven operators, using the Clarity(®) system (Elekta, Stockholm, Sweden). In total, 72 scans, 36 scans from the C-US and 36 scans from the A-US probes, were acquired. Two observers delineated the uterine structure, using the software-assisted segmentation in the Clarity workstation. The data of uterine volume, uterine centre of mass (COM) and maximum uterine lengths, in three orthogonal directions, were analyzed. RESULTS In 53% of the C-US scans, the whole uterus was captured, compared with 89% using the A-US. F-test on 36 scans demonstrated statistically significant differences in interobserver COM standard deviation (SD) when comparing the C-US with the A-US probe for the inferior-superior (p < 0.006), left-right (p < 0.012) and anteroposterior directions (p < 0.001). The median of the interobserver COM distance (Euclidean distance for 36 scans) was reduced from 8.5 (C-US) to 6.0 mm (A-US). An F-test on the 36 scans showed strong significant differences (p < 0.001) in the SD of the Euclidean interobserver distance when comparing the C-US with the A-US scans. The average Dice coefficient when comparing the two observers was 0.67 (C-US) and 0.75 (A-US). The predictive interval demonstrated better interobserver delineation concordance using the A-US probe. CONCLUSION The A-US probe imaging might be a better choice of image-guided radiotherapy system for correcting for daily uterine positional changes in cervical radiotherapy. ADVANCES IN KNOWLEDGE Using a novel A-US probe might reduce the uncertainty in interoperator variability during ultrasound scanning.
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Affiliation(s)
- Mariwan Baker
- 1 Department of Oncology, Radiotherapy Research Unit, Herlev Hospital, University of Copenhagen, Copenhagen, Denmark.,2 Center for Fast Ultrasound Imaging, Department of Electrical Engineering, Technical University of Denmark, Lyngby, Denmark.,3 Center for Nuclear Technologies, Technical University of Denmark, Roskilde, Denmark
| | | | - Claus F Behrens
- 1 Department of Oncology, Radiotherapy Research Unit, Herlev Hospital, University of Copenhagen, Copenhagen, Denmark
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Evaluation of a new transperineal ultrasound probe for inter-fraction image-guidance for definitive and post-operative prostate cancer radiotherapy. Phys Med 2016; 32:499-505. [PMID: 26851164 DOI: 10.1016/j.ejmp.2016.01.481] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 01/14/2016] [Accepted: 01/21/2016] [Indexed: 11/21/2022] Open
Abstract
PURPOSE The aim of this study was to evaluate a new system based on transperineal ultrasound (TP-US) acquisitions for prostate and post-prostatectomy pre-treatment positioning by comparing this device to cone-beam computed tomography (CBCT). METHODS The differences between CBCT/CT and TP-US/TP-US registrations were analyzed on 427 and 453 sessions for 13 prostate and 14 post-prostatectomy patients, respectively. The inter-operator variability (IOV) of the registration process, and the impact and variability of the probe pressure were also evaluated. RESULTS CBCT and TP-US shift agreements at ± 5 mm were 76.6%, 95.1%, 96.3% and 90.3%, 85.0%, 97.6% in anterior-posterior, superior-inferior and left-right directions, for prostate and post-prostatectomy patients, respectively. IOV values were similar between the 2 modalities. Displacements above 5 mm due to strong pressures were observed on both localizations, but such pressures were rarely reproduced during treatment courses. CONCLUSIONS High concordance between CBCT/CT and TP-US/TP-US localization of prostates or prostatic beds was found in this study. TP-US based prepositioning is a feasible method to ensure accurate treatment delivery, and represents an attractive alternative to invasive and/or irradiating imaging modalities.
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Ultrasound versus Cone-beam CT image-guided radiotherapy for prostate and post-prostatectomy pretreatment localization. Phys Med 2015; 31:997-1004. [PMID: 26422200 DOI: 10.1016/j.ejmp.2015.07.147] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Revised: 07/15/2015] [Accepted: 07/28/2015] [Indexed: 11/22/2022] Open
Abstract
PURPOSE To evaluate the accuracy of an intra-modality trans-abdominal ultrasound (TA-US) device against soft-tissue based Cone-Beam Computed tomography (CBCT) registration for prostate and post-prostatectomy pre-treatment positioning. METHODS The differences between CBCT and US shifts were calculated on 25 prostate cancer patients (cohort A) and 11 post-prostatectomy patients (cohort B), resulting in 284 and 106 paired shifts for cohorts A and B, respectively. As a second step, a corrective method was applied to the US registration results to decrease the systematic shifts observed between TA-US and CBCT results. This method consisted of subtracting the mean difference obtained between US and CBCT registration results during the first 3 sessions from the US registration results of the subsequent sessions. Inter-operator registration variability (IOV) was also investigated for both modalities. RESULTS After initial review, about 20% of the US images were excluded because of insufficient quality. The average differences between US and CBCT were: 2.8 ± 4.1 mm, -0.9 ± 4.2 mm, 0.4 ± 3.4 mm for cohort A and 1.3 ± 5.0 mm, -2.3 ± 4.6 mm, 0.5 ± 2.9 mm for cohort B, in the anterior-posterior (AP), superior-inferior (SI) and lateral (LR) directions, respectively. After applying the corrective method, only the differences in the AP direction remained significant (p < 0.05). The IOV values were between 0.6-2.0 mm and 2.1-3.5 mm for the CBCT and TA-US modalities, respectively. CONCLUSIONS Based on the obtained results and on the image quality, the TA-US imaging modality is not safely interchangeable with CBCT for pre-treatment repositioning. Treatment margins adaptation based on the correction of the systematic shifts should be considered.
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Three-Dimensional Ultrasound-Based Target Volume Delineation and Consequent Dose Calculation in Prostate Cancer Patients with Bilateral Hip Replacement: A Report of 4 Cases. TUMORI JOURNAL 2015; 101:e133-7. [DOI: 10.5301/tj.5000305] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/09/2015] [Indexed: 01/04/2023]
Abstract
Aim To investigate the role of 3D ultrasound (3D-US) in target volume delineation in prostate cancer radiotherapy. Methods Four patients with intermediate risk prostate cancer and metal artifacts on planning computed tomography (CT) due to previous bilateral hip replacement underwent 3D-US with the Clarity platform (Clarity System, Elekta, Stockholm, Sweden) to allow for image-guided procedures. Ultrasound and CT images were coregistered to allow for better delineation of the prostate gland and organs at risk (OAR). Electron density override (EDO) and standard electron density (EDS) methods were compared for appropriate dose calculation. Results 3D-US and planning CT minimized image artifacts, providing better evidence of patient anatomy, particularly regarding soft tissue visualization. Prostate gland and seminal vesicles were better delineated, particularly in the posterior aspect. Anterior rectal wall and bladder neck were more visible. No difference was found in terms of average planning target volume dose, D15%, or D25% for rectum or D15%, D25%, or D35% of bladder between EDO and EDS. Conclusions 3D-US proved to be a viable tool for target volume and OAR visualization in patients with prostate cancer with hip prostheses.
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Baker M, Behrens CF. Prostate displacement during transabdominal ultrasound image-guided radiotherapy assessed by real-time four-dimensional transperineal monitoring. Acta Oncol 2015. [PMID: 26203927 DOI: 10.3109/0284186x.2015.1061208] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Transabdominal ultrasound (TAUS) imaging is currently available for localizing the prostate in daily image-guided radiotherapy (IGRT). The aim of this study was to determine the induced prostate displacement during such TAUS imaging. The prostate displacement was monitored using a novel transperineal four-dimensional (4D) US (TPUS) system. MATERIAL AND METHODS Ten prostate cancer patients, with a mean age of 68 years (58/76), were US scanned in the computed tomography (CT) room utilizing the Clarity 4D TPUS monitoring system. The patients were asked to comply with a moderate bladder filling protocol. After US-CT fusion, the prostate volume was delineated and used as a reference for weekly US imaging in the treatment room. Immediately after treatment delivery the TPUS monitoring system was set up. During real-time monitoring of the prostate, a conventional 2D probe was applied to simulate a TAUS scan. The time dependent prostate displacements induced by the 2D probe pressure were recorded for the three orthogonal directions. In total 42 monitoring curves with applied 2D probe were recorded. RESULTS Data analysis of 42 US scans resulted in pressure induced prostate displacements with mean values (± 1 SD) (mm); inferior (+)-superior (I/S): (-0.1 ± 0.8); left (+)-right (L/R): (0.2 ± 0.7); and anterior (+)-posterior (A/P): (-0.1 ± 1.0). The majority of the displacements were within 1-2 mm. Only two scans (5%) (A/P direction) and 16% of Euclidean distances were larger than 2.0 mm. The largest displacement was 2.6 mm in the anterior direction. CONCLUSION The novel 4D TPUS system was capable of tracking and recording the prostate positional displacements. The study demonstrated that the prostate induced displacements due to applied TAUS IGRT are small, and in most cases clinically irrelevant to prostate radiotherapy.
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Affiliation(s)
- Mariwan Baker
- a Department of Oncology , Radiotherapy Research Unit, Herlev Hospital, University of Copenhagen , Herlev , Denmark
- b Center for Nuclear Technologies, Technical University of Denmark, DTU Risø Campus , Roskilde , Denmark
| | - Claus F Behrens
- a Department of Oncology , Radiotherapy Research Unit, Herlev Hospital, University of Copenhagen , Herlev , Denmark
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Western C, Hristov D, Schlosser J. Ultrasound Imaging in Radiation Therapy: From Interfractional to Intrafractional Guidance. Cureus 2015; 7:e280. [PMID: 26180704 PMCID: PMC4494460 DOI: 10.7759/cureus.280] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/20/2015] [Indexed: 11/05/2022] Open
Abstract
External beam radiation therapy (EBRT) is included in the treatment regimen of the majority of cancer patients. With the proliferation of hypofractionated radiotherapy treatment regimens, such as stereotactic body radiation therapy (SBRT), interfractional and intrafractional imaging technologies are becoming increasingly critical to ensure safe and effective treatment delivery. Ultrasound (US)-based image guidance systems offer real-time, markerless, volumetric imaging with excellent soft tissue contrast, overcoming the limitations of traditional X-ray or computed tomography (CT)-based guidance for abdominal and pelvic cancer sites, such as the liver and prostate. Interfractional US guidance systems have been commercially adopted for patient positioning but suffer from systematic positioning errors induced by probe pressure. More recently, several research groups have introduced concepts for intrafractional US guidance systems leveraging robotic probe placement technology and real-time soft tissue tracking software. This paper reviews various commercial and research-level US guidance systems used in radiation therapy, with an emphasis on hardware and software technologies that enable the deployment of US imaging within the radiotherapy environment and workflow. Previously unpublished material on tissue tracking systems and robotic probe manipulators under development by our group is also included.
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Affiliation(s)
- Craig Western
- Department of Mechanical Engineering, Stanford University
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Image-Guided Radiotherapy for Prostate Cancer using 3 Different Techniques: Localization Data of 186 Patients. TUMORI JOURNAL 2015; 101:273-80. [DOI: 10.5301/tj.5000322] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/14/2015] [Indexed: 11/20/2022]
Abstract
Aims and Background This study evaluates 3 different imaging modalities—ultrasound (US), stereoscopic X-ray imaging of implanted markers (Visicoils) (X-ray), and kV cone-beam computed tomography (CBCT)—to assess interfraction and intrafraction localization error during conformal radiation therapy of prostate cancer. Methods and Study Design The study population consisted of 186 consecutive prostate cancer patients treated with an image-guided radiotherapy (IGRT) hypofractionated protocol using 3 techniques: 32 with X-ray, 30 with CBCT, and 124 with US. Treatment dose of 70.2 Gy was delivered in 26 fractions with a conformal dynamic arcs technique. Interfraction prostate localization errors were determined for the 3 techniques. Moreover, interfraction and intrafraction prostate motion in terms of translations and rotations, as well as residual errors, were determined with X-ray. Results The systematic and random components of the prostate localization errors were as follows: ( 1 ) with X-ray 3.0 ± 3.4, 2.3 ± 2.7, 1.8 ± 2.3 mm in anterior-posterior (AP), superior-inferior (SI), and left-right (LR) directions and 1.8° ± 1.2°, 2.3° ± 1.5°, 2.7° ± 3.1°, for the yaw, roll, and pitch rotations; ( 2 ) with CBCT3.5 ± 4.2, 3.3 ± 3.3, 2.5 ± 3.1 mm in AP, SI, and LR directions; ( 3 ) with US 3.7 ± 4.7, 3.4 ± 4.3, 2.3 ± 3.5 mm in AP, SI, and LR directions. Residual errors with X-ray were less than 1 mm in all directions. Intrafraction prostate motion of less than 0.5 mm in LR and of the order of 1 mm in AP and SI directions was found. This led to a significant reduction of the margins, potentially important for dose escalation studies. Conclusions Daily on-line IGRT with stereoscopic X-ray imaging allowed a consistent PTV margin reduction considering residual interfraction prostate localization error and intrafraction motion. X-ray offers the best compromise among accuracy, reliability, dose to the patient, and time investment for daily IGRT treatment of prostate.
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Fontanarosa D, van der Meer S, Bamber J, Harris E, O'Shea T, Verhaegen F. Review of ultrasound image guidance in external beam radiotherapy: I. Treatment planning and inter-fraction motion management. Phys Med Biol 2015; 60:R77-114. [PMID: 25592664 DOI: 10.1088/0031-9155/60/3/r77] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
In modern radiotherapy, verification of the treatment to ensure the target receives the prescribed dose and normal tissues are optimally spared has become essential. Several forms of image guidance are available for this purpose. The most commonly used forms of image guidance are based on kilovolt or megavolt x-ray imaging. Image guidance can also be performed with non-harmful ultrasound (US) waves. This increasingly used technique has the potential to offer both anatomical and functional information.This review presents an overview of the historical and current use of two-dimensional and three-dimensional US imaging for treatment verification in radiotherapy. The US technology and the implementation in the radiotherapy workflow are described. The use of US guidance in the treatment planning process is discussed. The role of US technology in inter-fraction motion monitoring and management is explained, and clinical studies of applications in areas such as the pelvis, abdomen and breast are reviewed. A companion review paper (O'Shea et al 2015 Phys. Med. Biol. submitted) will extensively discuss the use of US imaging for intra-fraction motion quantification and novel applications of US technology to RT.
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Affiliation(s)
- Davide Fontanarosa
- Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center (MUMC), Maastricht 6201 BN, the Netherlands. Oncology Solutions Department, Philips Research, High Tech Campus 34, Eindhoven 5656 AE, the Netherlands
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Presles B, Fargier-Voiron M, Biston MC, Lynch R, Munoz A, Liebgott H, Pommier P, Rit S, Sarrut D. Semiautomatic registration of 3D transabdominal ultrasound images for patient repositioning during postprostatectomy radiotherapy. Med Phys 2014; 41:122903. [DOI: 10.1118/1.4901642] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
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Lediju Bell MA, Sen HT, Iordachita I, Kazanzides P, Wong J. In vivo reproducibility of robotic probe placement for a novel ultrasound-guided radiation therapy system. J Med Imaging (Bellingham) 2014; 1:025001. [PMID: 26158038 DOI: 10.1117/1.jmi.1.2.025001] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Revised: 06/08/2014] [Accepted: 06/17/2014] [Indexed: 11/14/2022] Open
Abstract
Ultrasound can provide real-time image guidance of radiation therapy, but the probe-induced tissue deformations cause local deviations from the treatment plan. If placed during treatment planning, the probe causes streak artifacts in required computed tomography (CT) images. To overcome these challenges, we propose robot-assisted placement of an ultrasound probe, followed by replacement with a geometrically identical, CT-compatible model probe. In vivo reproducibility was investigated by implanting a canine prostate, liver, and pancreas with three 2.38-mm spherical markers in each organ. The real probe was placed to visualize the markers and subsequently replaced with the model probe. Each probe was automatically removed and returned to the same position or force. Under position control, the median three-dimensional reproducibility of marker positions was 0.6 to 0.7 mm, 0.3 to 0.6 mm, and 1.1 to 1.6 mm in the prostate, liver, and pancreas, respectively. Reproducibility was worse under force control. Probe substitution errors were smallest for the prostate (0.2 to 0.6 mm) and larger for the liver and pancreas (4.1 to 6.3 mm), where force control generally produced larger errors than position control. Results indicate that position control is better than force control for this application, and the robotic approach has potential, particularly for relatively constrained organs and reproducibility errors that are smaller than established treatment margins.
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Affiliation(s)
- Muyinatu A Lediju Bell
- Johns Hopkins University , Laboratory for Computational Sensing and Robotics, Baltimore, Maryland 21218, United States
| | - H Tutkun Sen
- Johns Hopkins University , Laboratory for Computational Sensing and Robotics, Baltimore, Maryland 21218, United States ; Johns Hopkins University , Department of Computer Science, Baltimore, Maryland 21218, United States
| | - Iulian Iordachita
- Johns Hopkins University , Laboratory for Computational Sensing and Robotics, Baltimore, Maryland 21218, United States ; Johns Hopkins University , Department of Mechanical Engineering, Baltimore, Maryland 21218, United States
| | - Peter Kazanzides
- Johns Hopkins University , Laboratory for Computational Sensing and Robotics, Baltimore, Maryland 21218, United States ; Johns Hopkins University , Department of Computer Science, Baltimore, Maryland 21218, United States
| | - John Wong
- Johns Hopkins University , Department of Radiation Oncology, Baltimore, Maryland 21287, United States
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