1
|
Chen D, Motlagh SAO, Stappen FV, Labarbe R, Bell B, Kim M, Teo BKK, Dong L, Zou W, Diffenderfer ES. Secondary neutron dosimetry for conformal FLASH proton therapy. Med Phys 2024. [PMID: 38597815 DOI: 10.1002/mp.17050] [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: 10/31/2023] [Revised: 03/12/2024] [Accepted: 03/13/2024] [Indexed: 04/11/2024] Open
Abstract
BACKGROUND Cyclotron-based proton therapy systems utilize the highest proton energies to achieve an ultra-high dose rate (UHDR) for FLASH radiotherapy. The deep-penetrating range associated with this high energy can be modulated by inserting a uniform plate of proton-stopping material, known as a range shifter, in the beam path at the nozzle to bring the Bragg peak within the target while ensuring high proton transport efficiency for UHDR. Aluminum has been recently proposed as a range shifter material mainly due to its high compactness and its mechanical properties. A possible drawback lies in the fact that aluminum has a larger cross-section of producing secondary neutrons compared to conventional plastic range shifters. Accordingly, an increase in secondary neutron contamination was expected during the delivery of range-modulated FLASH proton therapy, potentially heightening neutron-induced carcinogenic risks to the patient. PURPOSE We conducted neutron dosimetry using simulations and measurements to evaluate excess dose due to neutron exposure during UHDR proton irradiation with aluminum range shifters compared to plastic range shifters. METHODS Monte Carlo simulations in TOPAS were performed to investigate the secondary neutron production characteristics with aluminum range shifter during 225 MeV single-spot proton irradiation. The computational results were validated against measurements with a pair of ionization chambers in an out-of-field region ( ≤ $\le$ 30 cm) and with a Proton Recoil Scintillator-Los Alamos rem meter in a far-out-of-field region (0.5-2.5 m). The assessments were repeated with solid water slabs as a surrogate for the conventional range shifter material to evaluate the impact of aluminum on neutron yield. The results were compared with the International Electrotechnical Commission (IEC) standards to evaluate the clinical acceptance of the secondary neutron yield. RESULTS For a range modulation up to 26 cm in water, the maximum simulated and measured values of out-of-field secondary neutron dose equivalent per therapeutic dose with aluminum range shifter were found to be( 0.57 ± 0.02 ) mSv/Gy $(0.57\pm 0.02)\ \text{mSv/Gy}$ and( 0.46 ± 0.04 ) mSv/Gy $(0.46\pm 0.04)\ \text{mSv/Gy}$ , respectively, overall higher than the solid water cases (simulation:( 0.332 ± 0.003 ) mSv/Gy $(0.332\pm 0.003)\ \text{mSv/Gy}$ ; measurement:( 0.33 ± 0.03 ) mSv/Gy $(0.33\pm 0.03)\ \text{mSv/Gy}$ ). The maximum far out-of-field secondary neutron dose equivalent was found to be (8.8 ± 0.5 $8.8 \pm 0.5$ ) μ Sv / Gy $\umu {\rm Sv/Gy}$ and (1.62 ± 0.02 $1.62 \pm 0.02$ ) μ Sv / Gy $\umu {\rm Sv/Gy}$ for the simulations and rem meter measurements, respectively, also higher than the solid water counterparts (simulation: (3.3 ± 0.3 $3.3 \pm 0.3$ ) μ Sv / Gy $\umu {\rm Sv/Gy}$ ; measurement: (0.63 ± 0.03 $0.63 \pm 0.03$ ) μ Sv / Gy $\umu {\rm Sv/Gy}$ ). CONCLUSIONS We conducted simulations and measurements of secondary neutron production under proton irradiation at FLASH energy with range shifters. We found that the secondary neutron yield increased when using aluminum range shifters compared to conventional materials while remaining well below the non-primary radiation limit constrained by the IEC regulations.
Collapse
Affiliation(s)
- Dixin Chen
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | | | - Rudi Labarbe
- Ion Beam Applications S.A. (IBA), Louvain-la-Neuve, Belgium
| | - Beryl Bell
- Ion Beam Applications S.A. (IBA), Louvain-la-Neuve, Belgium
| | - Michele Kim
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Boon-Keng Kevin Teo
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Lei Dong
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Wei Zou
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | |
Collapse
|
2
|
Benzazon N, Colnot J, de Kermenguy F, Achkar S, de Vathaire F, Deutsch E, Robert C, Diallo I. Analytical models for external photon beam radiotherapy out-of-field dose calculation: a scoping review. Front Oncol 2023; 13:1197079. [PMID: 37228501 PMCID: PMC10203488 DOI: 10.3389/fonc.2023.1197079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 04/24/2023] [Indexed: 05/27/2023] Open
Abstract
A growing body of scientific evidence indicates that exposure to low dose ionizing radiation (< 2 Gy) is associated with a higher risk of developing radio-induced cancer. Additionally, it has been shown to have significant impacts on both innate and adaptive immune responses. As a result, the evaluation of the low doses inevitably delivered outside the treatment fields (out-of-field dose) in photon radiotherapy is a topic that is regaining interest at a pivotal moment in radiotherapy. In this work, we proposed a scoping review in order to identify evidence of strengths and limitations of available analytical models for out-of-field dose calculation in external photon beam radiotherapy for the purpose of implementation in clinical routine. Papers published between 1988 and 2022 proposing a novel analytical model that estimated at least one component of the out-of-field dose for photon external radiotherapy were included. Models focusing on electrons, protons and Monte-Carlo methods were excluded. The methodological quality and potential limitations of each model were analyzed to assess their generalizability. Twenty-one published papers were selected for analysis, of which 14 proposed multi-compartment models, demonstrating that research efforts are directed towards an increasingly detailed description of the underlying physical phenomena. Our synthesis revealed great inhomogeneities in practices, in particular in the acquisition of experimental data and the standardization of measurements, in the choice of metrics used for the evaluation of model performance and even in the definition of regions considered out-of-the-field, which makes quantitative comparisons impossible. We therefore propose to clarify some key concepts. The analytical methods do not seem to be easily suitable for massive use in clinical routine, due to the inevitable cumbersome nature of their implementation. Currently, there is no consensus on a mathematical formalism that comprehensively describes the out-of-field dose in external photon radiotherapy, partly due to the complex interactions between a large number of influencing factors. Out-of-field dose calculation models based on neural networks could be promising tools to overcome these limitations and thus favor a transfer to the clinic, but the lack of sufficiently large and heterogeneous data sets is the main obstacle.
Collapse
Affiliation(s)
- Nathan Benzazon
- Unité Mixte de Recherche (UMR) 1030 Radiothérapie Moléculaire et Innovation Thérapeutique, ImmunoRadAI, Université Paris-Saclay, Institut Gustave Roussy, Inserm, Villejuif, France
- Department of Radiation Oncology, Gustave Roussy, Villejuif, France
| | - Julie Colnot
- Unité Mixte de Recherche (UMR) 1030 Radiothérapie Moléculaire et Innovation Thérapeutique, ImmunoRadAI, Université Paris-Saclay, Institut Gustave Roussy, Inserm, Villejuif, France
- Department of Radiation Oncology, Gustave Roussy, Villejuif, France
- THERYQ, PMB-Alcen, Peynier, France
| | - François de Kermenguy
- Unité Mixte de Recherche (UMR) 1030 Radiothérapie Moléculaire et Innovation Thérapeutique, ImmunoRadAI, Université Paris-Saclay, Institut Gustave Roussy, Inserm, Villejuif, France
- Department of Radiation Oncology, Gustave Roussy, Villejuif, France
| | - Samir Achkar
- Department of Radiation Oncology, Gustave Roussy, Villejuif, France
| | - Florent de Vathaire
- Unité Mixte de Recherche (UMR) 1018 Centre de Recherche en épidémiologie et Santé des Populations (CESP), Radiation Epidemiology Team, Université Paris-Saclay, Institut Gustave Roussy, Inserm, Villejuif, France
| | - Eric Deutsch
- Unité Mixte de Recherche (UMR) 1030 Radiothérapie Moléculaire et Innovation Thérapeutique, ImmunoRadAI, Université Paris-Saclay, Institut Gustave Roussy, Inserm, Villejuif, France
- Department of Radiation Oncology, Gustave Roussy, Villejuif, France
| | - Charlotte Robert
- Unité Mixte de Recherche (UMR) 1030 Radiothérapie Moléculaire et Innovation Thérapeutique, ImmunoRadAI, Université Paris-Saclay, Institut Gustave Roussy, Inserm, Villejuif, France
- Department of Radiation Oncology, Gustave Roussy, Villejuif, France
| | - Ibrahima Diallo
- Unité Mixte de Recherche (UMR) 1030 Radiothérapie Moléculaire et Innovation Thérapeutique, ImmunoRadAI, Université Paris-Saclay, Institut Gustave Roussy, Inserm, Villejuif, France
- Department of Radiation Oncology, Gustave Roussy, Villejuif, France
| |
Collapse
|
3
|
Pazzaglia S, Eidemüller M, Lumniczky K, Mancuso M, Ramadan R, Stolarczyk L, Moertl S. Out-of-field effects: lessons learned from partial body exposure. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2022; 61:485-504. [PMID: 36001144 PMCID: PMC9722818 DOI: 10.1007/s00411-022-00988-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 08/03/2022] [Indexed: 05/27/2023]
Abstract
Partial body exposure and inhomogeneous dose delivery are features of the majority of medical and occupational exposure situations. However, mounting evidence indicates that the effects of partial body exposure are not limited to the irradiated area but also have systemic effects that are propagated outside the irradiated field. It was the aim of the "Partial body exposure" session within the MELODI workshop 2020 to discuss recent developments and insights into this field by covering clinical, epidemiological, dosimetric as well as mechanistic aspects. Especially the impact of out-of-field effects on dysfunctions of immune cells, cardiovascular diseases and effects on the brain were debated. The presentations at the workshop acknowledged the relevance of out-of-field effects as components of the cellular and organismal radiation response. Furthermore, their importance for the understanding of radiation-induced pathologies, for the discovery of early disease biomarkers and for the identification of high-risk organs after inhomogeneous exposure was emphasized. With the rapid advancement of clinical treatment modalities, including new dose rates and distributions a better understanding of individual health risk is urgently needed. To achieve this, a deeper mechanistic understanding of out-of-field effects in close connection to improved modelling was suggested as priorities for future research. This will support the amelioration of risk models and the personalization of risk assessments for cancer and non-cancer effects after partial body irradiation.
Collapse
Affiliation(s)
- S. Pazzaglia
- Laboratory of Biomedical Technologies, ENEA CR-Casaccia, Via Anguillarese 301, 00123 Rome, Italy
| | - M. Eidemüller
- Institute of Radiation Medicine, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
| | - K. Lumniczky
- Department of Radiobiology and Radiohygiene, Unit of Radiation Medicine, National Public Health Centre, Albert Florian u. 2-6, 1097 Budapest, Hungary
| | - M. Mancuso
- Laboratory of Biomedical Technologies, ENEA CR-Casaccia, Via Anguillarese 301, 00123 Rome, Italy
| | - R. Ramadan
- Radiobiology Unit, Belgian Nuclear Research Centre (SCK CEN), Mol, Belgium
| | - L. Stolarczyk
- Danish Centre for Particle Therapy, Palle Juul-Jensens Boulevard 25, 8200 Aarhus N, Denmark
| | - S. Moertl
- Federal Office for Radiation Protection, Ingolstädter Landstr. 1, 85764 Oberschleißheim, Germany
| |
Collapse
|
4
|
Wilson LJ, Bryce-Atkinson A, Green A, Li Y, Merchant TE, van Herk M, Vasquez Osorio E, Faught AM, Aznar MC. Image-based data mining applies to data collected from children. Phys Med 2022; 99:31-43. [PMID: 35609381 PMCID: PMC9197776 DOI: 10.1016/j.ejmp.2022.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 04/14/2022] [Accepted: 05/07/2022] [Indexed: 11/25/2022] Open
Abstract
PURPOSE Image-based data mining (IBDM) is a novel voxel-based method for analyzing radiation dose responses that has been successfully applied in adult data. Because anatomic variability and side effects of interest differ for children compared to adults, we investigated the feasibility of IBDM for pediatric analyses. METHODS We tested IBDM with CT images and dose distributions collected from 167 children (aged 10 months to 20 years) who received proton radiotherapy for primary brain tumors. We used data from four reference patients to assess IBDM sensitivity to reference selection. We quantified spatial-normalization accuracy via contour distances and deviations of the centers-of-mass of brain substructures. We performed dose comparisons with simplified and modified clinical dose distributions with a simulated effect, assessing their accuracy via sensitivity, positive predictive value (PPV) and Dice similarity coefficient (DSC). RESULTS Spatial normalizations and dose comparisons were insensitive to reference selection. Normalization discrepancies were small (average contour distance < 2.5 mm, average center-of-mass deviation < 6 mm). Dose comparisons identified differences (p < 0.01) in 81% of simplified and all modified clinical dose distributions. The DSCs for simplified doses were high (peak frequency magnitudes of 0.9-1.0). However, the PPVs and DSCs were low (maximum 0.3 and 0.4, respectively) in the modified clinical tests. CONCLUSIONS IBDM is feasible for childhood late-effects research. Our findings may inform cohort selection in future studies of pediatric radiotherapy dose responses and facilitate treatment planning to reduce treatment-related toxicities and improve quality of life among childhood cancer survivors.
Collapse
Affiliation(s)
- Lydia J Wilson
- St. Jude Children's Research Hospital, Department of Radiation Oncology, Memphis, TN, USA.
| | - Abigail Bryce-Atkinson
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Andrew Green
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Yimei Li
- St. Jude Children's Research Hospital, Department of Biostatistics, Memphis, TN, USA
| | - Thomas E Merchant
- St. Jude Children's Research Hospital, Department of Radiation Oncology, Memphis, TN, USA
| | - Marcel van Herk
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Eliana Vasquez Osorio
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Austin M Faught
- St. Jude Children's Research Hospital, Department of Radiation Oncology, Memphis, TN, USA
| | - Marianne C Aznar
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| |
Collapse
|
5
|
Shrestha S, Newhauser WD, Donahue WP, Pérez-Andújar A. Stray neutron radiation exposures from proton therapy: physics-based analytical models of neutron spectral fluence, kerma and absorbed dose. Phys Med Biol 2022; 67. [DOI: 10.1088/1361-6560/ac7377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 05/25/2022] [Indexed: 11/11/2022]
Abstract
Abstract
Objective. Patients who receive proton beam therapy are exposed to unwanted stray neutrons. Stray radiations increase the risk of late effects in normal tissues, such as second cancers and cataracts, and may cause implanted devices such as pacemakers to malfunction. Compared to therapeutic beams, little attention has been paid to modeling stray neutron exposures. In the past decade, substantial progress was made to develop semiempirical models of stray neutron dose equivalent, but models to routinely calculate neutron absorbed dose and kerma are still lacking. The objective of this work was to develop a new physics based analytical model to calculate neutron spectral fluence, kerma, and absorbed dose in a water phantom. Approach. We developed the model using dosimetric data from Monte Carlo simulations and neutron kerma coefficients from the literature. The model explicitly considers the production, divergence, scattering, and attenuation of neutrons. Neutron production was modeled for 120–250 MeV proton beams impinging on a variety of materials. Fluence, kerma and dose calculations were performed in a 30 × 180 × 44 cm3 phantom at points up to 43 cm in depth and 80 cm laterally. Main Results. Predictions of the analytical model agreed reasonably with corresponding values from Monte Carlo simulations, with a mean difference in average energy deposited of 20%, average kerma coefficient of 21%, and absorbed dose to water of 49%. Significance. The analytical model is simple to implement and use, requires less configuration data that previously reported models, and is computationally fast. This model appears potentially suitable for integration in treatment planning system, which would enable risk calculations in prospective and retrospective cases, providing a powerful tool for epidemiological studies and clinical trials.
Collapse
|
6
|
Wakeford R, Hauptmann M. The risk of cancer following high, and very high, doses of ionising radiation. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2022; 42:020518. [PMID: 35671754 DOI: 10.1088/1361-6498/ac767b] [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: 01/13/2022] [Accepted: 06/07/2022] [Indexed: 06/15/2023]
Abstract
It is established that moderate-to-high doses of ionising radiation increase the risk of subsequent cancer in the exposed individual, but the question arises as to the risk of cancer from higher doses, such as those delivered during radiotherapy, accidents, or deliberate acts of malice. In general, the cumulative dose received during a course of radiation treatment is sufficiently high that it would kill a person if delivered as a single dose to the whole body, but therapeutic doses are carefully fractionated and high/very high doses are generally limited to a small tissue volume under controlled conditions. The very high cumulative doses delivered as fractions during radiation treatment are designed to inactivate diseased cells, but inevitably some healthy cells will also receive high/very high doses. How the doses (ranging from <1 Gy to tens of Gy) received by healthy tissues during radiotherapy affect the risk of second primary cancer is an increasingly important issue to address as more cancer patients survive the disease. Studies show that, except for a turndown for thyroid cancer, a linear dose-response for second primary solid cancers seems to exist over a cumulative gamma radiation dose range of tens of gray, but with a gradient of excess relative risk per Gy that varies with the type of second cancer, and which is notably shallower than that found in the Japanese atomic bomb survivors receiving a single moderate-to-high acute dose. The risk of second primary cancer consequent to high/very high doses of radiation is likely to be due to repopulation of heavily irradiated tissues by surviving stem cells, some of which will have been malignantly transformed by radiation exposure, although the exact mechanism is not known, and various models have been proposed. It is important to understand the mechanisms that lead to the raised risk of second primary cancers consequent to the receipt of high/very high doses, in particular so that the risks associated with novel radiation treatment regimens-for example, intensity modulated radiotherapy and volumetric modulated arc therapy that deliver high doses to the target volume while exposing relatively large volumes of healthy tissue to low/moderate doses, and treatments using protons or heavy ions rather than photons-may be properly assessed.
Collapse
Affiliation(s)
- Richard Wakeford
- Centre for Occupational and Environmental Health, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Michael Hauptmann
- Institute of Biostatistics and Registry Research, Brandenburg Medical School, Fehrbelliner Strasse 38, 16816 Neuruppin, Germany
| |
Collapse
|
7
|
Romero-Expósito M, Toma-Dasu I, Dasu A. Determining Out-of-Field Doses and Second Cancer Risk From Proton Therapy in Young Patients—An Overview. Front Oncol 2022; 12:892078. [PMID: 35712488 PMCID: PMC9197425 DOI: 10.3389/fonc.2022.892078] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 05/02/2022] [Indexed: 11/13/2022] Open
Abstract
Proton therapy has the potential to provide survival and tumor control outcomes comparable and frequently superior to photon therapy. This has led to a significant concern in the medical physics community on the risk for the induction of second cancers in all patients and especially in younger patients, as they are considered more radiosensitive than adults and have an even longer expected lifetime after treatment. Thus, our purpose is to present an overview of the research carried out on the evaluation of out-of-field doses linked to second cancer induction and the prediction of this risk. Most investigations consisted of Monte Carlo simulations in passive beam facilities for clinical scenarios. These works established that equivalent doses in organs could be up to 200 mSv or 900 mSv for a brain or a craniospinal treatment, respectively. The major contribution to this dose comes from the secondary neutrons produced in the beam line elements. Few works focused on scanned-beam facilities, but available data show that, for these facilities, equivalent doses could be between 2 and 50 times lower. Patient age is a relevant factor in the dose level, especially for younger patients (by means of the size of the body) and, in addition, in the predicted risk by models (due to the age dependence of the radiosensitivity). For risks, the sex of the patient also plays an important role, as female patients show higher sensitivity to radiation. Thus, predicted risks of craniospinal irradiation can range from 8% for a 15-year-old male patient to 58% for a 2-year-old female patient, using a risk model from a radiological protection field. These values must be taken with caution due to uncertainties in risk models, and then dosimetric evaluation of stray radiation becomes mandatory in order to complement epidemiological studies and be able to model appropriate dose–response functions for this dose range. In this sense, analytical models represent a useful tool and some models have been implemented to be used for young patients. Research carried out so far confirmed that proton beam therapy reduces the out-of-field doses and second cancer risk. However, further investigations may be required in scanned-beam delivery systems.
Collapse
Affiliation(s)
- Maite Romero-Expósito
- The Skandion Clinic, Uppsala, Sweden
- Oncology Pathology Department, Karolinska Institutet, Stockholm, Sweden
- *Correspondence: Maite Romero-Expósito,
| | - Iuliana Toma-Dasu
- Oncology Pathology Department, Karolinska Institutet, Stockholm, Sweden
- Medical Radiation Physics, Stockholm University, Stockholm, Sweden
| | - Alexandru Dasu
- The Skandion Clinic, Uppsala, Sweden
- Medical Radiation Sciences, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| |
Collapse
|
8
|
Tillery H, Moore M, Gallagher KJ, Taddei PJ, Leuro E, Argento DC, Moffitt GB, Kranz M, Carey M, Heymsfield S, Newhauser WD. Personalized 3D-printed anthropomorphic whole-body phantom irradiated by protons, photons, and neutrons. Biomed Phys Eng Express 2022; 8. [PMID: 35045408 DOI: 10.1088/2057-1976/ac4d04] [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: 10/24/2021] [Accepted: 01/19/2022] [Indexed: 11/12/2022]
Abstract
The objective of this study was to confirm the feasibility of three-dimensionally-printed (3D-printed), personalized whole-body anthropomorphic phantoms for radiation dose measurements in a variety of charged and uncharged particle radiation fields. We 3D-printed a personalized whole-body phantom of an adult female with a height of 154.8 cm, mass of 90.7 kg, and body mass index of 37.8 kg/m2. The phantom comprised of a hollow plastic shell filled with water and included a watertight access conduit for positioning dosimeters. It is compatible with a wide variety of radiation dosimeters, including ionization chambers that are suitable for uncharged and charged particles. Its mass was 6.8 kg empty and 98 kg when filled with water. Watertightness and mechanical robustness were confirmed after multiple experiments and transportations between institutions. The phantom was irradiated to the cranium with therapeutic beams of 170-MeV protons, 6-MV photons, and fast neutrons. Radiation absorbed dose was measured from the cranium to the pelvis along the longitudinal central axis of the phantom. The dose measurements were made using established dosimetry protocols and well-characterized instruments. For the therapeutic environments considered in this study, stray radiation from intracranial treatment beams was the lowest for proton therapy, intermediate for photon therapy, and highest for neutron therapy. An illustrative example set of measurements at the location of the thyroid for a square field of 5.3 cm per side resulted in 0.09, 0.59, and 1.93 cGy/Gy from proton, photon, and neutron beams, respectively. In this study, we found that 3D-printed personalized phantoms are feasible, inherently reproducible, and well-suited for therapeutic radiation measurements. The measurement methodologies we developed enabled the direct comparison of radiation exposures from neutron, proton, and photon beam irradiations.
Collapse
Affiliation(s)
- Hunter Tillery
- Radiation Medicine, Oregon Health & Science University, 3181 S.W. Sam Jackson Park Road, KPV4, Portland, Oregon, 97239-3098, UNITED STATES
| | - Meagan Moore
- Louisiana State University, 439-B Nicholson Hall, Tower Dr., Baton Rouge, Louisiana, 70803-4001, UNITED STATES
| | - Kyle Joseph Gallagher
- Radiation Medicine, Oregon Health & Science University, 3181 S.W. Sam Jackson Park Road, KPV4, Portland, Oregon, 97239-3098, UNITED STATES
| | - Phillip J Taddei
- Department of Radiation Oncology, Mayo Clinic, 200 First St. SW, Rochester, Minnesota, 55905, UNITED STATES
| | - Eric Leuro
- Seattle Cancer Care Alliance, 1570 N 115th St, Seattle, Washington, 98133, UNITED STATES
| | - David C Argento
- Radiation Oncology, University of Washington School of Medicine, 1959 NE Pacific St, Seattle, Washington, 98195, UNITED STATES
| | - Gregory B Moffitt
- Radiation Oncology, University of Washington School of Medicine, 1959 NE Pacific St, Seattle, Washington, 98195, UNITED STATES
| | - Marissa Kranz
- University of Washington School of Medicine, 1959 NE Pacific St, Seattle, Washington, 98195, UNITED STATES
| | - Margaret Carey
- Louisiana State University, 439-B Nicholson Hall, Tower Dr., Baton Rouge, Louisiana, 70803-4001, UNITED STATES
| | - Steven Heymsfield
- Louisiana State University, 439-B Nicholson Hall, Tower Dr., Baton Rouge, Louisiana, 70803-4001, UNITED STATES
| | - Wayne David Newhauser
- Louisiana State University, 439-B Nicholson Hall, Tower Dr., Baton Rouge, Louisiana, 70803-4001, UNITED STATES
| |
Collapse
|
9
|
Kollitz E, Han H, Kim CH, Pinto M, Schwarz M, Riboldi M, Kamp F, Belka C, Newhauser WD, Dedes G, Parodi K. A patient-specific hybrid phantom for calculating radiation dose and equivalent dose to the whole body. Phys Med Biol 2021; 67. [PMID: 34969024 DOI: 10.1088/1361-6560/ac4738] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 12/30/2021] [Indexed: 11/12/2022]
Abstract
OBJECTIVE As cancer survivorship increases, there is growing interest in minimizing the late effects of radiation therapy such as radiogenic second cancer, which may occur anywhere in the body. Assessing the risk of late effects requires knowledge of the dose distribution throughout the whole body, including regions far from the treatment field, beyond the typical anatomical extent of clinical CT scans. APPROACH A hybrid phantom was developed which consists of in-field patient CT images extracted from ground truth whole-body CT (WBCT) scans, out-of-field mesh phantoms scaled to basic patient measurements, and a blended transition region. Four of these hybrid phantoms were created, representing male and female patients receiving proton therapy treatment in pelvic and cranial sites. To assess the performance of the hybrid approach, we simulated treatments using the hybrid phantoms, the scaled and unscaled mesh phantoms, and the ground truth whole-body CTs. We calculated absorbed dose and equivalent dose in and outside of the treatment field, with a focus on neutrons induced in the patient by proton therapy. Proton and neutron dose was calculated using a general purpose Monte Carlo code. MAIN RESULTS The hybrid phantom provided equal or superior accuracy in calculated organ dose and equivalent dose values relative to those obtained using the mesh phantoms in 78% in all selected organs and calculated dose quantities. Comparatively the default mesh and scaled mesh were equal or superior to the other phantoms in 21% and 28% of cases respectively. SIGNIFICANCE The proposed methodology for hybrid synthesis provides a tool for whole-body organ dose estimation for individual patients without requiring CT scans of their entire body. Such a capability would be useful for personalized assessment of late effects and risk-optimization of treatment plans.
Collapse
Affiliation(s)
- Erika Kollitz
- Department of Medical Physics, Ludwig-Maximilians-Universitat Munchen, Ludwig-Maximilians-Universität München, Department for Medical Physics (LS Parodi), Am Coulombwall 1, Garching, Bayern, 85748, GERMANY
| | - Haegin Han
- Department of Nuclear Engineering, Hanyang University, 222, Wangsimni-ro, Seongdong-gu, Seongdong-gu, Seoul, 04763, Korea (the Republic of)
| | - Chan Hyeong Kim
- Department of Nuclear Engineering, Hanyang University, 222, Wangsimni-ro, Seongdong-gu, Seongdong-gu, Seoul, 04763, Korea (the Republic of)
| | - Marco Pinto
- Ludwig-Maximilians-Universitat Munchen, Ludwig-Maximilians-Universität München, Department for Medical Physics (LS Parodi), Am Coulombwall 1, Garching, Bayern, 85748, GERMANY
| | - Marco Schwarz
- Provincia autonoma di Trento Azienda Provinciale per i Servizi Sanitari, Via Alcide Degasperi 79, Trento, Trentino-Alto Adige, 38123, ITALY
| | - Marco Riboldi
- Department of Medical Physics, Ludwig-Maximilians-Universitat Munchen, Ludwig-Maximilians-Universität München, Department for Medical Physics (LS Parodi), Am Coulombwall 1, Munchen, Bayern, 85748, GERMANY
| | - Florian Kamp
- Radiotherapy, Klinikum der Universitat Munchen, Marchioninistraße 15, Munich, 81377, GERMANY
| | - Claus Belka
- Department of Radiation Oncology, Klinikum der Universitat Munchen, Marchioninistraße 15, Munchen, Bayern, 81377, GERMANY
| | - Wayne David Newhauser
- Department of Physics & Astronomy, Louisiana State University, 202 Nicholson Hall, Baton Rouge, Louisiana, 70803, UNITED STATES
| | - Georgios Dedes
- Department of Medical Physics, Ludwig-Maximilians-Universitat Munchen, Ludwig-Maximilians-Universität München, Department for Medical Physics (LS Parodi), Am Coulombwall 1, Munchen, Bayern, 85748, GERMANY
| | - Katia Parodi
- Experimental Physics Medical Physics, Ludwig-Maximilians-Universitat Munchen, Ludwig-Maximilians-Universität München, Department for Medical Physics (LS Parodi), Am Coulombwall 1, Munchen, Bayern, 85748, GERMANY
| |
Collapse
|
10
|
Hauri P, Radonic S, Vasi F, Ernst M, Sumila M, Mille MM, Lee C, Hartmann M, Schneider U. Development of whole-body representation and dose calculation in a commercial treatment planning system. Z Med Phys 2021; 32:159-172. [PMID: 34301443 PMCID: PMC9948842 DOI: 10.1016/j.zemedi.2021.05.001] [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: 01/15/2021] [Revised: 05/03/2021] [Accepted: 05/10/2021] [Indexed: 10/20/2022]
Abstract
For the epidemiological evaluation of long-term side effects of radiotherapy patients, it is important to know the doses to organs and tissues everywhere in the patient. Computed tomography (CT) images of the patients which contain the anatomical information are sometimes available for each treated patient. However, the available CT scans usually cover only the treated volume of the patient including the target and surrounding anatomy. To overcome this limitation, in this work we describe the development of a software tool using the Varian Eclipse Scripting API for extending a partial-body CT to a whole-body representation in the treatment planning system for dose calculation. The whole-body representation is created by fusing the partial-body CT with a similarly sized whole-body computational phantom selected from a library containing 64 phantoms of different heights, weights, and genders. The out-of-field dose is calculated with analytical models from the literature and merged with the treatment planning system-calculated dose. To test the method, the out-of-field dose distributions on the computational phantoms were compared to dose calculations on whole-body patient CTs. The mean doses, D2% and D98% were compared in 26 organs and tissues for 14 different treatment plans in 5 patients using 3D-CRT, IMRT, VMAT, coplanar and non-coplanar techniques. From these comparisons we found that mean relative differences between organ doses ranged from -10% and +20% with standard deviations of up to 40%. The developed method will help epidemiologists and researchers estimate organ doses outside the treated volume when only limited treatment planning CT information is available.
Collapse
Affiliation(s)
- Pascal Hauri
- Department of Physics, University of Zurich, Zurich, Switzerland,Radiotherapy Hirslanden, Hirslanden Medical Center, Aarau, Switzerland
| | - Stephan Radonic
- Department of Physics, University of Zurich, Zurich, Switzerland,Radiotherapy Hirslanden, Hirslanden Medical Center, Aarau, Switzerland,Corresponding author: Stephan Radonic, Department of Physics, University of Zurich, Zurich, Switzerland
| | - Fabiano Vasi
- Department of Physics, University of Zurich, Zurich, Switzerland,Radiotherapy Hirslanden, Hirslanden Medical Center, Aarau, Switzerland
| | - Marina Ernst
- Department of Physics, University of Zurich, Zurich, Switzerland
| | - Marcin Sumila
- Department of Physics, University of Zurich, Zurich, Switzerland,Radiotherapy Hirslanden, Hirslanden Medical Center, Aarau, Switzerland
| | - Matthew M. Mille
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD 20850, USA
| | - Choonsik Lee
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD 20850, USA
| | - Matthias Hartmann
- Department of Physics, University of Zurich, Zurich, Switzerland,Radiotherapy Hirslanden, Hirslanden Medical Center, Aarau, Switzerland
| | - Uwe Schneider
- Department of Physics, University of Zurich, Zurich, Switzerland,Radiotherapy Hirslanden, Hirslanden Medical Center, Aarau, Switzerland
| |
Collapse
|
11
|
Wilson LJ, Newhauser WD. Generalized approach for radiotherapy treatment planning by optimizing projected health outcome: preliminary results for prostate radiotherapy patients. Phys Med Biol 2021; 66:065007. [PMID: 33545710 DOI: 10.1088/1361-6560/abe3cf] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Research in cancer care increasingly focuses on survivorship issues, e.g. managing disease- and treatment-related morbidity and mortality occurring during and after treatment. This necessitates innovative approaches that consider treatment side effects in addition to tumor cure. Current treatment-planning methods rely on constrained iterative optimization of dose distributions as a surrogate for health outcomes. The goal of this study was to develop a generally applicable method to directly optimize projected health outcomes. We developed an outcome-based objective function to guide selection of the number, angle, and relative fluence weight of photon and proton radiotherapy beams in a sample of ten prostate-cancer patients by optimizing the projected health outcome. We tested whether outcome-optimized radiotherapy (OORT) improved the projected longitudinal outcome compared to dose-optimized radiotherapy (DORT) first for a statistically significant majority of patients, then for each individual patient. We assessed whether the results were influenced by the selection of treatment modality, late-risk model, or host factors. The results of this study revealed that OORT was superior to DORT. Namely, OORT maintained or improved the projected health outcome of photon- and proton-therapy treatment plans for all ten patients compared to DORT. Furthermore, the results were qualitatively similar across three treatment modalities, six late-risk models, and 10 patients. The major finding of this work was that it is feasible to directly optimize the longitudinal (i.e. long- and short-term) health outcomes associated with the total (i.e. therapeutic and stray) absorbed dose in all of the tissues (i.e. healthy and diseased) in individual patients. This approach enables consideration of arbitrary treatment factors, host factors, health endpoints, and times of relevance to cancer survivorship. It also provides a simpler, more direct approach to realizing the full beneficial potential of cancer radiotherapy.
Collapse
Affiliation(s)
- Lydia J Wilson
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803-4001, United States of America
| | - Wayne D Newhauser
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803-4001, United States of America.,Mary Bird Perkins Cancer Center, 4950 Essen Lane, Baton Rouge, LA 70809, United States of America
| |
Collapse
|
12
|
Yeom YS, Griffin K, Mille M, Jung JW, Lee C, Lee C. A dose voxel kernel method for rapid reconstruction of out-of-field neutron dose of patients in pencil beam scanning (PBS) proton therapy. Phys Med Biol 2020; 65:175015. [PMID: 32726766 PMCID: PMC10182832 DOI: 10.1088/1361-6560/abaa5f] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Monte Carlo (MC) radiation transport methods are used for dose calculation as 'gold standard.' However, the method is computationally time-consuming and thus impractical for normal tissue dose reconstructions for the large number of proton therapy patients required for epidemiologic investigations of late health effects. In the present study, we developed a new dose calculation method for the rapid reconstruction of out-of-field neutron dose to patients undergoing pencil beam scanning (PBS) proton therapy. The new dose calculation method is based on neutron dose voxel kernels (DVKs) generated by MC simulations of a proton pencil beam irradiating a water phantom (60 × 60 × 300 cm3), which was conducted using a MC proton therapy simulation code, TOPAS. The DVKs were generated for 19 beam energies (from 70 to 250 MeV with the 10 MeV interval) and three range shifter thicknesses (1, 3, and 5 cm). An in-house program was written in C++ to superimpose the DVKs onto a patient CT images according to proton beam characteristics (energy, position, and direction) available in treatment plans. The DVK dose calculation method was tested by calculating organ/tissue-specific neutron doses of 1- and 5-year-old whole-body computational phantoms where intracranial and craniospinal irradiations were simulated. The DVK-based doses generally showed reasonable agreement with those calculated by direct MC simulations with a detailed PBS model that were previously published, with differences mostly less than 30% and 10% for the intracranial and craniospinal irradiations, respectively. The computation time of the DVK method for one patient ranged from 1 to 30 min on a single CPU core of a personal computer, demonstrating significant improvement over the direct MC dose calculation requiring several days on high-performance computing servers. Our DVK-based dose calculation method will be useful when dosimetry is needed for the large number of patients such as for epidemiologic or clinical research.
Collapse
Affiliation(s)
- Yeon Soo Yeom
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD 20850, United States of America
| | | | | | | | | | | |
Collapse
|
13
|
Method to quickly and accurately calculate absorbed dose from therapeutic and stray photon exposures throughout the entire body in individual patients. Med Phys 2020; 47:2254-2266. [DOI: 10.1002/mp.14018] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 12/11/2019] [Accepted: 12/24/2019] [Indexed: 01/26/2023] Open
|
14
|
Hälg RA, Schneider U. Neutron dose and its measurement in proton therapy-current State of Knowledge. Br J Radiol 2020; 93:20190412. [PMID: 31868525 PMCID: PMC7066952 DOI: 10.1259/bjr.20190412] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 12/06/2019] [Accepted: 12/19/2019] [Indexed: 12/26/2022] Open
Abstract
Proton therapy has shown dosimetric advantages over conventional radiation therapy using photons. Although the integral dose for patients treated with proton therapy is low, concerns were raised about late effects like secondary cancer caused by dose depositions far away from the treated area. This is especially true for neutrons and therefore the stray dose contribution from neutrons in proton therapy is still being investigated. The higher biological effectiveness of neutrons compared to photons is the main cause of these concerns. The gold-standard in neutron dosimetry is measurements, but performing neutron measurements is challenging. Different approaches have been taken to overcome these difficulties, for instance with newly developed neutron detectors. Monte Carlo simulations is another common technique to assess the dose from secondary neutrons. Measurements and simulations are used to develop analytical models for fast neutron dose estimations. This article tries to summarize the developments in the different aspects of neutron dose in proton therapy since 2017. In general, low neutron doses have been reported, especially in active proton therapy. Although the published biological effectiveness of neutrons relative to photons regarding cancer induction is higher, it is unlikely that the neutron dose has a large impact on the second cancer risk of proton therapy patients.
Collapse
|
15
|
Irazola L, Sánchez-Nieto B, García-Hernández MT, Terrón JA, Roselló J, Ortiz-Seidel M, Béjar MJ, Linares R, Vélazquez S, Sánchez-Doblado F. 10-MV SBRT FFF IRRADIATION TECHNIQUE IS ASSOCIATED TO THE LOWEST PERIPHERAL DOSE: THE OUTCOME OF 142 TREATMENT PLANS FOR THE 10 MOST COMMON TUMOUR LOCATIONS. RADIATION PROTECTION DOSIMETRY 2019; 185:183-195. [PMID: 30649534 DOI: 10.1093/rpd/ncy292] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 12/06/2018] [Accepted: 12/30/2018] [Indexed: 06/09/2023]
Abstract
There is a growing interest in the combined use of Stereotactic Body Radiation Therapy (SBRT) with Flattening Filter Free (FFF) due to the high local control rates and reduced treatment times, compared to conventionally fractionated treatments. It has been suggested that they may also provide a better radiation protection to radiotherapy patients as a consequence of the expected decrease in peripheral doses. This work aims to determine this reduction in unattended out-of-field regions, where no CT information is available but an important percentage of second primary cancers occur. For that purpose, ten different cases suitable for SBRT were chosen. Thus, 142 different treatment plans including SBRT, as well as 3D-CRT, IMRT and VMAT (with standard fractionation) in low and high energies for Varian (FF and FFF), Siemens and Elekta machines were created. Then, photon and neutron peripheral dose in 14 organs were assessed and compared using two analytical models. For the prostate case, uncomplicated and cancer free control probability estimation was also carried out. As a general behavior, SBRT plans led to the lowest peripheral doses followed by 3D-CRT, VMAT and IMRT, in this order. Unflattened beams proved to be the most effective in reducing peripheral doses, especially for 10 MV. The obtained results suggest that FFF beams for SBRT with 10 MV represent the best compromise between dose delivery efficiency and peripheral dose reduction.
Collapse
Affiliation(s)
- L Irazola
- Departamento de Fisiología Médica y Biofísica, Facultad de Medicina, Universidad de Sevilla, Sevilla, Spain
- Servicio de Radiofísica, Hospital Universitario Virgen Macarena, Sevilla, Spain
| | - B Sánchez-Nieto
- Instituto de Física, Pontificia Universidad Católica de Chile, Santiago, Chile
| | | | - J A Terrón
- Departamento de Fisiología Médica y Biofísica, Facultad de Medicina, Universidad de Sevilla, Sevilla, Spain
- Servicio de Radiofísica, Hospital Universitario Virgen Macarena, Sevilla, Spain
| | - J Roselló
- Servicio de Radiofísica ERESA, Hospital General Universitario, Valencia, Spain
| | - M Ortiz-Seidel
- Departamento de Fisiología Médica y Biofísica, Facultad de Medicina, Universidad de Sevilla, Sevilla, Spain
- Servicio de Radiofísica, Hospital Universitario Virgen Macarena, Sevilla, Spain
| | - M J Béjar
- Servicio de Radiofísica, Hospital Universitario Ramón y Cajal, Madrid, Spain
| | - R Linares
- Servicio de Radiofísica, Hospital Infanta Luisa, Sevilla, Spain
| | - S Vélazquez
- Servicio de Radiofísica, Hospital Universitario Virgen del Rocío, Sevilla Spain
| | - F Sánchez-Doblado
- Departamento de Fisiología Médica y Biofísica, Facultad de Medicina, Universidad de Sevilla, Sevilla, Spain
- Servicio de Radiofísica, Hospital Universitario Virgen Macarena, Sevilla, Spain
| |
Collapse
|
16
|
Schneider CW, Newhauser WD, Wilson LJ, Kapsch RP. A physics-based analytical model of absorbed dose from primary, leakage, and scattered photons from megavoltage radiotherapy with MLCs. ACTA ACUST UNITED AC 2019; 64:185017. [DOI: 10.1088/1361-6560/ab303a] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
|
17
|
Nystrom H, Jensen MF, Nystrom PW. Treatment planning for proton therapy: what is needed in the next 10 years? Br J Radiol 2019; 93:20190304. [PMID: 31356107 DOI: 10.1259/bjr.20190304] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Treatment planning is the process where the prescription of the radiation oncologist is translated into a deliverable treatment. With the complexity of contemporary radiotherapy, treatment planning cannot be performed without a computerized treatment planning system. Proton therapy (PT) enables highly conformal treatment plans with a minimum of dose to tissues outside the target volume, but to obtain the most optimal plan for the treatment, there are a multitude of parameters that need to be addressed. In this review areas of ongoing improvements and research in the field of PT treatment planning are identified and discussed. The main focus is on issues of immediate clinical and practical relevance to the PT community highlighting the needs for the near future but also in a longer perspective. We anticipate that the manual tasks performed by treatment planners in the future will involve a high degree of computational thinking, as many issues can be solved much better by e.g. scripting. More accurate and faster dose calculation algorithms are needed, automation for contouring and planning is required and practical tools to handle the variable biological efficiency in PT is urgently demanded just to mention a few of the expected improvements over the coming 10 years.
Collapse
Affiliation(s)
- Hakan Nystrom
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark.,Skandionkliniken, Uppsala, Sweden
| | | | - Petra Witt Nystrom
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark.,Skandionkliniken, Uppsala, Sweden
| |
Collapse
|
18
|
Dabaja BS, Hoppe BS, Plastaras JP, Newhauser W, Rosolova K, Flampouri S, Mohan R, Mikhaeel NG, Kirova Y, Specht L, Yahalom J. Proton therapy for adults with mediastinal lymphomas: the International Lymphoma Radiation Oncology Group guidelines. Blood 2018; 132:1635-1646. [PMID: 30108066 PMCID: PMC6212652 DOI: 10.1182/blood-2018-03-837633] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 07/19/2018] [Indexed: 12/25/2022] Open
Abstract
Among adult lymphoma survivors, radiation treatment techniques that increase the excess radiation dose to organs at risk (OARs) put patients at risk for increased side effects, especially late toxicities. Minimizing radiation to OARs in adults patients with Hodgkin and non-Hodgkin lymphomas involving the mediastinum is the deciding factor for the choice of treatment modality. Proton therapy may help to reduce the radiation dose to the OARs and reduce toxicities, especially the risks for cardiac morbidity and second cancers. Because proton therapy may have some disadvantages, identifying the patients and the circumstances that may benefit the most from proton therapy is important. We present modern guidelines to identify adult lymphoma patients who may derive the greatest benefit from proton therapy, along with an analysis of the advantages and disadvantages of proton treatment.
Collapse
Affiliation(s)
- Bouthaina Shbib Dabaja
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX
| | - Bradford S Hoppe
- Department of Radiation Oncology, University of Florida, Jacksonville, FL
| | - John P Plastaras
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA
| | - Wayne Newhauser
- Department of Radiation Physics, University of Louisiana, Baton Rouge, LA
| | - Katerina Rosolova
- Proton Therapy Department, Proton Therapy Center Czech, Prague, Czech Republic
- Department of Oncology, Charles University in Prague and Motol University Hospital, Prague, Czech Republic
| | - Stella Flampouri
- Department of Radiation Oncology, University of Florida, Jacksonville, FL
| | - Radhe Mohan
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX
| | - N George Mikhaeel
- Department of Radiation Oncology, Guy's and St. Thomas' Hospital, London, United Kingdom
| | - Youlia Kirova
- Department of Radiation Oncology, Institut Curie, Paris, France
| | - Lena Specht
- Department of Oncology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark; and
| | - Joachim Yahalom
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY
| |
Collapse
|
19
|
Gallagher KJ, Taddei PJ. Independent application of an analytical model for secondary neutron equivalent dose produced in a passive-scattering proton therapy treatment unit. Phys Med Biol 2018; 63:15NT04. [PMID: 29978833 DOI: 10.1088/1361-6560/aad1bc] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The purpose of this study was to independently apply an analytical model for equivalent dose from neutrons produced in a passive-scattering proton therapy treatment unit, H. To accomplish this objective, we applied the previously-published model to treatment plans of two pediatric patients. Their model accounted for neutrons generated by mono-energetic proton beams stopping in a closed aperture. To implement their model to a clinical setting, we adjusted it to account for the area of a collimating aperture, energy modulation, air gap between the treatment unit and patient, and radiation weighting factor. We used the adjusted model to estimate H per prescribed proton absorbed dose, D Rx , for the passive-scattering proton therapy beams of two children, a 9-year-old girl and 10-year-old boy, who each received intracranial boost fields as part of their treatment. In organs and tissues at risk for radiation-induced subsequent malignant neoplasms, T, we calculated the mass-averaged H, H T , per D Rx . Finally, we compared H T /D Rx values to those of previously-published Monte Carlo (MC) simulations of these patients' fields. H T /D Rx values of the adjusted model deviated from the MC result for each organ on average by 20.8 ± 10.0% and 44.2 ± 17.6% for the girl and boy, respectively. The adjusted model underestimated the MC result in all T of each patient, with the exception of the girl's bladder, for which the adjusted model overestimated H T /D Rx by 3.1%. The adjusted model provided a better estimate of H T /D Rx than the unadjusted model. That is, between the two models, the adjusted model reduced the deviation from the MC result by approximately 37.0% and 46.7% for the girl and boy, respectively. We found that the previously-published analytical model, combined with adjustment factors to enhance its clinical applicability, predicted H T /D Rx in out-of-field organs and tissues at risk for subsequent malignant neoplasms with acceptable accuracy. This independent application demonstrated that the analytical model may be useful broadly for clinicians and researchers to calculate equivalent dose from neutrons produced externally to the patient in passive-scattering proton therapy.
Collapse
Affiliation(s)
- Kyle J Gallagher
- Oregon Health and Science University, Portland, OR, United States of America. Oregon State University, Corvallis, OR, United States of America
| | | |
Collapse
|
20
|
Williams JP, Newhauser W. Normal tissue damage: its importance, history and challenges for the future. Br J Radiol 2018; 92:20180048. [PMID: 29616836 DOI: 10.1259/bjr.20180048] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Sir Oliver Scott, a philanthropist and radiation biologist and, therefore, the epitome of a gentleman and a scholar, was an early Director of the BECC Radiobiology Research Unit at Mount Vernon. His tenure preceded that of Jack Fowler, with both contributing to basic, translational and clinical thought and application in radiation across the globe. With respect to this review, Fowler's name in particular has remained synonymous with the use of models, both animal and mathematical, that assess and quantify the biological mechanisms that underlie radiation-associated normal tissue toxicities. An understanding of these effects is critical to the optimal use of radiation therapy in the clinic; however, the role that basic sciences play in clinical practice has been undergoing considerable change in recent years, particularly in the USA, where there has been a growing emphasis on engineering and imaging to improve radiation delivery, with empirical observations of clinical outcome taking the place of models underpinned by evidence from basic science experiments. In honour of Scott and Fowler's work, we have taken this opportunity to review how our respective fields of radiation biology and radiation physics have intertwined over the years, affecting the clinical use of radiation with respect to normal tissue outcomes. We discuss the past and current achievements, with the hope of encouraging a revived interest in physics and biology as they relate to radiation oncology practice, since, like Scott and Fowler, we share the goal of improving the future outlook for cancer patients.
Collapse
Affiliation(s)
- Jacqueline P Williams
- Departments of Environmental Medicine and Radiation Oncology, University of Rochester Medical Center, Rochester, NY, USA
| | - Wayne Newhauser
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA, USA
| |
Collapse
|