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Liang X, Li P, Wu Q. A novel AP/PA total body irradiation technique using abutting IMRT fields at extended SSD. J Appl Clin Med Phys 2024; 25:e14213. [PMID: 38425126 PMCID: PMC11005982 DOI: 10.1002/acm2.14213] [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: 06/22/2023] [Revised: 11/06/2023] [Accepted: 11/07/2023] [Indexed: 03/02/2024] Open
Abstract
PURPOSE To develop a Total Body Irradiation (TBI) technique using IMRT at extended SSD that can be performed in any size Linac room. METHODS Patients studied were placed on a platform close to the floor, directly under the gantry with cranial-caudal axis parallel to the gantry rotation plane and at SSD ∼200 cm. Two abutting fields with the same external isocenter at gantry angles of ±21˚, collimator angle of 90˚, and field size of 25 × 40 cm2 are employed for both supine and prone positions. An iterative optimization algorithm was developed to generate a uniform dose at the patient mid-plane with adequate shielding to critical organs such as lungs and kidneys. The technique was validated in both phantom and patient CT images for treatment planning, and dose measurement and QA were performed in phantom. RESULTS A uniform dose distribution in the mid-plane within ±5% of the prescription dose was reached after a few iterations. This was confirmed with ion-chamber measurements in phantom. The mean dose to lungs and kidneys can be adjusted according to clinical requirements and can be as low as ∼25% of the prescription dose. For a typical prescription dose of 200 cGy/fraction, the total MU was ∼2400/1200 for the superior/inferior field. The overall treatment time for both supine/prone positions was ∼54 min to meet the maximum absorbed dose rate criteria of 15 cGy/min. IMRT QA with portal dosimetry shows excellent agreement. CONCLUSIONS We have developed a promising TBI technique using abutting IMRT fields at extended SSD. The patient is in a comfortable recumbent position with good reproducibility and less motion during treatment. An additional benefit of this technique is that full 3D dose distribution is available from the TPS with a DVH summary for organs of interest. The technique allows precise sparing of lungs and kidneys and can be executed in any linac room.
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Affiliation(s)
- Xiaomin Liang
- Medical Physics Graduate ProgramDuke Kunshan UniversityKunshanJiangsuChina
| | - Peixiong Li
- Medical Physics Graduate ProgramDuke Kunshan UniversityKunshanJiangsuChina
| | - Qiuwen Wu
- Department of Radiation OncologyDuke University Medical CenterDurhamNorth CarolinaUSA
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Gharial J, Guilcher G, Truong T, Shah R, Desai S, Rojas-Vasquez M, Kangarloo B, Lewis V. Busulfan with 400 centigray of total body irradiation and higher dose fludarabine: An alternative regimen for hematopoietic stem cell transplantation in pediatric acute lymphoblastic leukemia. Pediatr Blood Cancer 2024; 71:e30844. [PMID: 38217082 DOI: 10.1002/pbc.30844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Revised: 12/01/2023] [Accepted: 12/21/2023] [Indexed: 01/14/2024]
Abstract
BACKGROUND Hematopoietic stem cell transplantation can be curative for children with difficult-to-treat leukemia. The conditioning regimen utilized is known to influence outcomes. We report outcomes of the conditioning regimen used at the Alberta Children's Hospital, consisting of busulfan (with pharmacokinetic target of 3750 μmol*min/L/day ±10%) for 4 days, higher dose (250 mg/m2 ) fludarabine and 400 centigray (cGy) of total body irradiation. PROCEDURE This retrospective study involved children receiving transplant for acute lymphoblastic leukemia (ALL). It compared children who fell within the target range for busulfan with those who were either not measured or were measured and fell outside this range. All other treatment factors were identical. RESULTS Twenty-nine children (17 within target) were evaluated. All subjects engrafted neutrophils with a median [interquartile range] time of 14 days [8-30 days]. The cumulative incidence of acute graft-versus-host disease was 44.8% [95% confidence interval, CI: 35.6%-54.0%], while chronic graft-versus-host disease was noted in 16.0% [95% CI: 8.7%-23.3%]. At 2 years, the overall survival was 78.1% [95% CI: 70.8%-86.4%] and event-free survival was 74.7% [95% CI: 66.4%-83.0%]. Cumulative incidence of relapse was 11.3% [95% CI: 5.1%-17.5%]. There were no statistically significant differences in between the group that received targeted busulfan compared with the untargeted group. CONCLUSION Our conditioning regiment for children with ALL resulted in outcomes comparable to standard treatment with acceptable toxicities and significant reduction in radiation dose. Targeting busulfan dose in this cohort did not result in improved outcomes.
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Affiliation(s)
- Jaspreet Gharial
- Section of Pediatric Hematology Oncology and Bone Marrow Transplantation, Alberta Children's Hospital, Calgary, Alberta, Canada
| | - Gregory Guilcher
- Section of Pediatric Hematology Oncology and Bone Marrow Transplantation, Alberta Children's Hospital, Calgary, Alberta, Canada
| | - Tony Truong
- Section of Pediatric Hematology Oncology and Bone Marrow Transplantation, Alberta Children's Hospital, Calgary, Alberta, Canada
| | - Ravi Shah
- Section of Pediatric Hematology Oncology and Bone Marrow Transplantation, Alberta Children's Hospital, Calgary, Alberta, Canada
| | - Sunil Desai
- Division of Pediatric Hematology/Oncology & Palliative Care, Stollery Children's Hospital, Edmonton, Alberta, Canada
| | - Marta Rojas-Vasquez
- Division of Pediatric Hematology/Oncology & Palliative Care, Stollery Children's Hospital, Edmonton, Alberta, Canada
| | - Bill Kangarloo
- Pharmacokinetic Scientist, Alberta Blood and Marrow Transplant Program, Foothills Hospital, and Tom Baker Cancer Centre, Calgary, Alberta, Canada
| | - Victor Lewis
- Section of Pediatric Hematology Oncology and Bone Marrow Transplantation, Alberta Children's Hospital, Calgary, Alberta, Canada
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Hering H, Effeney B, Brady C, Hargrave C. An evaluation of ankle and foot bolus in paediatric modulated arc total body irradiation (MATBI). J Med Radiat Sci 2024. [PMID: 38468597 DOI: 10.1002/jmrs.780] [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: 06/29/2023] [Accepted: 03/01/2024] [Indexed: 03/13/2024] Open
Abstract
INTRODUCTION This retrospective planning study aimed to evaluate the role of bolus in achieving dose uniformity in the ankles and feet in paediatric patients undergoing Modulated Arc Total Body Irradiation (MATBI) treatment and to identify patient factors that may negate or warrant its use. METHODS The clinically treated plans of 20 paediatric patients who received MATBI treatment utilising ankle and foot bolus (Bolus plan) were compared with two retrospectively generated plans; a plan with bolus removed and no re-optimisation (No Bolus plan), and a re-optimised plan without bolus attempting to achieve equal dosimetry to the clinical plan via monitor unit adjustment (MU plan). Descriptive statistics were used to evaluate the dose uniformity criteria of ±10% coverage of the reference dose (RD) for each subregion of the ankle and foot for the three plans. The impact of patient height, weight, and age at the time of treatment was evaluated using Spearman's correlation. RESULTS Variation in doses >10% RD was minimal across the three plans, with an average D1cc difference < 0.4Gy. For the ankle and foot regions in the Bolus plans, the volume receiving at least 90% of the RD (V90) was on average > 92%. In No Bolus and MU plans, there was an average reduction of 24.5% and 23.2% V90 coverage respectively in the toes. Spearman's correlation suggests height has the strongest relationship to D1cc. CONCLUSION This study validated the continued use of ankle and foot bolus to achieve dosimetric goals for paediatric MATBI treatments, particularly V90 coverage across all heights.
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Affiliation(s)
- Hannah Hering
- School of Clinical Sciences, Faculty of Health, Queensland University of Technology (QUT), Brisbane, Queensland, Australia
- Radiation Oncology Princess Alexandra Hospital-Raymond Terrace, Metro South Health Service, South Brisbane, Queensland, Australia
| | - Beth Effeney
- Radiation Oncology Princess Alexandra Hospital-Raymond Terrace, Metro South Health Service, South Brisbane, Queensland, Australia
| | - Carole Brady
- Radiation Oncology Princess Alexandra Hospital-Raymond Terrace, Metro South Health Service, South Brisbane, Queensland, Australia
| | - Catriona Hargrave
- School of Clinical Sciences, Faculty of Health, Queensland University of Technology (QUT), Brisbane, Queensland, Australia
- Radiation Oncology Princess Alexandra Hospital-Raymond Terrace, Metro South Health Service, South Brisbane, Queensland, Australia
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Frederick R, Van Dyke L, Hudson A, Pierce G. Advanced automated treatment planning for total body irradiation: Implementation and effects on standardization. Phys Med 2023; 112:102623. [PMID: 37356420 DOI: 10.1016/j.ejmp.2023.102623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 05/29/2023] [Accepted: 06/11/2023] [Indexed: 06/27/2023] Open
Abstract
PURPOSE This work describes the automation of our volumetric modulated arc therapy (VMAT) total body irradiation (TBI) treatment planning. It also aims to determine if plan standardization is impacted by automation. METHODS We introduced automated beam placement for TBI in March 2021. For manual beam placement pre-2021, Python-modified DICOM files were imported to pre-set cumulative meterset weights, with other parameters selected by dosimetrists. Our automated planning script automates these processes and sets gantry stop angles and isocentre placement. To determine the impact of automation on plan standardization, we performed a retrospective review of a matched cohort of 168 patients. Plan parameters were compared with an external standard, and passing rates compared between patient cohorts. The dosimetric impact was investigated by comparing a Body-5 mm homogeneity index (HI = D2%/D98%) and mean lung dose (MLD) between cohorts. RESULTS Results are listed for manual and automated groups respectively. Median (range) passing rates were 97.7% (96.1-100) and 99.2% (98.3-100). Automated plans had a significantly higher passing rate (p ≪ 0.05) and smaller variance (p = 0.001). Most failures were attributed to human error. Automated plans also had more consistent parameter identifiers. After considering dimensional outliers, median (range) Body-5 mm HI were 1.18 (1.14-1.23) and 1.18 (1.15-1.26), and mean ± standard deviation MLD were 103.8 ± 1.3% and 104.1 ± 0.9%. Variances were not significantly different between Body-5 mm HI (p = 0.092) but were for MLD (p = 0.013). CONCLUSIONS Implementation of automated planning in TBI resulted in significantly improved plan standardization. The decrease in variance of the MLD for the automated planning group points towards a potential dosimetric benefit of automation.
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Affiliation(s)
- Rebecca Frederick
- Department of Medical Physics, Tom Baker Cancer Centre, 1331 29 Street NW, Calgary, Alberta T2N 4N2, Canada; Department of Physics and Astronomy, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada.
| | - Lukas Van Dyke
- Department of Medical Physics, Tom Baker Cancer Centre, 1331 29 Street NW, Calgary, Alberta T2N 4N2, Canada
| | - Alana Hudson
- Department of Medical Physics, Tom Baker Cancer Centre, 1331 29 Street NW, Calgary, Alberta T2N 4N2, Canada; Department of Oncology, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
| | - Greg Pierce
- Department of Physics and Astronomy, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada; Department of Oncology, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada; Varian Medical Systems, Inc., 3100 Hansen Way, Palo Alto, CA 94304, United States
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Misson-Yates S, Cunningham R, Gonzalez R, Diez P, Clark CH. Optimised conformal total body irradiation: a heterogeneous practice, so where next? Br J Radiol 2023; 96:20220650. [PMID: 36475820 PMCID: PMC10078861 DOI: 10.1259/bjr.20220650] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The use of volumetric arc therapy and inverse planning has been in routine use in radiotherapy for two decades. However, use in total body irradiation (TBI) has been more recent and few guidelines exist as to how to plan or verify. This has led to heterogeneous approaches. The goal of this review is to provide an overview of current advanced planning and dosimetry verification protocols used in optimised conformal TBI as a basis for investigating the need for greater standardisation in TBI.
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Affiliation(s)
- Sarah Misson-Yates
- Department of Medical Physics, Guy's Cancer Centre, Guy's and St Thomas' NHS Foundation Trust, London, UK
- School of Biomedical Engineering & Imaging Sciences, King's College London, London, United Kingdom
| | - Rissa Cunningham
- Department of Medical Physics, Guy's Cancer Centre, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Regina Gonzalez
- Department of Medical Physics, Guy's Cancer Centre, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Patricia Diez
- Radiotherapy Physics, National Radiotherapy Trials Quality Assurance Group (RTTQA), Mount Vernon Cancer Centre, Northwood, UK
| | - 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
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Cananoglu M, Hurmuz P, Yeginer M, Ozyigit G. Planning and dosimetric evaluation of three total body irradiation techniques: Standard SSD VMAT, Extended SSD VMAT and Extended SSD Field-in-Field. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2023; 62:73-81. [PMID: 36269391 DOI: 10.1007/s00411-022-00999-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 10/01/2022] [Indexed: 06/16/2023]
Abstract
The aim of this study was to dosimetrically compare three total body irradiation (TBI) techniques which can be delivered by a standard linear accelerator, and to deduce which one is preferable. Specifically, Extended Source to Surface Distance (SSD) Field-in-Field (FiF), Extended SSD Volumetric Modulated Arc Therapy (VMAT), and Standard SSD VMAT TBI techniques were dosimetrically evaluated. Percent depth dose and dose profile measurements were made under treatment conditions for each specified technique. After having generated treatment plans with a treatment planning system (TPS), dose homogeneity and critical organ doses were investigated on a Rando phantom using radiochromic films and optically stimulated luminescence dosimeters (OSLDs). TBI dose of 12 Gy in six fractions was prescribed for each technique. The gamma index (5%/5 mm) was used for the analysis of radiochromic films. Passing rates for Extended SSD FiF, Extended SSD VMAT and Standard SSD VMAT techniques were found to be 90%, 87% and 94%, respectively. OSLD measurements were within ± 5% agreement with TPS calculations for the first two techniques whereas the agreement was found to be within ± 3% for the Standard SSD VMAT technique. TPS calculations demonstrated that mean lung doses in the first two techniques were around 8.5 Gy while it was kept around 7 Gy in Standard SSD VMAT. It is concluded that Standard SSD VMAT is superior in sparing the lung tissue while all three TBI techniques are feasible in clinical practice with acceptable dose homogeneity. In the absence of VMAT-based treatment planning, Extended SSD FiF would be a reasonable choice compared to other conventional techniques.
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Affiliation(s)
- Mert Cananoglu
- Department of Radiation Oncology, Faculty of Medicine, Hacettepe University, 06100, Ankara, Turkey
| | - Pervin Hurmuz
- Department of Radiation Oncology, Faculty of Medicine, Hacettepe University, 06100, Ankara, Turkey.
| | - Mete Yeginer
- Department of Radiation Oncology, Faculty of Medicine, Hacettepe University, 06100, Ankara, Turkey
| | - Gokhan Ozyigit
- Department of Radiation Oncology, Faculty of Medicine, Hacettepe University, 06100, Ankara, Turkey
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Strolin S, Paolani G, Santoro M, Cercenelli L, Bortolani B, Ammendolia I, Cammelli S, Cicoria G, Win PW, Morganti AG, Marcelli E, Strigari L. Improving total body irradiation with a dedicated couch and 3D-printed patient-specific lung blocks: A feasibility study. Front Oncol 2023; 12:1046168. [PMID: 36741733 PMCID: PMC9893493 DOI: 10.3389/fonc.2022.1046168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 11/16/2022] [Indexed: 01/20/2023] Open
Abstract
Introduction Total body irradiation (TBI) is an important component of the conditioning regimen in patients undergoing hematopoietic stem cell transplants. TBI is used in very few patients and therefore it is generally delivered with standard linear accelerators (LINACs) and not with dedicated devices. Severe pulmonary toxicity is the most common adverse effect after TBI, and patient-specific lead blocks are used to reduce mean lung dose. In this context, online treatment setup is crucial to achieve precise positioning of the lung blocks. Therefore, in this study we aim to report our experience at generating 3D-printed patient-specific lung blocks and coupling a dedicated couch (with an integrated onboard image device) with a modern LINAC for TBI treatment. Material and methods TBI was planned and delivered (2Gy/fraction given twice a day, over 3 days) to 15 patients. Online images, to be compared with planned digitally reconstructed radiographies, were acquired with the couch-dedicated Electronic Portal Imaging Device (EPID) panel and imported in the iView software using a homemade Graphical User Interface (GUI). In vivo dosimetry, using Metal-Oxide Field-Effect Transistors (MOSFETs), was used to assess the setup reproducibility in both supine and prone positions. Results 3D printing of lung blocks was feasible for all planned patients using a stereolithography 3D printer with a build volume of 14.5×14.5×17.5 cm3. The number of required pre-TBI EPID-images generally decreases after the first fraction. In patient-specific quality assurance, the difference between measured and calculated dose was generally<2%. The MOSFET measurements reproducibility along each treatment and patient was 2.7%, in average. Conclusion The TBI technique was successfully implemented, demonstrating that our approach is feasible, flexible, and cost-effective. The use of 3D-printed patient-specific lung blocks have the potential to personalize TBI treatment and to refine the shape of the blocks before delivery, making them extremely versatile.
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Affiliation(s)
- Silvia Strolin
- Department of Medical Physics, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Giulia Paolani
- Department of Medical Physics, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy,*Correspondence: Giulia Paolani, ; Lidia Strigari,
| | - Miriam Santoro
- Department of Medical Physics, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Laura Cercenelli
- eDIMES Lab-Laboratory of Bioengineering, Department of Experimental Diagnostic and Specialty Medicine, (DIMES), Alma Mater Studiorum University of Bologna, Bologna, Italy
| | - Barbara Bortolani
- eDIMES Lab-Laboratory of Bioengineering, Department of Experimental Diagnostic and Specialty Medicine, (DIMES), Alma Mater Studiorum University of Bologna, Bologna, Italy
| | - Ilario Ammendolia
- Radiation Oncology, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Silvia Cammelli
- Radiation Oncology, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy,Department of Experimental, Diagnostic and Specialty Medicine-DIMES, Alma Mater Studiorum University of Bologna, Bologna, Italy
| | - Gianfranco Cicoria
- Department of Medical Physics, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Phyo Wai Win
- Department of Medical Physics, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Alessio G. Morganti
- Radiation Oncology, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy,Department of Experimental, Diagnostic and Specialty Medicine-DIMES, Alma Mater Studiorum University of Bologna, Bologna, Italy
| | - Emanuela Marcelli
- eDIMES Lab-Laboratory of Bioengineering, Department of Experimental Diagnostic and Specialty Medicine, (DIMES), Alma Mater Studiorum University of Bologna, Bologna, Italy
| | - Lidia Strigari
- Department of Medical Physics, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy,*Correspondence: Giulia Paolani, ; Lidia Strigari,
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Maerz M, Treutwein M, Nabo J, Dobler B. Three-dimensional printers applied for the production of beam blocks in total body irradiation treatment. J Appl Clin Med Phys 2022; 23:e13592. [PMID: 35290701 PMCID: PMC9121048 DOI: 10.1002/acm2.13592] [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: 10/07/2021] [Revised: 01/20/2022] [Accepted: 03/01/2022] [Indexed: 12/02/2022] Open
Abstract
Purpose Total body irradiation (TBI) in extended source surface distance (SSD) is a common treatment technique before hematopoietic stem cell transplant. The lungs are organs at risk, which often are treated with a lower dose than the whole body. Methods This can be achieved by the application of blocks. Three‐dimensional (3D) printers are a modern tool to be used in the production process of these blocks. Results We demonstrate the applicability of a specific printer and printing material, describe the process, and evaluate the accuracy of the product. Conclusion The blocks and apertures were found to be applicable in clinical routine.
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Affiliation(s)
- Manuel Maerz
- Department of Radiotherapy, Regensburg University Medical Center, Regensburg, Germany
| | - Marius Treutwein
- Department of Radiotherapy, Regensburg University Medical Center, Regensburg, Germany
| | - Jan Nabo
- Department for Mathematics and Computer Science, Ostbayerische Technische Hochschule Regensburg, Regensburg, Germany
| | - Barbara Dobler
- Department of Radiotherapy, Regensburg University Medical Center, Regensburg, Germany
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Hansen AT, Rose HK, Yates ES, Hansen J, Petersen JB. Two compound techniques for total body irradiation. Tech Innov Patient Support Radiat Oncol 2021; 21:1-7. [PMID: 34977366 PMCID: PMC8683645 DOI: 10.1016/j.tipsro.2021.11.006] [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] [Received: 09/19/2021] [Revised: 11/10/2021] [Accepted: 11/30/2021] [Indexed: 01/21/2023] Open
Abstract
INTRODUCTION Total body irradiation (TBI) is an important treatment modality that is used in combination with chemotherapy in many stem cell transplantation protocols. Therefore, the quality of the irradiation is important. Two techniques for planning and delivering TBI are presented and compared. METHODS AND MATERIALS The technique named ExIMRT is a combination of manually shaped conventional fields from an extended SSD and isocentric IMRT fields. The technique named ExVMAT is a combination of conventional and IMRT fields from an extended SSD and isocentric VMAT fields. Dosimetric data from 32 patients who were planned and treated according to one of the two techniques were compared. RESULTS When comparing the two techniques, it is determined that the ExVMAT technique is able to significantly reduce the mean total volume overdosed by 120% from 408 to 12 cm3. The dose covering 98% of the total lung volume is significantly increased by this technique from a mean of 9.7 Gy to 10.3 Gy. Additionally, the dose covering 2% of the total kidney volume is significantly decreased from a mean of 12.8 to 12.5 Gy. Furthermore, the population-based variance of the median dose to the total lung volume, the heart and the volume of the body prescribed to 12.5 Gy is significantly reduced. The results are obtained without compromising overall treatment quality as treatment time or dose rate to the lungs. CONCLUSION Using the ExVMAT technique, a superior dose distribution can be delivered both from a patient and a population perspective compared to the ExIMRT technique.
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Affiliation(s)
- Anders T. Hansen
- Department of Medical Physics, Aarhus University Hospital, Aarhus, Denmark,Corresponding author at: Department of Medical Physics, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, 8200 Aarhus N, Denmark.
| | - Hanne K. Rose
- Department of Oncology, Aarhus University Hospital, Aarhus, Denmark
| | - Esben S. Yates
- Department of Medical Physics, Aarhus University Hospital, Aarhus, Denmark
| | - Jolanta Hansen
- Department of Medical Physics, Aarhus University Hospital, Aarhus, Denmark
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Hoeben BAW, Wong JYC, Fog LS, Losert C, Filippi AR, Bentzen SM, Balduzzi A, Specht L. Total Body Irradiation in Haematopoietic Stem Cell Transplantation for Paediatric Acute Lymphoblastic Leukaemia: Review of the Literature and Future Directions. Front Pediatr 2021; 9:774348. [PMID: 34926349 PMCID: PMC8678472 DOI: 10.3389/fped.2021.774348] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Accepted: 11/03/2021] [Indexed: 12/13/2022] Open
Abstract
Total body irradiation (TBI) has been a pivotal component of the conditioning regimen for allogeneic myeloablative haematopoietic stem cell transplantation (HSCT) in very-high-risk acute lymphoblastic leukaemia (ALL) for decades, especially in children and young adults. The myeloablative conditioning regimen has two aims: (1) to eradicate leukaemic cells, and (2) to prevent rejection of the graft through suppression of the recipient's immune system. Radiotherapy has the advantage of achieving an adequate dose effect in sanctuary sites and in areas with poor blood supply. However, radiotherapy is subject to radiobiological trade-offs between ALL cell destruction, immune and haematopoietic stem cell survival, and various adverse effects in normal tissue. To diminish toxicity, a shift from single-fraction to fractionated TBI has taken place. However, HSCT and TBI are still associated with multiple late sequelae, leaving room for improvement. This review discusses the past developments of TBI and considerations for dose, fractionation and dose-rate, as well as issues regarding TBI setup performance, limitations and possibilities for improvement. TBI is typically delivered using conventional irradiation techniques and centres have locally developed heterogeneous treatment methods and ways to achieve reduced doses in several organs. There are, however, limitations in options to shield organs at risk without compromising the anti-leukaemic and immunosuppressive effects of conventional TBI. Technological improvements in radiotherapy planning and delivery with highly conformal TBI or total marrow irradiation (TMI), and total marrow and lymphoid irradiation (TMLI) have opened the way to investigate the potential reduction of radiotherapy-related toxicities without jeopardising efficacy. The demonstration of the superiority of TBI compared with chemotherapy-only conditioning regimens for event-free and overall survival in the randomised For Omitting Radiation Under Majority age (FORUM) trial in children with high-risk ALL makes exploration of the optimal use of TBI delivery mandatory. Standardisation and comprehensive reporting of conventional TBI techniques as well as cooperation between radiotherapy centres may help to increase the ratio between treatment outcomes and toxicity, and future studies must determine potential added benefit of innovative conformal techniques to ultimately improve quality of life for paediatric ALL patients receiving TBI-conditioned HSCT.
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Affiliation(s)
- Bianca A. W. Hoeben
- Department of Radiation Oncology, University Medical Center Utrecht, Utrecht, Netherlands
- Princess Máxima Center for Pediatric Oncology, Utrecht, Netherlands
| | - Jeffrey Y. C. Wong
- Department of Radiation Oncology, City of Hope National Medical Center and Beckman Research Institute, Duarte, CA, United States
| | - Lotte S. Fog
- Alfred Health Radiation Oncology, The Alfred Hospital, Melbourne, VIC, Australia
| | - Christoph Losert
- Department of Radiation Oncology, University Hospital, Ludwig Maximilian University of Munich, Munich, Germany
| | - Andrea R. Filippi
- Department of Radiation Oncology, Fondazione IRCCS Policlinico San Matteo and University of Pavia, Pavia, Italy
| | - Søren M. Bentzen
- Division of Biostatistics and Bioinformatics, Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Adriana Balduzzi
- Stem Cell Transplantation Unit, Clinica Paediatrica Università degli Studi di Milano Bicocca, Monza, Italy
| | - Lena Specht
- Department of Oncology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
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Naessig M, Hernandez S, Astorga NR, McCulloch J, Saenz D, Myers P, Rasmussen K, Stathakis S, Ha CS, Papanikolaou N, Ford J, Kirby N. A customizable aluminum compensator system for total body irradiation. J Appl Clin Med Phys 2021; 22:36-44. [PMID: 34432944 PMCID: PMC8504611 DOI: 10.1002/acm2.13393] [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] [Received: 07/10/2020] [Revised: 07/15/2021] [Accepted: 07/28/2021] [Indexed: 11/08/2022] Open
Abstract
Purpose To develop a simplified aluminum compensator system for total body irradiation (TBI) that is easy to assemble and modify in a short period of time for customized patient treatments. Methods The compensator is composed of a combination of 0.3 cm thick aluminum bars, two aluminum T‐tracks, spacers, and metal bolts. The system is mounted onto a plexiglass block tray. The design consists of 11 fixed sectors spanning from the patient's head to feet. The outermost sectors utilize 7.6 cm wide aluminum bars, while the remaining sectors use 2.5 cm wide aluminum bars. There is a magnification factor of 5 from the compensator to the patient treatment plane. Each bar of aluminum is interconnected at each adjacent sector with a tongue and groove arrangement and fastened to the T‐track using a metal washer, bolt, and nut. Inter‐bar leakage of the compensator was tested using a water tank and diode. End‐to‐end measurements were performed with an ion chamber in a solid water phantom and also with a RANDO phantom using internal and external optically stimulated luminescent detectors (OSLDs). In‐vivo patient measurements from the first 20 patients treated with this aluminum compensator were compared to those from 20 patients treated with our previously used lead compensator system. Results The compensator assembly time was reduced to 20–30 min compared to the 2–4 h it would take with the previous lead design. All end‐to‐end measurements were within 10% of that expected. The median absolute in‐vivo error for the aluminum compensator was 3.7%, with 93.8% of measurements being within 10% of that expected. The median error for the lead compensator system was 5.3%, with 85.1% being within 10% of that expected. Conclusion This design has become the standard compensator at our clinic. It allows for quick assembly and customization along with meeting the Task Group 29 recommendations for dose uniformity.
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Affiliation(s)
- Madison Naessig
- Department of Radiation Oncology, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA.,Department of Nuclear Engineering, Texas A&M University, College Station, Texas, USA
| | - Soleil Hernandez
- Department of Nuclear Engineering, Texas A&M University, College Station, Texas, USA
| | - Nestor Rodrigo Astorga
- Department of Radiation Oncology, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - James McCulloch
- Department of Radiation Oncology, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Daniel Saenz
- Department of Radiation Oncology, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Pamela Myers
- Department of Radiation Oncology, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Karl Rasmussen
- Department of Radiation Oncology, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Sotirios Stathakis
- Department of Radiation Oncology, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Chul S Ha
- Department of Radiation Oncology, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Niko Papanikolaou
- Department of Radiation Oncology, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - John Ford
- Department of Nuclear Engineering, Texas A&M University, College Station, Texas, USA
| | - Neil Kirby
- Department of Radiation Oncology, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
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12
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Aldrovandi LG, Farías RO, Mauri MF, Mairal ML. Commissioning of a three-dimensional arc-based technique for total body irradiation. J Appl Clin Med Phys 2021; 22:123-142. [PMID: 34258860 PMCID: PMC8425872 DOI: 10.1002/acm2.13355] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 03/25/2021] [Accepted: 06/16/2021] [Indexed: 11/24/2022] Open
Abstract
The purpose of this study is to describe the commissioning of a novel three‐dimensional arc‐based technique for total body irradiation (TBI) treatments. The development and implementation of this technique allowed our institution to transition from a bilateral two‐dimensional (2D) technique to a methodology based on volumetric dose calculation. The methodology described in this work is a derivation from the MATBI technique, with the static fields being replaced by four contiguous arc‐fields for each anterior and posterior incidence. The reduced number of fields we employed makes it possible to reach a satisfactory dose uniformity through manual optimization in a straightforward process. We use the Eclipse anisotropic analytical algorithm (AAA) algorithm, commissioned with preconfigured beam data for a 6 MV photon beam, at standard SSD (100 cm). A thorough evaluation of the accuracy of the AAA algorithm at an extended distance (approximately 200 cm) was carried out. For the evaluation, we compared measured and calculated percentage depth–dose and profiles that included open‐field, penumbra, and out‐of‐field regions. The analysis was performed for both static and arc fields, taking into consideration unshielded fields and also in the presence of lung shielding blocks. End‐to‐end tests were carried out for our institutional template plan by two means: with a 2D ion chamber array detector in solid phantom and using Gafchromic films in an anthropomorphic phantom. The results obtained in this work demonstrate that the Eclipse AAA algorithm commissioned for standard treatments can be safely used with our TBI planning technique. Moreover, this technique proved to be a highly efficient path to replace conventional treatment techniques, providing a homogeneous dose distribution, dosimetric robustness, and shorter treatment times. In addition, as inherited from the MATBI technique, our methodology can be implemented in small treatment rooms, with no need for ancillary equipment.
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Affiliation(s)
- León G Aldrovandi
- Departamento de Física Médica, Mevaterapia Oncología Radiante, Ciudad Autónoma de Buenos Aires, Argentina
| | - Rubén O Farías
- Departamento de Física Médica, Mevaterapia Oncología Radiante, Ciudad Autónoma de Buenos Aires, Argentina
| | - María F Mauri
- Departamento de Física Médica, Mevaterapia Oncología Radiante, Ciudad Autónoma de Buenos Aires, Argentina
| | - María L Mairal
- Departamento de Física Médica, Mevaterapia Oncología Radiante, Ciudad Autónoma de Buenos Aires, Argentina
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13
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Hoeben BA, Pazos M, Albert MH, Seravalli E, Bosman ME, Losert C, Boterberg T, Manapov F, Ospovat I, Milla SM, Abakay CD, Engellau J, Kos G, Supiot S, Bierings M, Janssens GO. Towards homogenization of total body irradiation practices in pediatric patients across SIOPE affiliated centers. A survey by the SIOPE radiation oncology working group. Radiother Oncol 2021; 155:113-119. [DOI: 10.1016/j.radonc.2020.10.032] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 10/07/2020] [Accepted: 10/21/2020] [Indexed: 02/06/2023]
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14
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Cleuziou JP, Desgranges C, Henry I, Jaumot M, Chartier P, Sihanath R, Carré M, Bulabois CE, Cahn JY, Pasteris C, Balosso J, Gabelle-Flandin I, Verry C, Giraud JY. Total body irradiation using helical tomotherapy: Set-up experience and in-vivo dosimetric evaluation. Cancer Radiother 2021; 25:213-221. [PMID: 33402290 DOI: 10.1016/j.canrad.2020.07.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 07/02/2020] [Accepted: 07/07/2020] [Indexed: 11/25/2022]
Abstract
PURPOSE Helical Tomotherapy (HT) appears as a valuable technique for total body irradiation (TBI) to create highly homogeneous and conformal dose distributions with more precise repositioning than conventional TBI techniques. The aim of this work is to describe the technique implementation, including treatment preparation, planning and dosimetric monitoring of TBI delivered in our institution from October 2016 to March 2019. MATERIAL AND METHOD Prior to patient care, irradiation protocol was set up using physical phantoms. Gafchromic films were used to assess dose distribution homogeneity and evaluate imprecise patient positioning impact. Sixteen patients' irradiations with a prescribed dose of 12Gy were delivered in 6 fractions of 2Gy over 3 days. Pre-treatment quality assurance (QA) was performed for the verification of dose distributions at selected positions. In addition, in-vivo dosimetry was carried out using optically stimulated luminescence dosimeters (OSLD). RESULTS Planning evaluation, as well as results of pre-treatment verifications, are presented. In-vivo dosimetry showed the strong consistency of OSLD measured doses. OSLD mean relative dose differences between measurement and calculation were respectively +0,96% and -2% for armpit and hands locations, suggesting better reliability for armpit OSLD positioning. Repercussion of both longitudinal and transversal positioning inaccuracies on phantoms is depicted up to 2cm shifts. CONCLUSION The full methodology to set up TBI protocol, as well as dosimetric evaluation and pre-treatment QA, were presented. Our investigations reveal strong correspondence between planned and delivered doses shedding light on the dose reliability of OSLD for HT based TBI in-vivo dosimetry.
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Affiliation(s)
- J-P Cleuziou
- Service de radiothérapie, centre hospitalier universitaire Grenoble-Alpes (CHUGA), CS 10217, Grenoble cedex 9, France
| | - C Desgranges
- Service de radiothérapie, centre hospitalier universitaire Grenoble-Alpes (CHUGA), CS 10217, Grenoble cedex 9, France
| | - I Henry
- Service de radiothérapie, centre hospitalier universitaire Grenoble-Alpes (CHUGA), CS 10217, Grenoble cedex 9, France
| | - M Jaumot
- Service de radiothérapie, centre hospitalier universitaire Grenoble-Alpes (CHUGA), CS 10217, Grenoble cedex 9, France
| | - P Chartier
- Service de radiothérapie, centre hospitalier universitaire Grenoble-Alpes (CHUGA), CS 10217, Grenoble cedex 9, France
| | - R Sihanath
- Service de radiothérapie, centre hospitalier universitaire Grenoble-Alpes (CHUGA), CS 10217, Grenoble cedex 9, France
| | - M Carré
- Service d'hématologie, centre hospitalier universitaire Grenoble-Alpes (CHUGA), CS 10217, Grenoble cedex 9, France
| | - C E Bulabois
- Service d'hématologie, centre hospitalier universitaire Grenoble-Alpes (CHUGA), CS 10217, Grenoble cedex 9, France
| | - J-Y Cahn
- Service d'hématologie, centre hospitalier universitaire Grenoble-Alpes (CHUGA), CS 10217, Grenoble cedex 9, France
| | - C Pasteris
- Service de radiothérapie, centre hospitalier universitaire Grenoble-Alpes (CHUGA), CS 10217, Grenoble cedex 9, France
| | - J Balosso
- Service de radiothérapie, centre hospitalier universitaire Grenoble-Alpes (CHUGA), CS 10217, Grenoble cedex 9, France
| | - I Gabelle-Flandin
- Service de radiothérapie, centre hospitalier universitaire Grenoble-Alpes (CHUGA), CS 10217, Grenoble cedex 9, France
| | - C Verry
- Service de radiothérapie, centre hospitalier universitaire Grenoble-Alpes (CHUGA), CS 10217, Grenoble cedex 9, France
| | - J-Y Giraud
- Service de radiothérapie, centre hospitalier universitaire Grenoble-Alpes (CHUGA), CS 10217, Grenoble cedex 9, France.
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15
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Frederick R, Hudson A, Balogh A, Cao JQ, Pierce G. Standardized flattening filter free volumetric modulated arc therapy plans based on anteroposterior width for total body irradiation. J Appl Clin Med Phys 2020; 21:75-86. [PMID: 32043760 PMCID: PMC7075390 DOI: 10.1002/acm2.12827] [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] [Received: 06/04/2019] [Revised: 01/09/2020] [Accepted: 01/10/2020] [Indexed: 12/17/2022] Open
Abstract
In this work, the feasibility of using flattening filter free (FFF) beams in volumetric modulated arc therapy (VMAT) total body irradiation (TBI) treatment planning to decrease protracted beam‐on times for these treatments was investigated. In addition, a methodology was developed to generate standardized VMAT TBI treatment plans based on patient physical dimensions to eliminate plan optimization time. A planning study cohort of 47 TBI patients previously treated with optimized VMAT ARC 6 MV beams was retrospectively examined. These patients were sorted into six categories depending on height and anteroposterior (AP) width at the umbilicus. Using Varian Eclipse, clinical 40 cm × 10 cm open field arcs were substituted with 6 MV FFF. Mid‐plane lateral dose profiles in conjunction with relative arc output factors (RAOF) yielded how far a given multileaf collimator (MLC) leaf must move in order to achieve a mid‐plane 100% isodose for a specific control point. Linear interpolation gave the dynamic MLC aperture for the entire arc for each patient AP width category, which was subsequently applied through Python scripting. All FFF VMAT TBI plans were then evaluated by two radiation oncologists and deemed clinically acceptable. The FFF and clinical VMAT TBI plans had similar Body–5 mm D98% distributions, but overall the FFF plans had statistically significantly increased or broader Body–5 mm D2% and mean lung dose distributions. These differences are not considered clinically significant. Median beam‐on times for the FFF and clinical VMAT TBI plans were 11.07 and 18.06 min, respectively, and planning time for the FFF VMAT TBI plans was reduced by 34.1 min. In conclusion, use of FFF beams in VMAT TBI treatment planning resulted in dose homogeneity similar to our current VMAT TBI technique. Clinical dosimetric criteria were achieved for a majority of patients while planning and calculated beam‐on times were reduced, offering the possibility of improved patient experience.
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Affiliation(s)
- Rebecca Frederick
- Department of Medical Physics, Tom Baker Cancer Centre, Calgary, AB, Canada.,Department of Physics and Astronomy, University of Calgary, Calgary, AB, Canada
| | - Alana Hudson
- Department of Medical Physics, Tom Baker Cancer Centre, Calgary, AB, Canada.,Department of Oncology, University of Calgary, Calgary, AB, Canada
| | - Alex Balogh
- Department of Oncology, University of Calgary, Calgary, AB, Canada.,Division of Radiation Oncology, Tom Baker Cancer Centre, Calgary, AB, Canada
| | - Jeffrey Q Cao
- Department of Oncology, University of Calgary, Calgary, AB, Canada.,Division of Radiation Oncology, Tom Baker Cancer Centre, Calgary, AB, Canada
| | - Greg Pierce
- Department of Medical Physics, Tom Baker Cancer Centre, Calgary, AB, Canada.,Department of Physics and Astronomy, University of Calgary, Calgary, AB, Canada.,Department of Oncology, University of Calgary, Calgary, AB, Canada
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16
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Losert C, Shpani R, Kießling R, Freislederer P, Li M, Walter F, Niyazi M, Reiner M, Belka C, Corradini S. Novel rotatable tabletop for total-body irradiation using a linac-based VMAT technique. Radiat Oncol 2019; 14:244. [PMID: 31888680 PMCID: PMC6937701 DOI: 10.1186/s13014-019-1445-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Accepted: 12/12/2019] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND Volumetric Modulated Arc Therapy (VMAT) techniques have recently been implemented in clinical practice for total-body irradiation (TBI). To date, most techniques still use special couches, translational tables, or other self-made immobilization devices for dose delivery. Aim of the present study was to report the first results of a newly developed rotatable tabletop designed for VMAT-TBI. METHODS The VMAT-TBI technique theoretically allows the use of any standard positioning device at the linear accelerator. Nevertheless, the main problem is that patients taller than 120 cm cannot be treated in one position due to the limited cranial-caudal couch shift capacities of the linac. Therefore, patients are usually turned from a head-first supine position (HFS) to a feet-first supine position (FFS) to overcome this limitation. The newly developed rotatable tabletop consists completely of carbon fiber, including the ball bearing within the base plate of the rotation unit. The patient can be turned 180° from a HFS to a FFS position within a few seconds, without the need of repositioning. RESULTS The first 20 patients had a median age of 47 years, and received TBI before bone marrow transplantation for acute myeloid leukemia. Most patients (13/20) received a TBI dose of 4 Gy in 2 fractions, twice daily. The mean number of applied monitor units (MU) was 6476 MU using a multi-arcs and multi-isocenter VMAT-TBI technique. The tabletop has been successfully used in daily clinical practice and helped to keep the treatment times at an acceptable level. During the first treatment fraction, the mean overall treatment time (OTT) was 57 min. Since no additional image guidance was used in fraction 2 of the same day, the OTT was reduced to mean 38 min. CONCLUSIONS The easy and reproducible rotation of the patient on the treatment couch using the rotatable tabletop, is time-efficient and overcomes the need of repositioning the patient after turning from a HFS to a FFS position during VMAT TBI. Furthermore, it prevents couch-gantry collisions, incorrect isocenter shifts and beam mix-up due to predicted absolute table coordinates, which are recorded to the R + V system with the corresponding beams.
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Affiliation(s)
- Christoph Losert
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistr. 15, 81377, Munich, Germany
| | - Roel Shpani
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistr. 15, 81377, Munich, Germany
| | - Robert Kießling
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistr. 15, 81377, Munich, Germany
| | - Philipp Freislederer
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistr. 15, 81377, Munich, Germany
| | - Minglun Li
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistr. 15, 81377, Munich, Germany
| | - Franziska Walter
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistr. 15, 81377, Munich, Germany
| | - Maximilian Niyazi
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistr. 15, 81377, Munich, Germany
| | - Michael Reiner
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistr. 15, 81377, Munich, Germany
| | - Claus Belka
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistr. 15, 81377, Munich, Germany
| | - Stefanie Corradini
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistr. 15, 81377, Munich, Germany.
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