1
|
Kaushik S, Stützer K, Ödén J, Fredriksson A, Toma-Dasu I. Adaptive intensity modulated proton therapy using 4D robust planning: a proof-of-concept for the application of dose mimicking approach. Phys Med Biol 2024; 69:185010. [PMID: 39214132 DOI: 10.1088/1361-6560/ad75e0] [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: 05/24/2024] [Accepted: 08/30/2024] [Indexed: 09/04/2024]
Abstract
Objective.A four-dimensional robust optimisation (4DRO) is usually employed when the tumour respiratory motion needs to be addressed. However, it is computationally demanding, and an automated method is preferable for adaptive planning to avoid manual trial-and-error. This study proposes a 4DRO technique based on dose mimicking for automated adaptive planning.Approach.Initial plans for 4DRO intensity modulated proton therapy were created on an average CT for four patients with clinical target volume (CTV) in the lung, oesophagus, or pancreas, respectively. These plans were robustly optimised using three phases of four-dimensional computed tomography (4DCT) and accounting for setup and density uncertainties. Weekly 4DCTs were used for adaptive replanning, using a constant relative biological effectiveness (cRBE) of 1.1. Two methods were used: (1) template-based adaptive (TA) planning and (2) dose-mimicking-based adaptive (MA) planning. The plans were evaluated using variable RBE (vRBE) weighted doses and biologically consistent dose accumulation (BCDA).Main results.MA and TA plans had comparable CTV coverage except for one patient where the MA plan had a higher D98 and lower D2 but with an increased D2 in few organs at risk (OARs). CTV D98 deviations in non-adaptive plans from the initial plans were up to -7.2 percentage points (p.p.) in individual cases and -1.8 p.p. when using BCDA. For the OARs, MA plans showed a reduced mean dose and D2 compared to the TA plans, with few exceptions. The vRBE-weighted accumulated doses had a mean dose and D2 difference of up to 0.3 Gy and 0.5 Gy, respectively, in the OARs with respect to cRBE-weighted doses.Significance.MA plans indicate better performance in target coverage and OAR dose sparing compared to the TA plans in 4DRO adaptive planning. Moreover, MA method is capable of handling both forms of anatomical variation, namely, changes in density and relative shifts in the position of OARs.
Collapse
Affiliation(s)
- Suryakant Kaushik
- RaySearch Laboratories AB (Publ), Stockholm, Sweden
- Department of Physics, Medical Radiation Physics, Stockholm University, Stockholm, Sweden
- Department of Oncology and Pathology, Medical Radiation Physics, Karolinska Institutet, Stockholm, Sweden
| | - Kristin Stützer
- OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology-OncoRay, Dresden, Germany
| | - Jakob Ödén
- RaySearch Laboratories AB (Publ), Stockholm, Sweden
| | | | - Iuliana Toma-Dasu
- Department of Physics, Medical Radiation Physics, Stockholm University, Stockholm, Sweden
- Department of Oncology and Pathology, Medical Radiation Physics, Karolinska Institutet, Stockholm, Sweden
| |
Collapse
|
2
|
Sterpin E, Widesott L, Poels K, Hoogeman M, Korevaar EW, Lowe M, Molinelli S, Fracchiolla F. Robustness evaluation of pencil beam scanning proton therapy treatment planning: A systematic review. Radiother Oncol 2024; 197:110365. [PMID: 38830538 DOI: 10.1016/j.radonc.2024.110365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 04/30/2024] [Accepted: 05/29/2024] [Indexed: 06/05/2024]
Abstract
Compared to conventional radiotherapy using X-rays, proton therapy, in principle, allows better conformity of the dose distribution to target volumes, at the cost of greater sensitivity to physical, anatomical, and positioning uncertainties. Robust planning, both in terms of plan optimization and evaluation, has gained high visibility in publications on the subject and is part of clinical practice in many centers. However, there is currently no consensus on the methods and parameters to be used for robust optimization or robustness evaluation. We propose to overcome this deficiency by following the modified Delphi consensus method. This method first requires a systematic review of the literature. We performed this review using the PubMed and Web Of Science databases, via two different experts. Potential conflicts were resolved by a third expert. We then explored the different methods before focusing on clinical studies that evaluate robustness on a significant number of patients. Many robustness assessment methods are proposed in the literature. Some are more successful than others and their implementation varies between centers. Moreover, they are not all statistically or mathematically equivalent. The most sophisticated and rigorous methods have seen more limited application due to the difficulty of their implementation and their lack of widespread availability.
Collapse
Affiliation(s)
- E Sterpin
- KU Leuven - Department of Oncology, Laboratory of Experimental Radiotherapy, Leuven, Belgium; UCLouvain - Institution de Recherche Expérimentale et Clinique, Center of Molecular Imaging Radiotherapy and Oncology (MIRO), Brussels, Belgium; Particle Therapy Interuniversity Center Leuven - PARTICLE, Leuven, Belgium.
| | - L Widesott
- Proton Therapy Center - UO Fisica Sanitaria, Azienda Provinciale per i Servizi Sanitari (APSS), Trento, Italy
| | - K Poels
- Particle Therapy Interuniversity Center Leuven - PARTICLE, Leuven, Belgium; UZ Leuven, Department of Radiation Oncology, Leuven, Belgium
| | - M Hoogeman
- Erasmus Medical Center, Cancer Institute, Department of Radiotherapy, Rotterdam, the Netherlands; HollandPTC, Delft, the Netherlands
| | - E W Korevaar
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, the Netherlands
| | - M Lowe
- Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, UK
| | - S Molinelli
- Fondazione CNAO - Medical Physics Unit, Pavia, Italy
| | - F Fracchiolla
- Proton Therapy Center - UO Fisica Sanitaria, Azienda Provinciale per i Servizi Sanitari (APSS), Trento, Italy
| |
Collapse
|
3
|
Ödén J, Eriksson K, Pavoni B, Crezee H, Kok HP. A Novel Framework for Thermoradiotherapy Treatment Planning. Int J Radiat Oncol Biol Phys 2024; 119:1530-1544. [PMID: 38387812 DOI: 10.1016/j.ijrobp.2024.02.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 01/24/2024] [Accepted: 02/08/2024] [Indexed: 02/24/2024]
Abstract
PURPOSE Thermoradiotherapy combines radiation therapy with hyperthermia to increase therapeutic effectiveness. Currently, both modalities are optimized separately and in state-of-the-art research the enhanced therapeutic effect is evaluated using equivalent radiation dose in 2-Gy fractions (EQD2). This study proposes a novel thermoradiotherapy treatment planning framework with voxelwise EQD2 radiation therapy optimizing including thermal radiosensitization and direct thermal cytotoxicity. METHODS AND MATERIALS To demonstrate proof-of-concept of the planning framework, 3 strategies consisting of 20 radiation therapy fractions were planned for 4 prostate cancer cases with substantially different temperature distributions: (1) Conventional radiation therapy plan of 60 Gy combined with 4 hyperthermia sessions (RT60 + HT), (2) standalone uniform dose escalation to 68 Gy without hyperthermia (RT68), and (3) uniform target EQD2 that maximizes the tumor control probability (TCP) accounting for voxelwise thermal effects of 4 hyperthermia sessions without increasing normal tissue doses (RTHT + HT). Assessment included dose, EQD2, TCP, and rectal normal tissue complication probability (NTCP), alongside robustness analyses for TCP and NTCP against parameter uncertainties. RESULTS The estimated TCP of around 76% for RT60 without hyperthermia was increased to an average of 85.9% (range, 81.3%-90.5%) for RT60 + HT, 92.5% (92.4%-92.5%) for RT68, and 94.4% (91.7%-96.6%) for RTHT + HT. The corresponding averaged rectal NTCPs were 8.7% (7.9%-10.0%), 14.9% (13.8%-17.1%), and 8.4% (7.5%-9.7%), respectively. RT68 and RTHT + HT exhibited slightly enhanced TCP robustness against parameter uncertainties compared with RT60 + HT, and RT68 presented higher and less robust rectal NTCP values compared with the other planning strategies. CONCLUSIONS This study introduces an innovative thermoradiotherapy planning approach, integrating thermal effects into EQD2-based radiation therapy optimization. Results demonstrate an ability to achieve enhanced and uniform target EQD2 and TCP across various temperature distributions without elevating normal tissue EQD2 or NTCP compared with conventional methods. Although promising for improving clinical outcomes, realizable enhancements depend on accurate tumor- and tissue-specific data and precise quantification of hyperthermic effects, which are seamlessly integrable in the planning framework as they emerge.
Collapse
Affiliation(s)
- Jakob Ödén
- RaySearch Laboratories AB, Stockholm, Sweden.
| | | | | | - Hans Crezee
- Department of Radiation Oncology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands; Cancer Center Amsterdam, Treatment and Quality of Life, Cancer Biology and Immunology, Amsterdam, The Netherlands
| | - H Petra Kok
- Department of Radiation Oncology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands; Cancer Center Amsterdam, Treatment and Quality of Life, Cancer Biology and Immunology, Amsterdam, The Netherlands
| |
Collapse
|
4
|
Rana S, Manthala Padannayil N, Tran L, Rosenfeld AB, Saeed H, Kasper M. Quantifying the Dosimetric Impact of Proton Range Uncertainties on RBE-Weighted Dose Distributions in Intensity-Modulated Proton Therapy for Bilateral Head and Neck Cancer. Curr Oncol 2024; 31:3690-3697. [PMID: 39057144 PMCID: PMC11275331 DOI: 10.3390/curroncol31070272] [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: 05/05/2024] [Revised: 06/06/2024] [Accepted: 06/08/2024] [Indexed: 07/28/2024] Open
Abstract
BACKGROUND In current clinical practice, intensity-modulated proton therapy (IMPT) head and neck cancer (HNC) plans are generated using a constant relative biological effectiveness (cRBE) of 1.1. The primary goal of this study was to explore the dosimetric impact of proton range uncertainties on RBE-weighted dose (RWD) distributions using a variable RBE (vRBE) model in the context of bilateral HNC IMPT plans. METHODS The current study included the computed tomography (CT) datasets of ten bilateral HNC patients who had undergone photon therapy. Each patient's plan was generated using three IMPT beams to deliver doses to the CTV_High and CTV_Low for doses of 70 Gy(RBE) and 54 Gy(RBE), respectively, in 35 fractions through a simultaneous integrated boost (SIB) technique. Each nominal plan calculated with a cRBE of 1.1 was subjected to the range uncertainties of ±3%. The McNamara vRBE model was used for RWD calculations. For each patient, the differences in dosimetric metrices between the RWD and nominal dose distributions were compared. RESULTS The constrictor muscles, oral cavity, parotids, larynx, thyroid, and esophagus showed average differences in mean dose (Dmean) values up to 6.91 Gy(RBE), indicating the impact of proton range uncertainties on RWD distributions. Similarly, the brachial plexus, brain, brainstem, spinal cord, and mandible showed varying degrees of the average differences in maximum dose (Dmax) values (2.78-10.75 Gy(RBE)). The Dmean and Dmax to the CTV from RWD distributions were within ±2% of the dosimetric results in nominal plans. CONCLUSION The consistent trend of higher mean and maximum doses to the OARs with the McNamara vRBE model compared to cRBE model highlighted the need for consideration of proton range uncertainties while evaluating OAR doses in bilateral HNC IMPT plans.
Collapse
Affiliation(s)
- Suresh Rana
- Department of Radiation Oncology, Lynn Cancer Institute, Boca Raton Regional Hospital, Baptist Health South Florida, Boca Raton, FL 33486, USA
- Department of Radiation Oncology, Florida International University, Miami, FL 33199, USA
| | - Noufal Manthala Padannayil
- Department of Radiation Oncology, Lynn Cancer Institute, Boca Raton Regional Hospital, Baptist Health South Florida, Boca Raton, FL 33486, USA
| | - Linh Tran
- Centre for Medical Radiation Physics (CMRP), University of Wollongong, Wollongong, NSW 2522, Australia
| | - Anatoly B. Rosenfeld
- Centre for Medical Radiation Physics (CMRP), University of Wollongong, Wollongong, NSW 2522, Australia
| | - Hina Saeed
- Department of Radiation Oncology, Lynn Cancer Institute, Boca Raton Regional Hospital, Baptist Health South Florida, Boca Raton, FL 33486, USA
- Department of Radiation Oncology, Florida International University, Miami, FL 33199, USA
| | - Michael Kasper
- Department of Radiation Oncology, Lynn Cancer Institute, Boca Raton Regional Hospital, Baptist Health South Florida, Boca Raton, FL 33486, USA
| |
Collapse
|
5
|
Almhagen E, Dasu A, Johansson S, Traneus E, Ahnesjö A. Plan robustness and RBE influence for proton dose painting by numbers for head and neck cancers. Phys Med 2023; 115:103157. [PMID: 37939480 DOI: 10.1016/j.ejmp.2023.103157] [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: 04/28/2023] [Revised: 08/25/2023] [Accepted: 09/26/2023] [Indexed: 11/10/2023] Open
Abstract
PURPOSE To investigate the feasibility of dose painting by numbers (DPBN) with respect to robustness for proton therapy for head and neck cancers (HNC), and to study the influence of variable RBE on the TCP and OAR dose burden. METHODS AND MATERIALS Data for 19 patients who have been scanned pretreatment with PET-FDG and subsequently treated with photon therapy were used in the study. A dose response model developed for photon therapy was implemented in a TPS, allowing DPBN plans to be created. Conventional homogeneous dose and DPBN plans were created for each patient, optimized with either fixed RBE = 1.1 or a variable RBE model. Robust optimization was used to create clinically acceptable plans. To estimate the maximum potential loss in TCP due to actual SUV variations from the pre-treatment imaging, we applied a test case with randomized SUV distribution. RESULTS Regardless of the use of variable RBE for optimization or evaluation, a statistically significant increase (p < 0.001) in TCP was found for DPBN plans as compared to homogeneous dose plans. Randomizing the SUV distribution decreased the TCP for all plans. A correlation between TCP increase and variance of the SUV distribution and target volume was also found. CONCLUSION DPBN for protons and HNC is feasible and could lead to a TCP gain. Risks associated with the temporal variation of SUV distributions could be mitigated by imposing minimum doses to targets. The correlation found between TCP increase and SUV variance and target volume may be used for patient selection.
Collapse
Affiliation(s)
- Erik Almhagen
- Medical Radiation Sciences, Department of Immunology, Genetics and Pathology, Uppsala University, Akademiska Sjukhuset, Uppsala, Sweden; The Skandion Clinic, Uppsala, Sweden.
| | - Alexandru Dasu
- Medical Radiation Sciences, Department of Immunology, Genetics and Pathology, Uppsala University, Akademiska Sjukhuset, Uppsala, Sweden; The Skandion Clinic, Uppsala, Sweden
| | - Silvia Johansson
- Divison of Oncology, Department of Immunology, Genetics and Pathology, Uppsala University Hospital, Uppsala, Sweden
| | | | - Anders Ahnesjö
- Medical Radiation Sciences, Department of Immunology, Genetics and Pathology, Uppsala University, Akademiska Sjukhuset, Uppsala, Sweden
| |
Collapse
|
6
|
Kasamatsu K, Matsuura T, Yasuda K, Miyazaki K, Takao S, Tamura M, Otsuka M, Uchinami Y, Aoyama H. Hyperfractionated intensity-modulated proton therapy for pharyngeal cancer with variable relative biological effectiveness: A simulation study. Med Phys 2022; 49:7815-7825. [PMID: 36300598 DOI: 10.1002/mp.16064] [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: 06/30/2022] [Revised: 10/06/2022] [Accepted: 10/07/2022] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND The relative biological effectiveness (RBE) of proton is considered to be dependent on biological parameters and fractional dose. While hyperfractionated photon therapy was effective in the treatment of patients with head and neck cancers, its effect in intensity-modulated proton therapy (IMPT) under the variable RBE has not been investigated in detail. PURPOSE To study the effect of variable RBE on hyperfractionated IMPT for the treatment of pharyngeal cancer. We investigated the biologically effective dose (BED) to determine the theoretical effective hyperfractionated schedule. METHODS The treatment plans of three pharyngeal cancer patients were used to define the ΔBED for the clinical target volume (CTV) and soft tissue (acute and late reaction) as the difference between the BED for the altered schedule with variable RBE and conventional schedule with constant RBE. The ΔBED with several combinations of parameters (treatment days, number of fractions, and prescribed dose) was comprehensively calculated. Of the candidate schedules, the one that commonly gave a higher ΔBED for CTV was selected as the resultant schedule. The BED volume histogram was used to compare the influence of variable RBE and fractionation. RESULTS In the conventional schedule, compared with the constant RBE, the variable RBE resulted in a mean 2.6 and 2.7 Gy reduction of BEDmean for the CTV and soft tissue (acute reaction) of the three plans, respectively. Moreover, the BEDmean for soft tissue (late reaction) increased by 7.4 Gy, indicating a potential risk of increased RBE. Comprehensive calculation of the ΔBED resulted in the hyperfractionated schedule of 80.52 Gy (RBE = 1.1)/66 fractions in 6.5 weeks. When variable RBE was used, compared with the conventional schedule, the hyperfractionated schedule increased the BEDmean for CTV by 7.6 Gy; however, this was associated with a 7.8 Gy increase for soft tissue (acute reaction). The BEDmean for soft tissue (late reaction) decreased by 2.4 Gy. CONCLUSION The results indicated a potential effect of the variable RBE on IMPT for pharyngeal cancer but with the possibility that hyperfractionation could outweigh this effect. Although biological uncertainties require conservative use of the resultant schedule, hyperfractionation is expected to be an effective strategy in IMPT for pharyngeal cancer.
Collapse
Affiliation(s)
- Koki Kasamatsu
- Graduate School of Biomedical Science and Engineering, Hokkaido University, Sapporo, Japan
| | - Taeko Matsuura
- Faculty of Engineering, Hokkaido University, Sapporo, Japan.,Department of Medical Physics, Hokkaido University Hospital, Sapporo, Japan.,Proton Beam Therapy Center, Hokkaido University Hospital, Sapporo, Japan
| | - Koichi Yasuda
- Department of Radiation Oncology, Faculty and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Koichi Miyazaki
- Faculty of Engineering, Hokkaido University, Sapporo, Japan.,Department of Medical Physics, Hokkaido University Hospital, Sapporo, Japan.,Research and Development Group, Hitachi, Ltd., Hitachi-shi, Japan
| | - Seishin Takao
- Faculty of Engineering, Hokkaido University, Sapporo, Japan.,Department of Medical Physics, Hokkaido University Hospital, Sapporo, Japan.,Proton Beam Therapy Center, Hokkaido University Hospital, Sapporo, Japan
| | - Masaya Tamura
- Department of Medical Physics, Hokkaido University Hospital, Sapporo, Japan
| | - Manami Otsuka
- Department of Radiation Oncology, Faculty and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Yusuke Uchinami
- Department of Radiation Oncology, Faculty and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Hidefumi Aoyama
- Department of Radiation Oncology, Faculty and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| |
Collapse
|
7
|
Ramesh P, Lyu Q, Gu W, Ruan D, Sheng K. Reformulated McNamara RBE-weighted beam orientation optimization for intensity modulated proton therapy. Med Phys 2022; 49:2136-2149. [PMID: 35181892 PMCID: PMC9894336 DOI: 10.1002/mp.15552] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 02/01/2022] [Accepted: 02/13/2022] [Indexed: 02/04/2023] Open
Abstract
PURPOSE Empirical relative biological effectiveness (RBE) models have been used to estimate the biological dose in proton therapy but do not adequately capture the factors influencing RBE values for treatment planning. We reformulate the McNamara RBE model such that it can be added as a linear biological dose fidelity term within our previously developed sensitivity-regularized and heterogeneity-weighted beam orientation optimization (SHBOO) framework. METHODS Based on our SHBOO framework, we formulated the biological optimization problem to minimize total McNamara RBE dose to OARs. We solve this problem using two optimization algorithms: FISTA (McNam-FISTA) and Chambolle-Pock (McNam-CP). We compare their performances with a physical dose optimizer assuming RBE = 1.1 in all structures (PHYS-FISTA) and an LET-weighted dose model (LET-FISTA). Three head and neck patients were planned with the four techniques and compared on dosimetry and robustness. RESULTS Compared to Phys-FISTA, McNam-CP was able to match CTV [HI, Dmax, D95%, D98%] by [0.00, 0.05%, 1.4%, 0.8%]. McNam-FISTA and McNam-CP were able to significantly improve overall OAR [Dmean, Dmax] by an average of [36.1%,26.4%] and [29.6%, 20.3%], respectively. Regarding CTV robustness, worst [Dmax, V95%, D95%, D98%] improvement of [-6.6%, 6.2%, 6.0%, 4.8%] was reported for McNam-FISTA and [2.7%, 2.7%, 5.3%, -4.3%] for McNam-CP under combinations of range and setup uncertainties. For OARs, worst [Dmax, Dmean] were improved by McNam-FISTA and McNam-CP by an average of [25.0%, 19.2%] and [29.5%, 36.5%], respectively. McNam-FISTA considerably improved dosimetry and CTV robustness compared to LET-FISTA, which achieved better worst-case OAR doses. CONCLUSION The four optimization techniques deliver comparable biological doses for the head and neck cases. Besides modest CTV coverage and robustness improvement, OAR biological dose and robustness were substantially improved with both McNam-FISTA and McNam-CP, showing potential benefit for directly incorporating McNamara RBE in proton treatment planning.
Collapse
Affiliation(s)
- Pavitra Ramesh
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Qihui Lyu
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Wenbo Gu
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Dan Ruan
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Ke Sheng
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, CA 90095, USA
| |
Collapse
|
8
|
Liu C, Bradley JA, Zheng D, Vega RBM, Beltran CJ, Mendenhall N, Liang X. RBE-weighted dose and its impact on the risk of acute coronary event for breast cancer patients treated with intensity modulated proton therapy. J Appl Clin Med Phys 2022; 23:e13527. [PMID: 35060317 PMCID: PMC8992952 DOI: 10.1002/acm2.13527] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 12/11/2021] [Accepted: 12/22/2021] [Indexed: 11/06/2022] Open
Abstract
PURPOSE To evaluate the relative biological effectiveness (RBE)-weighted dose to the heart and to estimate RBE uncertainties when assuming a constant RBE of 1.1, for breast cancer patients receiving intensity-modulated proton therapy (IMPT). Further, to study the impact of RBE uncertainties on the risk of an acute coronary event (ACE). MATERIAL AND METHODS We analyzed 20 patients who received IMPT to either the left breast (n = 10) or left chest wall (n = 10) and regional lymph nodes. The Monte Carlo simulation engine, MCsquare, was used to simulate the dose-averaged linear energy transfer (LETd) map. The RBE-weighted dose to the heart and its substructures was calculated using three different RBE models. The risk of ACE was estimated per its linear relationship with mean heart dose (MHD) as established by Darby et al. RESULTS The median MHD increased from 1.33 GyRBE assuming an RBE of 1.1 to 1.64, 1.87, and 1.99 GyRBE when using the RBE-weighted dose models. The median values (and ranges) of the excess absolute risk of ACE were 0.4% (0.1%-0.8%) when assuming an RBE of 1.1, and 0.6% (0.2%-1.0%), 0.6% (0.2%-1.1%), and 0.7% (0.2%-1.1%) with the RBE-weighted models. For our patient cohort, the maximum excess absolute risk of ACE increased by 0.3% with the RBE-weighted doses compared to the constant RBE of 1.1, reaching an excess absolute ACE risk of 1.1%. The interpatient LETd variation was small for the relevant high-dose regions of the heart. CONCLUSION All three RBE models predicted a higher biological dose compared to the clinical standard dose assuming a constant RBE of 1.1. An underestimation of the biological dose results in underestimation of the ACE risk. Analyzing the voxel-by-voxel biological dose and the LET map alongside clinical outcomes is warranted in the development of a more accurate normal-tissue complication probability model.
Collapse
Affiliation(s)
- Chunbo Liu
- University of Florida Health Proton Therapy InstituteJacksonvilleFloridaUSA
| | - Julie A. Bradley
- Department of Radiation OncologyUniversity of Florida College of MedicineJacksonvilleFloridaUSA
| | - Dandan Zheng
- Department of Radiation OncologyUniversity of Nebraska Medical CenterOmahaNebraskaUSA
| | - Raymond B. Mailhot Vega
- Department of Radiation OncologyUniversity of Florida College of MedicineJacksonvilleFloridaUSA
| | - Chris J. Beltran
- Mayo ClinicDepartment of Radiation OncologyJacksonvilleFloridaUSA
| | - Nancy Mendenhall
- Department of Radiation OncologyUniversity of Florida College of MedicineJacksonvilleFloridaUSA
| | - Xiaoying Liang
- Mayo ClinicDepartment of Radiation OncologyJacksonvilleFloridaUSA
| |
Collapse
|
9
|
Hahn C, Ödén J, Dasu A, Vestergaard A, Fuglsang Jensen M, Sokol O, Pardi C, Bourhaleb F, Leite A, de Marzi L, Smith E, Aitkenhead A, Rose C, Merchant M, Kirkby K, Grzanka L, Pawelke J, Lühr A. Towards harmonizing clinical linear energy transfer (LET) reporting in proton radiotherapy: a European multi-centric study. Acta Oncol 2022; 61:206-214. [PMID: 34686122 DOI: 10.1080/0284186x.2021.1992007] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 10/06/2021] [Indexed: 10/20/2022]
Abstract
BACKGROUND Clinical data suggest that the relative biological effectiveness (RBE) in proton therapy (PT) varies with linear energy transfer (LET). However, LET calculations are neither standardized nor available in clinical routine. Here, the status of LET calculations among European PT institutions and their comparability are assessed. MATERIALS AND METHODS Eight European PT institutions used suitable treatment planning systems with their center-specific beam model to create treatment plans in a water phantom covering different field arrangements and fulfilling commonly agreed dose objectives. They employed their locally established LET simulation environments and procedures to determine the corresponding LET distributions. Dose distributions D1.1 and DRBE assuming constant and variable RBE, respectively, and LET were compared among the institutions. Inter-center variability was assessed based on dose- and LET-volume-histogram parameters. RESULTS Treatment plans from six institutions fulfilled all clinical goals and were eligible for common analysis. D1.1 distributions in the target volume were comparable among PT institutions. However, corresponding LET values varied substantially between institutions for all field arrangements, primarily due to differences in LET averaging technique and considered secondary particle spectra. Consequently, DRBE using non-harmonized LET calculations increased inter-center dose variations substantially compared to D1.1 and significantly in mean dose to the target volume of perpendicular and opposing field arrangements (p < 0.05). Harmonizing LET reporting (dose-averaging, all protons, LET to water or to unit density tissue) reduced the inter-center variability in LET to the order of 10-15% within and outside the target volume for all beam arrangements. Consequentially, inter-institutional variability in DRBE decreased to that observed for D1.1. CONCLUSION Harmonizing the reported LET among PT centers is feasible and allows for consistent multi-centric analysis and reporting of tumor control and toxicity in view of a variable RBE. It may serve as basis for harmonized variable RBE dose prescription in PT.
Collapse
Affiliation(s)
- Christian Hahn
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
- Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
- German Cancer Consortium (DKTK), Partner Site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany
- Medical Physics and Radiotherapy, Department of Physics, TU Dortmund University, Dortmund, Germany
| | - Jakob Ödén
- RaySearch Laboratories AB, Stockholm, Sweden
| | - Alexandru Dasu
- The Skandion Clinic, Uppsala, Sweden
- Medical Radiation Sciences, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Anne Vestergaard
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
| | | | - Olga Sokol
- GSI Helmholtz Centre for Heavy Ion Research, Darmstadt, Germany
| | - Claudia Pardi
- I-SEE (Internet-Simulation Evaluation Envision), Torino, Italy
| | - Faiza Bourhaleb
- I-SEE (Internet-Simulation Evaluation Envision), Torino, Italy
| | - Amélia Leite
- Institut Curie, PSL Research University, Radiation Oncology Department, Proton Therapy Centre, Centre Universitaire, Orsay, France
| | - Ludovic de Marzi
- Institut Curie, PSL Research University, Radiation Oncology Department, Proton Therapy Centre, Centre Universitaire, Orsay, France
- Institut Curie, PSL Research University, University Paris Saclay, Inserm LITO, Orsay, France
| | - Edward Smith
- Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, UK
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, UK
| | - Adam Aitkenhead
- Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, UK
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, UK
| | - Christopher Rose
- Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, UK
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, UK
| | - Michael Merchant
- Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, UK
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, UK
| | - Karen Kirkby
- Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, UK
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, UK
| | - Leszek Grzanka
- Institute of Nuclear Physics Polish Academy of Sciences, Krakow, Poland
| | - Jörg Pawelke
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany
| | - Armin Lühr
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
- German Cancer Consortium (DKTK), Partner Site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany
- Medical Physics and Radiotherapy, Department of Physics, TU Dortmund University, Dortmund, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany
| |
Collapse
|
10
|
Engeseth GM, Hysing LB, Yepes P, Pettersen HES, Mohan R, Fuller CD, Stokkevåg CH, Wu R, Zhang X, Frank SJ, Gunn GB. Impact of RBE variations on risk estimates of temporal lobe necrosis in patients treated with intensity-modulated proton therapy for head and neck cancer. Acta Oncol 2022; 61:215-222. [PMID: 34534047 PMCID: PMC9969227 DOI: 10.1080/0284186x.2021.1979248] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Temporal lobe necrosis (TLN) is a potential late effect after radiotherapy for skull base head and neck cancer (HNC). Several photon-derived dose constraints and normal tissue complication probability (NTCP) models have been proposed, however variation in relative biological effectiveness (RBE) may challenge the applicability of these dose constraints and models in proton therapy. The purpose of this study was therefore to investigate the influence of RBE variations on risk estimates of TLN after Intensity-Modulated Proton Therapy for HNC. MATERIAL AND METHODS Seventy-five temporal lobes from 45 previously treated patients were included in the analysis. Sixteen temporal lobes had radiation associated Magnetic Resonance image changes (TLIC) suspected to be early signs of TLN. Fixed (RWDFix) and variable RBE-weighed doses (RWDVar) were calculated using RBE = 1.1 and two RBE models, respectively. RWDFix and RWDVar for temporal lobes were compared using Friedman's test. Based on RWDFix, six NTCP models were fitted and internally validated through bootstrapping. Estimated probabilities from RWDFix and RWDVar were compared using paired Wilcoxon test. Seven dose constraints were evaluated separately for RWDFix and RWDVar by calculating the observed proportion of TLIC in temporal lobes meeting the specific dose constraints. RESULTS RWDVar were significantly higher than RWDFix (p < 0.01). NTCP model performance was good (AUC:0.79-0.84). The median difference in estimated probability between RWDFix and RWDVar ranged between 5.3% and 20.0% points (p < 0.01), with V60GyRBE and DMax at the smallest and largest differences, respectively. The proportion of TLIC was higher for RWDFix (4.0%-13.1%) versus RWDVar (1.3%-5.3%). For V65GyRBE ≤ 0.03 cc the proportion of TLIC was less than 5% for both RWDFix and RWDVar. CONCLUSION NTCP estimates were significantly influenced by RBE variations. Dmax as model predictor resulted in the largest deviations in risk estimates between RWDFix and RWDVar. V65GyRBE ≤ 0.03 cc was the most consistent dose constraint for RWDFix and RWDVar.
Collapse
Affiliation(s)
- Grete May Engeseth
- University of Texas MD Anderson Cancer Center, Department of Radiation Oncology, Houston, USA,Haukeland University Hospital, Department of Oncology and Medical Physics, Bergen, Norway,University of Bergen, Department of Clinical Science, Bergen, Norway,Corresponding author: Grete May Engeseth, , Haukeland University Hospital, Department of Oncology and Medical Physics, Postboks 1400, 5021 Bergen
| | - Liv Bolstad Hysing
- Haukeland University Hospital, Department of Oncology and Medical Physics, Bergen, Norway,University of Bergen, Department of Physics and Technology, Bergen, Norway
| | - Pablo Yepes
- Rice University, Physics and Astronomy Department, Houston, USA
| | | | - Rahde Mohan
- University of Texas MD Anderson Cancer Center, Department of Radiation Physics, Houston, USA
| | - Clifton Dave Fuller
- University of Texas MD Anderson Cancer Center, Department of Radiation Oncology, Houston, USA
| | - Camilla Hanquist Stokkevåg
- Haukeland University Hospital, Department of Oncology and Medical Physics, Bergen, Norway,University of Bergen, Department of Physics and Technology, Bergen, Norway
| | - Richard Wu
- University of Texas MD Anderson Cancer Center, Department of Radiation Oncology, Houston, USA
| | - Xiaodong Zhang
- University of Texas MD Anderson Cancer Center, Department of Radiation Oncology, Houston, USA
| | - Steven Jay Frank
- University of Texas MD Anderson Cancer Center, Department of Radiation Oncology, Houston, USA
| | - Gary Brandon Gunn
- University of Texas MD Anderson Cancer Center, Department of Radiation Oncology, Houston, USA
| |
Collapse
|
11
|
Deng W, Yang Y, Liu C, Bues M, Mohan R, Wong WW, Foote RH, Patel SH, Liu W. A Critical Review of LET-Based Intensity-Modulated Proton Therapy Plan Evaluation and Optimization for Head and Neck Cancer Management. Int J Part Ther 2021; 8:36-49. [PMID: 34285934 PMCID: PMC8270082 DOI: 10.14338/ijpt-20-00049.1] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 10/14/2020] [Indexed: 12/15/2022] Open
Abstract
In this review article, we review the 3 important aspects of linear-energy-transfer (LET) in intensity-modulated proton therapy (IMPT) for head and neck (H&N) cancer management. Accurate LET calculation methods are essential for LET-guided plan evaluation and optimization, which can be calculated either by analytical methods or by Monte Carlo (MC) simulations. Recently, some new 3D analytical approaches to calculate LET accurately and efficiently have been proposed. On the other hand, several fast MC codes have also been developed to speed up the MC simulation by simplifying nonessential physics models and/or using the graphics processor unit (GPU)–acceleration approach. Some concepts related to LET are also briefly summarized including (1) dose-weighted versus fluence-weighted LET; (2) restricted versus unrestricted LET; and (3) microdosimetry versus macrodosimetry. LET-guided plan evaluation has been clinically done in some proton centers. Recently, more and more studies using patient outcomes as the biological endpoint have shown a positive correlation between high LET and adverse events sites, indicating the importance of LET-guided plan evaluation in proton clinics. Various LET-guided plan optimization methods have been proposed to generate proton plans to achieve biologically optimized IMPT plans. Different optimization frameworks were used, including 2-step optimization, 1-step optimization, and worst-case robust optimization. They either indirectly or directly optimize the LET distribution in patients while trying to maintain the same dose distribution and plan robustness. It is important to consider the impact of uncertainties in LET-guided optimization (ie, LET-guided robust optimization) in IMPT, since IMPT is sensitive to uncertainties including both the dose and LET distributions. We believe that the advancement of the LET-guided plan evaluation and optimization will help us exploit the unique biological characteristics of proton beams to improve the therapeutic ratio of IMPT to treat H&N and other cancers.
Collapse
Affiliation(s)
- Wei Deng
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, USA
| | - Yunze Yang
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, USA
| | - Chenbin Liu
- Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital & Shenzhen Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Shenzhen, Guangdong, China
| | - Martin Bues
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, USA
| | - Radhe Mohan
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - William W Wong
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, USA
| | - Robert H Foote
- Department of Radiation Oncology, Mayo Clinic, Rochester, MN, USA
| | - Samir H Patel
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, USA
| | - Wei Liu
- Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, USA
| |
Collapse
|
12
|
Sterpin E, Rivas ST, Van den Heuvel F, George B, Lee JA, Souris K. Development of robustness evaluation strategies for enabling statistically consistent reporting. Phys Med Biol 2021; 66:045002. [PMID: 33296875 DOI: 10.1088/1361-6560/abd22f] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Robustness evaluation of proton therapy treatment plans is essential for ensuring safe treatment delivery. However, available evaluation procedures feature a limited exploration of the actual robustness of the plan and generally do not provide confidence levels. This study compared established and more sophisticated robustness evaluation procedures, with quantified confidence levels. We have evaluated several robustness evaluation methods for 5 bilateral head-and-neck patients optimized considering spot scanning delivery and with a conventional CTV-to-PTV margin of 4 mm. Method (1) good practice scenario selection (GPSS) (e.g. +/- 4 mm setup error 3% range uncertainty); (2) statistically sound scenario selection (SSSS) either only on or both on and inside isoprobability hypersurface encompassing 90% of the possible errors; (3) statistically sound dosimetric selection (SSDS). In the last method, the 90% best plans were selected according to either target coverage quantified by D 95 (SSDS_D 95) or to an approximation of the final objective function (OF) used during treatment optimization (SSDS_OF). For all methods, we have considered systematic setup and systematic range errors. A mix of systematic and random setup errors were also simulated for SSDS, but keeping the same conventional margin of 4 mm. All robustness evaluations have been performed using the fast Monte Carlo dose engine MCsquare. Both SSSS strategies yielded on average very similar results. SSSS and GPSS yield comparable values for target coverage (within 0.5 Gy). The most noticeable differences were found for the CTV between GPSS, on the one hand, and SSDS_D 95 and SSDS_OF, on the other hand (average worst-case D 98 were 2.8 and 2.0 Gy larger than for GPSS, respectively). Simulating explicitly random errors in SSDS improved almost all DVH metrics. We have observed that the width of DVH-bands and the confidence levels depend on the method chosen to sample the scenarios. Statistically sound estimation of the robustness of the plan in the dosimetric space may provide an improved insight on the actual robustness of the plan for a given confidence level.
Collapse
Affiliation(s)
- E Sterpin
- KU Leuven, Department of Oncology, Laboratory of Experimental Radiotherapy, Leuven, Belgium
- Université catholique de Louvain, Institut de Recherche Expérimentale et Clinique, Center of Molecular Imaging, Radiotherapy and Oncology (MIRO), Brussels, Belgium
| | - Sara T Rivas
- Université catholique de Louvain, Institut de Recherche Expérimentale et Clinique, Center of Molecular Imaging, Radiotherapy and Oncology (MIRO), Brussels, Belgium
| | - F Van den Heuvel
- CRUK/MRC Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
- Dept of Haematology/Oncology, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - B George
- CRUK/MRC Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
| | - J A Lee
- Université catholique de Louvain, Institut de Recherche Expérimentale et Clinique, Center of Molecular Imaging, Radiotherapy and Oncology (MIRO), Brussels, Belgium
| | - K Souris
- Université catholique de Louvain, Institut de Recherche Expérimentale et Clinique, Center of Molecular Imaging, Radiotherapy and Oncology (MIRO), Brussels, Belgium
| |
Collapse
|
13
|
Liu C, Zheng D, Bradley JA, Mailhot Vega RB, Zhang Y, Indelicato DJ, Mendenhall N, Liang X. Incorporation of the LETd-weighted biological dose in the evaluation of breast intensity-modulated proton therapy plans. Acta Oncol 2021; 60:252-259. [PMID: 33063569 DOI: 10.1080/0284186x.2020.1834141] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
PURPOSE To evaluate the LETd-weighted biological dose to OARs in proton therapy for breast cancer and to study the relationship of the LETd-weighted biological dose relative to the standard dose (RBE = 1.1) and thereby to provide estimations of the biological dose uncertainties with the standard dose calculations (RBE = 1.1) commonly used in clinical practice. METHOD This study included 20 patients who received IMPT treatment to the whole breast/chest wall and regional lymph nodes. The LETd distributions were calculated along with the physical dose using an open-source Monte Carlo simulation package, MCsquare. Using the McMahon linear model, the LETd-weighted biological dose was computed from the physical dose and LETd. OAR doses were compared between the Dose (RBE = 1.1) and the LETd-weighted biological dose, on brachial plexus, rib, heart, esophagus, and Ipsilateral lung. RESULTS On average, the LETd-weighted biological dose compared to the Dose (RBE = 1.1) was higher by 8% for the brachial plexus D0.1 cc, 13% for the ribs D0.5 cc, 24% for mean heart dose, and 10% for the esophagus D0.1 cc, respectively. The LETd-weighted doses to the Ipsilateral lung V5, V10, and V20 were comparable to the Dose (RBE = 1.1). No statistically significant difference in biological dose enhancement to OARs was observed between the intact breast group and the CW group, with the exception of the ribs: the CW group experienced slightly greater biological dose enhancement (13% vs. 12%, p = 0.04) to the ribs than the intact breast group. CONCLUSION Enhanced biological dose was observed compared to standard dose with assumed RBE of 1.1 for the heart, ribs, esophagus, and brachial plexus in breast/CW and regional nodal IMPT plans. Variable RBE models should be considered in the evaluation of the IMPT breast plans, especially for OARs located near the end of range of a proton beam. Clinical outcome studies are needed to validate model predictions for clinical toxicities.
Collapse
Affiliation(s)
- Chunbo Liu
- Department of Radiation Oncology, University of Florida College of Medicine, Jacksonville, FL, USA
- School of Physical Sciences, University of Science and Technology of China, Hefei, China
| | - Dandan Zheng
- Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Julie A. Bradley
- Department of Radiation Oncology, University of Florida College of Medicine, Jacksonville, FL, USA
| | - Raymond B. Mailhot Vega
- Department of Radiation Oncology, University of Florida College of Medicine, Jacksonville, FL, USA
| | - Yawei Zhang
- Department of Radiation Oncology, University of Florida College of Medicine, Jacksonville, FL, USA
| | - Daniel J. Indelicato
- Department of Radiation Oncology, University of Florida College of Medicine, Jacksonville, FL, USA
| | - Nancy Mendenhall
- Department of Radiation Oncology, University of Florida College of Medicine, Jacksonville, FL, USA
| | - Xiaoying Liang
- Department of Radiation Oncology, University of Florida College of Medicine, Jacksonville, FL, USA
| |
Collapse
|
14
|
Marteinsdottir M, Wang CC, McNamara A, Depauw N, Shin J, Paganetti H. The impact of variable relative biological effectiveness in proton therapy for left-sided breast cancer when estimating normal tissue complications in the heart and lung. Phys Med Biol 2021; 66:035023. [PMID: 33522498 DOI: 10.1088/1361-6560/abd230] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The aim of this study was to evaluate the clinical impact of relative biological effectiveness (RBE) variations in proton beam scanning treatment (PBS) for left-sided breast cancer versus the assumption of a fixed RBE of 1.1, particularly in the context of comparisons with photon-based three-dimensional conformal radiotherapy (3DCRT) and volumetric modulated arc therapy (VMAT). Ten patients receiving radiation treatment to the whole breast/chest wall and regional lymph nodes were selected for each modality. For PBS, the dose distributions were re-calculated with both a fixed RBE and a variable RBE using an empirical RBE model. Dosimetric indices based on dose-volume histogram analysis were calculated for the entire heart wall, left anterior descending artery (LAD) and left lung. Furthermore, normal tissue toxicity probabilities for different endpoints were evaluated. The results show that applying a variable RBE significantly increases the RBE-weighted dose and consequently the calculated dosimetric indices increases for all organs compared to a fixed RBE. The mean dose to the heart and the maximum dose to the LAD and the left lung are significantly lower for PBS assuming a fixed RBE compared to 3DCRT. However, no statistically significant difference is seen when a variable RBE is applied. For a fixed RBE, lung toxicities are significantly lower compared to 3DCRT but when applying a variable RBE, no statistically significant differences are noted. A disadvantage is seen for VMAT over both PBS and 3DCRT. One-to-one plan comparison on 8 patients between PBS and 3DCRT shows similar results. We conclude that dosimetric analysis for all organs and toxicity estimation for the left lung might be underestimated when applying a fixed RBE for protons. Potential RBE variations should therefore be considered as uncertainty bands in outcome analysis.
Collapse
Affiliation(s)
- Maria Marteinsdottir
- Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA 02114, United States of America. Faculty of Physical Sciences, University of Iceland, Dunhaga 5, IS-107 Reykjavik, Iceland
| | | | | | | | | | | |
Collapse
|
15
|
Fjæra LF, Indelicato DJ, Ytre-Hauge KS, Muren LP, Lassen-Ramshad Y, Toussaint L, Dahl O, Stokkevåg CH. Spatial Agreement of Brainstem Dose Distributions Depending on Biological Model in Proton Therapy for Pediatric Brain Tumors. Adv Radiat Oncol 2021; 6:100551. [PMID: 33490724 PMCID: PMC7811129 DOI: 10.1016/j.adro.2020.08.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 08/13/2020] [Accepted: 08/20/2020] [Indexed: 11/02/2022] Open
Abstract
Purpose During radiation therapy for pediatric brain tumors, the brainstem is a critical organ at risk, possibly with different radio-sensitivity across its substructures. In proton therapy, treatment planning is currently performed using a constant relative biological effectiveness (RBE) of 1.1 (RBE1.1), whereas preclinical studies point toward spatial variability of this factor. To shed light on this biological uncertainty, we investigated the spatial agreement between isodose maps produced by different RBE models, with emphasis on (smaller) substructures of the brainstem. Methods and Materials Proton plans were recalculated using Monte Carlo simulations in 3 anonymized pediatric patients with brain tumors (a craniopharyngioma, a low-grade glioma, and a posterior fossa ependymoma) to obtain dose and linear energy transfer distributions. Doses and volume metrics for the brainstem and its substructures were calculated using a constant RBE1.1, 4 phenomenological RBE models with varying (α/β)x parameters, and with a simpler linear energy transfer-dependent model. The spatial agreement between the dose distributions of constant RBE1.1 versus the variable RBE models was compared using the Dice similarity coefficient. Results The spatial agreement between the variable RBE dose distributions and RBE1.1 decreased with increasing isodose levels in all patient cases. The patient with ependymoma showed the greatest variation in dose and dose volumes, where V50Gy(RBE) in the brainstem increased from 32% (RBE1.1) to 35% to 49% depending on the applied model, corresponding to a spatial agreement (Dice similarity coefficient) between 0.79 and 0.95. The remaining patients showed similar trends, however, with lower absolute values due to lower brainstem doses. Conclusions All phenomenological RBE models fully enclosed the isodose volumes of the constant RBE1.1, and the volumes based on variable RBE spatially agreed. The spatial agreement was dependent on the isodose level, where higher isodose levels showed larger expansions and less agreement between the variable RBE models and RBE1.1.
Collapse
Affiliation(s)
| | - Daniel J Indelicato
- Department of Radiation Oncology, University of Florida, Jacksonville, Florida
| | | | - Ludvig P Muren
- Department of Medical Physics, Aarhus University/Aarhus University Hospital, Denmark
| | | | - Laura Toussaint
- Department of Medical Physics, Aarhus University/Aarhus University Hospital, Denmark
| | - Olav Dahl
- Department of Oncology and Medical Physics, Haukeland University Hospital, Bergen, Norway
| | - Camilla H Stokkevåg
- Department of Oncology and Medical Physics, Haukeland University Hospital, Bergen, Norway
| |
Collapse
|
16
|
Silicon 3D Microdetectors for Microdosimetry in Hadron Therapy. MICROMACHINES 2020; 11:mi11121053. [PMID: 33260634 PMCID: PMC7760635 DOI: 10.3390/mi11121053] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 11/10/2020] [Accepted: 11/12/2020] [Indexed: 11/17/2022]
Abstract
The present overview describes the evolution of new microdosimeters developed in the National Microelectronics Center in Spain (IMB-CNM, CSIC), ranging from the first ultra-thin 3D diodes (U3DTHINs) to the advanced 3D-cylindrical microdetectors, which have been developed over the last 10 years. In this work, we summarize the design, main manufacture processes, and electrical characterization of these devices. These sensors were specifically customized for use in particle therapy and overcame some of the technological challenges in this domain, namely the low noise capability, well-defined sensitive volume, high spatial resolution, and pile-up robustness. Likewise, both architectures reduce the loss of charge carriers due to trapping effects, the charge collection time, and the voltage required for full depletion compared to planar silicon detectors. In particular, a 3D‒cylindrical architecture with electrodes inserted into the silicon bulk and with a very well‒delimited sensitive volume (SV) mimicked a cell array with shapes and sizes similar to those of mammalian cells for the first time. Experimental tests of the carbon beamlines at the Grand Accélérateur National d’Lourds (GANIL, France) and Centro Nazionale Adroterapia Oncologica (CNAO, Italy) showed the feasibility of the U3DTHINs in hadron therapy beams and the good performance of the 3D‒cylindrical microdetectors for assessing linear energy distributions of clinical beams, with clinical fluence rates of 5 × 107 s−1cm−2 without saturation. The dose-averaged lineal energies showed a generally good agreement with Monte Carlo simulations. The results indicated that these devices can be used to characterize the microdosimetric properties in hadron therapy, even though the charge collection efficiency (CCE) and electronic noise may pose limitations on their performance, which is studied and discussed herein. In the last 3D‒cylindrical microdetector generation, we considerably improved the CCE due to the microfabrication enhancements, which have led to shallower and steeper dopant profiles. We also summarize the successive microdosimetric characterizations performed with both devices in proton and carbon beamlines.
Collapse
|
17
|
Hahn C, Eulitz J, Peters N, Wohlfahrt P, Enghardt W, Richter C, Lühr A. Impact of range uncertainty on clinical distributions of linear energy transfer and biological effectiveness in proton therapy. Med Phys 2020; 47:6151-6162. [PMID: 33118161 DOI: 10.1002/mp.14560] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 10/01/2020] [Accepted: 10/20/2020] [Indexed: 12/14/2022] Open
Abstract
PURPOSE Increased radiation response after proton irradiation, such as late radiation-induced toxicity, is determined by high dose and elevated linear energy transfer (LET). Steep dose-averaged LET (LETd ) gradients and elevated LETd occur at the end of proton range and might be particularly sensitive to uncertainties in range prediction. Therefore, this study quantified LETd distributions and the impact of range uncertainty in robust dose-optimized proton treatment plans and assessed the biological effect in normal tissues and tumors of patients. METHODS For each of six cancer patients (two brain, head-and-neck, and prostate), two nominal treatment plans were robustly dose optimized using single- and multi-field optimization, respectively. For each plan, two additional scenarios with ±3.5% range deviation relative to the nominal plan were derived by global rescaling of stopping-power ratios. Dose and LETd distributions were calculated for each scenario using the beam parameters of the corresponding nominal plan. The variability in relative biological effectiveness (RBE) and probability of late radiation-induced brain toxicity (PIC ) was assessed. RESULTS The optimization technique (single- vs multi-field) had a negligible impact on the LETd distributions in the clinical target volume (CTV) and in most organs at risk (OARs). LETd distributions in the CTV were rather homogeneous with arithmetic mean of LETd below 3.2 keV/µm and robust against range deviations. The RBE variability within the CTV induced by range uncertainty was small (≤0.05, 95% confidence interval). In OARs, LETd hotspots (>7 keV/µm) occurred and LETd distributions were inhomogeneous and sensitive to range deviations. LETd hotspots and the impact of range deviations were most prominent in OARs of brain tumor patients which translated in RBE values exceeding 1.1 in all brain OARs. The near-maximum predicted PIC in healthy brain tissue of brain tumor patients was smaller than 5% and occurred adjacent to the CTV. Range deviations induced absolute differences in PIC up to 1.2%. CONCLUSIONS Robust dose optimization generates LETd distributions in the target volume robust against range deviations. The current findings support using a constant RBE within the CTV. The impact of range deviations on the considered probability of late radiation-induced toxicity in brain tissue was limited for robust dose-optimized treatment plans. Incorporation of LETd in robust optimization frameworks may further reduce uncertainty related to the RBE-weighted dose estimation in normal tissues.
Collapse
Affiliation(s)
- Christian Hahn
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany.,Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.,Department of Medical Physics and Radiotherapy, Faculty of Physics, TU Dortmund University, Dortmund, Germany
| | - Jan Eulitz
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany.,Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.,Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany
| | - Nils Peters
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany.,Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany
| | - Patrick Wohlfahrt
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, USA
| | - Wolfgang Enghardt
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany.,Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.,Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany.,German Cancer Consortium (DKTK), Partner Site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Christian Richter
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany.,Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.,Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany.,German Cancer Consortium (DKTK), Partner Site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Armin Lühr
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany.,Department of Medical Physics and Radiotherapy, Faculty of Physics, TU Dortmund University, Dortmund, Germany.,Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany.,German Cancer Consortium (DKTK), Partner Site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany
| |
Collapse
|
18
|
Toma-Dasu I, Dasu A, Vestergaard A, Witt Nyström P, Nyström H. RBE for proton radiation therapy - a Nordic view in the international perspective. Acta Oncol 2020; 59:1151-1156. [PMID: 33000988 DOI: 10.1080/0284186x.2020.1826573] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
BACKGROUND This paper presents an insight into the critical discussions and the current strategies of the Nordic countries for handling the variable proton relative biological effectiveness (RBE) as presented at The Nordic Collaborative Workshop for Particle Therapy that took place at the Skandion Clinic on 14th and 15th of November 2019. MATERIAL AND METHODS In the current clinical practice at the two proton centres in operation at the date, Skandion Clinic, and the Danish Centre for Particle Therapy, a constant proton RBE of 1.1 is applied. The potentially increased effectiveness at the end of the particle range is however considered at the stage of treatment planning at both places based on empirical observations and knowledge. More elaborated strategies to evaluate the plans and mitigate the problem are intensely investigated internationally as well at the two centres. They involve the calculation of the dose-averaged linear energy transfer (LETd) values and the assessment of their distributions corroborated with the distribution of the dose and the location of the critical clinical structures. RESULTS Methods and tools for LETd calculations are under different stages of development as well as models to account for the variation of the RBE with LETd, dose per fraction, and type of tissue. The way they are currently used for evaluation and optimisation of the plans and their robustness are summarised. A critical but not exhaustive discussion of their potential future implementation in the clinical practice is also presented. CONCLUSIONS The need for collaboration between the clinical proton centres in establishing common platforms and perspectives for treatment planning evaluation and optimisation is highlighted as well as the need of close interaction with the research academic groups that could offer a complementary perspective and actively help developing methods and tools for clinical implementation of the more complex metrics for considering the variable effectiveness of the proton beams.
Collapse
Affiliation(s)
- Iuliana Toma-Dasu
- Department of Physics, Medical Radiation Physics, Stockholm University, Stockholm, Sweden
- Department of Oncology and Pathology, Medical Radiation Physics, Karolinska Institutet, Stockholm, Sweden
| | - Alexandru Dasu
- The Skandion Clinic, Uppsala, Sweden
- Medical Radiation Sciences, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | | | - Petra Witt Nyström
- The Skandion Clinic, Uppsala, Sweden
- Danish Centre for Particle Therapy, Aarhus, Denmark
| | | |
Collapse
|
19
|
Ma J, Wan Chan Tseung HS, Courneyea L, Beltran C, Herman MG, Remmes NB. Robust radiobiological optimization of ion beam therapy utilizing Monte Carlo and microdosimetric kinetic model. ACTA ACUST UNITED AC 2020; 65:155020. [DOI: 10.1088/1361-6560/aba08b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
20
|
Ytre-Hauge KS, Fjæra LF, Rørvik E, Dahle TJ, Dale JE, Pilskog S, Stokkevåg CH. Inter-patient variations in relative biological effectiveness for cranio-spinal irradiation with protons. Sci Rep 2020; 10:6212. [PMID: 32277106 PMCID: PMC7148381 DOI: 10.1038/s41598-020-63164-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 03/23/2020] [Indexed: 12/30/2022] Open
Abstract
Cranio-spinal irradiation (CSI) using protons has dosimetric advantages compared to photons and is expected to reduce risk of adverse effects. The proton relative biological effectiveness (RBE) varies with linear energy transfer (LET), tissue type and dose, but a variable RBE has not replaced the constant RBE of 1.1 in clinical treatment planning. We examined inter-patient variations in RBE for ten proton CSI patients. Variable RBE models were used to obtain RBE and RBE-weighted doses. RBE was quantified in terms of dose weighted organ-mean RBE ([Formula: see text] = mean RBE-weighted dose/mean physical dose) and effective RBE of the near maximum dose (D2%), i.e. RBED2% = [Formula: see text], where subscripts RBE and phys indicate that the D2% is calculated based on an RBE model and the physical dose, respectively. Compared to the median [Formula: see text] of the patient population, differences up to 15% were observed for the individual [Formula: see text] values found for the thyroid, while more modest variations were seen for the heart (6%), lungs (2%) and brainstem (<1%). Large inter-patient variation in RBE could be correlated to large spread in LET and dose for these organs at risk (OARs). For OARs with small inter-patient variations, the results show that applying a population based RBE in treatment planning may be a step forward compared to using RBE of 1.1. OARs with large inter-patient RBE variations should ideally be selected for patient-specific biological or RBE robustness analysis if the physical doses are close to known dose thresholds.
Collapse
Affiliation(s)
| | - Lars Fredrik Fjæra
- Department of Physics and Technology, University of Bergen, Bergen, Norway
| | - Eivind Rørvik
- Department of Medical Physics, Oslo University Hospital, The Radium Hospital, Oslo, Norway
| | - Tordis J Dahle
- Department of Physics and Technology, University of Bergen, Bergen, Norway
| | - Jon Espen Dale
- Department of Oncology and Medical Physics, Haukeland University Hospital, Bergen, Norway
| | - Sara Pilskog
- Department of Oncology and Medical Physics, Haukeland University Hospital, Bergen, Norway
| | - Camilla H Stokkevåg
- Department of Oncology and Medical Physics, Haukeland University Hospital, Bergen, Norway
| |
Collapse
|
21
|
Proton therapy for head and neck squamous cell carcinomas: A review of the physical and clinical challenges. Radiother Oncol 2020; 147:30-39. [PMID: 32224315 DOI: 10.1016/j.radonc.2020.03.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 02/21/2020] [Accepted: 03/05/2020] [Indexed: 12/12/2022]
Abstract
The quality of radiation therapy has been shown to significantly influence the outcomes for head and neck squamous cell carcinoma (HNSCC) patients. The results of dosimetric studies suggest that intensity-modulated proton therapy (IMPT) could be of added value for HNSCC by being more effective than intensity-modulated (photon) radiation therapy (IMRT) for reducing side effects of radiation therapy. However, the physical properties of protons make IMPT more sensitive than photons to planning uncertainties. This could potentially have a negative effect on the quality of IMPT planning and delivery. For this review, the three French proton therapy centers collaborated to evaluate the differences between IMRT and IMPT. The review explored the effects of these uncertainties and their management for developing a robust and optimized IMPT treatment delivery plan to achieve clinical outcomes that are superior to those for IMRT. We also provide practical suggestions for the management of HNSCC carcinoma with IMPT. Because metallic dental implants can increase range uncertainties (3-10%), patient preparation for IMPT may require more systematic removal of in-field alien material than is done for IMRT. Multi-energy CT may be an alternative to calculate more accurately the dose distribution. The practical aspects that we describe are essential to guarantee optimal quality in radiation therapy in both model-based and randomized clinical trials.
Collapse
|
22
|
Scholz M. State-of-the-Art and Future Prospects of Ion Beam Therapy: Physical and Radiobiological Aspects. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2020. [DOI: 10.1109/trpms.2019.2935240] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
23
|
Ödén J, Toma‐Dasu I, Witt Nyström P, Traneus E, Dasu A. Spatial correlation of linear energy transfer and relative biological effectiveness with suspected treatment‐related toxicities following proton therapy for intracranial tumors. Med Phys 2019; 47:342-351. [DOI: 10.1002/mp.13911] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 10/07/2019] [Accepted: 11/04/2019] [Indexed: 12/24/2022] Open
Affiliation(s)
- Jakob Ödén
- Department of Physics Medical Radiation Physics Stockholm University Stockholm171 76Sweden
- RaySearch Laboratories AB Stockholm111 34Sweden
| | - Iuliana Toma‐Dasu
- Department of Physics Medical Radiation Physics Stockholm University Stockholm171 76Sweden
- Department of Oncology and Pathology Medical Radiation Physics Karolinska Institutet Stockholm17176Sweden
| | - Petra Witt Nyström
- The Skandion Clinic Uppsala752 37Sweden
- Danish Centre for Particle Therapy Aarhus8200Denmark
| | | | | |
Collapse
|
24
|
Gutierrez A, Rompokos V, Li K, Gillies C, D’Souza D, Solda F, Fersht N, Chang YC, Royle G, Amos RA, Underwood T. The impact of proton LET/RBE modeling and robustness analysis on base-of-skull and pediatric craniopharyngioma proton plans relative to VMAT. Acta Oncol 2019; 58:1765-1774. [PMID: 31429359 PMCID: PMC6882303 DOI: 10.1080/0284186x.2019.1653496] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 08/04/2019] [Indexed: 11/04/2022]
Abstract
Purpose: Pediatric craniopharyngioma, adult base-of-skull sarcoma and chordoma cases are all regarded as priority candidates for proton therapy. In this study, a dosimetric comparison between volumetric modulated arc therapy (VMAT) and intensity modulated proton therapy (IMPT) was first performed. We then investigated the impact of physical and biological uncertainties. We assessed whether IMPT plans remained dosimetrically superior when such uncertainty estimates were considered, especially with regards to sparing organs at risk (OARs).Methodology: We studied 10 cases: four chondrosarcoma, two chordoma and four pediatric craniopharyngioma. VMAT and IMPT plans were created according to modality-specific protocols. For IMPT, we considered (i) variable RBE modeling using the McNamara model for different values of (α/β)x, and (ii) robustness analysis with ±3 mm set-up and 3.5% range uncertainties.Results: When comparing the VMAT and IMPT plans, the dosimetric advantages of IMPT were clear: IMPT led to reduced integral dose and, typically, improved CTV coverage given our OAR constraints. When physical robustness analysis was performed for IMPT, some uncertainty scenarios worsened the CTV coverage but not usually beyond that achieved by VMAT. Certain scenarios caused OAR constraints to be exceeded, particularly for the brainstem and optical chiasm. However, variable RBE modeling predicted even more substantial hotspots, especially for low values of (α/β)x. Variable RBE modeling often prompted dose constraints to be exceeded for critical structures.Conclusion: For base-of-skull and pediatric craniopharyngioma cases, both physical and biological robustness analyses should be considered for IMPT: these analyses can substantially affect the sparing of OARs and comparisons against VMAT. All proton RBE modeling is subject to high levels of uncertainty, but the clinical community should remain cognizant possible RBE effects. Careful clinical and imaging follow-up, plus further research on end-of-range RBE mitigation strategies such as LET optimization, should be prioritized for these cohorts of proton patients.
Collapse
Affiliation(s)
- A. Gutierrez
- Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - V. Rompokos
- Department of Radiotherapy Physics, University College London Hospitals NHS Foundation Trust, London, United Kingdom
| | - K. Li
- Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - C. Gillies
- Department of Radiotherapy Physics, University College London Hospitals NHS Foundation Trust, London, United Kingdom
| | - D. D’Souza
- Department of Radiotherapy Physics, University College London Hospitals NHS Foundation Trust, London, United Kingdom
| | - F. Solda
- Department of Clinical Oncology, University College London Hospitals NHS Foundation Trust, London, United Kingdom
| | - N. Fersht
- Department of Clinical Oncology, University College London Hospitals NHS Foundation Trust, London, United Kingdom
| | - Y.-C. Chang
- Department of Clinical Oncology, University College London Hospitals NHS Foundation Trust, London, United Kingdom
| | - G. Royle
- Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - R. A. Amos
- Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - T. Underwood
- Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| |
Collapse
|
25
|
Sánchez‐Parcerisa D, López‐Aguirre M, Dolcet Llerena A, Udías JM. MultiRBE: Treatment planning for protons with selective radiobiological effectiveness. Med Phys 2019; 46:4276-4284. [DOI: 10.1002/mp.13718] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 06/19/2019] [Accepted: 07/10/2019] [Indexed: 12/12/2022] Open
Affiliation(s)
- Daniel Sánchez‐Parcerisa
- Grupo de Física Nuclear & IPARCOS, Departamento de Estructura de la Materia, Física Térmica y Electrónica CEI Moncloa Universidad Complutense de Madrid 28040Madrid Spain
- Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC) Madrid Spain
| | - Miguel López‐Aguirre
- Grupo de Física Nuclear & IPARCOS, Departamento de Estructura de la Materia, Física Térmica y Electrónica CEI Moncloa Universidad Complutense de Madrid 28040Madrid Spain
- Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC) Madrid Spain
| | | | - José Manuel Udías
- Grupo de Física Nuclear & IPARCOS, Departamento de Estructura de la Materia, Física Térmica y Electrónica CEI Moncloa Universidad Complutense de Madrid 28040Madrid Spain
- Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC) Madrid Spain
| |
Collapse
|
26
|
Yock AD, Mohan R, Flampouri S, Bosch W, Taylor PA, Gladstone D, Kim S, Sohn J, Wallace R, Xiao Y, Buchsbaum J. Robustness Analysis for External Beam Radiation Therapy Treatment Plans: Describing Uncertainty Scenarios and Reporting Their Dosimetric Consequences. Pract Radiat Oncol 2019; 9:200-207. [PMID: 30562614 PMCID: PMC6571070 DOI: 10.1016/j.prro.2018.12.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 11/24/2018] [Accepted: 12/08/2018] [Indexed: 12/25/2022]
Abstract
PURPOSE With external beam radiation therapy, uncertainties in treatment planning and delivery can result in an undesirable dose distribution delivered to the patient that can compromise the benefit of treatment. Techniques including geometric margins and probabilistic optimization have been used effectively to mitigate the effects of uncertainties. However, their broad application is inconsistent and can compromise the conclusions derived from cross-technique and cross-modality comparisons. METHODS AND MATERIALS Conventional methods to deal with treatment planning and delivery uncertainties are described, and robustness analysis is presented as a framework that is applicable across treatment techniques and modalities. RESULTS This report identifies elements that are imperative to include when conducting a robustness analysis and describing uncertainties and their dosimetric effects. CONCLUSION The robustness analysis approach described here is presented to promote reliable plan evaluation and dose reporting, particularly during clinical trials conducted across institutions and treatment modalities.
Collapse
Affiliation(s)
- Adam D Yock
- Vanderbilt University Medical Center, Nashville, Tennessee
| | - Radhe Mohan
- University of Texas, MD Anderson Cancer Center, Houston, Texas
| | - Stella Flampouri
- University of Florida, Health Proton Therapy Institute, Jacksonville, Florida
| | | | - Paige A Taylor
- University of Texas, MD Anderson Cancer Center, Houston, Texas
| | - David Gladstone
- Geisel School of Medicine at Dartmouth, Hannover, New Hampshire
| | - Siyong Kim
- Virginia Commonwealth University, Richmond, Virginia
| | - Jason Sohn
- Allegheny Health Network, Pittsburgh, Pennsylvania
| | | | - Ying Xiao
- University of Pennsylvania, Philadelphia, Pennsylvania
| | - Jeff Buchsbaum
- National Cancer Institute, National Institutes of Health, Bethesda, Maryland.
| |
Collapse
|
27
|
Yepes P, Adair A, Frank SJ, Grosshans DR, Liao Z, Liu A, Mirkovic D, Poenisch F, Titt U, Wang Q, Mohan R. Fixed- versus Variable-RBE Computations for Intensity Modulated Proton Therapy. Adv Radiat Oncol 2018; 4:156-167. [PMID: 30706024 PMCID: PMC6349601 DOI: 10.1016/j.adro.2018.08.020] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 08/16/2018] [Accepted: 08/16/2018] [Indexed: 11/30/2022] Open
Abstract
Purpose To evaluate how using models of proton therapy that incorporate variable relative biological effectiveness (RBE) versus the current practice of using a fixed RBE of 1.1 affects dosimetric indices on treatment plans for large cohorts of patients treated with intensity modulated proton therapy (IMPT). Methods and Materials Treatment plans for 4 groups of patients who received IMPT for brain, head-and-neck, thoracic, or prostate cancer were selected. Dose distributions were recalculated in 4 ways: 1 with a fast-dose Monte Carlo calculator with fixed RBE and 3 with RBE calculated to 3 different models—McNamara, Wedenberg, and repair-misrepair-fixation. Differences among dosimetric indices (D02, D50, D98, and mean dose) for target volumes and organs at risk (OARs) on each plan were compared between the fixed-RBE and variable-RBE calculations. Results In analyses of all target volumes, for which the main concern is underprediction or RBE less than 1.1, none of the models predicted an RBE less than 1.05 for any of the cohorts. For OARs, the 2 models based on linear energy transfer, McNamara and Wedenberg, systematically predicted RBE >1.1 for most structures. For the mean dose of 25% of the plans for 2 OARs, they predict RBE equal to or larger than 1.4, 1.3, 1.3, and 1.2 for brain, head-and-neck, thorax, and prostate, respectively. Systematically lower increases in RBE are predicted by repair-misrepair-fixation, with a few cases (eg, femur) in which the RBE is less than 1.1 for all plans. Conclusions The variable-RBE models predict increased doses to various OARs, suggesting that strategies to reduce high-dose linear energy transfer in critical structures should be developed to minimize possible toxicity associated with IMPT.
Collapse
Affiliation(s)
- Pablo Yepes
- Physics and Astronomy Department, Rice University, Houston, Texas.,Department of Radiation Physics, The University of Texas MD Anderson Cancer, Houston, Texas
| | - Antony Adair
- Physics and Astronomy Department, Rice University, Houston, Texas.,Department of Radiation Physics, The University of Texas MD Anderson Cancer, Houston, Texas
| | - Steven J Frank
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer, Houston, Texas
| | - David R Grosshans
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer, Houston, Texas.,Experimental Radiation Oncology, The University of Texas MD Anderson Cancer, Houston, Texas
| | - Zhongxing Liao
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer, Houston, Texas
| | - Amy Liu
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer, Houston, Texas
| | - Dragan Mirkovic
- Department of Radiation Physics, The University of Texas MD Anderson Cancer, Houston, Texas
| | - Falk Poenisch
- Department of Radiation Physics, The University of Texas MD Anderson Cancer, Houston, Texas
| | - Uwe Titt
- Department of Radiation Physics, The University of Texas MD Anderson Cancer, Houston, Texas
| | - Qianxia Wang
- Physics and Astronomy Department, Rice University, Houston, Texas.,Department of Radiation Physics, The University of Texas MD Anderson Cancer, Houston, Texas
| | - Radhe Mohan
- Department of Radiation Physics, The University of Texas MD Anderson Cancer, Houston, Texas
| |
Collapse
|
28
|
Henry T, Ödén J. Interlaced proton grid therapy – Linear energy transfer and relative biological effectiveness distributions. Phys Med 2018; 56:81-89. [DOI: 10.1016/j.ejmp.2018.10.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 10/03/2018] [Accepted: 10/30/2018] [Indexed: 12/25/2022] Open
|
29
|
Traneus E, Ödén J. Introducing Proton Track-End Objectives in Intensity Modulated Proton Therapy Optimization to Reduce Linear Energy Transfer and Relative Biological Effectiveness in Critical Structures. Int J Radiat Oncol Biol Phys 2018; 103:747-757. [PMID: 30395906 DOI: 10.1016/j.ijrobp.2018.10.031] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 09/10/2018] [Accepted: 10/25/2018] [Indexed: 12/25/2022]
Abstract
PURPOSE We propose the use of proton track-end objectives in intensity modulated proton therapy (IMPT) optimization to reduce the linear energy transfer (LET) and the relative biological effectiveness (RBE) in critical structures. METHODS AND MATERIALS IMPT plans were generated for 3 intracranial patient cases (1.8 Gy (RBE) in 30 fractions) and 3 head-and-neck patient cases (2 Gy (RBE) in 35 fractions), assuming a constant RBE of 1.1. Two plans were generated for each patient: (1) physical dose objectives only (DOSEopt) and (2) same dose objectives as the DOSEopt plan, with additional proton track-end objectives (TEopt). The track-end objectives penalized protons stopping in the risk volume of choice. Dose evaluations were made using a RBE of 1.1 and the LET-dependent Wedenberg RBE model, together with estimates of normal tissue complication probabilities (NTCPs). In addition, the distributions of proton track-ends and dose-average LET (LETd) were analyzed. RESULTS The TEopt plans reduced the mean LETd in the critical structures studied by an average of 37% and increased the mean LETd in the primary clinical target volume (CTV) by an average of 23%. This was achieved through a redistribution of the proton track-ends, concurrently keeping the physical dose distribution virtually unchanged compared to the DOSEopt plans. This resulted in substantial RBE-weighted dose (DRBE) reductions, allowing the TEopt plans to meet all clinical goals for both RBE models and reduce the NTCPs by 0 to 19 percentage points compared to the DOSEopt plans, assuming the Wedenberg RBE model. The DOSEopt plans met all clinical goals assuming a RBE of 1.1 but failed 10 of 19 normal tissue goals assuming the Wedenberg RBE model. CONCLUSIONS Proton track-end objectives allow for LETd reductions in critical structures without compromising the physical target dose. This approach permits the lowering of DRBE and NTCP in critical structures, independent of the variable RBE model used, and it could be introduced in clinical practice without changing current protocols based on the constant RBE of 1.1.
Collapse
Affiliation(s)
| | - Jakob Ödén
- RaySearch Laboratories AB, Stockholm, Sweden; Department of Physics, Medical Radiation Physics, Stockholm University, Stockholm, Sweden.
| |
Collapse
|
30
|
Rørvik E, Fjæra LF, Dahle TJ, Dale JE, Engeseth GM, Stokkevåg CH, Thörnqvist S, Ytre-Hauge KS. Exploration and application of phenomenological RBE models for proton therapy. Phys Med Biol 2018; 63:185013. [PMID: 30102240 DOI: 10.1088/1361-6560/aad9db] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The relative biological effectiveness (RBE) of protons varies with multiple physical and biological factors. Phenomenological RBE models have been developed to include such factors in the estimation of a variable RBE, in contrast to the clinically applied constant RBE of 1.1. In this study, eleven published phenomenological RBE models and two plan-based models were explored and applied to simulated patient cases. All models were analysed with respect to the distribution and range of linear energy transfer (LET) and reference radiation fractionation sensitivity ((α/β) x ) of their respective experimental databases. Proton therapy plans for a spread-out Bragg peak in water and three patient cases (prostate adenocarcinoma, pituitary adenoma and thoracic sarcoma) were optimised using an RBE of 1.1 in the Eclipse™ treatment planning system prior to recalculation and modelling in the FLUKA Monte Carlo code. Model estimated dose-volume parameters for the planning target volumes (PTVs) and organs at risk (OAR) were compared. The experimental in vitro databases for the various models differed greatly in the range of (α/β) x values and dose-averaged LET (LETd). There were significant variations between the model estimations, which arose from fundamental differences in the database definitions and model assumptions. The greatest variations appeared in organs with low (α/β) x and high LETd, e.g. biological doses given to late responding OARs located distal to the target in the treatment field. In general, the variation in maximum dose (D2%) was larger than the variation in mean dose and other dose metrics, with D2% of the left optic nerve ((α/β) x = 2.1 Gy) in the pituitary adenoma case showing the greatest discrepancies between models: 28-52 Gy(RBE), while D2% for RBE1.1 was 30 Gy(RBE). For all patient cases, the estimated mean RBE to the PTV was in the range 1.09-1.29 ((α/β) x = 1.5/3.1/10.6 Gy). There were considerable variations between the estimations of RBE and RBE-weighted doses from the different models. These variations were a consequence of fundamental differences in experimental databases, model assumptions and regression techniques. The results from the implementation of RBE models in dose planning studies should be evaluated in light of these deviations.
Collapse
Affiliation(s)
- Eivind Rørvik
- Department of Physics and Technology, University of Bergen, Bergen, Norway. Author to whom any correspondence should be addressed
| | | | | | | | | | | | | | | |
Collapse
|
31
|
Normal tissue sparing potential of scanned proton beams with and without respiratory gating for the treatment of internal mammary nodes in breast cancer radiotherapy. Phys Med 2018; 52:81-85. [PMID: 30139613 DOI: 10.1016/j.ejmp.2018.06.639] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 06/26/2018] [Accepted: 06/29/2018] [Indexed: 01/26/2023] Open
Abstract
Proton therapy has shown potential for reducing doses to normal tissues in breast cancer radiotherapy. However data on the impact of protons when including internal mammary nodes (IMN) in the target for breast radiotherapy is comparatively scarce. This study aimed to evaluate normal tissue doses when including the IMN in regional RT with scanned proton beams, with and without respiratory gating. The study cohort was composed of ten left-sided breast patients CT-scanned during enhanced inspiration gating (EIG) and free-breathing (FB). Proton plans were designed for the target including or excluding the IMN. Targets and organs-at-risk were delineated according to RTOG guidelines. Comparison was performed between dosimetric parameters characterizing target coverage and OAR radiation burden. Statistical significance of differences was tested using a paired, two-tailed Student's t-test. Inclusion of the IMN in the target volume led to a small increase of the cardiopulmonary burden. The largest differences were seen for the ipsilateral lung where the mean dose increased from 6.1 to 6.6 Gy (RBE) (P < 0.0001) in FB plans and from 6.9 to 7.4 Gy (RBE) (P = 0.003) in EIG plans. Target coverage parameters were very little affected by the inclusion of IMN into the treatment target. Radiotherapy with scanned proton beams has the potential of maintaining low cardiovascular burden when including the IMN into the target, irrespective of whether respiratory gating is used or not.
Collapse
|
32
|
Lühr A, von Neubeck C, Krause M, Troost EGC. Relative biological effectiveness in proton beam therapy - Current knowledge and future challenges. Clin Transl Radiat Oncol 2018; 9:35-41. [PMID: 29594249 PMCID: PMC5862688 DOI: 10.1016/j.ctro.2018.01.006] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2018] [Revised: 01/25/2018] [Accepted: 01/27/2018] [Indexed: 12/25/2022] Open
Affiliation(s)
- Armin Lühr
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany.,German Cancer Consortium (DKTK), Partner Site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany.,Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany.,Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Cläre von Neubeck
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany.,German Cancer Consortium (DKTK), Partner Site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Mechthild Krause
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany.,German Cancer Consortium (DKTK), Partner Site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany.,Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany.,National Center for Tumor Diseases (NCT), Partner Site Dresden, Germany; German Cancer Research Center (DKFZ), Heidelberg, Germany; Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany; Helmholtz Association/Helmholtz-Zentrum Dresden - Rossendorf (HZDR), Dresden, Germany.,Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Esther G C Troost
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany.,German Cancer Consortium (DKTK), Partner Site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany.,Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany.,National Center for Tumor Diseases (NCT), Partner Site Dresden, Germany; German Cancer Research Center (DKFZ), Heidelberg, Germany; Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany; Helmholtz Association/Helmholtz-Zentrum Dresden - Rossendorf (HZDR), Dresden, Germany.,Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| |
Collapse
|
33
|
Ödén J, DeLuca PM, Orton CG. The use of a constant RBE=1.1 for proton radiotherapy is no longer appropriate. Med Phys 2017; 45:502-505. [PMID: 29091284 DOI: 10.1002/mp.12646] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 10/25/2017] [Indexed: 02/03/2023] Open
Affiliation(s)
- Jakob Ödén
- Department of Physics, Medical Radiation Physics, Stockholm University, S-171 76, Stockholm, Sweden
- RaySearch Laboratories, S-111 34, Stockholm, Sweden
| | - Paul M DeLuca
- Department of Medical Physics, University of Wisconsin, Madison, WI, 53705-2275, USA
| | | |
Collapse
|
34
|
Ödén J, Toma-Dasu I, Eriksson K, Flejmer AM, Dasu A. The influence of breathing motion and a variable relative biological effectiveness in proton therapy of left-sided breast cancer. Acta Oncol 2017; 56:1428-1436. [PMID: 28826308 DOI: 10.1080/0284186x.2017.1348625] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND Proton breast radiotherapy has been suggested to improve target coverage as well as reduce cardiopulmonary and integral dose compared with photon therapy. This study aims to assess this potential when accounting for breathing motion and a variable relative biological effectiveness (RBE). METHODS Photon and robustly optimized proton plans were generated to deliver 50 Gy (RBE) in 25 fractions (RBE = 1.1) to the CTV (whole left breast) for 12 patients. The plan evaluation was performed using the constant RBE and a variable RBE model. Robustness against breathing motion, setup, range and RBE uncertainties was analyzed using CT data obtained at free-breathing, breath-hold-at-inhalation and breath-hold-at-exhalation. RESULTS All photon and proton plans (RBE = 1.1) met the clinical goals. The variable RBE model predicted an average RBE of 1.18 for the CTVs (range 1.14-1.21) and even higher RBEs in organs at risk (OARs). However, the dosimetric impact of this latter aspect was minor due to low OAR doses. The normal tissue complication probability (NTCP) for the lungs was low for all patients (<1%), and similar for photons and protons. The proton plans were generally considered robust for all patients. However, in the most extreme scenarios, the lowest dose received by 98% of the CTV dropped from 96 to 99% of the prescribed dose to around 92-94% for both protons and photons. Including RBE uncertainties in the robustness analysis resulted in substantially higher worst-case OAR doses. CONCLUSIONS Breathing motion seems to have a minor effect on the plan quality for breast cancer. The variable RBE might impact the potential benefit of protons, but could probably be neglected in most cases where the physical OAR doses are low. However, to be able to identify outlier cases at risk for high OAR doses, the biological evaluation of proton plans taking into account the variable RBE is recommended.
Collapse
Affiliation(s)
- Jakob Ödén
- Department of Physics, Medical Radiation Physics, Stockholm University, Stockholm, Sweden
- RaySearch Laboratories, Stockholm, Sweden
| | - Iuliana Toma-Dasu
- Department of Physics, Medical Radiation Physics, Stockholm University, Stockholm, Sweden
- Department of Oncology and Pathology, Medical Radiation Physics, Karolinska Institutet, Stockholm, Sweden
| | | | - Anna Maria Flejmer
- Department of Oncology and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - Alexandru Dasu
- The Skandion Clinic, Uppsala, Sweden
- Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
| |
Collapse
|
35
|
Lühr A, von Neubeck C, Helmbrecht S, Baumann M, Enghardt W, Krause M. Modeling in vivo relative biological effectiveness in particle therapy for clinically relevant endpoints. Acta Oncol 2017; 56:1392-1398. [PMID: 28849720 DOI: 10.1080/0284186x.2017.1356468] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
BACKGROUND The relative biological effectiveness (RBE) of particle therapy compared to photon radiotherapy is known to be variable but the exact dependencies are still subject to debate. In vitro data suggested that RBE is to a large extend independent of ion type if parametrized by the beam quality Q. This study analyzed the RBE dependence of pre-clinical data on late toxicity with an emphasis on the beam quality. MATERIAL AND METHODS Published pre-clinical RBE dose-response data of the spinal cord following one and two fractions of photon and carbon ion irradiation were compiled. The beam quality for each treatment condition was obtained from Monte Carlo simulations. The αp and βp parameters of the linear-quadratic (LQ) model for particle irradiation were determined from the pre-clinical data and was provided as a function of Q. An introduced model proposed αp to increase linearly with Q and βp to remain constant. RBE values predicted by the model were compared to the published data. RESULTS The αp parameter was highly correlated with Q (R2 = 0.96) with a linear slope of 0.019 Gy-1. No significant variation of βp with Q was found. RBE and Q were also highly correlated (R2 = 0.98) for one and two fractions. The (extrapolated) RBE at Q = 0 (theoretical photon limit) for one and two fractions was 1.22 and significantly larger than 1 (p = .004). The model reproduced the dependence of RBE on fractionation well. CONCLUSIONS Fraction dose and beam quality Q were sufficient to describe the RBE variability for a late toxicity model within a carbon ion treatment field. Assuming the independence of the identified RBE parameters on the ion type might suggest the translation of variable (pre-) clinical RBE data from carbon ion to proton therapy.
Collapse
Affiliation(s)
- Armin Lühr
- OncoRay – National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden – Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden ? Rossendorf, Institute of Radiooncology – OncoRay, Dresden, Germany
- German Cancer Consortium (DKTK), Partner Site Dresden and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Cläre von Neubeck
- OncoRay – National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden – Rossendorf, Dresden, Germany
- German Cancer Consortium (DKTK), Partner Site Dresden and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Stephan Helmbrecht
- OncoRay – National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden – Rossendorf, Dresden, Germany
| | - Michael Baumann
- OncoRay – National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden – Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden ? Rossendorf, Institute of Radiooncology – OncoRay, Dresden, Germany
- German Cancer Research Center (DKFZ), Heidelberg, Germany
- National Center for Tumor Diseases (NCT), Partner Site Dresden, Dresden, Germany
| | - Wolfgang Enghardt
- OncoRay – National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden – Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden ? Rossendorf, Institute of Radiooncology – OncoRay, Dresden, Germany
- German Cancer Consortium (DKTK), Partner Site Dresden and German Cancer Research Center (DKFZ), Heidelberg, Germany
- National Center for Tumor Diseases (NCT), Partner Site Dresden, Dresden, Germany
- Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Mechthild Krause
- OncoRay – National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden – Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden ? Rossendorf, Institute of Radiooncology – OncoRay, Dresden, Germany
- German Cancer Consortium (DKTK), Partner Site Dresden and German Cancer Research Center (DKFZ), Heidelberg, Germany
- National Center for Tumor Diseases (NCT), Partner Site Dresden, Dresden, Germany
- Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| |
Collapse
|
36
|
Ulrich S, Wieser HP, Cao W, Mohan R, Bangert M. Impact of respiratory motion on variable relative biological effectiveness in 4D-dose distributions of proton therapy. Acta Oncol 2017; 56:1420-1427. [PMID: 28828913 DOI: 10.1080/0284186x.2017.1354131] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND Organ motion during radiation therapy with scanned protons leads to deviations between the planned and the delivered physical dose. Using a constant relative biological effectiveness (RBE) of 1.1 linearly maps these deviations into RBE-weighted dose. However, a constant value cannot account for potential nonlinear variations in RBE suggested by variable RBE models. Here, we study the impact of motion on recalculations of RBE-weighted dose distributions using a phenomenological variable RBE model. MATERIAL AND METHODS 4D-dose calculation including variable RBE was implemented in the open source treatment planning toolkit matRad. Four scenarios were compared for one field and two field proton treatments for a liver cancer patient assuming (α∕β)x = 2 Gy and (α∕β)x = 10 Gy: (A) the optimized static dose distribution with constant RBE, (B) a static recalculation with variable RBE, (C) a 4D-dose recalculation with constant RBE and (D) a 4D-dose recalculation with variable RBE. For (B) and (D), the variable RBE was calculated by the model proposed by McNamara. For (C), the physical dose was accumulated with direct dose mapping; for (D), dose-weighted radio-sensitivity parameters of the linear quadratic model were accumulated to model synergistic irradiation effects on RBE. RESULTS Dose recalculation with variable RBE led to an elevated biological dose at the end of the proton field, while 4D-dose recalculation exhibited random deviations everywhere in the radiation field depending on the interplay of beam delivery and organ motion. For a single beam treatment assuming (α∕β)x = 2 Gy, D95% was 1.98 Gy (RBE) (A), 2.15 Gy (RBE) (B), 1.81 Gy (RBE) (C) and 1.98 Gy (RBE) (D). The homogeneity index was 1.04 (A), 1.08 (B), 1.23 (C) and 1.25 (D). CONCLUSION For the studied liver case, intrafractional motion did not reduce the modulation of the RBE-weighted dose postulated by variable RBE models for proton treatments.
Collapse
Affiliation(s)
- Silke Ulrich
- Department of Medical Physics in Radiation Therapy, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - Hans-Peter Wieser
- Department of Medical Physics in Radiation Therapy, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - Wenhua Cao
- Department of Radiation Physics, MD Anderson Cancer Center, Houston, TX, USA
| | - Radhe Mohan
- Department of Radiation Physics, MD Anderson Cancer Center, Houston, TX, USA
| | - Mark Bangert
- Department of Medical Physics in Radiation Therapy, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| |
Collapse
|
37
|
Impact of physiological breathing motion for breast cancer radiotherapy with proton beam scanning – An in silico study. Phys Med 2017; 39:88-94. [DOI: 10.1016/j.ejmp.2017.06.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2017] [Revised: 05/31/2017] [Accepted: 06/02/2017] [Indexed: 02/08/2023] Open
|
38
|
Grassberger C, Paganetti H. Varying relative biological effectiveness in proton therapy: knowledge gaps versus clinical significance. Acta Oncol 2017; 56:761-762. [PMID: 28464735 DOI: 10.1080/0284186x.2017.1316516] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Clemens Grassberger
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Harald Paganetti
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| |
Collapse
|