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Felisi M, Monti AF, Lizio D, Nici S, Pellegrini RG, Riga S, Bortolato B, Brambilla MG, Carbonini C, Abujami M, Carsana C, Sibio D, Potente C, Vanzulli A, Palazzi MF, Torresin A. MRI only in a patient with prostate cancer with bilateral metal hip prostheses: case study. TUMORI JOURNAL 2021; 107:NP41-NP44. [PMID: 33629653 DOI: 10.1177/0300891621997549] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVE To outline a practical method of performing prostate cancer radiotherapy in patients with bilateral metal hip prostheses with the standard resources available in a modern general hospital. The proposed workflow is based exclusively on magnetic resonance imaging (MRI) to avoid computed tomography (CT) artifacts. CASE DESCRIPTION This study concerns a 73-year-old man with bilateral hip prostheses with an elevated risk prostate cancer. Magnetic resonance images with assigned electron densities were used for planning purposes, generating a synthetic CT (sCT). Imaging acquisition was performed with an optimized Dixon sequence on a 1.5T MRI scanner. The images were contoured by autosegmentation software, based on an MRI database of 20 patients. The sCT was generated assigning averaged electron densities to each contour. Two volumetric modulated arc therapy plans, a complete arc and a partial one, where the beam entrances through the prostheses were avoided for about 50° on both sides, were compared. The feasibility of matching daily cone beam CT (CBCT) with MRI reference images was also tested by visual evaluations of different radiation oncologists. CONCLUSIONS The use of magnetic resonance images improved accuracy in targets and organs at risk (OARs) contouring. The complete arc plan was chosen because of 10% lower mean and maximum doses to prostheses with the same planning target volume coverage and OAR sparing. The image quality of the match between performed CBCTs and MRI was considered acceptable. The proposed method seems promising to improve radiotherapy treatments for this complex category of patients.
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Affiliation(s)
- Marco Felisi
- Medical Physics Department, ASST Grande Ospedale Metropolitano Niguarda, Milano, Italy
| | - Angelo Filippo Monti
- Medical Physics Department, ASST Grande Ospedale Metropolitano Niguarda, Milano, Italy
| | - Domenico Lizio
- Medical Physics Department, ASST Grande Ospedale Metropolitano Niguarda, Milano, Italy
| | - Stefania Nici
- Medical Physics Department, ASST Grande Ospedale Metropolitano Niguarda, Milano, Italy
| | | | - Stefano Riga
- Medical Physics Department, ASST Grande Ospedale Metropolitano Niguarda, Milano, Italy
| | - Barbara Bortolato
- Radiotherapy Department, ASST Grande Ospedale Metropolitano Niguarda, Milano, Italy
| | | | - Claudia Carbonini
- Medical Physics Department, ASST Grande Ospedale Metropolitano Niguarda, Milano, Italy
| | - Mohammed Abujami
- Medical Physics Department, ASST Grande Ospedale Metropolitano Niguarda, Milano, Italy
| | - Chiara Carsana
- Radiotherapy Department, ASST Grande Ospedale Metropolitano Niguarda, Milano, Italy
| | - Daniela Sibio
- Radiotherapy Department, ASST Grande Ospedale Metropolitano Niguarda, Milano, Italy
| | - Carmelina Potente
- Radiotherapy Department, ASST Grande Ospedale Metropolitano Niguarda, Milano, Italy
| | - Angelo Vanzulli
- Radiology Department, ASST Grande Ospedale Metropolitano Niguarda, Milano, Italy
| | | | - Alberto Torresin
- Medical Physics Department, ASST Grande Ospedale Metropolitano Niguarda, Milano, Italy
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Transperineal ultrasound for aiding target volume delineation and monitoring during prostate cancer radiotherapy in men with bilateral hip prostheses. JOURNAL OF RADIOTHERAPY IN PRACTICE 2020. [DOI: 10.1017/s1460396920000758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
AbstractAims:To investigate the use of co-registration of the computerised tomography (CT) planning scan with transperineal ultrasound (TPUS) as an aid to the delineation of the clinical target volume (CTV), and the use of TPUS as a tool for inter- and intra-fractional monitoring in men with bilateral hip prostheses (b-P) undergoing prostate radiotherapy.Materials and methods:We marked the CTV of three patients with and without the co-registered TPUS images. A metal artefact reduction algorithm was utilised. Two patients were treated with intensity-modulated radiotherapy (IMRT) and one with volumetric-modulated arc therapy (VMAT). The inter- and intra-fractional monitoring details were reviewed retrospectively.Results:Clinician marking with TPUS/CT fusion improved the confidence of prostate CTV delineation leading to a consistent change in volumes across two observers. Inter- and intra-fractional monitoring was possible using TPUS as image guidance, as it is for those patients with non-prosthetic hips.Findings:Using TPUS in the radiotherapy workflow has enabled us to more confidently plan, treat and monitor patients with b-HP. Due to transperineal image acquisition, the ultrasound images are not affected by the presence of hip prostheses, which are outside the field of view.
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Bottero M, Dipasquale G, Lancia A, Miralbell R, Jaccard M, Zilli T. Electromagnetic Transponder Localization and Real-Time Tracking for Prostate Cancer Radiation Therapy: Clinical Impact of Metallic Hip Prostheses. Pract Radiat Oncol 2020; 10:e538-e542. [PMID: 32201320 DOI: 10.1016/j.prro.2020.03.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 01/27/2020] [Accepted: 03/09/2020] [Indexed: 10/24/2022]
Abstract
PURPOSE Our purpose was to assess the ability of electromagnetic transponders (EMTs) to localize and track movements in patients with prostate cancer (PCa) with metallic hip prostheses (MHPs) treated with curative radiation therapy (RT). METHODS AND MATERIALS Data sets of 8 PCa patients with MHPs (3 bilateral and 5 unilateral) treated between 2016 and 2018 with RT and EMT tracking were retrospectively assessed. The distances between the 3 EMTs (apex to left, left to right, right to apex) and the isocenter were calculated both on planning computed tomography (CT) and cone beam CT (CBCT) at the first treatment fraction and compared with data reported by Calypso. EMT position and treatment interruptions triggered by Calypso were analyzed for all evaluable treatment fractions (n = 120). Localization accuracy was quantified by recording the geometric residual value (expected limit ≤0.2 cm) at the RT setup. RESULTS The Calypso system was able to localize and track prostate position without any detectable interference from MHP. For every treatment fraction, the agreement between the CBCT images and Calypso guidance was optimal, with EMTs always within the defined tolerance (ie, CT-Calypso or CBCT-Calypso measured differences in inter-EMT distances within 0.3 cm). EMT to isocenter distances measured by Calypso reproduced CT data and were confirmed on CBCT scans. During RT, the EMT centroid exceeded the threshold 24 times (20% of all fractions): 5 times in the left-right, 15 times in the anteroposterior, and 4 times in the superoinferior directions. The largest motions recorded were in the anteroposterior axis: 0.6 cm anteriorly and 0.5 cm posteriorly in patients with unilateral and bilateral MHP, respectively. CONCLUSIONS Our study represents the first clinical experience assessing the localization and tracking accuracy of Calypso EMTs during curative RT of patients with PCa with unilateral or bilateral MHP.
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Affiliation(s)
- Marta Bottero
- Radiation Oncology, Geneva University Hospital, Geneva, Switzerland.
| | | | - Andrea Lancia
- Radiation Oncology, Geneva University Hospital, Geneva, Switzerland; Department of Radiation Oncology, Fondazione IRCCS Policlinico San Matteo, Pavia
| | | | - Maud Jaccard
- Radiation Oncology, Geneva University Hospital, Geneva, Switzerland
| | - Thomas Zilli
- Radiation Oncology, Geneva University Hospital, Geneva, Switzerland; Faculty of Medicine, Geneva University, Geneva, Switzerland
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M R B, F S, S H, S B. Investigating the Impact of Knee Prosthesis in Patients' Body on Radiation Dose Distribution: A Monte Carlo Approach. J Biomed Phys Eng 2019; 9:345-354. [PMID: 31341880 PMCID: PMC6613162 DOI: 10.31661/jbpe.v0i0.1047] [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] [Received: 11/05/2018] [Accepted: 12/09/2018] [Indexed: 11/27/2022]
Abstract
Background: Metal prostheses in patients affect the radiotherapy dose distribution. Metal prostheses with high density and atomic number cause major changes in scattering and attenuation of radiation. The present study aims to assess the impact of metal knee prosthesis with various dimensions and materials on radiotherapy dose distribution.
Material and Methods: In this research, the Varian Linac and water phantom were simulated using the MCNPX code. Dose distribution of photon beam in a water phantom, with and without the presence of knee prostheses made of cobalt-chromium-molybdenum alloy, steel, titanium, and titanium alloy used in men and women was investigated using the Monte Carlo simulation.
Results: The prosthesis led to an increase in dose in comparison with cases that there was used no prosthesis. According to values of the depth dose percentage, the maximum dose increase was found to be 6.8%, 6.1%, 4%, and 4.29%, and dose reduction 41.18%, 40.66%, 37.76%, and 37.51% for prosthetics with men’s knee dimensions made of cobalt-chromium-molybdenum alloy, steel, titanium alloy, and titanium, respectively. Above all, does increasing to 6.4%, 5.9%, 3.8%, and 3.94% and doses reducing to 40.87%, 40.36%, 36.94%, and 36.69 were observed in prosthetics for women. The highest amount of dose reduction for men’s prostheses made of mentioned materials was found to be 48.75%, 47.7%, 45%, and 45.8%, respectively. In addition, it was 46.36%, 45.8%, 43.8%, and 43.95% for women’s prostheses, respectively.
Conclusion: Material will have a significant impact if a part of the knee bone places behind the prosthesis. According to the obtained values, it is recommended to utilize prostheses made of titanium and titanium alloys for knee arthroplasty. The prosthesis can either increase or decrease dose in tumor or lead to increase dose at organs at risk.
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Affiliation(s)
- Bayatiani M R
- Ph.D of Medical Physics. Assistant professor, Department of Medical Physics and Radiotherapy, Arak university of Medical Sciences and Khansari hospital, Arak, Iran
| | - Seif F
- Ph.D of Medical Physics. Assistant professor, Department of Medical Physics and Radiotherapy, Arak university of Medical Sciences and Khansari hospital, Arak, Iran
| | - Hamidi S
- Ph.D of Physics. Associate professor, Department of Physics, Arak University, Arak, Iran
| | - Bagheri S
- Ms.c of Physics, Department of Physics, Arak University, Arak, Iran
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Hagen M, Kretschmer M, Würschmidt F, Gauer T, Giro C, Karsten E, Lorenzen J. Clinical relevance of metal artefact reduction in computed tomography (iMAR) in the pelvic and head and neck region: Multi-institutional contouring study of gross tumour volumes and organs at risk on clinical cases. J Med Imaging Radiat Oncol 2019; 63:842-851. [PMID: 31265214 DOI: 10.1111/1754-9485.12924] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 06/03/2019] [Indexed: 11/27/2022]
Abstract
INTRODUCTION Artefacts caused by dental implants and hip replacements may impede target volume definition and dose calculation accuracy. The iterative metal artefact reduction (iMAR) algorithm can provide a solution for this problem. The present study compares delineation of gross tumour volumes (GTVs) and organs at risk (OARs) in the pelvic and the head and neck (H & N) regions using computed tomography (CT) with and without iMAR, and thus the practical applicability of iMAR for routine clinical use. METHODS The native planning CT and CT-iMAR data of two typical clinical cases with image-distorting artefacts were used for multi-institutional contouring and analysis using the Dice similarity coefficient (DSC). GTV/OAR contours were compared with an intraobserver approach and compared to predefined reference structures. RESULTS Mean volume for GTVprostate in the intraobserver approach decreased from 87 ± 44 cm3 (native CT) to 75 ± 22 cm3 (CT-iMAR) (P = 0.168). Compared to the reference, DSC values for GTVP rostate increased from 0.68 ± 0.15 to 0.78 ± 0.07 (CT vs. iMAR) (P < 0.05). In the H & N region, the reference for GTVT ongue (34 cm3 ) was underestimated on both data sets. No significant improvement in DSC values (0.83 ± 0.06 (native CT) versus 0.86 ± 0.06 (CT-iMAR)) was observed. CONCLUSION The use of iMAR improves the anatomical delineation at the transition of prostate and bladder in cases of bilateral hip replacement. In the H & N region, anatomical residual structures and experience were apparently sufficient for precise contouring.
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Affiliation(s)
| | | | | | - Tobias Gauer
- Department of Radiotherapy and Radio-Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | - Elias Karsten
- Department of Radiotherapy, University Medical Center Schleswig-Holstein, Kiel, Germany
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Wyatt J, McCallum H. Applying a commercial atlas-based synthetic Computed Tomography algorithm to patients with hip prostheses for prostate Magnetic Resonance-only radiotherapy. Radiother Oncol 2019; 133:100-105. [PMID: 30935564 DOI: 10.1016/j.radonc.2018.12.029] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 12/24/2018] [Accepted: 12/30/2018] [Indexed: 01/24/2023]
Abstract
BACKGROUND AND PURPOSE Magnetic Resonance (MR)-only prostate radiotherapy has recently been clinically implemented using commercial synthetic Computed Tomography (sCT) algorithms. However patients with hip prostheses have been excluded from all MR-only research to date and assumed to require dedicated sCT algorithms. This study aimed to investigate the dosimetric accuracy of applying a commercial sCT algorithm, based on an atlas of patients without hip prostheses, to patients with prostheses. MATERIALS AND METHODS 18 patients with unilateral hip prostheses received MR and CT scans in the radiotherapy position. sCTs were generated from the MR using a commercial algorithm. The clinical Volumetric Modulated Arc Therapy (VMAT) plan, consisting of partial arcs which avoided the prosthesis, was recalculated using the sCT and the dose distribution compared. RESULTS The mean isocentre dose difference was ΔD = (-0.4 ± 0.2)% (mean ± standard error of the mean (sem), range - 1.9%, 1.1%) and the mean differences in Planning Target Volume, bladder and rectum mean doses were ≤0.3%. The 3D global gamma pass rate with dose difference 1% and distance to agreement 1 mm within the body was ΓBody1/1 = (95.0 ± 0.5)% (sem) and within the 50% isodose volume, which excluded the prosthesis, was Γ50%1/1 = (98.5 ± 0.4)% (sem). The pass rate within the PTV was ΓPTV2/2 ≥ 99.7% for all patients, although for PTVs close (≤3.5 cm) to the prosthesis ΓPTV1/1 < 85% for three patients. The sCT did not accurately represent the prosthesis with a mean difference in radiological isocentre depth near the prosthesis of ΔdOutsideRad = (15.8 ± 2.6) mm (sem). However inside the treatment plan arc the difference was ΔdInsideRad = (-1.8 ± 0.5) mm (sem). CONCLUSIONS Using a commercial prostate sCT algorithm for patients with unilateral hip prostheses is dosimetrically accurate (<0.5%) as long as the routine prosthesis-avoidance treatment planning approach is used and the PTV is >3.5 cm from the prosthesis. This suggests MR-only prostate radiotherapy can be extended to patients with hip prostheses without requiring a specific sCT algorithm.
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Affiliation(s)
- Jonathan Wyatt
- Northern Centre for Cancer Care, Newcastle Upon Tyne Hospitals NHS Foundation Trust, Newcastle, UK.
| | - Hazel McCallum
- Northern Centre for Cancer Care, Newcastle Upon Tyne Hospitals NHS Foundation Trust, Newcastle, UK
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Martin JM, Supiot S, Keall PJ, Catton CN. Moderately hypofractionated prostate external-beam radiotherapy: an emerging standard. Br J Radiol 2018; 91:20170807. [PMID: 29322821 PMCID: PMC6223284 DOI: 10.1259/bjr.20170807] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 01/05/2018] [Accepted: 01/08/2018] [Indexed: 01/01/2023] Open
Abstract
Research over recent years has demonstrated that curative external-beam radiotherapy can be safely and efficaciously delivered with roughly half the number of treatments which was previously considered standard. We review the data supporting this change in practice, methods for implementation, as well as emerging future directions.
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Affiliation(s)
- Jarad M Martin
- School of Medicine and Public Health, University of Newcastle, Callaghan, New South Wales, NSW, Australia
| | - Stephane Supiot
- Département de Radiothérapie, Institut de Cancérologie de l'Ouest, Saint-Herblain, France
| | - Paul J Keall
- Radiation Physics Laboratory, Sydney Medical School, University of Sydney, Sydney, New South Wales, NSW, Australia
| | - Charles N Catton
- Radiation Medicine Program, Princess Margaret Hospital, University of Toronto, Toronto, ON, Canada
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Mahuvava C, Du Plessis FCP. Dosimetry Effects Caused by Unilateral and Bilateral Hip Prostheses: A Monte Carlo Case Study in Megavoltage Photon Radiotherapy for Computed Tomography Data without Metal Artifacts. J Med Phys 2018; 43:236-246. [PMID: 30636849 PMCID: PMC6299754 DOI: 10.4103/jmp.jmp_70_18] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Background: Hip prostheses (HPs) are routinely used in hip augmentation to replace painful or dysfunctional hip joints. However, high-density and high-atomic-number (Z) inserts may cause dose perturbations in the target volume and interface regions. Aim: To evaluate the dosimetric influence of various HPs during megavoltage conformal radiotherapy (RT) of the prostate using Monte Carlo (MC) simulations. Materials and Methods: BEAMnrc and DOSXYZnrc MC user-codes were respectively used to simulate the linac head and to calculate 3D absorbed dose distributions in a computed tomography (CT)-based phantom. A novel technique was used to synthetically introduce HPs into the raw patient CT dataset. The prosthesis materials evaluated were stainless steel (SS316L), titanium (Ti6Al4V), and ultra-high-molecular-weight polyethylene (UHMWPE). Four, five, and six conformal photon fields of 6–20 MV were used. Results: The absorbed dose within and beyond metallic prostheses dropped significantly due to beam attenuation. For bilateral HPs, the target dose reduction ranged up to 23% and 17% for SS316L and Ti6Al4V, respectively. For unilateral HP, the respective dose reductions were 19% and 12%. Dose enhancement was always <1% for UHMWPE. The 6-field plan produced the best target coverage. Up to 38% dose increase was found at the bone–SS316L proximal interface. Conclusions: The novel technique used enabled the complete exclusion of metal artifacts in the CT dataset. High-energy plans with more oblique beams can help minimize dose attenuation through HPs. Shadowing and interface effects are density dependent and greatest for SS316L, while UHMWPE poses negligible dose perturbation.
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Affiliation(s)
- Courage Mahuvava
- Department of Medical Physics, Faculty of Health Sciences, University of the Free State, Bloemfontein, South Africa
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Zaorsky NG, Showalter TN, Ezzell GA, Nguyen PL, Assimos DG, D'Amico AV, Gottschalk AR, Gustafson GS, Keole SR, Liauw SL, Lloyd S, McLaughlin PW, Movsas B, Prestidge BR, Taira AV, Vapiwala N, Davis BJ. ACR Appropriateness Criteria for external beam radiation therapy treatment planning for clinically localized prostate cancer, part II of II. Adv Radiat Oncol 2017; 2:437-454. [PMID: 29114613 PMCID: PMC5605284 DOI: 10.1016/j.adro.2017.03.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 03/10/2017] [Indexed: 12/21/2022] Open
Abstract
PURPOSE To present the most updated American College of Radiology (ACR) Appropriateness Criteria formed by an expert panel on the appropriate delivery of external beam radiation to manage stage T1 and T2 prostate cancer (in the definitive setting and post-prostatectomy) and to provide clinical variants with expert recommendations based on accompanying Appropriateness Criteria for target volumes and treatment planning. METHODS AND MATERIALS The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a panel of multidisciplinary experts. The guideline development and revision process includes an extensive analysis of current medical literature from peer-reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In instances in which evidence is lacking or equivocal, expert opinion may supplement available evidence to recommend imaging or treatment. RESULTS The panel summarizes the most recent and relevant literature on the topic, including organ motion and localization methods, image guidance, and delivery techniques (eg, 3-dimensional conformal intensity modulation). The panel presents 7 clinical variants, including (1) a standard case and cases with (2) a distended rectum, (3) a large-volume prostate, (4) bilateral hip implants, (5) inflammatory bowel disease, (6) prior prostatectomy, and (7) a pannus extending into the radiation field. Each case outlines the appropriate techniques for simulation, treatment planning, image guidance, dose, and fractionation. Numerical rating and commentary is given for each treatment approach in each variant. CONCLUSIONS External beam radiation is a key component of the curative management of T1 and T2 prostate cancer. By combining the most recent medical literature, these Appropriateness Criteria can aid clinicians in determining the appropriate treatment delivery and personalized approaches for individual patients.
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Affiliation(s)
| | | | - Gary A. Ezzell
- Mayo Clinic, Phoenix, Arizona (research author [contributing])
| | - Paul L. Nguyen
- Dana-Farber Cancer Institute/Brigham and Women's Hospital, Boston, Massachusetts (panel vice-chair)
| | - Dean G. Assimos
- University of Alabama School of Medicine, Birmingham, Alabama (American Urological Association)
| | - Anthony V. D'Amico
- Dana-Farber Cancer Institute/Brigham and Women's Hospital, Boston, Massachusetts (American Society of Clinical Oncology)
| | | | | | | | | | - Shane Lloyd
- Huntsman Cancer Hospital, Salt Lake City, Utah
| | | | | | | | - Al V. Taira
- Mills Peninsula Hospital, San Mateo, California
| | - Neha Vapiwala
- University of Pennsylvania, Philadelphia, Pennsylvania
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Pollard JM, Wen Z, Sadagopan R, Wang J, Ibbott GS. The future of image-guided radiotherapy will be MR guided. Br J Radiol 2017; 90:20160667. [PMID: 28256898 DOI: 10.1259/bjr.20160667] [Citation(s) in RCA: 130] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Advances in image-guided radiotherapy (RT) have allowed for dose escalation and more precise radiation treatment delivery. Each decade brings new imaging technologies to help improve RT patient setup. Currently, the most frequently used method of three-dimensional pre-treatment image verification is performed with cone beam CT. However, more recent developments have provided RT with the ability to have on-board MRI coupled to the teleradiotherapy unit. This latest tool for treating cancer is known as MR-guided RT. Several varieties of these units have been designed and installed in centres across the globe. Their prevalence, history, advantages and disadvantages are discussed in this review article. In preparation for the next generation of image-guided RT, this review also covers where MR-guided RT might be heading in the near future.
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Affiliation(s)
| | - Zhifei Wen
- UT MD Anderson Cancer Center, Houston, TX, USA
| | | | - Jihong Wang
- UT MD Anderson Cancer Center, Houston, TX, USA
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11
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Zaorsky NG, Showalter TN, Ezzell GA, Nguyen PL, Assimos DG, D'Amico AV, Gottschalk AR, Gustafson GS, Keole SR, Liauw SL, Lloyd S, McLaughlin PW, Movsas B, Prestidge BR, Taira AV, Vapiwala N, Davis BJ. ACR Appropriateness Criteria ® external beam radiation therapy treatment planning for clinically localized prostate cancer, part I of II. Adv Radiat Oncol 2016; 2:62-84. [PMID: 28740916 PMCID: PMC5514238 DOI: 10.1016/j.adro.2016.10.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 10/12/2016] [Indexed: 12/24/2022] Open
Affiliation(s)
| | | | | | - Gary A Ezzell
- Mayo Clinic, Phoenix, Arizona (research author, contributing)
| | - Paul L Nguyen
- Dana-Farber Cancer Institute/Brigham and Women's Hospital, Boston, Massachusetts (panel vice-chair)
| | - Dean G Assimos
- University of Alabama School of Medicine, Birmingham, Alabama (American Urological Association)
| | - Anthony V D'Amico
- Dana-Farber Cancer Institute/Brigham and Women's Hospital, Boston, Massachusetts (American Society of Clinical Oncology)
| | | | | | | | | | - Shane Lloyd
- Huntsman Cancer Hospital, Salt Lake City, Utah
| | | | | | | | - Al V Taira
- Mills Peninsula Hospital, San Mateo, California
| | - Neha Vapiwala
- University of Pennsylvania, Philadelphia, Pennsylvania
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12
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McPartlin AJ, Li XA, Kershaw LE, Heide U, Kerkmeijer L, Lawton C, Mahmood U, Pos F, van As N, van Herk M, Vesprini D, van der Voort van Zyp J, Tree A, Choudhury A. MRI-guided prostate adaptive radiotherapy - A systematic review. Radiother Oncol 2016; 119:371-80. [PMID: 27162159 DOI: 10.1016/j.radonc.2016.04.014] [Citation(s) in RCA: 114] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 04/08/2016] [Accepted: 04/09/2016] [Indexed: 11/29/2022]
Abstract
Dose escalated radiotherapy improves outcomes for men with prostate cancer. A plateau for benefit from dose escalation using EBRT may not have been reached for some patients with higher risk disease. The use of increasingly conformal techniques, such as step and shoot IMRT or more recently VMAT, has allowed treatment intensification to be achieved whilst minimising associated increases in toxicity to surrounding normal structures. To support further safe dose escalation, the uncertainties in the treatment target position will need be minimised using optimal planning and image-guided radiotherapy (IGRT). In particular the increasing usage of profoundly hypo-fractionated stereotactic therapy is predicated on the ability to confidently direct treatment precisely to the intended target for the duration of each treatment. This article reviews published studies on the influences of varies types of motion on daily prostate position and how these may be mitigated to improve IGRT in future. In particular the role that MRI has played in the generation of data is discussed and the potential role of the MR-Linac in next-generation IGRT is discussed.
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Affiliation(s)
- A J McPartlin
- The Christie NHS Foundation Trust and Manchester Cancer Research Centre, University of Manchester, Manchester Academic Health Sciences Centre, UK
| | - X A Li
- Medical College of Wisconsin, USA
| | - L E Kershaw
- The Christie NHS Foundation Trust and Manchester Cancer Research Centre, University of Manchester, Manchester Academic Health Sciences Centre, UK
| | - U Heide
- Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, The Netherlands
| | - L Kerkmeijer
- University Medical Center Utrecht, The Netherlands
| | - C Lawton
- Medical College of Wisconsin, USA
| | - U Mahmood
- MD Anderson Cancer Center, Houston, USA
| | - F Pos
- Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, The Netherlands
| | - N van As
- Royal Marsden Hospital, UK; Institute of Cancer Research, UK
| | - M van Herk
- The Christie NHS Foundation Trust and Manchester Cancer Research Centre, University of Manchester, Manchester Academic Health Sciences Centre, UK
| | - D Vesprini
- Sunnybrook Health Sciences Centre, University of Toronto, Canada
| | | | - A Tree
- Royal Marsden Hospital, UK
| | - A Choudhury
- The Christie NHS Foundation Trust and Manchester Cancer Research Centre, University of Manchester, Manchester Academic Health Sciences Centre, UK.
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Starobinets O, Korn N, Iqbal S, Noworolski SM, Zagoria R, Kurhanewicz J, Westphalen AC. Practical aspects of prostate MRI: hardware and software considerations, protocols, and patient preparation. Abdom Radiol (NY) 2016; 41:817-30. [PMID: 27193785 DOI: 10.1007/s00261-015-0590-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The use of multiparametric MRI scans for the evaluation of men with prostate cancer has increased dramatically and is likely to continue expanding as new developments come to practice. However, it has not yet gained the same level of acceptance of other imaging tests. Partly, this is because of the use of suboptimal protocols, lack of standardization, and inadequate patient preparation. In this manuscript, we describe several practical aspects of prostate MRI that may facilitate the implementation of new prostate imaging programs or the expansion of existing ones.
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Affiliation(s)
- Olga Starobinets
- Graduate Group of Bioengineering, Department of Radiology and Biomedical Imaging, University of California San Francisco, 185 Berry Street, Box 0946, San Francisco, CA, 94143, USA
| | - Natalie Korn
- Graduate Group of Bioengineering, Department of Radiology and Biomedical Imaging, University of California San Francisco, 185 Berry Street, Box 0946, San Francisco, CA, 94143, USA
| | - Sonam Iqbal
- Graduate Group of Bioengineering, Department of Radiology and Biomedical Imaging, University of California San Francisco, 185 Berry Street, Box 0946, San Francisco, CA, 94143, USA
| | - Susan M Noworolski
- Graduate Group of Bioengineering, Department of Radiology and Biomedical Imaging, University of California San Francisco, 185 Berry Street, Box 0946, San Francisco, CA, 94143, USA
| | - Ronald Zagoria
- Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Avenue, M372, Box 0628, San Francisco, CA, 94143, USA
| | - John Kurhanewicz
- Graduate Group of Bioengineering, Department of Radiology and Biomedical Imaging, University of California San Francisco, 1700 4th Street, Ste. 203, San Francisco, CA, 94158, USA
| | - Antonio C Westphalen
- Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Avenue, M372, Box 0628, San Francisco, CA, 94143, USA.
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14
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Falcinelli L, Palumbo I, Radicchia V, Arcidiacono F, Lancellotta V, Montesi G, Matrone F, Zucchetti C, Marcantonini M, Bini V, Aristei C. Prostate cancer: contouring target and organs at risk by kilovoltage and megavoltage CT and MRI in patients with and without hip prostheses. Br J Radiol 2015; 88:20150509. [PMID: 26462970 DOI: 10.1259/bjr.20150509] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
OBJECTIVE In radiotherapy treatment, planning target volume and organs at risk are contoured on kilovoltage CT (kVCT) images. Unlike MR images, kVCT does not provide precise information on target volume extension. Since neither kVCT nor MRI may be suitable for contouring in patients with ferrous hip prostheses, this study evaluated whether megavoltage CT (MVCT) reduced interobserver variability. METHODS Two patients without hip prostheses and one patient (Patient 3) with hip prostheses were enrolled. Six radiation oncologists contoured prostate, rectum and bladder on kVCT (Patients 1 and 3), MRI (Patient 2) and MVCT images (Patient 3). MVCT was acquired with fine, normal and coarse modalities. Interobserver variability for each organ was analysed using conformity index (CI) and coefficient of variation (CV). RESULTS In patients without hip prostheses, CIs were higher in prostate contouring with MRI than with kVCT, indicating lower interobserver variability with MRI. Very slight variations were seen in rectum and bladder contouring. In the patient with hip prostheses (Patient 3), contouring on kVCT lowered CI and increased CV in the prostate, bladder and rectum. The differences were more marked in the prostate. Only fine modality MVCT reduced interobserver variability and only for the prostate. CONCLUSION Even though greater noise and less soft-tissue contrast increase contouring variability with MVCT than with kVCT, lack of artefacts on MVCT could provide better image definition by this modality in hip prosthesis patients in whom MRI is precluded. ADVANCES IN KNOWLEDGE We recommend the fine modality MVCT for contouring hip prostheses patients.
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Affiliation(s)
- Lorenzo Falcinelli
- 1 Department of Onco-Haematological and Gastroenterological Science, Radiation Oncology Division, Perugia General Hospital, Perugia, Italy
| | - Isabella Palumbo
- 2 Radiation Oncology Section, Department of Surgical and Biomedical Sciences, University of Perugia and Perugia General Hospital, Perugia, Italy
| | - Valentina Radicchia
- 2 Radiation Oncology Section, Department of Surgical and Biomedical Sciences, University of Perugia and Perugia General Hospital, Perugia, Italy
| | - Fabio Arcidiacono
- 2 Radiation Oncology Section, Department of Surgical and Biomedical Sciences, University of Perugia and Perugia General Hospital, Perugia, Italy
| | - Valentina Lancellotta
- 2 Radiation Oncology Section, Department of Surgical and Biomedical Sciences, University of Perugia and Perugia General Hospital, Perugia, Italy
| | - Giampaolo Montesi
- 2 Radiation Oncology Section, Department of Surgical and Biomedical Sciences, University of Perugia and Perugia General Hospital, Perugia, Italy
| | - Fabio Matrone
- 2 Radiation Oncology Section, Department of Surgical and Biomedical Sciences, University of Perugia and Perugia General Hospital, Perugia, Italy
| | - Claudio Zucchetti
- 3 Department of Imaging and Laboratory Diagnosis, Medical Physics Unit, Perugia General Hospital, Perugia, Italy
| | - Marta Marcantonini
- 3 Department of Imaging and Laboratory Diagnosis, Medical Physics Unit, Perugia General Hospital, Perugia, Italy
| | - Vittorio Bini
- 4 Internal Medicine, Endocrine and Metabolic Sciences Section, Perugia General Hospital, Perugia, Italy
| | - Cynthia Aristei
- 2 Radiation Oncology Section, Department of Surgical and Biomedical Sciences, University of Perugia and Perugia General Hospital, Perugia, Italy
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15
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Gardner SJ, Wen N, Kim J, Liu C, Pradhan D, Aref I, Cattaneo R, Vance S, Movsas B, Chetty IJ, Elshaikh MA. Contouring variability of human- and deformable-generated contours in radiotherapy for prostate cancer. Phys Med Biol 2015; 60:4429-47. [PMID: 25988718 DOI: 10.1088/0031-9155/60/11/4429] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This study was designed to evaluate contouring variability of human-and deformable-generated contours on planning CT (PCT) and CBCT for ten patients with low-or intermediate-risk prostate cancer. For each patient in this study, five radiation oncologists contoured the prostate, bladder, and rectum, on one PCT dataset and five CBCT datasets. Consensus contours were generated using the STAPLE method in the CERR software package. Observer contours were compared to consensus contour, and contour metrics (Dice coefficient, Hausdorff distance, Contour Distance, Center-of-Mass [COM] Deviation) were calculated. In addition, the first day CBCT was registered to subsequent CBCT fractions (CBCTn: CBCT2-CBCT5) via B-spline Deformable Image Registration (DIR). Contours were transferred from CBCT1 to CBCTn via the deformation field, and contour metrics were calculated through comparison with consensus contours generated from human contour set. The average contour metrics for prostate contours on PCT and CBCT were as follows: Dice coefficient-0.892 (PCT), 0.872 (CBCT-Human), 0.824 (CBCT-Deformed); Hausdorff distance-4.75 mm (PCT), 5.22 mm (CBCT-Human), 5.94 mm (CBCT-Deformed); Contour Distance (overall contour)-1.41 mm (PCT), 1.66 mm (CBCT-Human), 2.30 mm (CBCT-Deformed); COM Deviation-2.01 mm (PCT), 2.78 mm (CBCT-Human), 3.45 mm (CBCT-Deformed). For human contours on PCT and CBCT, the difference in average Dice coefficient between PCT and CBCT (approx. 2%) and Hausdorff distance (approx. 0.5 mm) was small compared to the variation between observers for each patient (standard deviation in Dice coefficient of 5% and Hausdorff distance of 2.0 mm). However, additional contouring variation was found for the deformable-generated contours (approximately 5.0% decrease in Dice coefficient and 0.7 mm increase in Hausdorff distance relative to human-generated contours on CBCT). Though deformable contours provide a reasonable starting point for contouring on CBCT, we conclude that contours generated with B-Spline DIR require physician review and editing if they are to be used in the clinic.
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Affiliation(s)
- Stephen J Gardner
- Department of Radiation Oncology, Josephine Ford Cancer Institute, Henry Ford Health System, Detroit, MI 48202, USA
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16
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Dirix P, Haustermans K, Vandecaveye V. The value of magnetic resonance imaging for radiotherapy planning. Semin Radiat Oncol 2015; 24:151-9. [PMID: 24931085 DOI: 10.1016/j.semradonc.2014.02.003] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The success of highly conformal radiotherapy techniques in the sparing of normal tissues or in dose escalation, or both, relies heavily on excellent imaging. Because of its superior soft tissue contrast, magnetic resonance imaging is increasingly being used in radiotherapy treatment planning. This review discusses the current clinical evidence to support the pivotal role of magnetic resonance imaging in radiation oncology.
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Affiliation(s)
- Piet Dirix
- Department of Radiation Oncology, Leuvens Kankerinstituut (LKI), University Hospitals Leuven, Leuven, Belgium; Department of Radiology, Leuvens Kankerinstituut (LKI), University Hospitals Leuven, Leuven, Belgium.
| | - Karin Haustermans
- Department of Radiation Oncology, Leuvens Kankerinstituut (LKI), University Hospitals Leuven, Leuven, Belgium; Department of Oncology, KU Leuven, Leuven, Belgium
| | - Vincent Vandecaveye
- Department of Radiology, Leuvens Kankerinstituut (LKI), University Hospitals Leuven, Leuven, Belgium; Department of Imaging & Pathology, KU Leuven, Leuven, Belgium
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17
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Chapman D, Smith S, Barnett R, Bauman G, Yartsev S. Optimization of tomotherapy treatment planning for patients with bilateral hip prostheses. Radiat Oncol 2014; 9:43. [PMID: 24491230 PMCID: PMC3922545 DOI: 10.1186/1748-717x-9-43] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Accepted: 02/02/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND To determine the effect of different imaging options and the most efficient imaging strategy for treatment planning of patients with hip prostheses. METHODS The planning kilovoltage CT (kVCT) and daily megavoltage CT (MVCT) studies for three prostate cancer patients with bilateral hip prostheses were used for creating hybrid kVCT/MVCT image sets. Treatment plans were created for kVCT images alone, hybrid kVCT/MVCT images, and MVCT images alone using the same dose prescription and planning parameters. The resulting dose volume histograms were compared. The orthopedic metal artifact reduction (O-MAR) reconstruction tool for kVCT images and different MVCT options were investigated with a water tank fit with double hip prostheses. Treatment plans were created for all imaging options and calculated dose was compared with the one measured by a pin-point ion chamber. RESULTS On average for three patients, the D35% for the bladder was 8% higher in plans based on MVCT images and 7% higher in plans based on hybrid images, compared to the plans based on kVCT images alone. Likewise, the D35% for the rectum was 3% higher than the kVCT based plan for both hybrid and MVCT plans. The average difference in planned D99% in the PTV compared to kVCT plans was 0.9% and 0.1% for MVCT and hybrid plans, respectively. For the water tank with hip prostheses phantom, the kVCT plan with O-MAR correction applied showed better agreement between the measured and calculated dose than the original image set, with a difference of -1.9% compared to 3.3%. The measured doses for the MVCT plans were lower than the calculated dose due to image size limitations. The best agreement was for the kVCT/MVCT hybrid plans with the difference between calculated and measured dose around 1%. CONCLUSION MVCT image provides better visualization of patient anatomy and hybrid kVCT/MVCT study enables more accurate calculations using updated MVCT relative electron density calibration.
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Affiliation(s)
| | | | | | | | - Slav Yartsev
- London Regional Cancer Program, London Health Sciences Centre, 790 Commissioners Road East, London, ON N6A 4L6, Canada.
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18
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Prospective multi-center dosimetry study of low-dose Iodine-125 prostate brachytherapy performed after transurethral resection. J Contemp Brachytherapy 2013; 5:63-9. [PMID: 23878549 PMCID: PMC3708148 DOI: 10.5114/jcb.2013.36174] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Revised: 06/05/2013] [Accepted: 06/25/2013] [Indexed: 11/17/2022] Open
Abstract
Purpose To evaluate in a multicenter setting the ability of centers to perform pre-implant permanent prostate brachytherapy planning, fulfilling dosimetric goals and constraints based on the Groupe de Curiethérapie-European Society for Radiotherapy and Oncology guidelines in the setting of implantation after prior prostate transurethral resection (TURP). Material and methods A reference transrectal ultrasound image set of the prostate gland from a patient who had undergone TURP was used. Contouring of the prostate, clinical target volume and organs at risk was performed by the coordinating center. Goals and constraints regarding the dosimetry were defined. Results Seventeen of twenty-five centers invited to participate were able to import the Digital Imaging and Communications in Medicine-images into their planning computer and plan the implant using the defined guidelines. All centers were able to plan treatment, and achieve the recommended objectives and constraints. However, sector analysis has shown a risk of under-dosage in the anterior part of the prostate. Conclusions Correct pre-implantation planning with adherence to protocol guidelines and in compliance with defined dosimetric constraints seems feasible in a post-TURP setting, at least on a theoretical basis. A prospective study evaluating the outcome of prostate brachytherapy performed after TURP can therefore be undertaken with an expectation of a correct dosimetry in the multicenter setting.
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Metcalfe P, Liney GP, Holloway L, Walker A, Barton M, Delaney GP, Vinod S, Tome W. The potential for an enhanced role for MRI in radiation-therapy treatment planning. Technol Cancer Res Treat 2013; 12:429-46. [PMID: 23617289 PMCID: PMC4527434 DOI: 10.7785/tcrt.2012.500342] [Citation(s) in RCA: 138] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The exquisite soft-tissue contrast of magnetic resonance imaging (MRI) has meant that the technique is having an increasing role in contouring the gross tumor volume (GTV) and organs at risk (OAR) in radiation therapy treatment planning systems (TPS). MRI-planning scans from diagnostic MRI scanners are currently incorporated into the planning process by being registered to CT data. The soft-tissue data from the MRI provides target outline guidance and the CT provides a solid geometric and electron density map for accurate dose calculation on the TPS computer. There is increasing interest in MRI machine placement in radiotherapy clinics as an adjunct to CT simulators. Most vendors now offer 70 cm bores with flat couch inserts and specialised RF coil designs. We would refer to these devices as MR-simulators. There is also research into the future application of MR-simulators independent of CT and as in-room image-guidance devices. It is within the background of this increased interest in the utility of MRI in radiotherapy treatment planning that this paper is couched. The paper outlines publications that deal with standard MRI sequences used in current clinical practice. It then discusses the potential for using processed functional diffusion maps (fDM) derived from diffusion weighted image sequences in tracking tumor activity and tumor recurrence. Next, this paper reviews publications that describe the use of MRI in patient-management applications that may, in turn, be relevant to radiotherapy treatment planning. The review briefly discusses the concepts behind functional techniques such as dynamic contrast enhanced (DCE), diffusion-weighted (DW) MRI sequences and magnetic resonance spectroscopic imaging (MRSI). Significant applications of MR are discussed in terms of the following treatment sites: brain, head and neck, breast, lung, prostate and cervix. While not yet routine, the use of apparent diffusion coefficient (ADC) map analysis indicates an exciting future application for functional MRI. Although DW-MRI has not yet been routinely used in boost adaptive techniques, it is being assessed in cohort studies for sub-volume boosting in prostate tumors.
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Affiliation(s)
- P Metcalfe
- Centre for Medical Radiation Physics, University of Wollongong, NSW, Australia.
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20
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Abstract
Over the last two decades, the computed tomography simulator became the standard of the contemporary radiotherapy treatment planning (RTP) process. Along the same time, the superb soft tissue contrast of magnetic resonance imaging (MRI) was widely incorporated into RTP through the process of image coregistration. This review summarizes the efforts of incorporation of MRI data into target definition process for RTP based on gained clinical evidence so far and opens a question whether the time is up for bringing a MRI-simulator as an additional standard imaging tool into radiation oncology departments.
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Affiliation(s)
- Slobodan Devic
- Department of Radiation Oncology, Jewish General Hospital, McGill University, Montréal, Québec, Canada.
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21
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Martin DA, Hruby G, Whitaker MK, Foo KYM. Constrained-beam inverse planning for intensity-modulated radiation therapy of prostate cancer patients with bilateral hip prostheses. J Med Imaging Radiat Oncol 2012; 56:703-7. [PMID: 23210592 DOI: 10.1111/j.1754-9485.2012.02456.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Accepted: 06/03/2012] [Indexed: 11/29/2022]
Abstract
Hip prostheses present a technical challenge in the planning of curative external beam radiation treatment for patients with prostate cancer. Bilateral prostheses compel planners to compromise between target coverage and avoidance of beam entry through the prostheses. Inverse planning systems given objectives to avoid dose to prostheses are overly restricted from allowing exit dose to them. We report a novel inverse planning technique for intensity-modulated radiation therapy of patients with prostate cancer and bilateral hip prostheses, by constraining beam characteristics rather than dose in the inverse planning process.
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Affiliation(s)
- Darren A Martin
- Department of Radiation Oncology, Royal Prince Alfred Hospital, Camperdown, Australia.
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22
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Prostate Contouring Variation: Can It Be Fixed? Int J Radiat Oncol Biol Phys 2012; 82:1923-9. [DOI: 10.1016/j.ijrobp.2011.02.050] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2010] [Revised: 02/16/2011] [Accepted: 02/22/2011] [Indexed: 11/21/2022]
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23
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Tzikas A, Karaiskos P, Papanikolaou N, Sandilos P, Koutsouveli E, Lavdas E, Scarleas C, Dardoufas K, Lind BK, Mavroidis P. Investigating the Clinical Aspects of Using CT vs. CT-MRI Images during Organ Delineation and Treatment Planning in Prostate Cancer Radiotherapy. Technol Cancer Res Treat 2011; 10:231-42. [DOI: 10.7785/tcrt.2012.500198] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
In order to apply highly conformal dose distributions, which are characterized by steep dose fall-offs, it is necessary to know the exact target location and extension. This study aims at evaluating the impact of using combined CT-MRI images in organ delineation compared to using CT images alone, on the clinical results. For 10 prostate cancer patients, the respective CT and MRI images at treatment position were acquired. The CTV was delineated using the CT and MRI images, separately, whereas bladder and rectum were delineated using the CT images alone. Based on the CT and MRI images, two CTVs were produced for each patient. The mutual information algorithm was used in the fusion of the two image sets. In this way, the structures drawn on the MRI images were transferred to the CT images in order to produce the treatment plans. For each set of structures of each patient, IMRT and 3D-CRT treatment plans were produced. The individual treatment plans were compared using the biologically effective uniform dose ([Formula: see text]) and the complication-free tumor control probability ( P+) concepts together with the DVHs of the targets and organs at risk and common dosimetric criteria. For the IMRT treatment, at the optimum dose level of the average CT and CT-MRI delineated CTV dose distributions, the P+ values are 74.7% in both cases for a [Formula: see text] of 91.5 Gy and 92.1 Gy, respectively. The respective average total control probabilities, PB are 90.0% and 90.2%, whereas the corresponding average total complication probabilities, PI are 15.3% and 15.4%. Similarly, for the 3D-CRT treatment, the average P+ values are 42.5% and 46.7%, respectively for a [Formula: see text] of 86.4 Gy and 86.7 Gy, respectively. The respective average PB values are 80.0% and 80.6%, whereas the corresponding average PI values are 37.4% and 33.8%, respectively. For both radiation modalities, the improvement mainly stems from the better sparing of rectum. According to these results, the expected clinical effectiveness of IMRT can be increased by a maximum Δ P+ of around 0.9%, whereas of 3D-CRT by about 4.2% when combined CT-MRI delineation is performed instead of using CT images alone. It is apparent that in both IMRT and 3D-CRT radiation modalities, the better knowledge of the CTV extension improved the produced dose distribution. It is shown that the CTV is irradiated more effectively, while the complication probabilities of bladder and rectum, which is the principal organs at risk, are lower in the CT-MRI based treatment plans.
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Affiliation(s)
- A. Tzikas
- Department of Medical Radiation Physics, Karolinska Institutet and Stockholm University, Sweden
| | - P. Karaiskos
- Department of Radiotherapy and Medical Physics, Hygeia Hospital, Athens, Greece
- Department of Medical Physics, Medical School, University of Athens, Athens, Greece
| | - N. Papanikolaou
- Department of Radiological Sciences, University of Texas Health Science Center, San Antonio, Texas, USA
| | - P. Sandilos
- Department of Radiotherapy and Medical Physics, Hygeia Hospital, Athens, Greece
- Department of Radiology, Areteion University Hospital, Athens, Greece
| | - E. Koutsouveli
- Department of Radiotherapy and Medical Physics, Hygeia Hospital, Athens, Greece
| | - E. Lavdas
- Department of Radiology, Larissa University Hospital, Larissa, Greece
| | - C. Scarleas
- Department of Radiotherapy and Medical Physics, Hygeia Hospital, Athens, Greece
| | - K. Dardoufas
- Department of Radiotherapy and Medical Physics, Hygeia Hospital, Athens, Greece
- Department of Radiology, Areteion University Hospital, Athens, Greece
| | - B. K. Lind
- Department of Medical Radiation Physics, Karolinska Institutet and Stockholm University, Sweden
| | - P. Mavroidis
- Department of Medical Radiation Physics, Karolinska Institutet and Stockholm University, Sweden
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Jameson MG, Holloway LC, Vial PJ, Vinod SK, Metcalfe PE. A review of methods of analysis in contouring studies for radiation oncology. J Med Imaging Radiat Oncol 2011; 54:401-10. [PMID: 20958937 DOI: 10.1111/j.1754-9485.2010.02192.x] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Inter-observer variability in anatomical contouring is the biggest contributor to uncertainty in radiation treatment planning. Contouring studies are frequently performed to investigate the differences between multiple contours on common datasets. There is, however, no widely accepted method for contour comparisons. The purpose of this study is to review the literature on contouring studies in the context of radiation oncology, with particular consideration of the contouring comparison methods they employ. A literature search, not limited by date, was conducted using Medline and Google Scholar with key words: contour, variation, delineation, inter/intra observer, uncertainty and trial dummy-run. This review includes a description of the contouring processes and contour comparison metrics used. The use of different processes and metrics according to tumour site and other factors were also investigated with limitations described. A total of 69 relevant studies were identified. The most common tumour sites were prostate (26), lung (10), head and neck cancers (8) and breast (7).The most common metric of comparison was volume used 59 times, followed by dimension and shape used 36 times, and centre of volume used 19 times. Of all 69 publications, 67 used a combination of metrics and two used only one metric for comparison. No clear relationships between tumour site or any other factors that may influence the contouring process and the metrics used to compare contours were observed from the literature. Further studies are needed to assess the advantages and disadvantages of each metric in various situations.
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Affiliation(s)
- Michael G Jameson
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia.
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Hayden AJ, Martin JM, Kneebone AB, Lehman M, Wiltshire KL, Skala M, Christie D, Vial P, McDowall R, Tai KH. Australian & New Zealand Faculty of Radiation Oncology Genito-Urinary Group: 2010 consensus guidelines for definitive external beam radiotherapy for prostate carcinoma. J Med Imaging Radiat Oncol 2010; 54:513-25. [DOI: 10.1111/j.1754-9485.2010.02214.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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26
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Baumann M, Hölscher T, Denham J. Fractionation in prostate cancer – Is it time after all? Radiother Oncol 2010; 96:1-5. [DOI: 10.1016/j.radonc.2010.06.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2010] [Accepted: 06/02/2010] [Indexed: 01/08/2023]
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27
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Thwaites DI, Verellen D. Vorsprung durch Technik: evolution, implementation, QA and safety of new technology in radiotherapy. Radiother Oncol 2010; 94:125-8. [PMID: 20170973 DOI: 10.1016/j.radonc.2010.02.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2010] [Accepted: 02/09/2010] [Indexed: 11/18/2022]
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