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Yoon S, Cao M, Aghdam N, Shabsovich D, Kahlon S, Ballas L, Collins S, Steinberg ML, Kishan AU. Prostate bed and organ-at-risk deformation: Prospective volumetric and dosimetric data from a phase II trial of stereotactic body radiotherapy after radical prostatectomy. Radiother Oncol 2020; 148:44-50. [PMID: 32311600 PMCID: PMC11288625 DOI: 10.1016/j.radonc.2020.04.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 03/26/2020] [Accepted: 04/06/2020] [Indexed: 11/28/2022]
Abstract
PURPOSE Stereotactic body radiotherapy (SBRT) in the post-prostatectomy setting is investigational. A major concern is the deformable prostate bed clinical target volume (CTV) and the closely juxtaposed organs-at-risk (OARs). We report a volumetric and dosimetric analysis of kilovoltage cone-beam CT (CBCT) data from the first 18 patients enrolled on a phase II trial of post-prostatectomy SBRT. With instructions on bladder filling and rectal preparation, we hypothesized acceptable CTV coverage while minimal overdosing to OARs could be achieved. METHODS All patients received 5 fractions of 6-6.8 Gy to the prostate bed. CBCT were taken prior to and halfway through each fraction. CTV and OARs were contoured for each CBCT. Changes in inter- and intra-fraction volume and dose were calculated. Relative changes in CTV V95%, bladder V32.5 Gy, and rectal V32.5 Gy and V27.5 Gy were evaluated. RESULTS Interfraction CTV volume remained stable, with median change +5.69% (IQR -1.73% to +9.84%). CTV V95% exhibited median change -0.74% (IQR -9.15% to -0.07%). Volumetric and dosimetric changes were minor from interfraction rotation and intrafraction motion. CTV V95% was ≥93% in 13 of 18 (72%) patients; in the remaining five, median change was -14.09% (IQR -16.64% to -13.56%). Interfraction CTV volume change was significantly larger among patients with CTV V95% <93% (+25.04% vs. +2.85%, p = 0.002). CONCLUSIONS With specific bladder and rectum filling protocols, CTV underdosing and overdosing to bladder and rectum are avoided in majority of patients. Changes in CTV shape may account for the underdosing that may be observed.
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Affiliation(s)
- Stephanie Yoon
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, United States
| | - Minsong Cao
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, United States
| | - Nima Aghdam
- Department of Radiation Medicine, Georgetown University, Washington, United States
| | - David Shabsovich
- David Geffen School of Medicine, University of California Los Angeles, United States
| | - Sartajdeep Kahlon
- David Geffen School of Medicine, University of California Los Angeles, United States
| | - Leslie Ballas
- Department of Radiation Oncology, University of Southern California, Los Angeles, United States
| | - Sean Collins
- Department of Radiation Medicine, Georgetown University, Washington, United States
| | - Michael Lee Steinberg
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, United States
| | - Amar U Kishan
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, United States.
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Elakshar S, Tsui JMG, Kucharczyk MJ, Tomic N, Fawaz ZS, Bahoric B, Papayanatos J, Chaddad A, Niazi T. Does Interfraction Cone Beam Computed Tomography Improve Target Localization in Prostate Bed Radiotherapy? Technol Cancer Res Treat 2019; 18:1533033819831962. [PMID: 30782085 PMCID: PMC6383090 DOI: 10.1177/1533033819831962] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Purpose: In this prospective phase II study, we investigated whether cone beam computed
tomography scan was a superior method of image-guided radiotherapy relative to 2D
orthogonal kilovoltage images in the post-radical prostatectomy setting. Methods: A total of 419 treatment fractions were included in this analysis. The shifts required
to align the patient for each treatment were performed using 3D matching between cone
beam computed tomography scans and the corresponding computed tomography images used for
planning. This was compared with the shifts obtained from 2D orthogonal kilovoltage
images, matching with the corresponding digitally reconstructed radiographs. Patients
did not have fiducials inserted to assist with localization. Interfractional changes in
the bladder and rectal volumes were subsequently measured on the cone beam computed
tomography images for each fraction and compared to the shift differences between
orthogonal kilovoltage and cone beam computed tomography scans. The proportion of
treatment fractions with a shift difference exceeding the planning target volume of 7
mm, between orthogonal kilovoltage and cone beam computed tomography scans, was
calculated. Results: The mean vertical, lateral, and longitudinal shifts resulted from 2D match between
orthogonal kilovoltage images and corresponding digitally reconstructed radiographs were
0.353 cm (interquartile range: 0.1-0.5), 0.346 cm (interquartile range: 0.1-0.5), and
0.289 cm (interquartile range: 0.1-0.4), compared to 0.388 cm (interquartile range:
0.1-0.5), 0.342 cm (interquartile range: 0.1-0.5), and 0.291 cm (interquartile range:
0.1-0.4) obtained from 3D match between cone beam computed tomography and planning
computed tomography scan, respectively. Our results show a significant difference
between the kilovoltage and cone beam computed tomography shifts in the
anterior–posterior direction (P = .01). The proportion of treatment
fractions in which the differences in kilovoltage and cone beam computed tomography
shifts between exceeded the 7 mm planning target volume margin was 6%, 2%, and 3% in the
anterior–posterior, lateral, and superior–inferior directions, respectively. Conclusion: We prospectively demonstrated that the daily use of volumetric cone beam computed
tomography for treatment localization in post-radical prostatectomy patients
demonstrated an increased need for a shift in patient position. This suggests that in
post-radical prostatectomy patients the daily cone beam computed tomography imaging
improved localization of the prostate bed and may have prevented a limited number of
geographic misses, compared to daily kilovoltage imaging that was not assisted with
fiducials.
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Affiliation(s)
- Sara Elakshar
- 1 McGill University, Jewish General Hospital, Montreal, Quebec, Canada
| | | | | | - Nada Tomic
- 4 Jewish General Hospital, Montreal, Quebec, Canada
| | | | | | | | - Ahmad Chaddad
- 2 McGill University Health Centre, Montreal, Quebec, Canada
| | - Tamim Niazi
- 1 McGill University, Jewish General Hospital, Montreal, Quebec, Canada
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Gawish A, Chughtai AA, Eble MJ. Dosimetric and volumetric effects in clinical target volume and organs at risk during postprostatectomy radiotherapy. Strahlenther Onkol 2018; 195:383-392. [PMID: 30334066 DOI: 10.1007/s00066-018-1381-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 10/03/2018] [Indexed: 12/25/2022]
Abstract
PURPOSE To assess the reproducibility of the dose-volume distribution of the initial simulation CT, generated using volumetric modulated arc therapy (VMAT) planning, during the radiotherapy of the prostatic bed based on weekly cone beam CTs (CBCT). METHODS Twenty-three patients, after radical prostatectomy were treated with adjuvant or salvage radiotherapy between July and December 2016 and considered for this evaluation. Weekly CBCT scans (n = 138) were imported into the treatment planning system, and the clinical tumor volume (CTV), the rectum and the bladder were contoured. The initially calculated dose distribution and the dose-volume histograms generated from weekly CBCTs were compared. The prostatic fossa dose coverage was assessed by the proportion of the CTV fully encompassed by the 95% and 98% isodose lines. Rectal and bladder volumes receiving 50, 60 and 65 Gy during the treatment were compared to the initial plan, with statistical significance determined using the one-sample t‑test. RESULTS Marked variations in the total organ volume of the rectum and the bladder were observed. The correlation between rectum volume and V50 was not significant (p = 0.487), while the bladder volume and V50 demonstrated a significant correlation. There was no correlation between urinary bladder volume and CTV. The change in rectal volume correlated significantly with CTV. The dose coverage (D98% and D95%) to the prostatic bed could be achieved for all patients due to the ventral shift in the volume differences of the rectum. CONCLUSION Weekly CBCTs can be considered as adequate verification tools to assess the interfractional variability of the CTV and organs at risk. The proven volume changes in the urinary bladder and the rectum do not compromise the final delivered dose in the CTV.
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Affiliation(s)
- Ahmed Gawish
- Department of Radiation Oncology, RWTH Aachen University, Pauwelsstraße 30, 52072, Aachen, Germany.
| | - Ahmed Ali Chughtai
- Department of Radiation Oncology, RWTH Aachen University, Pauwelsstraße 30, 52072, Aachen, Germany
| | - Michael J Eble
- Department of Radiation Oncology, RWTH Aachen University, Pauwelsstraße 30, 52072, Aachen, Germany
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Vilotte F, Antoine M, Bobin M, Latorzeff I, Supiot S, Richaud P, Thomas L, Leduc N, Guérif S, Iriondo-Alberdi J, de Crevoisier R, Sargos P. Post-Prostatectomy Image-Guided Radiotherapy: The Invisible Target Concept. Front Oncol 2017; 7:34. [PMID: 28337425 PMCID: PMC5343009 DOI: 10.3389/fonc.2017.00034] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 02/24/2017] [Indexed: 12/17/2022] Open
Abstract
In the era of intensity-modulated radiation therapy, image-guided radiotherapy (IGRT) appears crucial to control dose delivery and to promote dose escalation while allowing healthy tissue sparing. The place of IGRT following radical prostatectomy is poorly described in the literature. This review aims to highlight some key points on the different IGRT techniques applicable to prostatic bed radiotherapy. Furthermore, methods used to evaluate target motion and to reduce planning target volume margins will also be explored.
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Affiliation(s)
- Florent Vilotte
- Department of Radiotherapy, Institut Bergonié , Bordeaux Cedex , France
| | - Mickael Antoine
- Department of Medical Physics, Institut Bergonié , Bordeaux Cedex , France
| | - Maxime Bobin
- Department of Radiotherapy, Institut Bergonié , Bordeaux Cedex , France
| | - Igor Latorzeff
- Department of Radiotherapy, Groupe ONCORAD, Clinique Pasteur , Toulouse , France
| | - Stéphane Supiot
- Department of Radiotherapy, Institut de Cancérologie de L'Ouest René Gauducheau , Nantes , France
| | - Pierre Richaud
- Department of Radiotherapy, Institut Bergonié , Bordeaux Cedex , France
| | - Laurence Thomas
- Department of Radiotherapy, Institut Bergonié , Bordeaux Cedex , France
| | - Nicolas Leduc
- Department of Radiotherapy, Institut Bergonié , Bordeaux Cedex , France
| | - Stephane Guérif
- Department of Radiotherapy, CHU de Poitier , Poitiers , France
| | | | | | - Paul Sargos
- Department of Radiotherapy, Institut Bergonié , Bordeaux Cedex , France
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5
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Diot Q, Kavanagh B, Vinogradskiy Y, Garg K, Gaspar L, Miften M. Lung deformations and radiation-induced regional lung collapse in patients treated with stereotactic body radiation therapy. Med Phys 2016; 42:6477-87. [PMID: 26520737 DOI: 10.1118/1.4932624] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
PURPOSE To differentiate radiation-induced fibrosis from regional lung collapse outside of the high dose region in patients treated with stereotactic body radiation therapy (SBRT) for lung tumors. METHODS Lung deformation maps were computed from pre-treatment and post-treatment computed tomography (CT) scans using a point-to-point translation method. Fifty anatomical landmarks inside the lung (vessel or airway branches) were matched on planning and follow-up scans for the computation process. Two methods using the deformation maps were developed to differentiate regional lung collapse from fibrosis: vector field and Jacobian methods. A total of 40 planning and follow-ups CT scans were analyzed for 20 lung SBRT patients. RESULTS Regional lung collapse was detected in 15 patients (75%) using the vector field method, in ten patients (50%) using the Jacobian method, and in 12 patients (60%) by radiologists. In terms of sensitivity and specificity the Jacobian method performed better. Only weak correlations were observed between the dose to the proximal airways and the occurrence of regional lung collapse. CONCLUSIONS The authors presented and evaluated two novel methods using anatomical lung deformations to investigate lung collapse and fibrosis caused by SBRT treatment. Differentiation of these distinct physiological mechanisms beyond what is usually labeled "fibrosis" is necessary for accurate modeling of lung SBRT-induced injuries. With the help of better models, it becomes possible to expand the therapeutic benefits of SBRT to a larger population of lung patients with large or centrally located tumors that were previously considered ineligible.
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Affiliation(s)
- Quentin Diot
- Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Brian Kavanagh
- Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Yevgeniy Vinogradskiy
- Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Kavita Garg
- Department of Radiology, University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Laurie Gaspar
- Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Moyed Miften
- Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado 80045
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Sá AC, Peres A, Pereira M, Coelho CM, Monsanto F, Macedo A, Lamas A. Evaluating deviations in prostatectomy patients treated with IMRT. Rep Pract Oncol Radiother 2016; 21:266-70. [DOI: 10.1016/j.rpor.2015.11.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Accepted: 11/30/2015] [Indexed: 10/22/2022] Open
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Murray JR, McNair HA, Dearnaley DP. Rationale and development of image-guided intensity-modulated radiotherapy post-prostatectomy: the present standard of care? Cancer Manag Res 2015; 7:331-44. [PMID: 26635484 PMCID: PMC4646477 DOI: 10.2147/cmar.s51955] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The indications for post-prostatectomy radiotherapy have evolved over the last decade, although the optimal timing, dose, and target volume remain to be well defined. The target volume is susceptible to anatomical variations with its borders interfacing with the rectum and bladder. Image-guided intensity-modulated radiotherapy has become the gold standard for radical prostate radiotherapy. Here we review the current evidence for image-guided techniques with intensity-modulated radiotherapy to the prostate bed and describe current strategies to reduce or account for interfraction and intrafraction motion.
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Affiliation(s)
- Julia R Murray
- Academic Urology Unit, Institute of Cancer Research, London
- Department of Radiotherapy, The Royal Marsden NHS Foundation Trust, Sutton, UK
| | - Helen A McNair
- Department of Radiotherapy, The Royal Marsden NHS Foundation Trust, Sutton, UK
| | - David P Dearnaley
- Academic Urology Unit, Institute of Cancer Research, London
- Department of Radiotherapy, The Royal Marsden NHS Foundation Trust, Sutton, UK
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Prostate bed radiation therapy: the utility of ultrasound volumetric imaging of the bladder. Clin Oncol (R Coll Radiol) 2014; 26:789-96. [PMID: 25242000 DOI: 10.1016/j.clon.2014.08.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2014] [Revised: 07/10/2014] [Accepted: 08/12/2014] [Indexed: 12/30/2022]
Abstract
AIMS To evaluate the effect of incorporating daily ultrasound scanning to reduce variation in bladder filling before prostate bed radiotherapy. The primary aim was to confirm that coverage of the planning target volume (PTV) with the 95% isodose was within tolerance when the ultrasound-determined bladder volume was within individualised patient limits. MATERIALS AND METHODS Cone beam computed tomography (CBCT) images were acquired on 10 occasions during the course of treatment to assess systematic changes in rectal or bladder volume as part of a standard offline image-guided radiotherapy (IGRT) protocol. In addition, through a two-part study an ultrasound scan of the bladder was added to the IGRT protocol. In the Part 1 study, the ultrasound-determined bladder volume at the time of treatment simulation in 26 patients was compared with the simulation computed tomography cranio-caudal bladder length. The relationship between the two was used to establish bladder volume tolerance limits for the interventional component of the Part 2 study. In the Part 2 study, 24 patients underwent ultrasound scanning before treatment. When bladder volumes were outside the specified limits, they were asked to drink more water or void as appropriate until the volume was within tolerance. RESULTS Based on the results of the Part 1 study, a 100 ml tolerance was applied in the Part 2 study. Seventy-six per cent of patients found to have bladder volumes outside tolerance were able to satisfactorily adjust their bladder volumes on demand. Comparing the bladder volumes with the CBCT data revealed that the bladder scanner correctly predicted that the target volume would be accurately targeted (using surrogate end points) in 83% of treatment fractions. CONCLUSION A simple hand-held ultrasound bladder scanner provides a practical, inexpensive, online solution to confirming that the bladder volume is within acceptable, patient-specific limits before treatment delivery, with the potential to improve overall treatment accuracy.
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9
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Jones BL, Gan G, Kavanagh B, Miften M. Effect of endorectal balloon positioning errors on target deformation and dosimetric quality during prostate SBRT. Phys Med Biol 2013; 58:7995-8006. [PMID: 24169860 DOI: 10.1088/0031-9155/58/22/7995] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
An inflatable endorectal balloon (ERB) is often used during stereotactic body radiation therapy (SBRT) for treatment of prostate cancer in order to reduce both intrafraction motion of the target and risk of rectal toxicity. However, the ERB can exert significant force on the prostate, and this work assessed the impact of ERB position errors on deformation of the prostate and treatment dose metrics. Seventy-one cone-beam computed tomography (CBCT) image datasets of nine patients with clinical stage T1cN0M0 prostate cancer were studied. An ERB (Flexi-Cuff, EZ-EM, Westbury, NY) inflated with 60 cm(3) of air was used during simulation and treatment, and daily kilovoltage (kV) CBCT imaging was performed to localize the prostate. The shape of the ERB in each CBCT was analyzed to determine errors in position, size, and shape. A deformable registration algorithm was used to track the dose received by (and deformation of) the prostate, and dosimetric values such as D95, PTV coverage, and Dice coefficient for the prostate were calculated. The average balloon position error was 0.5 cm in the inferior direction, with errors ranging from 2 cm inferiorly to 1 cm superiorly. The prostate was deformed primarily in the AP direction, and tilted primarily in the anterior-posterior/superior-inferior plane. A significant correlation was seen between errors in depth of ERB insertion (DOI) and mean voxel-wise deformation, prostate tilt, Dice coefficient, and planning-to-treatment prostate inter-surface distance (p < 0.001). Dosimetrically, DOI is negatively correlated with prostate D95 and PTV coverage (p < 0.001). For the model of ERB studied, error in ERB position can cause deformations in the prostate that negatively affect treatment, and this additional aspect of setup error should be considered when ERBs are used for prostate SBRT. Before treatment, the ERB position should be verified, and the ERB should be adjusted if the error is observed to exceed tolerable values.
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Affiliation(s)
- Bernard L Jones
- Department of Radiation Oncology, University of Colorado School of Medicine 1665 Aurora Ct, MSF706, Aurora, CO 80045, USA
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Jones BL, Gan G, Diot Q, Kavanagh B, Timmerman RD, Miften M. Dosimetric and deformation effects of image‐guided interventions during stereotactic body radiation therapy of the prostate using an endorectal balloon. Med Phys 2012; 39:3080-8. [DOI: 10.1118/1.4711813] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- Bernard L. Jones
- Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Gregory Gan
- Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Quentin Diot
- Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Brian Kavanagh
- Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Robert D. Timmerman
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Moyed Miften
- Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado 80045
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A Comparison of the Acute Toxicity Profile between Two-dimensional and Three-dimensional Image-guided Radiotherapy for Postoperative Prostate Cancer. Clin Oncol (R Coll Radiol) 2011; 23:344-9. [DOI: 10.1016/j.clon.2011.01.505] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2010] [Revised: 12/08/2010] [Accepted: 12/16/2010] [Indexed: 11/17/2022]
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