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Choi GW, Suh Y, Das P, Herman J, Holliday E, Koay E, Koong AC, Krishnan S, Minsky BD, Smith GL, Taniguchi CM, Beddar S. Assessment of setup uncertainty in hypofractionated liver radiation therapy with a breath-hold technique using automatic image registration-based image guidance. Radiat Oncol 2019; 14:154. [PMID: 31470860 PMCID: PMC6717376 DOI: 10.1186/s13014-019-1361-6] [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: 02/14/2019] [Accepted: 08/21/2019] [Indexed: 12/25/2022] Open
Abstract
Background Target localization in radiation therapy is affected by numerous sources of uncertainty. Despite measures to minimize the breathing motion, the treatment of hypofractionated liver radiation therapy is further challenged by residual uncertainty coming from involuntary organ motion and daily changes in the shape and location of abdominal organs. To address the residual uncertainty, clinics implement image-guided radiation therapy at varying levels of soft-tissue contrast. This study utilized the treatment records from the patients that have received hypofractionated liver radiation therapy using in-room computed tomography (CT) imaging to assess the setup uncertainty and to estimate the appropriate planning treatment volume (PTV) margins in the absence of in-room CT imaging. Methods We collected 917 pre-treatment daily in-room CT images from 69 patients who received hypofractionated radiation therapy to the liver with the inspiration breath-hold technique. For each treatment, the daily CT was initially aligned to the planning CT based on the shape of the liver automatically using a CT-CT alignment software. After the initial alignment, manual shift corrections were determined by visual inspection of the two images, and the corrections were applied to shift the patient to the physician-approved treatment position. Considering the final alignment as the gold-standard setup, systematic and random uncertainties in the automatic alignment were quantified, and the uncertainties were used to calculate the PTV margins. Results The median discrepancy between the final and automatic alignment was 1.1 mm (0–24.3 mm), and 38% of treated fractions required manual corrections of ≥3 mm. The systematic uncertainty was 1.5 mm in the anterior-posterior (AP) direction, 1.1 mm in the left-right (LR) direction, and 2.4 mm in the superior-inferior (SI) direction. The random uncertainty was 2.2 mm in the AP, 1.9 mm in the LR, and 2.2 mm in the SI direction. The PTV margins recommended to be used in the absence of in-room CT imaging were 5.3 mm in the AP, 3.5 mm in the LR, and 5.1 mm in the SI direction. Conclusions Manual shift correction based on soft-tissue alignment is substantial in the treatment of the abdominal region. In-room CT can reduce PTV margin by up to 5 mm, which may be especially beneficial for dose escalation and normal tissue sparing in hypofractionated liver radiation therapy.
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Affiliation(s)
- Gye Won Choi
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Yelin Suh
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Prajnan Das
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Joseph Herman
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Emma Holliday
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Eugene Koay
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Albert C Koong
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Sunil Krishnan
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Bruce D Minsky
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Grace L Smith
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Cullen M Taniguchi
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Sam Beddar
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA. .,The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX, 77030, USA.
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Yang W, Fraass BA, Reznik R, Nissen N, Lo S, Jamil LH, Gupta K, Sandler H, Tuli R. Adequacy of inhale/exhale breathhold CT based ITV margins and image-guided registration for free-breathing pancreas and liver SBRT. Radiat Oncol 2014; 9:11. [PMID: 24401365 PMCID: PMC3896695 DOI: 10.1186/1748-717x-9-11] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Accepted: 12/08/2013] [Indexed: 12/28/2022] Open
Abstract
Purpose To evaluate use of breath-hold CTs and implanted fiducials for definition of the internal target volume (ITV) margin for upper abdominal stereotactic body radiation therapy (SBRT). To study the statistics of inter- and intra-fractional motion information. Methods and materials 11 patients treated with SBRT for locally advanced pancreatic cancer (LAPC) or liver cancer were included in the study. Patients underwent fiducial implantation, free-breathing CT and breath-hold CTs at end inhalation/exhalation. All patients were planned and treated with SBRT using volumetric modulated arc therapy (VMAT). Two margin strategies were studied: Strategy I uses PTV = ITV + 3 mm; Strategy II uses PTV = GTV + 1.5 cm. Both CBCT and kV orthogonal images were taken and analyzed for setup before patient treatments. Tumor motion statistics based on skeletal registration and on fiducial registration were analyzed by fitting to Gaussian functions. Results All 11 patients met SBRT planning dose constraints using strategy I. Average ITV margins for the 11 patients were 2 mm RL, 6 mm AP, and 6 mm SI. Skeletal registration resulted in high probability (RL = 69%, AP = 4.6%, SI = 39%) that part of the tumor will be outside the ITV. With the 3 mm ITV expansion (Strategy 1), the probability reduced to RL 32%, AP 0.3%, SI 20% for skeletal registration; and RL 1.2%, AP 0%, SI 7% for fiducial registration. All 7 pancreatic patients and 2 liver patients failed to meet SBRT dose constraints using strategy II. The liver dose was increased by 36% for the other 2 liver patients that met the SBRT dose constraints with strategy II. Conclusions Image guidance matching to skeletal anatomy is inadequate for SBRT positioning in the upper abdomen and usage of fiducials is highly recommended. Even with fiducial implantation and definition of an ITV, a minimal 3 mm planning margin around the ITV is needed to accommodate intra-fractional uncertainties.
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Affiliation(s)
- Wensha Yang
- Department of Radiation Oncology, Cedars Sinai Medical Center, Los Angeles, CA 90048, USA.
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Dzintars E, Papanikolaou N, Mavroidis P, Sadeghi A, Stathakis S. Application of an independent dose calculation software for estimating the impact of inter-fractional setup shifts in Helical Tomotherapy treatments. Phys Med 2013; 29:615-23. [PMID: 23044458 DOI: 10.1016/j.ejmp.2012.09.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2012] [Revised: 09/04/2012] [Accepted: 09/10/2012] [Indexed: 12/25/2022] Open
Abstract
The purpose of this study is to validate the capability of in-house independent point dose calculation software to be used as a second check for Helical Tomotherapy treatment plans. The software performed its calculations in homogenous conditions (using the Cheese phantom, which is a cylindrical phantom with radius 15 cm and length 18 cm) using a factor-based algorithm. Fifty patients, who were treated for pelvic (10), prostate (14), lung (10), head & neck (12) and brain (4) cancers, were used. Based on the individual patient kVCT images and the pretreatment MVCT images for each treatment fraction, the corresponding daily patient setup shifts in the IEC-X, IEC-Y, and IEC-Z directions were registered. For each patient, the registered fractional setup shifts were grouped into systematic and random shifts. The average systematic dosimetric variations showed small dose deviation for the different cancer types (1.0%-3.0%) compared to the planned dose. Of the fifty patients, only three had percent differences larger than 5%. The average random dosimetric variations showed relatively small dose deviations (0.2%-1.1%) compared to the planned dose. None of the patients had percent differences larger than 5%. By examining the individual fractions of each patient, it is observed that only in 31 out of 1358 fractions the percent differences exceeded the border of 5%. These results indicate that the overall dosimetric impact from systematic and random variations is small and that the software is a capable platform for independent point dose validation for the Helical Tomotherapy modality.
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Affiliation(s)
- Erik Dzintars
- Department of Radiation Oncology, University of Texas Health Science Center, San Antonio, TX, USA
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Willoughby T, Lehmann J, Bencomo JA, Jani SK, Santanam L, Sethi A, Solberg TD, Tome WA, Waldron TJ. Quality assurance for nonradiographic radiotherapy localization and positioning systems: report of Task Group 147. Med Phys 2012; 39:1728-47. [PMID: 22482598 DOI: 10.1118/1.3681967] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
New technologies continue to be developed to improve the practice of radiation therapy. As several of these technologies have been implemented clinically, the Therapy Committee and the Quality Assurance and Outcomes Improvement Subcommittee of the American Association of Physicists in Medicine commissioned Task Group 147 to review the current nonradiographic technologies used for localization and tracking in radiotherapy. The specific charge of this task group was to make recommendations about the use of nonradiographic methods of localization, specifically; radiofrequency, infrared, laser, and video based patient localization and monitoring systems. The charge of this task group was to review the current use of these technologies and to write quality assurance guidelines for the use of these technologies in the clinical setting. Recommendations include testing of equipment for initial installation as well as ongoing quality assurance. As the equipment included in this task group continues to evolve, both in the type and sophistication of technology and in level of integration with treatment devices, some of the details of how one would conduct such testing will also continue to evolve. This task group, therefore, is focused on providing recommendations on the use of this equipment rather than on the equipment itself, and should be adaptable to each user's situation in helping develop a comprehensive quality assurance program.
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Affiliation(s)
- Twyla Willoughby
- Task Group 147, Department of Radiation Physics, Orlando, FL, USA
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Moore JA, Gordon JJ, Anscher M, Silva J, Siebers JV. Comparisons of treatment optimization directly incorporating systematic patient setup uncertainty with a margin-based approach. Med Phys 2012; 39:1102-11. [PMID: 22320820 DOI: 10.1118/1.3679856] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
PURPOSE To develop a probabilistic treatment planning (PTP) method which is robust to systematic patient setup errors and to compare PTP plans with plans generated using a planning target volume (PTV) margin optimized to give the same target coverage probability as the PTP plan. METHODS Plans adhering to the RTOG-0126 protocol are developed for 28 prostate patients using PTP and margin-based planning. For PTP, an objective function that simultaneously considers multiple possible patient positions is developed. PTP plans are optimized using clinical target volume (CTV) structures and organ at risk (OAR) structures. The desired CTV coverage probability is 95%. Plans that cannot achieve a 95% CTV coverage probability are re-optimized with a desired CTV coverage probability reduced by 5% until the desired CTV coverage probability is achieved. Margin-based plans are created which achieve the same CTV coverage probability as the PTP plans by iterative adjustment of the CTV-to-PTV margin. Postoptimization, probabilistic dose-volume coverage metrics are used to compare the plans. RESULTS For equivalent target coverage probability, PTP plans significantly reduce coverage probability for rectum objectives (-17% for D(35) < 65 Gy, p = 0.0010; -23% for D(25) < 70 Gy, p < 0.0001; and -27% for D(15) < 75 Gy, p < 0.0001). Physician assessment indicates PTP plans are entirely preferred 71% of the time while margin-based plans are entirely preferred 7% of the time. CONCLUSIONS For plans having the same target coverage probability, PTP has potential to reduce rectal doses while maintaining CTV coverage probability. In blind comparisons, physicians prefer PTP plans over optimized margin plans.
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Affiliation(s)
- Joseph A Moore
- Department of Radiation Oncology, Virginia Commonwealth University, Richmond, VA 23298, USA.
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Seppenwoolde Y, Wunderink W, Wunderink-van Veen SR, Storchi P, Méndez Romero A, Heijmen BJM. Treatment precision of image-guided liver SBRT using implanted fiducial markers depends on marker-tumour distance. Phys Med Biol 2011; 56:5445-68. [PMID: 21813963 DOI: 10.1088/0031-9155/56/17/001] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The purpose of this study is to assess the accuracy of day-to-day predictions of liver tumour position using implanted gold markers as surrogates and to compare the method with alternative set-up strategies, i.e. no correction, vertebrae and 3D diaphragm-based set-up. Twenty patients undergoing stereotactic body radiation therapy (SBRT) with abdominal compression for primary or metastatic liver cancer were analysed. We determined the day-to-day correlation between gold marker and tumour positions in contrast-enhanced CT scans acquired at treatment preparation and before each treatment session. The influence of marker-tumour distance on the accuracy of prediction was estimated by introducing a method extension of the set-up error paradigm. The distance between gold markers and the centre of the tumour varied between 5 and 96 mm. Marker-guidance was superior to guiding treatment using other surrogates, although both the random and systematic components of the prediction error SD depended on the tumour-marker distance. For a marker-tumour distance of 4 cm, we observed σ = 1.3 mm and Σ = 1.6 mm. The 3D position of the diaphragm dome was the second best predictor. In conclusion, the tumour position can be predicted accurately using implanted markers, but marker-guided set-up accuracy decreases with increasing distance between implanted markers and the tumour.
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Affiliation(s)
- Y Seppenwoolde
- Department of Radiation Oncology, Daniel den Hoed Cancer Center, Erasmus Medical Center, Groene Hilledijk 301, 3075 EA Rotterdam, The Netherlands.
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Displacement of hepatic tumor at time to exposure in end-expiratory-triggered-pulse proton therapy. Radiother Oncol 2011; 99:124-30. [DOI: 10.1016/j.radonc.2011.05.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Revised: 04/18/2011] [Accepted: 05/03/2011] [Indexed: 01/14/2023]
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Vlad RM, Kolios MC, Moseley JL, Czarnota GJ, Brock KK. Evaluating the extent of cell death in 3D high frequency ultrasound by registration with whole-mount tumor histopathology. Med Phys 2010; 37:4288-97. [PMID: 20879589 DOI: 10.1118/1.3459020] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
PURPOSE High frequency ultrasound imaging, 10-30 MHz, has the capability to assess tumor response to radiotherapy in mouse tumors as early as 24 h after treatment administration. The advantage of this technique is that the image contrast is generated by changes in the physical properties of dying cells. Therefore, a subject can be imaged before and multiple times during the treatment without the requirement of injecting specialized contrast agents. This study is motivated by a need to provide metrics of comparison between the volume and localization of cell death, assessed from histology, with the volume and localization of cell death surrogate, assessed as regions with increased echogeneity from ultrasound images. METHODS The mice were exposed to radiation doses of 2, 4, and 8 Gy. Ultrasound images ivere collected from each tumor before and 24 h after exposure to radiation using a broadband 25 MHz center frequency transducer. After radiotherapy, tumors exhibited hyperechoic regions in ultrasound images that corresponded to areas of cell death in histology. The ultrasound and histological images were rigidly registered. The tumors and regions of cell death were manually outlined on histological images. Similarly, the tumors and hyperechoic regions were outlined on the ultrasound images. Each set of contours was converted to a volumetric mesh in order to compare the volumes and the localization of cell death in histological and ultrasound images. RESULTS A shrinkage factor of 17 +/- 2% was calculated from the difference in the tumor volumes evaluated from histological and ultrasound images. This was used to correct the tumor and cell death volumes assessed from histology. After this correction, the average absolute difference between the volume of cell death assessed from ultrasound and histological images was 11 +/- 14% and the volume overlap was 70 +/- 12%. CONCLUSIONS The method provided metrics of comparison between the volume of cell death assessed from histology and that assessed from ultrasound images. It was applied here to evaluate the capability of ultrasound imaging to assess early tumor response to radiotherapy in mouse tumors. Similarly, it can be applied in the future to evaluate the capability of ultrasound imaging to assess early tumor response to other modalities of cancer treatment. The study contributes to an understanding of the capabilities and limitation of ultrasound imaging at noninvasively detecting cell death. This provides a foundation for future developments regarding the use of ultrasound in preclinical and clinical applications to adapt treatments based on tumor response to cancer therapy.
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Affiliation(s)
- Roxana M Vlad
- Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario, Canada.
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Registration of on-board X-ray images with 4DCT: A proposed method of phase and setup verification for gated radiotherapy. Phys Med 2010; 26:117-25. [DOI: 10.1016/j.ejmp.2009.09.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2007] [Revised: 07/15/2009] [Accepted: 09/01/2009] [Indexed: 11/20/2022] Open
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Kuo HC, Liu WS, Wu A, Mah D, Chuang KS, Hong L, Yaparpalvi R, Guha C, Kalnicki S. Biological impact of geometric uncertainties: what margin is needed for intra-hepatic tumors? Radiat Oncol 2010; 5:48. [PMID: 20525298 PMCID: PMC2893459 DOI: 10.1186/1748-717x-5-48] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2010] [Accepted: 06/03/2010] [Indexed: 01/14/2023] Open
Abstract
Background To evaluate and compare the biological impact on different proposed margin recipes for the same geometric uncertainties for intra-hepatic tumors with different tumor cell types or clinical stages. Method Three different margin recipes based on tumor motion were applied to sixteen IMRT plans with a total of twenty two intra-hepatic tumors. One recipe used the full amplitude of motion measured from patients to generate margins. A second used 70% of the full amplitude of motion, while the third had no margin for motion. The biological effects of geometric uncertainty in these three situations were evaluated with Equivalent Uniform Doses (EUD) for various survival fractions at 2 Gy (SF2). Results There was no significant difference in the biological impact between the full motion margin and the 70% motion margin. Also, there was no significant difference between different tumor cell types. When the margin for motion was eliminated, the difference of the biological impact was significant among different cell types due to geometric uncertainties. Elimination of the motion margin requires dose escalation to compensate for the biological dose reduction due to the geometric misses during treatment. Conclusions Both patient-based margins of full motion and of 70% motion are sufficient to prevent serious dosimetric error. Clinical implementation of margin reduction should consider the tumor sensitivity to radiation.
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Affiliation(s)
- Hsiang-Chi Kuo
- Department of Radiation Oncology, Montefiore Medical Center, USA.
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Fujita H, Yamaguchi M, Bessho Y, Fujioka T, Fukuda H, Murase K. Patient setup verification procedure for a portal image in a computed radiography system with a high-resolution liquid-crystal display monitor. Radiol Phys Technol 2010; 3:46-52. [DOI: 10.1007/s12194-009-0075-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2009] [Revised: 10/28/2009] [Accepted: 10/29/2009] [Indexed: 11/27/2022]
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Moore JA, Gordon JJ, Anscher MS, Siebers JV. Comparisons of treatment optimization directly incorporating random patient setup uncertainty with a margin-based approach. Med Phys 2009; 36:3880-90. [PMID: 19810460 DOI: 10.1118/1.3176940] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The purpose of this study is to incorporate the dosimetric effect of random patient positioning uncertainties directly into a commercial treatment planning system's IMRT plan optimization algorithm through probabilistic treatment planning (PTP) and compare coverage of this method with margin-based planning. In this work, PTP eliminates explicit margins and optimizes directly on the estimated integral treatment dose to determine optimal patient dose in the presence of setup uncertainties. Twenty-eight prostate patient plans adhering to the RTOG-0126 criteria are optimized using both margin-based and PTP methods. Only random errors are considered. For margin-based plans, the planning target volume is created by expanding the clinical target volume (CTV) by 2.1 mm to accommodate the simulated 3 mm random setup uncertainty. Random setup uncertainties are incorporated into IMRT dose evaluation by convolving each beam's incident fluence with a sigma = 3 mm Gaussian prior to dose calculation. PTP optimization uses the convolved fluence to estimate dose to ensure CTV coverage during plan optimization. PTP-based plans are compared to margin-based plans with equal CTV coverage in the presence of setup errors based on dose-volume metrics. The sensitivity of the optimized plans to patient-specific setup uncertainty variations is assessed by evaluating dose metrics for dose distributions corresponding to halving and doubling of the random setup uncertainty used in the optimization. Margin-based and PTP-based plans show similar target coverage. A physician review shows that PTP is preferred for 21 patients, margin-based plans are preferred in 2 patients, no preference is expressed for 1 patient, and both autogenerated plans are rejected for 4 patients. For the PTP-based plans, the average CTV receiving the prescription dose decreases by 0.5%, while the mean dose to the CTV increases by 0.7%. The CTV tumor control probability (TCP) is the same for both methods with the exception of one case in which PTP gave a slightly higher TCP. For critical structures that do not meet the optimization criteria, PTP shows a decrease in the volume receiving the maximum specified dose. PTP reduces local normal tissue volumes receiving the maximum dose on average by 48%. PTP results in lower mean dose to all critical structures for all plans. PTP results in a 2.5% increase in the probability of uncomplicated control (P+), along with a 1.9% reduction in rectum normal tissue complication probability (NTCP), and a 0.7% reduction in bladder NTCP. PTP-based plans show improved conformality as compared with margin-based plans with an average PTP-based dosimetric margin at 7100 cGy of 0.65 cm compared with the margin-based 0.90 cm and a PTP-based dosimetric margin at 3960 cGy of 1.60 cm compared with the margin-based 1.90 cm. PTP-based plans show similar sensitivity to variations of the uncertainty during treatment from the uncertainty used in planning as compared to margin-based plans. For equal target coverage, when compared to margin-based plans, PTP results in equal or lower doses to normal structures. PTP results in more conformal plans than margin-based plans and shows similar sensitivity to variations in uncertainty.
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Affiliation(s)
- Joseph A Moore
- Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia 23298, USA.
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Nguyen TN, Moseley JL, Dawson LA, Jaffray DA, Brock KK. Adapting population liver motion models for individualized online image-guided therapy. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2009; 2008:3945-8. [PMID: 19163576 DOI: 10.1109/iembs.2008.4650073] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Respiratory motion varies on a daily basis in abdominal cancer patients, affecting the ability to successfully deliver local therapy and requiring increased treatment margins to account for this variation. Deformable registration techniques can accurately describe respiratory motion, however, online application can be limited by long computational times and user intervention. A technique has been developed to quickly quantify patient breathing motion from respiratory-sorted volumetric images by calculating 1D shifts in image intensities between spatially corresponding regions of interest (navigator channels) on patient's images. The 1D motion at the superior, inferior, anterior, and posterior liver edges was detected and applied to adapt a population liver respiratory motion model. For validation, deformable registration was performed for each patient using a validated technique, MORFEUS, for relative validation, and vessel bifurcations, identified on patient's inhale and exhale images, for absolute validation. The accuracy of the adapted-population model to describe the patient respiratory motion was (absolute mean +/- SD) 0.26 +/- 0.11 cm and 0.30 +/- 0.21 cm in the superior-inferior (SI) and anterior-posterior (AP) directions, respectively. The accuracy of predicting the tumor COM motion was 0.30 +/- 0.22 cm, and 0.34 +/- 0.31, while the absolute validation, based on bifurcations was 0.26 +/- 0.16 cm and 0.13 +/- 0.04 cm in the SI and AP directions, respectively. This technique was developed to complement and quickly adapt a full 3D biomechanical based deformable registration technique, MORFEUS, to be applied in the online setting.
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Affiliation(s)
- Thao-Nguyen Nguyen
- Department of Medical Biophysics, University of Toronto, Ontario, Canada.
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Lin L, Shi C, Eng T, Swanson G, Fuss M, Papanikolaou N. Evaluation of Inter-fractional Setup Shifts for Site-specific Helical Tomotherapy Treatments. Technol Cancer Res Treat 2009; 8:115-22. [DOI: 10.1177/153303460900800204] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
This paper proposes to summarize and analyze the daily patient setup shifts based on megavoltage computed tomography (MVCT) image registration results for Helical TomoTherapy® (HT) treatment. One hundred and fifty-five consecutive treatment plans for a total of 137 patients delivered by the HT unit through one year were collected in this study. The patient data included pelvis (26%), abdomen (23%), lung (21%), head and neck (10%), prostate (8%), and others (12%). All the translational and roll rotational shifts made via auto MVCT and kilovoltage computed tomography (kVCT) image registration were recorded at each fraction. Manual fine-tuning was followed if automatic registration result was not satisfactory. The mean shift ± one standard deviation (1 SD) was calculated for each patient based on the entire treatment course. For each treatment site, the average shift was analyzed as well as displacement in 3D vector. Statistical tests were performed to analyze the relationship of patient-specific, tumor site-specific, and fraction number association with the patient setup shifts. For all the treatment sites, the largest average shift was found in the anterior-posterior direction. The population standard deviations were between 1.2 and 5.6 mm for the X, Y, and Z directions and ranged from 0.2 to 0.6 degrees for the roll rotational correction. The largest standard deviations of the setup reproducibility in X, Y, and Z directions were found in lung patients (4.2 mm), abdomen, lung and spine patients (4.4 mm), and prostate patients (5.6 mm), respectively. The maximum 3D displacement was 10.9 mm for prostate patients' setup. ANOVA tests demonstrated the setup shifts were statistically different between patients even for those that were treated at the same tumor site in the translational directions. No strong correlation between the setup and the fraction number was found. In conclusion, the MVCT guided function in the HT treatment enables us to generate relatively accurate daily setup through registration with KVCT data sets. Our results indicate that lung, prostate, and abdominal patients are more prone to setup uncertainty and should be carefully evaluated.
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Affiliation(s)
- Lan Lin
- Department of Radiology
- Cancer Therapy and Research Center
| | - Chengyu Shi
- Department of Radiology
- Cancer Therapy and Research Center
| | - Tony Eng
- Cancer Therapy and Research Center
- Department of Radiation Oncology University of Texas Health Science Center at San Antonio 7703 Floyd Curl Drive San Antonio, TX 78229, USA
| | - Gregory Swanson
- Cancer Therapy and Research Center
- Department of Radiation Oncology University of Texas Health Science Center at San Antonio 7703 Floyd Curl Drive San Antonio, TX 78229, USA
| | - Martin Fuss
- Department of Radiation Medicine Oregon Health and Science University 3181 S. W. Sam Jackson Park Rd Portland, OR 97239, USA
| | - Niko Papanikolaou
- Department of Radiology
- Cancer Therapy and Research Center
- Department of Radiation Oncology University of Texas Health Science Center at San Antonio 7703 Floyd Curl Drive San Antonio, TX 78229, USA
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Glide-Hurst CK, Hugo GD, Liang J, Yan D. A simplified method of four-dimensional dose accumulation using the mean patient density representation. Med Phys 2009; 35:5269-77. [PMID: 19175086 DOI: 10.1118/1.3002304] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The purpose of this work was to demonstrate, both in phantom and patient, the feasibility of using an average 4DCT image set (AVG-CT) for 4D cumulative dose estimation. A series of 4DCT numerical phantoms and corresponding AVG-CTs were generated. For full 4D dose summation, static dose was calculated on each phase and cumulative dose was determined by combining each phase's static dose distribution with known tumor displacement. The AVG-CT cumulative dose was calculated similarly, although the same AVG-CT static dose distribution was used for all phases (i.e., tumor displacements). Four lung cancer cases were also evaluated for stereotactic body radiotherapy and conformal treatments; however, deformable image registration of the 4DCTs was used to generate the displacement vector fields (DVFs) describing patient-specific motion. Dose discrepancy between full 4D summation and AVG-CT approach was calculated and compared. For all phantoms, AVG-CT approximation yielded slightly higher cumulative doses compared to full 4D summation, with dose discrepancy increasing with increased tumor excursion. In vivo, using the AVG-CT coupled with deformable registration yielded clinically insignificant differences for all GTV parameters including the minimum, mean, maximum, dose to 99% of target, and dose to 1% of target. Furthermore, analysis of the spinal cord, esophagus, and heart revealed negligible differences in major dosimetric indices and dose coverage between the two dose calculation techniques. Simplifying 4D dose accumulation via the AVG-CT, while fully accounting for tumor deformation due to respiratory motion, has been validated, thereby, introducing the potential to streamline the use of 4D dose calculations in clinical practice, particularly for adaptive planning purposes.
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Trofimov A, Vrancic C, Chan TCY, Sharp GC, Bortfeld T. Tumor trailing strategy for intensity-modulated radiation therapy of moving targets. Med Phys 2008; 35:1718-33. [PMID: 18561647 DOI: 10.1118/1.2900108] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Internal organ motion during the course of radiation therapy of cancer affects the distribution of the delivered dose and, generally, reduces its conformality to the targeted volume. Previously proposed approaches aimed at mitigating the effect of internal motion in intensity-modulated radiation therapy (IMRT) included expansion of the target margins, motion-correlated delivery (e.g., respiratory gating, tumor tracking), and adaptive treatment plan optimization employing a probabilistic description of motion. We describe and test the tumor trailing strategy, which utilizes the synergy of motion-adaptive treatment planning and delivery methods. We regard the (rigid) target motion as a superposition of a relatively fast cyclic component (e.g., respiratory) and slow aperiodic trends (e.g., the drift of exhalation baseline). In the trailing approach, these two components of motion are decoupled and dealt with separately. Real-time motion monitoring is employed to identify the "slow" shifts, which are then corrected by applying setup adjustments. The delivery does not track the target position exactly, but trails the systematic trend due to the delay between the time a shift occurs, is reliably detected, and, subsequently, corrected. The "fast" cyclic motion is accounted for with a robust motion-adaptive treatment planning, which allows for variability in motion parameters (e.g., mean and extrema of the tidal volume, variable period of respiration, and expiratory duration). Motion-surrogate data from gated IMRT treatments were used to provide probability distribution data for motion-adaptive planning and to test algorithms that identified systematic trends in the character of motion. Sample IMRT fields were delivered on a clinical linear accelerator to a programmable moving phantom. Dose measurements were performed with a commercial two-dimensional ion-chamber array. The results indicate that by reducing intrafractional motion variability, the trailing strategy enhances relevance and applicability of motion-adaptive planning methods, and improves conformality of the delivered dose to the target in the presence of irregular motion. Trailing strategy can be applied to respiratory-gated treatments, in which the correction for the slow motion can increase the duty cycle, while robust probabilistic planning can improve management of the residual motion within the gate window. Similarly, trailing may improve the dose conformality in treatment of patients who exhibit detectable target motion of low amplitude, which is considered insufficient to provide a clinical indication for the use of respiratory-gated treatment (e.g., peak-to-peak motion of less than 10 mm). The mechanical limitations of implementing tumor trailing are less rigorous than those of real-time tracking, and the same technology could be used for both.
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Affiliation(s)
- Alexei Trofimov
- Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts 02114, USA.
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You SH, Seong J, Lee IJ, Koom WS, Jeon BC. Treatment Margin Assessment using Mega-Voltage Computed Tomography of a Tomotherapy Unit in the Radiotherapy of a Liver Tumor. ACTA ACUST UNITED AC 2008. [DOI: 10.3857/jkstro.2008.26.4.280] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Sei Hwan You
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University Health System, Seoul, Korea
| | - Jinsil Seong
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University Health System, Seoul, Korea
| | - Ik Jae Lee
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University Health System, Seoul, Korea
| | - Woong Sub Koom
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University Health System, Seoul, Korea
| | - Byeong Chul Jeon
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University Health System, Seoul, Korea
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Voroney JP, Brock KK, Eccles C, Haider M, Dawson LA. Prospective comparison of computed tomography and magnetic resonance imaging for liver cancer delineation using deformable image registration. Int J Radiat Oncol Biol Phys 2006; 66:780-91. [PMID: 17011453 DOI: 10.1016/j.ijrobp.2006.05.035] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2006] [Revised: 05/16/2006] [Accepted: 05/16/2006] [Indexed: 12/20/2022]
Abstract
PURPOSE The aim of this study was to compare magnetic resonance imaging (MRI) with computed tomography (CT) for liver cancer tumor definition for high-precision radiotherapy planning. METHODS AND MATERIALS Diagnostic quality MRI scans and triphasic CT scans, with the liver immobilized in exhale, were obtained at the time of radiation planning for 26 patients with unresectable liver metastases (n = 8), hepatocellular carcinoma (n = 10), and cholangiocarcinoma (n = 8). On the CT and MRI series best demonstrating the tumor, the liver and gross tumor volumes (GTVs) were contoured, and intrahepatic anatomic reference points were identified. Deformable registration was used to register the liver from the CT with that from the MRI. RESULTS A difference in the number of tumor foci was seen on CT vs. MRI in 5 patients with hepatocellular carcinoma: MRI showed more foci in 3 patients, CT in 2. After deformable registration of the livers, the population median of the average distance between the CT tumor surface and MRI tumor surface was 3.7 mm (2.2-21.3 mm). The median percentage of tumor surface area that differed by > or = 5 mm was 26% (1-86%). Median percentage concordance volumes were 81% (77-86%) in metastases, 77% (60-88%) in hepatocellular carcinoma and 64% (25-85%) in cholangiocarcinoma. CONCLUSION Differences between MRI-defined liver cancer GTVs and CT-defined GTVs can be substantial and are more common in primary liver cancer.
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Affiliation(s)
- Jon-Paul Voroney
- Radiation Medicine Program, Princess Margaret Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
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Abstract
Intensity-modulated radiation therapy is a delivery system that, when coupled with a treatment-planning optimization system, presents the opportunity to conform the dose to the target better than 3-dimensional conformal therapy, particularly in the case of concave targets. Appropriate clinical applications of this technology to challenging patient treatment scenarios requires careful consideration of issues related to target volume-dose heterogeneity and the influence of patient setup uncertainties. These issues are reviewed and illustrated. To date, clinical reports of these treatments for prostate and head and neck cancers have the most mature data. Those results are summarized here. Future applications of this technology can be expected to take careful, considered advantage of this technology to further rearrange dose distributions across target volumes to produce an integrated overall gain in treatment objectives. However, these innovative applications need to be approached with caution, preferably in prospective clinical trials that would help determine if the hypothetical clinical benefits are in fact realizable.
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Affiliation(s)
- Randall K Ten Haken
- Department of Radiation Oncology, University of Michigan Medical School, Ann Arbor, 48109-0010, USA.
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Kashani R, Koshani R, Balter JM, Hayman JA, Henning GT, van Herk M. Short-term and long-term reproducibility of lung tumor position using active breathing control (ABC). Int J Radiat Oncol Biol Phys 2006; 65:1553-9. [PMID: 16863932 DOI: 10.1016/j.ijrobp.2006.04.027] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2006] [Revised: 04/04/2006] [Accepted: 04/06/2006] [Indexed: 10/24/2022]
Abstract
PURPOSE To evaluate the short-term and long-term reproducibility of lung tumor position for scans acquired using an active breathing control (ABC) device. METHODS AND MATERIALS Ten patients with lung cancer were scanned over three sessions during the course of treatment. For each session, two scans were acquired at deep inhale, and one scan each at half of deep inhale and at exhale. Long-term reproducibility was evaluated by comparing the same breathing state scans from two sessions, with setup variation removed by skeletal alignment. Tumor alignment was based on intensity matching of a small volume around the tumor. For short-term reproducibility, the two inhale volumes from the same session were compared. RESULTS For the short-term reproducibility, the mean and the standard deviation (SD) of the displacement of the center of tumor were 0.0 (1.5) mm in anteroposterior (AP), 0.3 (1.4) mm in superior/inferior (SI), and 0.2 (0.7) mm in right/left (RL) directions. For long-term reproducibility, the mean (SD) were -1.3 (3.1) mm AP, -0.5 (3.8) mm SI, and 0.3 (1.6) mm RL for inhale and -0.2 (2.8) mm AP, 0.2 (2.1) mm SI, and -0.7 (1.1) mm RL for exhale. CONCLUSION The ABC device demonstrates very good short-term and long-term reproducibility. Increased long-term variability in position, primarily in the SI and AP directions, indicates the role of tumor-directed localization in combination with breath-held immobilization.
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Affiliation(s)
- Rojano Kashani
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI 48109-0010, USA.
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Chopra S, Dinshaw KA, Kamble R, Sarin R. Breast movement during normal and deep breathing, respiratory training and set up errors: implications for external beam partial breast irradiation. Br J Radiol 2006; 79:766-73. [PMID: 16940376 DOI: 10.1259/bjr/98024704] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
This study was designed to evaluate interfraction and intrafraction breast movement and to study the effect of respiratory training on respiratory indices. Five patients were immobilized in supine position in a vacuum bag and three-dimensional set up errors, respiratory movement of the breast during normal and deep breathing, tidal volume and breath hold time were recorded. All patients underwent respiratory training and all the respiratory indices were re-evaluated at the end of training. Cumulative maximum movement error (CMME) was calculated by adding directional maximum set up error and maximum post training movement during normal breathing. The mean set up deviation was 1.3 mm (SD +/- 0.5 mm), 1.3 mm (SD +/- 0.3 mm) and 4.4 mm (SD +/- 2.6 mm) in the mediolateral, superoinferior and anteroposterior dimensions. Pre-training mean of the maximum marker movement during normal breathing was 1.07 mm, 1.94 mm and 1.86 mm in the mediolateral, superoinferior and anteroposterior dimensions. During deep breathing these values were 2 mm, 5.5 mm and 4.8 mm. While respiratory training had negligible effect on breast movement during normal breathing, it resulted in a modest reduction during deep breathing (p = 0.2). The mean CMME recorded for these patients was 3.4 mm, 4.5 mm and 7.1 mm in the mediolateral, superoinferior and anteroposterior dimension. Respiratory training also resulted in an increase in breath hold time from a mean of 31 s to 44 s (p = 0.04) and tidal volume from a mean of 560 cm(3) to 1160 cm(3) (p = 0.04). With patients immobilized in the vacuum bag the CMMEs are relatively less. Individualized directional margins may aid in reduction of planning target volume (PTV).
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Affiliation(s)
- S Chopra
- Radiation Oncology, Tata Memorial Hospital, Mumbai, Maharashtra, India
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