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Milgrom SA, Dandapani SV, Wong J, Kalapurakal J, Smith KS, Han C, Simiele E, Hua CH, Fitzgerald TJ, Kry S, Wong K, Symons H, Kovalchuk N, Hiniker SM. Incorporating intensity modulated total body irradiation into a Children's Oncology Group trial: Rationale, techniques, and safeguards. Pediatr Blood Cancer 2024:e31185. [PMID: 39118225 DOI: 10.1002/pbc.31185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Revised: 06/21/2024] [Accepted: 06/22/2024] [Indexed: 08/10/2024]
Abstract
Historically, total body irradiation (TBI) has been delivered using static, parallel opposed photon beams (2D-TBI). Recently, centers have increasingly used intensity-modulated radiation therapy (IMRT) techniques for TBI. Relative to 2D-TBI, IMRT can reduce doses to critical organs (i.e., lungs and kidneys) while delivering myeloablative doses to the rest of the body, so it may decrease the risk of toxicity while maintaining oncologic outcomes. Despite these potential benefits, delivering TBI using IMRT introduces new challenges in treatment planning and delivery. We describe the extensive experience with IMRT-based TBI at Stanford University and City of Hope Cancer Center. These groups, and others, have reported favorable clinical outcomes and have developed methods to optimize treatment planning and delivery. A critical next step is to evaluate the broader adoption of this approach. Therefore, IMRT-based TBI will be incorporated into a prospective, multi-institutional Children's Oncology Group study with careful procedures and safeguards in place.
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Affiliation(s)
- Sarah A Milgrom
- Department of Radiation Oncology, University of Colorado, Aurora, Colorado, USA
| | | | - Jeffrey Wong
- Department of Radiation Oncology, City of Hope, Duarte, California, USA
| | - John Kalapurakal
- Department of Radiation Oncology, Northwestern Medicine, Chicago, Illinois, USA
| | - Koren S Smith
- Department of Radiation Oncology, Imaging and Radiation Oncology Core-Rhode Island, UMass Chan Medical School, Lincoln, Rhode Island, USA
| | - Chunhui Han
- Department of Radiation Oncology, City of Hope, Duarte, California, USA
| | - Eric Simiele
- Department of Radiation Oncology, Stanford University, Palo Alto, California, USA
| | - Chia-Ho Hua
- Department of Radiation Oncology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Thomas J Fitzgerald
- Department of Radiation Oncology, Imaging and Radiation Oncology Core-Rhode Island, UMass Chan Medical School, Lincoln, Rhode Island, USA
| | - Stephen Kry
- Division of Radiation Oncology, MD Anderson Cancer Center, Houston, Texas, USA
| | - Kenneth Wong
- Department of Radiation Oncology, University of Southern California, Los Angeles, California, USA
| | - Heather Symons
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins University, Baltimore, Maryland, USA
| | - Nataliya Kovalchuk
- Department of Radiation Oncology, Stanford University, Palo Alto, California, USA
| | - Susan M Hiniker
- Department of Radiation Oncology, Stanford University, Palo Alto, California, USA
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Seravalli E, Bosman ME, Han C, Losert C, Pazos M, Engström PE, Engellau J, Fulcheri CPL, Zucchetti C, Saldi S, Ferrer C, Ocanto A, Hiniker SM, Clark CH, Hussein M, Misson-Yates S, Kobyzeva DA, Loginova AA, Hoeben BAW. Technical recommendations for implementation of Volumetric Modulated Arc Therapy and Helical Tomotherapy Total Body Irradiation. Radiother Oncol 2024; 197:110366. [PMID: 38830537 DOI: 10.1016/j.radonc.2024.110366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 05/10/2024] [Accepted: 05/27/2024] [Indexed: 06/05/2024]
Abstract
As a component of myeloablative conditioning before allogeneic hematopoietic stem cell transplantation (HSCT), Total Body Irradiation (TBI) is employed in radiotherapy centers all over the world. In recent and coming years, many centers are changing their technical setup from a conventional TBI technique to multi-isocenter conformal arc therapy techniques such as Volumetric Modulated Arc Therapy (VMAT) or Helical Tomotherapy (HT). These techniques allow better homogeneity and control of the target prescription dose, and provide more freedom for individualized organ-at-risk sparing. The technical design of multi-isocenter/multi-plan conformal TBI is complex and should be developed carefully. A group of early adopters with conformal TBI experience using different treatment machines and treatment planning systems came together to develop technical recommendations and share experiences, in order to assist departments wishing to implement conformal TBI, and to provide ideas for standardization of practices.
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Affiliation(s)
- Enrica Seravalli
- Department of Radiation Oncology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Mirjam E Bosman
- Department of Radiation Oncology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Chunhui Han
- Department of Radiation Oncology, City of Hope National Medical Center, Duarte, CA, USA
| | - Christoph Losert
- Department of Radiation Oncology, University Hospital, LMU Munich, Germany
| | - Montserrat Pazos
- Department of Radiation Oncology, University Hospital, LMU Munich, Germany
| | - Per E Engström
- Department of Haematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden
| | - Jacob Engellau
- Department of Radiation Oncology, Skåne University Hospital, Lund, Sweden
| | | | - Claudio Zucchetti
- Section of Medical Physics, Perugia General Hospital, Perugia, Italy
| | - Simonetta Saldi
- Section of Radiation Oncology, Perugia General Hospital, Perugia, Italy
| | - Carlos Ferrer
- Department of Medical Physics and Radiation Protection, La Paz University Hospital, Madrid, Spain
| | - Abrahams Ocanto
- Department of Radiation Oncology, San Francisco de Asís University Hospital, GenesisCare, Madrid, Spain
| | - Susan M Hiniker
- Department of Radiation Oncology, Stanford University, Stanford, CA, USA
| | - Catharine H Clark
- Radiotherapy Physics, National Radiotherapy Trials Quality Assurance Group (RTTQA), Mount Vernon Cancer Centre, Northwood, UK; Metrology for Medical Physics Centre, National Physical Laboratory, Teddington, UK; Radiotherapy Physics, University College London Hospitals NHS Foundation Trust, London, UK; Medical Physics and Bioengineering Department, University College London, London, UK
| | - Mohammad Hussein
- Metrology for Medical Physics Centre, National Physical Laboratory, Teddington, UK
| | - Sarah Misson-Yates
- Medical Physics Department, Guy's and St Thomas' Hospital, London, UK; UK School of Biomedical Engineering & Imaging Sciences, King's College London, London, UK; National Physical Laboratory, Metrology for Medical Physics Centre, London, UK
| | - Daria A Kobyzeva
- Deptartment of Radiation Oncology, Dmitry Rogachev National Research Center of Pediatric Hematology, Oncology and Immunology, Moscow, Russia
| | - Anna A Loginova
- Deptartment of Radiation Oncology, Dmitry Rogachev National Research Center of Pediatric Hematology, Oncology and Immunology, Moscow, Russia
| | - Bianca A W Hoeben
- Department of Radiation Oncology, University Medical Center Utrecht, Utrecht, the Netherlands; Princess Máxima Center for Pediatric Oncology, Utrecht, the Netherlands.
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Burckbuchler T, Dehaynin N, Niederst C, Bartolucci L, Elazhar H, Jarnet D, Arbor F, Meyer P. Influence of the Planning Parameters of a New Algorithm on the Dosimetric Quality, Beam-On Time and Delivery Accuracy of Tomotherapy Plans. Cancers (Basel) 2024; 16:1883. [PMID: 38791961 PMCID: PMC11119142 DOI: 10.3390/cancers16101883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 05/06/2024] [Accepted: 05/13/2024] [Indexed: 05/26/2024] Open
Abstract
BACKGROUND This work aimed to determine the optimum VOLOTM Ultra algorithm parameters for tomotherapy treatments. METHODS 1056 treatment plans were generated with VOLOTM Ultra for 36 patients and six anatomical locations. The impact of varying four parameters was studied: the accelerated treatment (AT), leaf open/close time (LOT) cutoff, normal tissue objective (NTO) weight, and number of iterations. The beam-on time and dosimetric metrics were quantified for the target volumes and organs at risk (OARs). Delivery quality assurance measurements were obtained for 36 plans to assess the delivery accuracy. RESULTS The mean beam-on time for the helical tomotherapy and TomoDirect (TD) plans decreased by 26.6 ± 2.8% and 17.4 ± 4.3%, respectively, when the accelerated treatment parameter was increased from 0 to 10, at the expense of the planning target volume (PTV) coverage (2% lower D98%) and OAR dose (up to 15% increase). For TD plans, it seems preferable to systematically use an AT value of 10. Increasing the number of iterations beyond six seems unnecessary. In this study, an NTO weight of approximately 10 appears to be ideal and eliminates the need to use rings in the treatment plan. Finally, no correlation was found between the leaf open/close time cutoff and the delivery accuracy, while a leaf open/close cutoff of 60 ms seemed to degrade dosimetry quality. CONCLUSION Optimal values for the AT, LOT cutoff, NTO weight, and number of optimization rounds were identified and should help improve the management of patients whose tomotherapy treatments are planned with VOLOTM Ultra.
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Affiliation(s)
- Théo Burckbuchler
- Medical Physics Unit, Institut de Cancerologie de Strasbourg (ICANS), 17 Rue Albert Calmette, 67200 Strasbourg, France
| | - Nicolas Dehaynin
- Medical Physics Unit, Institut de Cancerologie de Strasbourg (ICANS), 17 Rue Albert Calmette, 67200 Strasbourg, France
| | - Claudine Niederst
- Medical Physics Unit, Institut de Cancerologie de Strasbourg (ICANS), 17 Rue Albert Calmette, 67200 Strasbourg, France
| | - Laurent Bartolucci
- Medical Physics Unit, Institut de Cancerologie de Strasbourg (ICANS), 17 Rue Albert Calmette, 67200 Strasbourg, France
| | - Halima Elazhar
- Medical Physics Unit, Institut de Cancerologie de Strasbourg (ICANS), 17 Rue Albert Calmette, 67200 Strasbourg, France
| | - Delphine Jarnet
- Medical Physics Unit, Institut de Cancerologie de Strasbourg (ICANS), 17 Rue Albert Calmette, 67200 Strasbourg, France
| | - Florence Arbor
- Medical Physics Unit, Institut de Cancerologie de Strasbourg (ICANS), 17 Rue Albert Calmette, 67200 Strasbourg, France
| | - Philippe Meyer
- Medical Physics Unit, Institut de Cancerologie de Strasbourg (ICANS), 17 Rue Albert Calmette, 67200 Strasbourg, France
- Team IMAGeS, ICUBE Laboratory, University of Strasbourg, CNRS, UMR 7357, 67412 Illkirch, France
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Marrazzo L, Redapi L, Pellegrini R, Voet P, Meattini I, Arilli C, Calusi S, Casati M, Chilà D, Compagnucci A, Talamonti C, Zani M, Livi L, Pallotta S. Fully automated volumetric modulated arc therapy technique for radiation therapy of locally advanced breast cancer. Radiat Oncol 2023; 18:176. [PMID: 37904150 PMCID: PMC10617151 DOI: 10.1186/s13014-023-02364-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 10/17/2023] [Indexed: 11/01/2023] Open
Abstract
BACKGROUND This study aimed to evaluate an a-priori multicriteria plan optimization algorithm (mCycle) for locally advanced breast cancer radiation therapy (RT) by comparing automatically generated VMAT (Volumetric Modulated Arc Therapy) plans (AP-VMAT) with manual clinical Helical Tomotherapy (HT) plans. METHODS The study included 25 patients who received postoperative RT using HT. The patient cohort had diverse target selections, including both left and right breast/chest wall (CW) and III-IV node, with or without internal mammary node (IMN) and Simultaneous Integrated Boost (SIB). The Planning Target Volume (PTV) was obtained by applying a 5 mm isotropic expansion to the CTV (Clinical Target Volume), with a 5 mm clip from the skin. Comparisons of dosimetric parameters and delivery/planning times were conducted. Dosimetric verification of the AP-VMAT plans was performed. RESULTS The study showed statistically significant improvements in AP-VMAT plans compared to HT for OARs (Organs At Risk) mean dose, except for the heart and ipsilateral lung. No significant differences in V95% were observed for PTV breast/CW and PTV III-IV, while increased coverage (higher V95%) was seen for PTV IMN in AP-VMAT plans. HT plans exhibited smaller values of PTV V105% for breast/CW and III-IV, with no differences in PTV IMN and boost. HT had an average (± standard deviation) delivery time of (17 ± 8) minutes, while AP-VMAT took (3 ± 1) minutes. The average γ passing rate for AP-VMAT plans was 97%±1%. Planning times reduced from an average of 6 h for HT to about 2 min for AP-VMAT. CONCLUSIONS Comparing AP-VMAT plans with clinical HT plans showed similar or improved quality. The implementation of mCycle demonstrated successful automation of the planning process for VMAT treatment of locally advanced breast cancer, significantly reducing workload.
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Affiliation(s)
- Livia Marrazzo
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, Florence, Italy.
- Medical Physics Unit, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy.
| | - Laura Redapi
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, Florence, Italy
- Medical Physics Unit, Azienda USL Toscana Centro, Pistoia-Prato, Italy
| | - Roberto Pellegrini
- Medical Affairs & Research Clinical Liaison, Elekta AB, Stockholm, Sweden
| | - Peter Voet
- Medical Affairs & Research Clinical Liaison, Elekta AB, Stockholm, Sweden
| | - Icro Meattini
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, Florence, Italy
- Radiation Oncology Unit, Oncology Department, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
| | - Chiara Arilli
- Medical Physics Unit, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
| | - Silvia Calusi
- Medical Physics Unit, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
| | - Marta Casati
- Medical Physics Unit, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
| | - Deborah Chilà
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, Florence, Italy
| | | | - Cinzia Talamonti
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, Florence, Italy
- Medical Physics Unit, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
| | - Margherita Zani
- Medical Physics Unit, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
| | - Lorenzo Livi
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, Florence, Italy
- Radiation Oncology Unit, Oncology Department, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
| | - Stefania Pallotta
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, Florence, Italy
- Medical Physics Unit, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
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Chen Q, Rong Y, Burmeister JW, Chao EH, Corradini NA, Followill DS, Li XA, Liu A, Qi XS, Shi H, Smilowitz JB. AAPM Task Group Report 306: Quality control and assurance for tomotherapy: An update to Task Group Report 148. Med Phys 2023; 50:e25-e52. [PMID: 36512742 DOI: 10.1002/mp.16150] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 09/22/2022] [Accepted: 11/28/2022] [Indexed: 12/15/2022] Open
Abstract
Since the publication of AAPM Task Group (TG) 148 on quality assurance (QA) for helical tomotherapy, there have been many new developments on the tomotherapy platform involving treatment delivery, on-board imaging options, motion management, and treatment planning systems (TPSs). In response to a need for guidance on quality control (QC) and QA for these technologies, the AAPM Therapy Physics Committee commissioned TG 306 to review these changes and make recommendations related to these technology updates. The specific objectives of this TG were (1) to update, as needed, recommendations on tolerance limits, frequencies and QC/QA testing methodology in TG 148, (2) address the commissioning and necessary QA checks, as a supplement to Medical Physics Practice Guidelines (MPPG) with respect to tomotherapy TPS and (3) to provide risk-based recommendations on the new technology implemented clinically and treatment delivery workflow. Detailed recommendations on QA tests and their tolerance levels are provided for dynamic jaws, binary multileaf collimators, and Synchrony motion management. A subset of TPS commissioning and QA checks in MPPG 5.a. applicable to tomotherapy are recommended. In addition, failure mode and effects analysis has been conducted among TG members to obtain multi-institutional analysis on tomotherapy-related failure modes and their effect ranking.
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Affiliation(s)
- Quan Chen
- Radiation Oncology, City of Hope Medical Center, Duarte, California, USA
| | - Yi Rong
- Department of Radiation Oncology, Mayo Clinic Hospitals, Phoenix, Arizona, USA
| | - Jay W Burmeister
- Karmanos Cancer Center, Gershenson R.O.C., Detroit, Michigan, USA
- Department of Oncology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | | | | | - David S Followill
- Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - X Allen Li
- Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - An Liu
- Radiation Oncology, City of Hope Medical Center, Duarte, California, USA
| | - X Sharon Qi
- Radiation Oncology, UCLA School of Medicine, Los Angeles, California, USA
| | - Hairong Shi
- Radiation Oncology, Oklahoma Cancer Specialists and Research Institute, Tulsa, Oklahoma, USA
| | - Jennifer B Smilowitz
- Human Oncology and Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin, USA
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Ju SG, Ahn YC, Kim YB, Kim JM, Kwon DY, Park BS, Yang K. Dosimetric comparison between VMAT plans using the fast-rotating O-ring linac with dual-layer stacked MLC and helical tomotherapy for nasopharyngeal carcinoma. Radiat Oncol 2022; 17:155. [PMID: 36096874 PMCID: PMC9465858 DOI: 10.1186/s13014-022-02124-0] [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: 03/29/2022] [Accepted: 08/30/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND To compare the dosimetric profiles of volumetric modulated arc therapy (VMAT) plans using the fast-rotating O-ring linac (the Halcyon system) based on a dual-layer stacked multi-leaf collimator and helical tomotherapy (HT) for nasopharyngeal cancer (NPCa). METHODS For 30 NPCa patients, three sets of RT plans were generated, under the same policy of contouring and dose constraints: HT plan; Halcyon VMAT plan with two arcs (HL2arc); and Halcyon VMAT plan with four arcs (HL4arc), respectively. The intended dose schedule was to deliver 67.2 Gy to the planning gross target volume (P-GTV) and 56.0 Gy to the planning clinical target volume (P-CTV) in 28 fractions using the simultaneously integrated boost concept. Target volumes and organ at risks dose metrics were evaluated for all plans. Normal tissue complication probabilities (NTCP) for esophagus, parotid glands, spinal cord, and brain stem were compared. RESULTS The HT plan achieved the best dose homogeneity index for both P_GTV and P_CTV, followed by the HL4arc and L2arc plans. No significant difference in the dose conformity index (CI) for P_GTV was observed between the HT plan (0.80) and either the HL2arc plan (0.79) or the HL4arc plan (0.83). The HL4arc plan showed the best CI for P_CTV (0.88), followed by the HL2arc plan (0.83) and the HT plan (0.80). The HL4arc plan (median, interquartile rage (Q1, Q3): 25.36 (22.22, 26.89) Gy) showed the lowest Dmean in the parotid glands, followed by the HT (25.88 (23.87, 27.87) Gy) and HL2arc plans (28.00 (23.24, 33.99) Gy). In the oral cavity (OC) dose comparison, the HT (22.03 (19.79, 24.85) Gy) plan showed the lowest Dmean compared to the HL2arc (23.96 (20.84, 28.02) Gy) and HL4arc (24.14 (20.17, 27.53) Gy) plans. Intermediate and low dose regions (40-65% of the prescribed dose) were well fit to the target volume in HL4arc, compared to the HT and HL2arc plans. All plans met the dose constraints for the other OARs with sufficient dose margins. The between-group differences in the median NTCP values for the parotid glands and OC were < 3.47% and < 1.7% points, respectively. CONCLUSIONS The dosimetric profiles of Halcyon VMAT plans were comparable to that of HT, and HL4arc showed better dosimetric profiles than HL2arc for NPCa.
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Affiliation(s)
- Sang Gyu Ju
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-Ro 81, Gangnam-Gu, Seoul, 06351, Republic of Korea
| | - Yong Chan Ahn
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-Ro 81, Gangnam-Gu, Seoul, 06351, Republic of Korea.
| | - Yeong-Bi Kim
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-Ro 81, Gangnam-Gu, Seoul, 06351, Republic of Korea
| | - Jin Man Kim
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-Ro 81, Gangnam-Gu, Seoul, 06351, Republic of Korea
| | - Dong Yeol Kwon
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-Ro 81, Gangnam-Gu, Seoul, 06351, Republic of Korea
| | - Byoung Suk Park
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-Ro 81, Gangnam-Gu, Seoul, 06351, Republic of Korea
| | - Kyungmi Yang
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-Ro 81, Gangnam-Gu, Seoul, 06351, Republic of Korea
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Loginova AA, Tovmasian DA, Lisovskaya AO, Kobyzeva DA, Maschan MA, Chernyaev AP, Egorov OB, Nechesnyuk AV. Optimized Conformal Total Body Irradiation methods with Helical TomoTherapy and Elekta VMAT: Implementation, Imaging, Planning and Dose Delivery for Pediatric Patients. Front Oncol 2022; 12:785917. [PMID: 35359412 PMCID: PMC8960917 DOI: 10.3389/fonc.2022.785917] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 02/10/2022] [Indexed: 11/13/2022] Open
Abstract
Optimized conformal total body irradiation (OC-TBI) is a highly conformal image guided method for irradiating the whole human body while sparing the selected organs at risk (OARs) (lungs, kidneys, lens). This study investigated the safety and feasibility of pediatric OC-TBI with the helical TomoTherapy (TomoTherapy) and volumetric modulated arc (VMAT) modalities and their implementation in routine clinical practice. This is the first study comparing the TomoTherapy and VMAT modalities in terms of treatment planning, dose delivery accuracy, and toxicity for OC-TBI in a single-center setting. The OC-TBI method with standardized dosimetric criteria was developed and implemented with TomoTherapy. The same OC-TBI approach was applied for VMAT. Standardized treatment steps, namely, positioning and immobilization, contouring, treatment planning strategy, plan evaluation, quality assurance, visualization and treatment delivery procedure were implemented for 157 patients treated with TomoTherapy and 52 patients treated with VMAT. Both modalities showed acceptable quality of the planned target volume dose coverage with simultaneous OARs sparing. The homogeneity of target irradiation was superior for TomoTherapy. Overall assessment of the OC-TBI dose delivery was performed for 30 patients treated with VMAT and 30 patients treated with TomoTherapy. The planned and delivered (sum of doses for all fractions) doses were compared for the two modalities in groups of patients with different heights. The near maximum dose values of the lungs and kidneys showed the most significant variation between the planned and delivered doses for both modalities. Differences in the patient size did not result in statistically significant differences for most of the investigated parameters in either the TomoTherapy or VMAT modality. TomoTherapy-based OC-TBI showed lower variations between planned and delivered doses, was less time-consuming and was easier to implement in routine practice than VMAT. We did not observe significant differences in acute and subacute toxicity between TomoTherapy and VMAT groups. The late toxicity from kidneys and lungs was not found during the 2.3 years follow up period. The study demonstrates that both modalities are feasible, safe and show acceptable toxicity. The standardized approaches allowed us to implement pediatric OC-TBI in routine clinical practice.
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Affiliation(s)
- Anna Anzorovna Loginova
- Dmitry Rogachev National Research Center of Pediatric Hematology, Oncology and Immunology, Moscow, Russia
- *Correspondence: Anna Anzorovna Loginova,
| | - Diana Anatolievna Tovmasian
- Dmitry Rogachev National Research Center of Pediatric Hematology, Oncology and Immunology, Moscow, Russia
- Faculty of Physics, Federal State Budget Educational Institution of Higher Education, M.V. Lomonosov Moscow State University, Moscow, Russia
| | | | - Daria Alexeevna Kobyzeva
- Dmitry Rogachev National Research Center of Pediatric Hematology, Oncology and Immunology, Moscow, Russia
| | | | - Alexander Petrovich Chernyaev
- Faculty of Physics, Federal State Budget Educational Institution of Higher Education, M.V. Lomonosov Moscow State University, Moscow, Russia
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Kouris P, Moutsatsos A, Pappas EP, Beli I, Pantelakos P, Karaiskos P, Pantelis E. Assessing the dose rate delivery of helical TomoTherapy prostate and head & neck treatments. Biomed Phys Eng Express 2021; 8. [PMID: 34755680 DOI: 10.1088/2057-1976/ac37cb] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 11/09/2021] [Indexed: 11/11/2022]
Abstract
The dose rate distributions delivered to 55 prostate and head & neck (H&N) cancer patients treated with a helical TomoTherapy (HT) system were resolved and assessed with regard to pitch and field width defined during treatment planning. Statistical analysis of the studied cases showed that the median treatment delivery time was 4.4 min and 6.3 min for the prostate and H&N cases, respectively. Dose rate volume histogram data for the studied cases showed that the 25% and 12% of the volume of the planning target volumes of the prostate and H&N cases are irradiated with a dose rate of greater or equal to 1 Gy min-1. Quartile dose rate (QDR) data confirmed that in HT, where the target is irradiated in slices, most of the dose is delivered to each voxel of the target when it travels within the beam. Analysis of the planning data from all cases showed that this lasts for 68 s (median value). QDRs results showed that using the 2.5 cm field width, 75% of the prescribed dose is delivered to target voxels with a median dose rate of at least 3.2 Gy min-1and 4.5 Gy min-1, for the prostate and H&N cases, respectively. Systematically higher dose rates were observed for the H&N cases due to the shallower depths of the lesions in this anatomical site. Delivered dose rates were also found to increase with field width and pitch setting, due to the higher output of the system which, in general, results in accordingly decreased total treatment time. The biological effect of the dose rate findings of this work needs to be further investigated using in-vitro studies and clinical treatment data.
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Affiliation(s)
- P Kouris
- Medical Physics Laboratory, Medical School, National and Kapodistrian University of Athens, 75 Mikras Asias, 11527 Athens, Greece
| | - A Moutsatsos
- Medical Physics Laboratory, Medical School, National and Kapodistrian University of Athens, 75 Mikras Asias, 11527 Athens, Greece.,Radiotherapy and Radiosurgery Department, Latropolis Clinic, 54-56 Ethnikis Antistaseos, 15231 Athens, Greece
| | - E P Pappas
- Radiotherapy and Radiosurgery Department, Latropolis Clinic, 54-56 Ethnikis Antistaseos, 15231 Athens, Greece
| | - I Beli
- Radiotherapy and Radiosurgery Department, Latropolis Clinic, 54-56 Ethnikis Antistaseos, 15231 Athens, Greece
| | - P Pantelakos
- Radiotherapy and Radiosurgery Department, Latropolis Clinic, 54-56 Ethnikis Antistaseos, 15231 Athens, Greece
| | - P Karaiskos
- Medical Physics Laboratory, Medical School, National and Kapodistrian University of Athens, 75 Mikras Asias, 11527 Athens, Greece
| | - E Pantelis
- Medical Physics Laboratory, Medical School, National and Kapodistrian University of Athens, 75 Mikras Asias, 11527 Athens, Greece.,Radiotherapy and Radiosurgery Department, Latropolis Clinic, 54-56 Ethnikis Antistaseos, 15231 Athens, Greece
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9
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Chang KH, Lee YH, Park BH, Han MC, Kim J, Kim H, Cho MS, Kang H, Lee H, Kim DW, Park K, Cho J, Kim YB, Kim JS, Hong CS. Statistical Analysis of Treatment Planning Parameters for Prediction of Delivery Quality Assurance Failure for Helical Tomotherapy. Technol Cancer Res Treat 2020; 19:1533033820979692. [PMID: 33302821 PMCID: PMC7734483 DOI: 10.1177/1533033820979692] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Purpose: This study aimed to investigate the parameters with a significant impact on delivery quality assurance (DQA) failure and analyze the planning parameters as possible predictors of DQA failure for helical tomotherapy. Methods: In total, 212 patients who passed or failed DQA measurements were retrospectively included in this study. Brain (n = 43), head and neck (n = 37), spinal (n = 12), prostate (n = 36), rectal (n = 36), pelvis (n = 13), cranial spinal irradiation and a treatment field including lymph nodes (n = 24), and other types of cancer (n = 11) were selected. The correlation between DQA results and treatment planning parameters were analyzed using logistic regression analysis. Receiver operating characteristic (ROC) curves, areas under the curves (AUCs), and the Classification and Regression Tree (CART) algorithm were used to analyze treatment planning parameters as possible predictors for DQA failure. Results: The AUC for leaf open time (LOT) was 0.70, and its cut-off point was approximately 30%. The ROC curve for the predicted probability calculated when the multivariate variable model was applied showed an AUC of 0.815. We confirmed that total monitor units, total dose, and LOT were significant predictors for DQA failure using the CART. Conclusions: The probability of DQA failure was higher when the percentage of LOT below 100 ms was higher than 30%. The percentage of LOT below 100 ms should be considered in the treatment planning process. The findings from this study may assist in the prediction of DQA failure in the future.
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Affiliation(s)
- Kyung Hwan Chang
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, South Korea
| | - Young Hyun Lee
- Eretec Inc. 401, Simin-daero, Dongan-gu, Anyang-si, Gyeonggi-do, South Korea
| | - Byung Hun Park
- Eretec Inc. 401, Simin-daero, Dongan-gu, Anyang-si, Gyeonggi-do, South Korea
| | - Min Cheol Han
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, South Korea
| | - Jihun Kim
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, South Korea
| | - Hojin Kim
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, South Korea
| | - Min-Seok Cho
- Department of Radiation Oncology, Yongin Severance Hospital, Yonsei University College of Medicine, Yongin, South Korea
| | - Hyokyeong Kang
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, South Korea
| | - Ho Lee
- Department of Radiation Oncology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea
| | - Dong Wook Kim
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, South Korea
| | - Kwangwoo Park
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, South Korea
| | - Jaeho Cho
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, South Korea
| | - Yong Bae Kim
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, South Korea
| | - Jin Sung Kim
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, South Korea
| | - Chae-Seon Hong
- Department of Radiation Oncology, Yongin Severance Hospital, Yonsei University College of Medicine, Yongin, South Korea
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10
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Konishi T, Ogawa H, Najima Y, Hashimoto S, Wada A, Adachi H, Konuma R, Kishida Y, Nagata A, Yamada Y, Kaito S, Mukae J, Marumo A, Noguchi Y, Toya T, Igarashi A, Kobayashi T, Ohashi K, Doki N, Karasawa K. Safety of total body irradiation using intensity-modulated radiation therapy by helical tomotherapy in allogeneic hematopoietic stem cell transplantation: a prospective pilot study. JOURNAL OF RADIATION RESEARCH 2020; 61:969-976. [PMID: 32888029 PMCID: PMC7674702 DOI: 10.1093/jrr/rraa078] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 07/05/2020] [Accepted: 08/20/2020] [Indexed: 05/28/2023]
Abstract
Total body irradiation using intensity-modulated radiation therapy total body irradiation (IMRT-TBI) by helical tomotherapy in allogeneic hematopoietic stem cell transplantation (allo-HSCT) allows for precise evaluation and adjustment of radiation dosage. We conducted a single-center pilot study to evaluate the safety of IMRT-TBI for allo-HSCT recipients. Patients with hematological malignancies in remission who were scheduled for allo-HSCT with TBI-based myeloablative conditioning were eligible. The primary endpoint was the incidence of adverse events (AEs). Secondary endpoints were engraftment rate, overall survival, relapse rate, non-relapse mortality, and the incidence of acute and chronic graft-versus-host disease (aGVHD and cGVHD, respectively). Between July 2018 and November 2018, ten patients were recruited with a median observation duration of 571 days after allo-HSCT (range, 496-614). D80% for planning target volume (PTV) in all patients was 12.01 Gy. Average D80% values for lungs, kidneys and lenses (right/left) were 7.50, 9.03 and 4.41/4.03 Gy, respectively. Any early AEs (within 100 days of allo-HSCT) were reported in all patients. Eight patients experienced oral mucositis and gastrointestinal symptoms. One patient experienced Bearman criteria grade 3 regimen-related toxicity (kidney and liver). All cases achieved neutrophil engraftment. There was no grade III-IV aGVHD or late AE. One patient died of sinusoidal obstruction syndrome 67 days after allo-HSCT. The remaining nine patients were alive and disease-free at final follow-up. Thus, IMRT-TBI was well tolerated in terms of early AEs in adult patients who underwent allo-HSCT; this warrants further study with longer observation times to monitor late AEs and efficacy.
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Affiliation(s)
| | | | - Yuho Najima
- Corresponding author. Hematology Division, Tokyo Metropolitan Cancer and Infectious Diseases Center, Komagome Hospital, 3-18-22 Hon-Komagome, Bunkyo-ku, Tokyo, Japan, 1138677, Phone: +81-3-3823-2101, Fax: +81-3-3823-5433,
| | - Shinpei Hashimoto
- Division of Radiation Oncology, Department of Radiology, Tokyo Metropolitan Cancer and Infectious Diseases Center, Komagome Hospital
| | - Atsushi Wada
- Hematology Division, Tokyo Metropolitan Cancer and Infectious Diseases Center, Komagome Hospital
| | - Hiroto Adachi
- Hematology Division, Tokyo Metropolitan Cancer and Infectious Diseases Center, Komagome Hospital
| | - Ryosuke Konuma
- Hematology Division, Tokyo Metropolitan Cancer and Infectious Diseases Center, Komagome Hospital
| | - Yuya Kishida
- Hematology Division, Tokyo Metropolitan Cancer and Infectious Diseases Center, Komagome Hospital
| | - Akihito Nagata
- Hematology Division, Tokyo Metropolitan Cancer and Infectious Diseases Center, Komagome Hospital
| | - Yuta Yamada
- Hematology Division, Tokyo Metropolitan Cancer and Infectious Diseases Center, Komagome Hospital
| | - Satoshi Kaito
- Hematology Division, Tokyo Metropolitan Cancer and Infectious Diseases Center, Komagome Hospital
| | - Junichi Mukae
- Hematology Division, Tokyo Metropolitan Cancer and Infectious Diseases Center, Komagome Hospital
| | - Atsushi Marumo
- Hematology Division, Tokyo Metropolitan Cancer and Infectious Diseases Center, Komagome Hospital
| | - Yuma Noguchi
- Hematology Division, Tokyo Metropolitan Cancer and Infectious Diseases Center, Komagome Hospital
| | - Takashi Toya
- Hematology Division, Tokyo Metropolitan Cancer and Infectious Diseases Center, Komagome Hospital
| | - Aiko Igarashi
- Hematology Division, Tokyo Metropolitan Cancer and Infectious Diseases Center, Komagome Hospital
| | - Takeshi Kobayashi
- Hematology Division, Tokyo Metropolitan Cancer and Infectious Diseases Center, Komagome Hospital
| | - Kazuteru Ohashi
- Hematology Division, Tokyo Metropolitan Cancer and Infectious Diseases Center, Komagome Hospital
| | - Noriko Doki
- Hematology Division, Tokyo Metropolitan Cancer and Infectious Diseases Center, Komagome Hospital
| | - Katsuyuki Karasawa
- Division of Radiation Oncology, Department of Radiology, Tokyo Metropolitan Cancer and Infectious Diseases Center, Komagome Hospital
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11
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Ju SG, Ahn YC, Kim YB, Park SG, Choi YM, Na CH, Hong CS, Oh D, Kwon DY, Kim CC, Kim DH. Development of a Tongue Immobilization Device Using a 3D Printer for Intensity Modulated Radiation Therapy of Nasopharyngeal Cancer Patients. Cancer Res Treat 2020; 53:45-54. [PMID: 32972044 PMCID: PMC7812000 DOI: 10.4143/crt.2020.572] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 09/14/2020] [Indexed: 11/22/2022] Open
Abstract
Purpose This study aimed to reduce radiation doses to the tongue, a patient-specific semi-customized tongue immobilization device (SCTID) was developed using a 3D printer for helical tomotherapy (HT) of nasopharyngeal cancer (NPCa). Dosimetric characteristics and setup stability of the SCTID were compared with those of a standard mouthpiece (SMP). Materials and Methods For displacement and robust immobilization of the tongue, the SCTID consists of four parts: upper and lower tooth stoppers, tongue guider, tongue-tip position guide bar, and connectors. With the SCTID and SMP, two sets of planning computed tomography and HT plans were obtained for 10 NPCa patients. Dosimetric and geometric characteristics were compared. Position reproducibility of the tongue with SCTID was evaluated by comparing with planned dose and adaptive accumulated dose of the tongue and base of the tongue based on daily setup mega-voltage computed tomography. Results Using the SCTID, the tongue was effectively displaced from the planning target volume compared to the SMP. The median mucosa of the tongue (M-tongue) dose was significantly reduced (20.7 Gy vs. 27.8 Gy). The volumes of the M-tongue receiving a dose of 15 Gy, 30 Gy, and 45 Gy and the volumes of the mucosa of oral cavity and oropharynx (M-OC/OP) receiving a dose of 45 Gy and 60 Gy were significantly lower than using the SMP. No significant differences was observed between the planned dose and the accumulated adaptive dose in any dosimetric characteristics of the tongue and base of tongue. Conclusion SCTID can not only reduce the dose to the M-tongue and M-OC/OP dramatically, when compared to SMP, but also provide excellent reproducibility and easy visual verification.
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Affiliation(s)
- Sang Gyu Ju
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Yong Chan Ahn
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.,Department of Medical Device Management and Research, Samsung Advanced Institute for Health Science & Technology, Sungkyunkwan University, Seoul, Korea
| | - Yeong-Bi Kim
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Seung Gyu Park
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Yoo-Mi Choi
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.,Department of Medical Device Management and Research, Samsung Advanced Institute for Health Science & Technology, Sungkyunkwan University, Seoul, Korea
| | - Cho Hee Na
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.,Department of Medical Device Management and Research, Samsung Advanced Institute for Health Science & Technology, Sungkyunkwan University, Seoul, Korea
| | - Chae-Seon Hong
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Korea
| | - Dongryul Oh
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Dong Yeol Kwon
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Cheol Chong Kim
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Dong Hyeon Kim
- Institute of Advanced Convergence Technology, Kyungpook National University, Daegu, Korea
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12
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Santos T, Ventura T, Mateus J, Capela M, Lopes MDC. On the complexity of helical tomotherapy treatment plans. J Appl Clin Med Phys 2020; 21:107-118. [PMID: 32363800 PMCID: PMC7386195 DOI: 10.1002/acm2.12895] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 04/09/2020] [Accepted: 04/13/2020] [Indexed: 11/08/2022] Open
Abstract
PURPOSE Multiple metrics are proposed to characterize and compare the complexity of helical tomotherapy (HT) plans created for different treatment sites. METHODS A cohort composed of 208 HT plans from head and neck (105), prostate (51) and brain (52) tumor sites was considered. For each plan, 14 complexity metrics were calculated. Those metrics evaluate the percentage of leaves with small opening times or approaching the projection duration, the percentage of closed leaves, the amount of tongue-and-groove effect, and the overall modulation of the planned sinogram. To enable data visualization, an approach based on principal component analysis was followed to reduce the dataset dimensionality. This allowed the calculation of a global plan complexity score. The correlation between plan complexity and pretreatment verification results using the Spearman's rank correlation coefficients was investigated. RESULTS According to the global score, the most complex plans were the head and neck tumor cases, followed by the prostate and brain lesions irradiated with stereotactic technique. For almost all individual metrics, head and neck plans confirmed to be the plans with the highest complexity. Nevertheless, prostate cases had the highest percentage of leaves with an opening time approaching the projection duration, whereas the stereotactic brain plans had the highest percentage of closed leaves per projection. Significant correlations between some of the metrics and the pretreatment verification results were identified for the stereotactic brain group. CONCLUSIONS The proposed metrics and the global score demonstrated to be useful to characterize and quantify the complexity of HT plans of different treatment sites. The reported differences inter- and intra-group may be valuable to guide the planning process aiming at reducing uncertainties and harmonize planning strategies.
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Affiliation(s)
- Tania Santos
- Physics Department, University of Coimbra, Coimbra, Portugal.,Medical Physics Department, IPOCFG, E.P.E, Coimbra, Portugal
| | - Tiago Ventura
- Medical Physics Department, IPOCFG, E.P.E, Coimbra, Portugal
| | - Josefina Mateus
- Medical Physics Department, IPOCFG, E.P.E, Coimbra, Portugal
| | - Miguel Capela
- Medical Physics Department, IPOCFG, E.P.E, Coimbra, Portugal
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13
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Hong CS, Kim MJ, Kim J, Chang KH, Park K, Kim DW, Han MC, Yoon HI, Kim JS, Lee H. Feasibility of hybrid TomoHelical- and TomoDirect-based volumetric gradient matching technique for total body irradiation. Radiat Oncol 2019; 14:233. [PMID: 31856870 PMCID: PMC6924057 DOI: 10.1186/s13014-019-1435-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 12/02/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Tomotherapy-based total body irradiation (TBI) is performed using the head-first position (HFP) and feet-first position (FFP) due to treatment length exceeding the 135 cm limit. To reduce the dosimetric variation at the match lines, we propose and verify a volumetric gradient matching technique (VGMT) by combining TomoHelical (TH) and TomoDirect (TD) modes. METHODS Two planning CT image sets were acquired with HFP and FFP using 15 × 55 × 18 cm3 of solid water phantom. Planning target volume (PTV) was divided into upper, lower, and gradient volumes. The junction comprised 2-cm thick five and seven gradient volumes (5-GVs and 7-GVs) to create a dose distribution with a gentle slope. TH-IMRT and TD-IMRT plans were generated with 5-GVs and 7-GVs. The setup error in the calculated dose was assessed by shifting dose distribution of the FFP plan by 5, 10, 15, and 20 mm in the longitudinal direction and comparing it with the original. Doses for 95% (D95) and 5% of the PTV (D5) were calculated for all simulated setup error plans. Absolute dose measurements were performed using an ionization chamber in the junction. RESULTS The TH&TD plan produced a linear gradient in junction volume, comparable to that of the TH&TH plan. D5 of the PTV was 110% of the prescribed dose when the FFP plan was shifted 0.7 cm and 1.2 cm in the superior direction for 5-GVs and 7-GVs. D95 of the PTV decreased to < 90% of the prescribed dose when the FF plan was shifted 1.1 cm and 1.3 cm in the inferior direction for 5-GVs and 7-GVs. The absolute measured dose showed a good correlation with the calculated dose in the gradient junction volume. The average percent difference (±SD) in all measured points was - 0.7 ± 1.6%, and the average dose variations between depths was - 0.18 ± 1.07%. CONCLUSION VGMT can create a linear dose gradient across the junction area in both TH&TH and TH&TD and can minimize the dose sensitivity to longitudinal setup errors in tomotherapy-based TBI.
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Affiliation(s)
- Chae-Seon Hong
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemoon-gu, Seoul, 03722, South Korea
| | - Min-Joo Kim
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemoon-gu, Seoul, 03722, South Korea
| | - Jihun Kim
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemoon-gu, Seoul, 03722, South Korea
| | - Kyung Hwan Chang
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemoon-gu, Seoul, 03722, South Korea
| | - Kwangwoo Park
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemoon-gu, Seoul, 03722, South Korea
| | - Dong Wook Kim
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemoon-gu, Seoul, 03722, South Korea
| | - Min Cheol Han
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemoon-gu, Seoul, 03722, South Korea
| | - Hong In Yoon
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemoon-gu, Seoul, 03722, South Korea
| | - Jin Sung Kim
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemoon-gu, Seoul, 03722, South Korea.
| | - Ho Lee
- Department of Radiation Oncology, Gangnam Severance Hospital, Yonsei University College of Medicine, 211 Eonju-ro, Gangnam-gu, Seoul, 06273, South Korea.
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14
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The impact of the offset distance between the planning target volume and isocenter on irradiation time in TomoTherapy: A phantom study. Phys Med 2019; 63:19-24. [PMID: 31221404 DOI: 10.1016/j.ejmp.2019.05.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Revised: 04/19/2019] [Accepted: 05/18/2019] [Indexed: 11/23/2022] Open
Abstract
PURPOSE The influence of the offset distance from treatment target to gantry isocenter (GIC) on the dosimetric parameter and irradiation time was investigated using TomoTherapy METHODS: The reference position was defined as the centers of both the I'mRT phantom and planning target volume (PTV) with a spherical of 4 cm diameter aligned with the GIC. The dose calculations were performed in two offset methods with 2 and 12 Gy/fr, Method 1. The PTV was moved from 0.0 to 12.5 cm along the RL direction and -5.0 to 5.0 cm along the AP direction (PTV offset), Method 2. The phantom was moved from 0.0 to -7.5 cm along the RL direction and -5.0 to 5.0 cm along the AP direction (Phantom offset). The maximum, minimum and mean doses, homogeneity index, conformity index, irradiation time, and monitor unit were compared. RESULTS The irradiation times increased with increasing PTV offset. The increases in the irradiation time were 54.4% and 40.8% at PTV offsets of 12.5 cm along the RL direction for 2 and 12 Gy/fr, while the increases were 20.1% and 15.0% at a PTV offset of 5.0 cm along the AP direction. An increased irradiation time was not observed for the phantom offset. The offset didn't affect the other parameters. CONCLUSIONS The PTV location offset of ≥5 cm from the GIC along the RL and AP axes increased the irradiation time; therefore, the PTV should be aligned with the GIC as much as possible to reduce the irradiation time on TomoTherapy.
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15
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Hong CS, Oh D, Ju SG, Ahn YC, Na CH, Kwon DY, Kim CC. Development of a semi-customized tongue displacement device using a 3D printer for head and neck IMRT. Radiat Oncol 2019; 14:79. [PMID: 31088472 PMCID: PMC6515618 DOI: 10.1186/s13014-019-1289-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 05/06/2019] [Indexed: 11/22/2022] Open
Abstract
Purpose To reduce radiation doses to the tongue, a patient-specific semi-customized tongue displacement device (SCTDD) was developed using a 3D printer (3DP) for head and neck (H&N) radiation therapy (RT). Dosimetric characteristics of the SCTDD were compared with those of a standard mouthpiece (SMP). Materials and methods The SCTDD consists of three parts: a mouthpiece, connector with an immobilization mask, and tongue displacer, which can displace the tongue to the contralateral side of the planning target volume. Semi-customization was enabled by changing the thickness and length of the SCTDD. The instrument was printed using a 3DP with a biocompatible material. With the SCTDD and SMP, two sets of planning computed tomography (CT) and tomotherapy plans were obtained for seven H&N cancer patients. Dosimetric and geometric characteristics were compared. Results Using the SCTDD, the tongue was effectively displaced from the planning target volume without significant tongue volume change compared to the SMP. The median tongue dose was significantly reduced (29.6 Gy vs. 34.3 Gy). The volumes of the tongue receiving a dose of 15 Gy, 30 Gy, 35 Gy, 45 Gy, and 60 Gy were significantly lower than using the SMP. Conclusion The SCTDD significantly decreased the radiation dose to the tongue compared to the SMP, which may potentially reduce RT-related tongue toxicity.
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Affiliation(s)
- Chae-Seon Hong
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-Ro 81 ,Gangnam-Gu, Seoul, 06351, Republic of Korea.,Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Dongryul Oh
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-Ro 81 ,Gangnam-Gu, Seoul, 06351, Republic of Korea
| | - Sang Gyu Ju
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-Ro 81 ,Gangnam-Gu, Seoul, 06351, Republic of Korea.
| | - Yong Chan Ahn
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-Ro 81 ,Gangnam-Gu, Seoul, 06351, Republic of Korea.,Department of Medical Device Management and Research, Samsung Advanced Institute for Health Science & Technology, Sungkyunkwan University, Seoul, Republic of Korea
| | - Cho Hee Na
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-Ro 81 ,Gangnam-Gu, Seoul, 06351, Republic of Korea.,Department of Medical Device Management and Research, Samsung Advanced Institute for Health Science & Technology, Sungkyunkwan University, Seoul, Republic of Korea
| | - Dong Yeol Kwon
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-Ro 81 ,Gangnam-Gu, Seoul, 06351, Republic of Korea
| | - Cheol Chong Kim
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-Ro 81 ,Gangnam-Gu, Seoul, 06351, Republic of Korea
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16
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Howitz S, Wiezorek T, Wittig A, Vorwerk H, Zink K. Fluence-weighted average subfield size in helical TomoTherapy. Z Med Phys 2019; 29:337-348. [PMID: 31056376 DOI: 10.1016/j.zemedi.2019.03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 03/29/2019] [Accepted: 03/30/2019] [Indexed: 11/25/2022]
Abstract
INTRODUCTION Helical TomoTherapy allows a highly conformal dose distribution to complex target geometries with a good protection of organs at risk. However, the small field sizes associated with this method are a possible source of dosimetrical uncertainties. The IAEA has published detector-specific field output correction factors for static fields of the TomoTherapy in the TRS483. This work investigates the average subfield size of helical TomoTherapy plans. MATERIAL AND METHODS A new parameter for helical TomoTherapy was defined - the fluence-weighted average subfield size. The subfield sizes were extracted from the leaf-opening time sinograms in the RT-plan files for 30 clinical prostate and head and neck plans and were put in relation to Delat4 Phantom+ measurement results. Additionally the influence of planning parameters on the subfield size was studied by varying the modulation factor, number of iterations and pitch in the dose optimization and calculation for three different clinical indications H&N, prostate and rectum cancer. Selected plans were dosimetrically verified by Delta4 measurements to examine the reliability in dependence of the average subfield size. Furthermore, the impact of the planning parameters on a) the dose distribution, with regard to the planning target volume and regions at risks, and b) machine characteristics such as delivery time, actual modulation factor and leaf-opening times were evaluated. RESULTS The average equivalent square subfield lengths (s¯eq) of the two investigated indications did not differ significantly - prostate plans: 2.75±0.14cm and H&N plans: 2.70±0.16cm, both with a jaw width of 2.5cm. No correlation between field size and measured dose deviation was detected. The number of iterations and the modulation factor have a considerable influence on the average subfield size. The higher the planned modulation factor and the more iterations are used during optimization, the smaller is the subfield size. In our pilot study plans were calculated with field sizes s¯eq between 4.2cm and 1.7cm, with a jaw width of 2.5cm. Again, the measurement results of Delta4 showed no significant deviation from the doses calculated by the TomoTherapy planning system for the whole range of subfield sizes, and no significant correlation between field sizes and dose deviations was found. As expected, the clinical dose distribution improved with increasing modulation factor and an increasing number of iterations. The compromise between an improved dose distribution and smaller s¯eq was shown. CONCLUSION In this work, a method was presented to determine the average subfield size for helical TomoTherapy plans. The response of the Delta4 did not show any dependence on field size in the range of the field sizes covered by the studied plans. The influence of the subfield sizes on other dosimetry systems remains to be investigated.
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Affiliation(s)
- Simon Howitz
- University Hospital Jena, Department of Radiation Oncology, Germany; Institute for Medical Physics and Radiation Protection IMPS, University of Applied Science - THM, Giessen, Germany; Philipps-University, Marburg, Germany.
| | - Tilo Wiezorek
- University Hospital Jena, Department of Radiation Oncology, Germany
| | - Andrea Wittig
- University Hospital Jena, Department of Radiation Oncology, Germany
| | | | - Klemens Zink
- Institute for Medical Physics and Radiation Protection IMPS, University of Applied Science - THM, Giessen, Germany; University Medical Center Giessen-Marburg, Department of Radiation Oncology, Germany; Frankfurt Institute for Advanced Studies (FIAS), Frankfurt, Germany
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17
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Haraldsson A, Engleson J, Bäck SÅJ, Engelholm S, Engström PE. A Helical tomotherapy as a robust low-dose treatment alternative for total skin irradiation. J Appl Clin Med Phys 2019; 20:44-54. [PMID: 31033159 PMCID: PMC6522990 DOI: 10.1002/acm2.12579] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 03/01/2019] [Accepted: 03/05/2019] [Indexed: 11/06/2022] Open
Abstract
Mycosis fungoides is a disease with manifestation of the skin that has traditionally been treated with electron therapy. In this paper, we present a method of treating the entire skin with megavoltage photons using helical tomotherapy (HT), verified through a phantom study and clinical dosimetric data from our first two treated patients. A whole body phantom was fitted with a wetsuit as bolus, and scanned with computer tomography. We accounted for variations in daily setup using virtual bolus in the treatment plan optimization. Positioning robustness was tested by moving the phantom, and recalculating the dose at different positions. Patient treatments were verified with in vivo film dosimetry and dose reconstruction from daily imaging. Reconstruction of the actual delivered dose to the patients showed similar target dose as the robustness test of the phantom shifted 10 mm in all directions, indicating an appropriate approximation of the anticipated setup variation. In vivo film measurements agreed well with the calculated dose confirming the choice of both virtual and physical bolus parameters. Despite the complexity of the treatment, HT was shown to be a robust and feasible technique for total skin irradiation. We believe that this technique can provide a viable option for Tomotherapy centers without electron beam capability.
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Affiliation(s)
- André Haraldsson
- Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden.,Medical Radiation Physics, Department of clinical sciences, Lund University, Lund, Sweden
| | - Jens Engleson
- Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden
| | - Sven Å J Bäck
- Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden.,Medical Radiation Physics, Department of clinical sciences, Lund University, Lund, Sweden
| | - Silke Engelholm
- Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden
| | - Per E Engström
- Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden
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Haraldsson A, Engellau J, Lenhoff S, Engelholm S, Bäck S, Engström PE. Implementing safe and robust Total Marrow Irradiation using Helical Tomotherapy - A practical guide. Phys Med 2019; 60:162-167. [PMID: 31000078 DOI: 10.1016/j.ejmp.2019.03.032] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 03/22/2019] [Accepted: 03/30/2019] [Indexed: 11/16/2022] Open
Abstract
Total Marrow Irradiation (TMI) with Helical Tomotherapy is a radiotherapy treatment technique that targets bone marrow and sanctuary sites prior to stem cell or bone marrow transplantation (SCT/BMT). TMI is a complex procedure that involves several critical steps that all need to be carefully addressed for a successful implementation, such as dose homogeneity in field junctions, choice of target margins, integrity of treatment and back-up planning. In this work we present our solution for a robust and reproducible workflow throughout the treatment chain and data for twenty-three patients treated to date. MATERIAL & METHODS Patients were immobilized in a whole body vacuum cushion and thermoplastic mask. CT-scanning and treatment were performed in two parts with field matching at the upper thigh. Target consisted of marrow containing bone and sanctuary sites. Lungs, kidneys, bowel, heart and liver were defined as organs at risk (OAR). A fast surface scanning system was used to position parts of the body not covered by the imaging system (MVCT) as well as to reduce treatment time. RESULTS All patients completed their treatment and could proceed with SCT/BMT. Doses to OARs were significantly reduced and target dose homogeneity was improved compared to TBI. Robustness tests performed on field matching and patient positioning support that the field junction technique is adequate. Replacing MVCT with optical surface scanning reduced the treatment time by 25 min per fraction. CONCLUSION The methodology presented here has shown to provide a safe, robust and reproducible treatment for Total Marrow Irradiation using Tomotherapy.
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Affiliation(s)
- André Haraldsson
- Medical Radiation Physics, Lund University, Lund, Sweden; Department of Haematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden.
| | - Jacob Engellau
- Medical Radiation Physics, Lund University, Lund, Sweden; Department of Haematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden
| | - Stig Lenhoff
- Department of Haematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden
| | - Silke Engelholm
- Department of Haematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden
| | - Sven Bäck
- Department of Haematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden
| | - Per E Engström
- Department of Haematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden
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Kasai Y, Fukuyama Y, Terashima H, Nakamura K, Sasaki T. Dose evaluation indices for total body irradiation using TomoDirect with different numbers of ports: A comparison with the TomoHelical method. J Appl Clin Med Phys 2019; 20:129-135. [PMID: 30721567 PMCID: PMC6370990 DOI: 10.1002/acm2.12540] [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] [Received: 08/01/2018] [Revised: 12/17/2018] [Accepted: 01/08/2019] [Indexed: 11/09/2022] Open
Abstract
TomoDirect has been reported to have some advantages over TomoHelical in delivering total body irradiation (TBI). This study aimed to investigate the relationships between the number of ports and the dose evaluation indices in low‐dose TBI in TomoDirect mode using 2–12 ports and to compare these data with those for the TomoHelical mode in a simulation study. Thirteen patients underwent low‐dose TBI in TomoHelical mode from June 2015 to June 2016. We used the same computed tomography data sets for these patients to create new treatment plans for upper‐body parts using TomoDirect mode with 2–12 beam angles as well as TomoHelical mode. The prescription was 4 Gy in two equal fractions. For the TomoDirect data, we generated plans with 2–12 ports with approximately equally spaced angles; the modulation factor, field width, and pitch were 2.0, 5.0 cm, and 0.500, respectively. For the TomoHelical plans, the modulation factor, field width, and pitch were 2.0, 5.0 cm, and 0.397, respectively. D2, D98, D50, and the homogeneity index (HI) were evaluated to compare TomoDirect plans having 2–12 ports with the TomoHelical plan. Using TomoDirect plans, D2 with four ports or fewer, D98 with 10 ports or fewer, D50 with four ports or fewer and HI with five ports or fewer showed statistically significantly worse results than the TomoHelical plan. With the TomoDirect plans, D2 with seven ports or more, D50 with eight ports or more, and HI with eight ports or more showed statistically significant improvement compared with the TomoHelical plan. All of the dose evaluation indices of the TomoDirect plans showed a tendency to improve as the number of ports increased. TomoDirect plans showed statistically significant improvement of D2, D50, and HI compared with the TomoHelical plan. Therefore, we conclude that TomoDirect can provide better dose distribution in low‐dose TBI with TomoTherapy.
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Affiliation(s)
- Yuki Kasai
- Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka City, Fukuoka, 812-8582, Japan
| | - Yukihide Fukuyama
- Department of Radiology, Harasanshin Hospital, 1-8 Taihakumachi, Hakata-ku, Fukuoka City, Fukuoka, 812-0033, Japan
| | - Hiromi Terashima
- Department of Radiology, Harasanshin Hospital, 1-8 Taihakumachi, Hakata-ku, Fukuoka City, Fukuoka, 812-0033, Japan
| | - Katsumasa Nakamura
- Department of Radiation Oncology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu City, Shizuoka, 431-3192, Japan
| | - Tomonari Sasaki
- Department of Health Sciences, Faculty of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka City, Fukuoka, 812-8582, Japan
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Binny D, Lancaster CM, Byrne M, Kairn T, V Trapp J, Crowe SB. Tomotherapy treatment site specific planning using statistical process control. Phys Med 2018; 53:32-39. [PMID: 30241752 DOI: 10.1016/j.ejmp.2018.08.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 06/26/2018] [Accepted: 08/05/2018] [Indexed: 10/28/2022] Open
Abstract
BACKGROUND This study investigated planned MLC distribution and treatment region specific plan parameters to recommend optimal delivery parameters based on statistical process techniques. METHODS A cohort of 28 head and neck, 19 pelvic and 23 brain pre-treatment plans were delivered on a helical tomotherapy system using 2.5 cm field width. Parameters such as gantry period, leaf open time (LOT), actual modulation factor, LOT sonogram, treatment duration and couch travel were investigated to derive optimal range for plans that passed acceptable delivery quality assurance. The results were compared against vendor recommendations and previous publications. RESULTS No correlation was observed between vendor recommended gantry period and percentage of minimum leaf open times. The range of gantry period (min-max) observed was 16-21 s for head and neck, 15-22 s for pelvis and 13-18 s for brain plans respectively. It was also noted that the highest percentage (average (X-) ± SD) of leaf open times for a minimum time of 100 ms was seen for brain plans (53.9 ± 9.2%) compared to its corresponding head and neck (34.5 ± 4.2%) and pelvic (32.0 ± 9.4%) plans respectively. CONCLUSIONS We have proposed that treatment site specific delivery parameters be used during planning that are based on the treatment centre and have detailed recommendations and limitations for the studied cohort. This may enable to improve efficiency of treatment deliveries by reducing inaccuracies in MLC distribution.
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Affiliation(s)
- Diana Binny
- Radiation Oncology Centres, Redlands, Australia; Queensland University of Technology, Brisbane, Australia; Cancer Care Services, Royal Brisbane and Women's Hospital, Brisbane, Australia.
| | - Craig M Lancaster
- Cancer Care Services, Royal Brisbane and Women's Hospital, Brisbane, Australia
| | - Mikel Byrne
- Radiation Oncology Centres, Wahroonga, Australia
| | - Tanya Kairn
- Queensland University of Technology, Brisbane, Australia; Cancer Care Services, Royal Brisbane and Women's Hospital, Brisbane, Australia
| | - Jamie V Trapp
- Queensland University of Technology, Brisbane, Australia
| | - Scott B Crowe
- Queensland University of Technology, Brisbane, Australia; Cancer Care Services, Royal Brisbane and Women's Hospital, Brisbane, Australia
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Shimizu H, Sasaki K, Kubota T, Fukuma H, Aoyama T, Iwata T, Tachibana H, Kodaira T. Interfacility variation in treatment planning parameters in tomotherapy: field width, pitch, and modulation factor. JOURNAL OF RADIATION RESEARCH 2018; 59:664-668. [PMID: 29868727 PMCID: PMC6151637 DOI: 10.1093/jrr/rry042] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 03/02/2018] [Indexed: 06/08/2023]
Abstract
Several studies have reported changes in dose distribution and delivery time based on the value of specific planning parameters [field width (FW), pitch, and modulation factor (MF)] in tomotherapy. However, the variation in the parameters between different facilities is unknown. The purpose of this study was to determine standard values of the above parameters for cases of head and neck cancer (HNC) and prostate cancer (PC) in Japan. In this survey, a web-based questionnaire was sent to 48 facilities performing radiation therapy with tomotherapy in March 2016. The deadline for data submission was April 2016. In the questionnaire, the values of the planning parameters usually used were requested and 23 responses were received, representing a response rate of 48% (23/48). The FW selected was 2.5 cm in most facilities, and facilities with a tomoEDGE license used dynamic FW rather than fixed FW. Facilities changed the pitch based on FW, dose per fraction, or target offset more frequently in HNC than in PC. In contrast, >50% of the facilities used the magic number proposed by Kissick et al. Median preset MFs (range, min to max) in HNC and PC were 2.4 (1.8-2.8) and 2.0 (1.8-3.0), respectively, and MF values showed large variations between the facilities. Our results are likely to be useful to several facilities designing treatment plans in tomotherapy.
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Affiliation(s)
- Hidetoshi Shimizu
- Department of Radiation Oncology, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-Ku, Nagoya, Aichi, Japan
- Graduate School of Radiological Technology, Gunma Prefectural College of Health Sciences, 323-1 Kamioki, Maebashi, Gunma, Japan
| | - Koji Sasaki
- Graduate School of Radiological Technology, Gunma Prefectural College of Health Sciences, 323-1 Kamioki, Maebashi, Gunma, Japan
| | - Takashi Kubota
- Department of Radiation Oncology, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-Ku, Nagoya, Aichi, Japan
| | - Hiroshi Fukuma
- Department of Radiology, Nagoya City University Hospital, 1-Kawasumi, Mizuho-Cho, Mizuho-Ku, Nagoya, Aichi, Japan
| | - Takahiro Aoyama
- Department of Radiation Oncology, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-Ku, Nagoya, Aichi, Japan
| | - Tohru Iwata
- Department of Radiation Oncology, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-Ku, Nagoya, Aichi, Japan
| | - Hiroyuki Tachibana
- Department of Radiation Oncology, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-Ku, Nagoya, Aichi, Japan
| | - Takeshi Kodaira
- Department of Radiation Oncology, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-Ku, Nagoya, Aichi, Japan
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Hui C, Chen Q, Khandelwal S, Neal B, Watkins W. Detection of dose delivery variations on TomoTherapy using on-board detector based verification. Phys Med Biol 2018; 63:14NT02. [DOI: 10.1088/1361-6560/aacebb] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Hong CS, Ju SG, Ahn YC, Yoo GS, Noh JM, Oh D, Chung K, Pyo H, Jo K. Normal lung sparing Tomotherapy technique in stage III lung cancer. Radiat Oncol 2017; 12:167. [PMID: 29110732 PMCID: PMC5674800 DOI: 10.1186/s13014-017-0905-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 10/14/2017] [Indexed: 12/25/2022] Open
Abstract
PURPOSE Radiation pneumonitis (RP) has been a challenging obstacle in treating stage III lung cancer patients. Beam angle optimization (BAO) technique for Tomotherapy was developed to reduce the normal lung dose for stage III non-small cell lung cancer (NSCLC). Comparative analyses on plan quality by 3 different Intensity-modulated radiation therapy (IMRT) methods with BAO were done. MATERIALS AND METHODS Ten consecutive stage IIIB NSCLC patients receiving linac-based static IMRT (L-IMRT) with total 66 Gy in 33 fractions to the PTV were selected. Two additional Tomotherapy-based IMRT plans (helical beam (TH-IMRT) and static beam (TD-IMRT)) were generated on each patient. To reduce the normal lung dose, Beam angles were optimized by using complete and directional block functions in Tomotherapy based on knowledge based statistical analysis. Plan quality was compared with target coverage, normal organ sparing capability, and normal tissue complication probability (NTCP). Actual beam delivery times and risk of RP related with planning target volume (PTV) were also evaluated. RESULTS The best PTV coverage measured by conformity index and homogeneity index was achievable by TH-IMRT (0.82 and 1.06), followed by TD-IMRT (0.81 and 1.07) and L-IMRT (0.75 and 1.08). Mean lung dose was the lowest in TH-IMRT plan followed by TD-IMRT and L-IMRT, all of which were ≤20 Gy. TH-IMRT plan could significantly lower the lung volumes receiving low to medium dose levels: V5~30 when compared to L-IMRT plan; and V5~20 when compared to TD-IMRT plan, respectively. TD-IMRT plan was significantly better than L-IMRT with respects to V20 and V30 and there was no significant difference with respect to V40 among three plans. The NTCP of the lung was the lowest in TH-IMRT plan, followed by TD-IMRT and L-IMRT (6.42% vs. 6.53% vs. 8.11%). Beam delivery time was the shortest in TD-IMRT plan followed by L-IMRT. As PTV length increased, NTCP and Mean lung dose proportionally increased significantly in all three plans. CONCLUSION Advantageous profiles by TH-IMRT could be achieved by BAO by complete and directional block functions. Current observation could help radiation oncologists to make wise selection of IMRT method for stage IIIB NSCLC.
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Affiliation(s)
- Chae-Seon Hong
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-Ro 81, Gangnam-Gu, Seoul, 06351, South Korea
| | - Sang Gyu Ju
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-Ro 81, Gangnam-Gu, Seoul, 06351, South Korea.
| | - Yong Chan Ahn
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-Ro 81, Gangnam-Gu, Seoul, 06351, South Korea.
- Department of Medical Device Management and Research, SAIHST, Sungkyunkwan University, Irwon-Ro 81, Gangnam-Gu, Seoul, 06351, South Korea.
| | - Gyu Sang Yoo
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-Ro 81, Gangnam-Gu, Seoul, 06351, South Korea
| | - Jae Myoung Noh
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-Ro 81, Gangnam-Gu, Seoul, 06351, South Korea
| | - Dongryul Oh
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-Ro 81, Gangnam-Gu, Seoul, 06351, South Korea
| | - Kwangzoo Chung
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-Ro 81, Gangnam-Gu, Seoul, 06351, South Korea
| | - Hongryull Pyo
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-Ro 81, Gangnam-Gu, Seoul, 06351, South Korea
| | - Kwanghyun Jo
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-Ro 81, Gangnam-Gu, Seoul, 06351, South Korea
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Shimizu H, Sasaki K, Tachibana H, Tomita N, Makita C, Nakashima K, Yokoi K, Kubota T, Yoshimoto M, Iwata T, Kodaira T. Analysis of modulation factor to shorten the delivery time in helical tomotherapy. J Appl Clin Med Phys 2017; 18:83-87. [PMID: 28444831 PMCID: PMC5689868 DOI: 10.1002/acm2.12075] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 02/14/2017] [Accepted: 02/17/2017] [Indexed: 11/12/2022] Open
Abstract
A low modulation factor (MF) maintaining a good dose distribution contributes to the shortening of the delivery time and efficiency of the treatment plan in helical tomotherapy. The purpose of this study was to reduce the delivery time using initial values and the upper limit values of MF. First, patients with head and neck cancer (293 cases) or prostate cancer (181 cases) treated between June 2011 and July 2015 were included in the analysis of MF values. The initial MF value (MFinitial ) was defined as the average MFactual value, and the upper limit of the MF value (MFUL ) was defined according the following equation: MFUL = 2 × standard deviation of MFactual value + the average MFactual Next, a treatment plan was designed for patients with head and neck cancer (62 cases) and prostate cancer (13 cases) treated between December 2015 and June 2016. The average MFactual value for the nasopharynx, oropharynx, hypopharynx, and prostate cases decreased from 2.1 to 1.9 (p = 0.0006), 1.9 to 1.6 (p < 0.0001), 2.0 to 1.7 (p < 0.0001), and 1.8 to 1.6 (p = 0.0004) by adapting the MFinitial and the MFUL values, respectively. The average delivery time for the nasopharynx, oropharynx, hypopharynx, and prostate cases also decreased from 19.9 s cm-1 to 16.7 s cm-1 (p < 0.0001), 15.0 s cm-1 to 13.9 s cm-1 (p = 0.025), 15.1 s cm-1 to 13.8 s cm-1 (p = 0.015), and 23.6 s cm-1 to 16.9 s cm-1 (p = 0.008) respectively. The delivery time was shortened by the adaptation of MFinitial and MFUL values with a reduction in the average MFactual for head and neck cancer and prostate cancer cases.
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Affiliation(s)
- Hidetoshi Shimizu
- Department of Radiation Oncology, Aichi Cancer Center Hospital, Nagoya, Aichi, Japan
| | - Koji Sasaki
- Department of radiation therapy education and research, Graduate School of Radiological Technology, Gunma Prefectural College of Health Sciences, Maebashi, Gunma, Japan
| | - Hiroyuki Tachibana
- Department of Radiation Oncology, Aichi Cancer Center Hospital, Nagoya, Aichi, Japan
| | - Natsuo Tomita
- Department of Radiation Oncology, Aichi Cancer Center Hospital, Nagoya, Aichi, Japan
| | - Chiyoko Makita
- Department of Radiation Oncology, Aichi Cancer Center Hospital, Nagoya, Aichi, Japan
| | - Kuniyasu Nakashima
- Department of Radiation Oncology, Aichi Cancer Center Hospital, Nagoya, Aichi, Japan
| | - Kazushi Yokoi
- Department of Radiation Oncology, Aichi Cancer Center Hospital, Nagoya, Aichi, Japan
| | - Takashi Kubota
- Department of Radiation Oncology, Aichi Cancer Center Hospital, Nagoya, Aichi, Japan
| | - Manabu Yoshimoto
- Department of Radiology, Aichi Cancer Center Aichi Hospital, Okazaki, Aichi, Japan
| | - Tohru Iwata
- Department of Radiation Oncology, Aichi Cancer Center Hospital, Nagoya, Aichi, Japan
| | - Takeshi Kodaira
- Department of Radiation Oncology, Aichi Cancer Center Hospital, Nagoya, Aichi, Japan
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Deshpande S, Geurts M, Vial P, Metcalfe P, Lee M, Holloway L. Clinical significance of treatment delivery errors for helical TomoTherapy nasopharyngeal plans – A dosimetric simulation study. Phys Med 2017; 33:159-169. [PMID: 28110824 DOI: 10.1016/j.ejmp.2017.01.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2016] [Revised: 12/06/2016] [Accepted: 01/07/2017] [Indexed: 11/17/2022] Open
Affiliation(s)
- Shrikant Deshpande
- Liverpool and Macarthur Cancer Therapy Centres and Ingham Institute, Sydney, NSW, Australia; Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia.
| | - Mark Geurts
- Department of Human Oncology, School of Medicine and Public Health, University of Wisconsin-Madison, USA.
| | - Philip Vial
- Liverpool and Macarthur Cancer Therapy Centres and Ingham Institute, Sydney, NSW, Australia; Institute of Medical Physics, School of Physics, University of Sydney, Sydney, NSW, Australia.
| | - Peter Metcalfe
- Liverpool and Macarthur Cancer Therapy Centres and Ingham Institute, Sydney, NSW, Australia; Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia.
| | - Mark Lee
- Liverpool and Macarthur Cancer Therapy Centres and Ingham Institute, Sydney, NSW, Australia.
| | - Lois Holloway
- Liverpool and Macarthur Cancer Therapy Centres and Ingham Institute, Sydney, NSW, Australia; Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia; Institute of Medical Physics, School of Physics, University of Sydney, Sydney, NSW, Australia; South West Clinical School, University of New South Wales, Sydney, NSW, Australia.
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Crop F, Pasquier D, Baczkiewic A, Doré J, Bequet L, Steux E, Gadroy A, Bouillon J, Florence C, Muszynski L, Lacour M, Lartigau E. Surface imaging, laser positioning or volumetric imaging for breast cancer with nodal involvement treated by helical TomoTherapy. J Appl Clin Med Phys 2016; 17:200-211. [PMID: 27685103 PMCID: PMC5874112 DOI: 10.1120/jacmp.v17i5.6041] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 05/19/2016] [Accepted: 05/10/2016] [Indexed: 11/23/2022] Open
Abstract
A surface imaging system, Catalyst (C-Rad), was compared with laser-based positioning and daily mega voltage computed tomography (MVCT) setup for breast patients with nodal involvement treated by helical TomoTherapy. Catalyst-based positioning performed better than laser-based positioning. The respective modalities resulted in a standard deviation (SD), 68% confidence interval (CI) of positioning of left-right, craniocaudal, anterior-posterior, roll: 2.4 mm, 2.7 mm, 2.4 mm, 0.9° for Catalyst positioning, and 6.1 mm, 3.8 mm, 4.9 mm, 1.1° for laser-based positioning, respectively. MVCT-based precision is a combination of the interoperator variability for MVCT fusion and the patient movement during the time it takes for MVCT and fusion. The MVCT fusion interoperator variability for breast patients was evaluated at one SD left-right, craniocaudal, ant-post, roll as: 1.4 mm, 1.8 mm, 1.3 mm, 1.0°. There was no statistically significant difference between the automatic MVCT registration result and the manual adjustment; the automatic fusion results were within the 95% CI of the mean result of 10 users, except for one specific case where the patient was positioned with large yaw. We found that users add variability to the roll correction as the automatic registration was more consistent. The patient position uncertainty confidence interval was evaluated as 1.9 mm, 2.2 mm, 1.6 mm, 0.9° after 4 min, and 2.3 mm, 2.8 mm, 2.2 mm, 1° after 10 min. The combination of this patient movement with MVCT fusion interoperator variability results in total standard deviations of patient posi-tion when treatment starts 4 or 10 min after initial positioning of, respectively: 2.3 mm, 2.8 mm, 2.0 mm, 1.3° and 2.7 mm, 3.3 mm, 2.6 mm, 1.4°. Surface based positioning arrives at the same precision when taking into account the time required for MVCT imaging and fusion. These results can be used on a patient-per-patient basis to decide which positioning system performs the best after the first 5 fractions and when daily MVCT can be omitted. Ideally, real-time monitoring is required to reduce important intrafraction movement.
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Meyer P, Bouhours H, Dehaynin N, Jarnet D, Gantier M, Karamanoukian D, Niederst C. The optimal tomotherapy treatment planning parameters for extremity soft tissue sarcomas. Phys Med 2015; 31:542-52. [PMID: 26032005 DOI: 10.1016/j.ejmp.2015.05.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Revised: 04/30/2015] [Accepted: 05/07/2015] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND AND PURPOSE To determine the optimum combination of treatment parameters between pitch, field width (FW) and modulation factor (MF) for extremity sarcomas in tomotherapy. MATERIALS AND METHODS Six patients previously treated for extremity sarcomas (3 arms and 3 legs) with tomotherapy were included in this study. 288 treatment plans were recalculated, corresponding to all combinations between 2 FW (2.5 and 5 cm), 4 MF (1.5, 2, 2.5 and 3) and 6 pitches (0.215, 0.287, 0.43 and 3 off-axis pitches). The treatment parameters (MF, FW or pitch) are modified between each plan, and the calculation is relaunched for 400 iterations, without modifying the optimisation constraints of the plan under which the patient has been treated. RESULTS We suggest eliminating the 0.43 pitch and never combining a 0.215 pitch with an MF ≤ 2. We also do not recommend using an MF = 1.5 unless treatment time is an absolute priority over plan quality. We did not see any advantage in using Chen off-axis pitches, except for targets far from the axis (>15 cm) treated with a high pitch. A combination of MF = 2/FW = 5 cm/pitch = 0.287 gives plans of acceptable quality, combined with reduced treatment times. These conclusions are true only for extremity sarcomas treated in 2 Gy/fraction. CONCLUSIONS We have shown that the choice of pitch/MF/FW combination is crucial for the treatment of extremity sarcomas in tomotherapy: some produce good dosimetric quality with a reduced irradiation time, while others may increase the time without improving the quality.
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Affiliation(s)
- Philippe Meyer
- Division of Medical Physics, Department of Radiotherapy, Paul Strauss Center, Strasbourg, France.
| | - Hugo Bouhours
- Division of Medical Physics, Department of Radiotherapy, Paul Strauss Center, Strasbourg, France
| | - Nicolas Dehaynin
- Division of Medical Physics, Department of Radiotherapy, Paul Strauss Center, Strasbourg, France
| | - Delphine Jarnet
- Division of Medical Physics, Department of Radiotherapy, Paul Strauss Center, Strasbourg, France
| | - Matthieu Gantier
- Division of Medical Physics, Department of Radiotherapy, Paul Strauss Center, Strasbourg, France
| | - Diran Karamanoukian
- Division of Medical Physics, Department of Radiotherapy, Paul Strauss Center, Strasbourg, France
| | - Claudine Niederst
- Division of Medical Physics, Department of Radiotherapy, Paul Strauss Center, Strasbourg, France
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Stambaugh C, Nelms B, Wolf T, Mueller R, Geurts M, Opp D, Moros E, Zhang G, Feygelman V. Measurement-guided volumetric dose reconstruction for helical tomotherapy. J Appl Clin Med Phys 2015; 16:5298. [PMID: 26103199 PMCID: PMC5690083 DOI: 10.1120/jacmp.v16i2.5298] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 10/20/2014] [Accepted: 10/21/2014] [Indexed: 11/23/2022] Open
Abstract
It was previously demonstrated that dose delivered by a conventional linear accelerator using IMRT or VMAT can be reconstructed - on patient or phantom datasets - using helical diode array measurements and a technique called planned dose perturbation (PDP). This allows meaningful and intuitive analysis of the agreement between the planned and delivered dose, including direct comparison of the dose-volume histograms. While conceptually similar to modulated arc techniques, helical tomotherapy introduces significant challenges to the PDP formalism, arising primarily from TomoTherapy delivery dynamics. The temporal characteristics of the delivery are of the same order or shorter than the dosimeter's update interval (50 ms). Additionally, the prevalence of often small and complex segments, particularly with the 1 cm Y jaw setting, lead to challenges related to detector spacing. Here, we present and test a novel method of tomotherapy-PDP (TPDP) designed to meet these challenges. One of the novel techniques introduced for TPDP is organization of the subbeams into larger subunits called sectors, which assures more robust synchronization of the measurement and delivery dynamics. Another important change is the optional application of a correction based on ion chamber (IC) measurements in the phantom. The TPDP method was validated by direct comparisons to the IC and an independent, biplanar diode array dosimeter previously evaluated for tomotherapy delivery quality assurance. Nineteen plans with varying complexity were analyzed for the 2.5 cm tomotherapy jaw setting and 18 for the 1 cm opening. The dose differences between the TPDP and IC were 1.0% ± 1.1% and 1.1% ± 1.1%, for 2.5 and 1.0 cm jaw plans, respectively. Gamma analysis agreement rates between TPDP and the independent array were: 99.1%± 1.8% (using 3% global normalization/3 mm criteria) and 93.4% ± 7.1% (using 2% global/2 mm) for the 2.5 cm jaw plans; for 1 cm plans, they were 95.2% ± 6.7% (3% G/3) and 83.8% ± 12% (2% G/2). We conclude that TPDP is capable of volumetric dose reconstruction with acceptable accuracy. However, the challenges of fast tomotherapy delivery dynamics make TPDP less precise than the IMRT/VMAT PDP version, particularly for the 1 cm jaw setting.
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Takahashi Y, Verneris MR, Dusenbery K, Wilke C, Storme G, Weisdorf DJ, Hui SK. Peripheral dose heterogeneity due to the thread effect in total marrow irradiation with helical tomotherapy. Int J Radiat Oncol Biol Phys 2013; 87:832-9. [PMID: 24011657 PMCID: PMC3805769 DOI: 10.1016/j.ijrobp.2013.07.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Revised: 07/03/2013] [Accepted: 07/15/2013] [Indexed: 10/26/2022]
Abstract
PURPOSE To report potential dose heterogeneity leading to underdosing at different skeletal sites in total marrow irradiation (TMI) with helical tomotherapy due to the thread effect and provide possible solutions to reduce this effect. METHODS AND MATERIALS Nine cases were divided into 2 groups based on patient size, defined as maximum left-to-right arm distance (mLRD): small mLRD (≤47 cm) and large mLRD (>47 cm). TMI treatment planning was conducted by varying the pitch and modulation factor while a jaw size (5 cm) was kept fixed. Ripple amplitude, defined as the peak-to-trough dose relative to the average dose due to the thread effect, and the dose-volume histogram (DVH) parameters for 9 cases with various mLRD was analyzed in different skeletal regions at off-axis (eg, bones of the arm or femur), at the central axis (eg, vertebrae), and planning target volume (PTV), defined as the entire skeleton plus 1-cm margin. RESULTS Average ripple amplitude for a pitch of 0.430, known as one of the magic pitches that reduce thread effect, was 9.2% at 20 cm off-axis. No significant differences in DVH parameters of PTV, vertebrae, or femur were observed between small and large mLRD groups for a pitch of ≤0.287. Conversely, in the bones of the arm, average differences in the volume receiving 95% and 107% dose (V95 and V107, respectively) between large and small mLRD groups were 4.2% (P=.016) and 16% (P=.016), respectively. Strong correlations were found between mLRD and ripple amplitude (rs=.965), mLRD and V95 (rs=-.742), and mLRD and V107 (rs=.870) of bones of the arm. CONCLUSIONS Thread effect significantly influences DVH parameters in the bones of the arm for large mLRD patients. By implementing a favorable pitch value and adjusting arm position, peripheral dose heterogeneity could be reduced.
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Affiliation(s)
- Yutaka Takahashi
- Masonic Cancer Center, Division of Hematology, Oncology and Bone Marrow Transplantation
| | - Michael R. Verneris
- Department of Pediatrics, Division of Hematology, Oncology and Bone Marrow Transplantation
| | | | | | - Guy Storme
- Department of Radiotherapy, Universitair Ziekenhuis Brussel
| | | | - Susanta K Hui
- Masonic Cancer Center, Division of Hematology, Oncology and Bone Marrow Transplantation
- Department of Therapeutic Radiology, University of Minnesota
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Chen M, Chao E, Lu W. Quantitative characterization of tomotherapy MVCT dosimetry. Med Dosim 2013; 38:280-6. [PMID: 23558147 DOI: 10.1016/j.meddos.2013.02.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Revised: 12/12/2012] [Accepted: 02/03/2013] [Indexed: 10/27/2022]
Abstract
Megavoltage computed tomography (MVCT) is used as image guidance for patient setup in almost every tomotherapy treatment. Frequent use of ionizing radiation for image guidance has raised concern of imaging dose. The purpose of this work is to quantify and characterize tomotherapy MVCT dosimetry. Our dose calculation was based on a commissioned dose engine, and the calculation result was compared with film measurement. We studied dose profiles, center dose, maximal dose, surface dose, and mean dose on homogeneous cylindrical water phantoms of various diameters for various scanning parameters, including 3 different jaw openings (of nominal value J4, J1, and J0.1) and couch speeds (fine, normal, and coarse). The comparison between calculation and film measurement showed good agreement. In particular, the thread pattern on the film of the helical delivery matched very well with calculation. For the J1 jaw and coarse imaging mode, the maximum difference between calculation and measurement was about 6% of the center dose. Calculation on various sizes of synthesized phantoms showed that the center dose decreases almost linearly as the phantom diameter increases, and that the fine mode (couch speed of 4mm/rotation) received twice the dose of the normal mode (couch speed of 8mm/rotation) and 3 times that of the coarse mode (couch speed of 12mm/rotation) as expected. The maximal dose ranged from 100% to ∼200% of the center dose, with increasing ratios for larger phantoms, smaller jaws, and faster couch speed. For all jaw settings and couch speeds, the mean dose and average surface dose vary from 95% to 125% of the center dose with increasing ratios for larger phantoms. We present a quantitative dosimetric characterization of the tomotherapy MVCT in terms of scanning parameters, phantom size, center dose, maximal dose, surface dose, and mean dose. The results can provide an overall picture of dose distribution and a reference data set that enables estimation of CT dose index for the tomotherapy MVCT.
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Affiliation(s)
- Mingli Chen
- 21st Century Oncology, Madison, WI 53719, USA.
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