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Chvetsov AV, Muzi M. Equivalent uniform aerobic dose in radiotherapy for hypoxic tumors. Phys Med Biol 2024; 69:10.1088/1361-6560/ad31c8. [PMID: 38457839 PMCID: PMC11197763 DOI: 10.1088/1361-6560/ad31c8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 03/08/2024] [Indexed: 03/10/2024]
Abstract
Objective.Equivalent uniform aerobic dose (EUAD) is proposed for comparison of integrated cell survival in tumors with different distributions of hypoxia and radiation dose.Approach.The EUAD assumes that for any non-uniform distributions of radiation dose and oxygen enhancement ratio (OER) within a tumor, there is a uniform distribution of radiation dose under hypothetical aerobic conditions with OER = 1 that produces equal integrated survival of clonogenic cells. This definition of EUAD has several advantages. First, the EUAD allows one to compare survival of clonogenic cells in tumors with intra-tumor and inter-tumor variation of radio sensitivity due to hypoxia because the cell survival is recomputed under the same benchmark oxygen level (OER = 1). Second, the EUAD for homogeneously oxygenated tumors is equal to the concept of equivalent uniform dose.Main results. We computed the EUAD using radiotherapy dose and the OER derived from the18F-Fluoromisonidazole PET (18F-FMISO PET) images of hypoxia in patients with glioblastoma, the most common and aggressive type of primary malignant brain tumor. The18F-FMISO PET images include a distribution of SUV (Standardized Uptake Value); therefore, the SUV is converted to partial oxygen pressure (pO2) and then to the OER. The prognostic value of EUAD in radiotherapy for hypoxic tumors is demonstrated using correlation between EUAD and overall survival (OS) in radiotherapy for glioblastoma. The correction to the EUAD for the absolute hypoxic volume that traceable to the tumor control probability improves the correlation with OS.Significance. While the analysis proposed in this research is based on the18F-FMISO PET images for glioblastoma, the EUAD is a universal radiobiological concept and is not associated with any specific cancer or any specific PET or MRI biomarker of hypoxia. Therefore, this research can be generalized to other cancers, for example stage III lung cancer, and to other hypoxia biomarkers.
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Affiliation(s)
- Alexei V Chvetsov
- Department of Radiation Oncology, University of Washington, 1959 NE Pacific Street, Seattle, WA, 98195, United States of America
| | - Mark Muzi
- Department of Radiology, University of Washington, 1959 NE Pacific Street, Seattle, WA, 98195, United States of America
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Wei Z, Peng X, Wang Y, Yang L, He L, Liu Z, Wang J, Mu X, Li R, Xiao J. Influence of target dose heterogeneity on dose sparing of normal tissue in peripheral lung tumor stereotactic body radiation therapy. Radiat Oncol 2021; 16:167. [PMID: 34461954 PMCID: PMC8404286 DOI: 10.1186/s13014-021-01891-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Accepted: 08/17/2021] [Indexed: 02/08/2023] Open
Abstract
OBJECTIVE To evaluate the influence of target dose heterogeneity on normal tissue dose sparing for peripheral lung tumor stereotactic body radiation therapy (SBRT). METHODS Based on the volumetric-modulated arc therapy (VMAT) technique, three SBRT plans with homogeneous, moderate heterogeneous, and heterogeneous (HO, MHE, and HE) target doses were compared in 30 peripheral lung tumor patients. The prescription dose was 48 Gy in 4 fractions. Ten rings outside the PTV were created to limit normal tissue dosage and evaluate dose falloff. RESULTS When MHE and HE plans were compared to HO plans, the conformity index of the PTV was increased by approximately 0.08. The median mean lung dose (MLD), V5, V10, V20 of whole lung, D2%, D1cc, D2cc of the rib, V30 of the rib, D2% and the maximum dose (Dmax) of the skin, and D2% and Dmax of most mediastinal organs at risk (OARs) and spinal cord were reduced by up to 4.51 Gy or 2.8%. Analogously, the median Dmax, D2% and mean dose of rings were reduced by 0.71 to 8.46 Gy; and the median R50% and D2cm were reduced by 2.1 to 2.3 and 7.4% to 8.0%, respectively. Between MHE and HE plans there was little to no difference in OARs dose and dose falloff beyond the target. Furthermore, the dose sparing of rib V30 and the mean dose of rings were negatively correlated with the rib and rings distance from tumor, respectively. CONCLUSIONS For peripheral lung tumor SBRT, target conformity, normal tissue dose, and dose falloff around the target could be improved by loosening or abandoning homogeneity. While there was negligible further dose benefit for the maximum target dose above 125% of the prescription, dose sparing of normal tissue derived from a heterogeneous target decreased as the distance from the tumor increased.
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Affiliation(s)
- Zhigong Wei
- Department of Biotherapy, Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Xingchen Peng
- Department of Biotherapy, Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Yan Wang
- School of Computer Science, Sichuan University, Chengdu, 610000, China
| | - Lianlian Yang
- Department of Biotherapy, Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Ling He
- Department of Biotherapy, Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Zheran Liu
- Department of Biotherapy, Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Jingjing Wang
- Department of Biotherapy, Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Xiaoli Mu
- Department of Biotherapy, Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Ruidan Li
- Department of Biotherapy, Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Jianghong Xiao
- Department of Radiation Oncology, Cancer Center, West China Hospital, Sichuan University, No.37 Guoxue Alley, Wuhou District, Chengdu, 610041, Sichuan, China.
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Bu X, Zhang J, Tian F, Wang X, Wu L, Tian W. Value of Diffusion-Weighted Magnetic Resonance Imaging Combined with miR-18a Level in Predicting Radiosensitivity of Cervical Cancer. Med Sci Monit 2018; 24:7271-7278. [PMID: 30308669 PMCID: PMC6194752 DOI: 10.12659/msm.910990] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Background Radioresistance during radiotherapy of cervical cancer often leads to treatment failure; therefore, there is an urgent need to develop effective predictive indicators of radiosensitivity for cervical cancer patients. Material/Methods Cervical cancer cells were collected from 40 patients who received surgical resections. The relationships between apparent diffusion coefficient (ADC) values of masses before surgery and different micro-RNAs (miRNA) levels (miR-18a, miR-132, and miR-145) of these cells were investigated. Cervical cancer cells were divided into 4 groups according to the ADC values of original tumor tissues and expression level of miR-18a. Then, these cells were exposed with irradiation both in vitro and in vivo. Results Advanced cervical cancer showed lower ADC values in magnetic resonance imaging. miR-18a, miR-132, and miR-145 all were increased in the cervical cancer tissues, while miR-18a showed a more marked negative correlation with ADC values. The results of in vitro and in vivo assays showed that higher expression of miR-18a in cervical cancer cells leads to more radiosensitivity, especially in cells from cancer tissues with lower ADC values. Conclusions The combination of ADC values with expression level of miR-18a may be a new and reliable predictor for radiosensitivity of cervical cancer, helping cervical cancer patients with low ADC values and high expressions of miR-18a to achieve better outcomes in radiotherapy.
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Affiliation(s)
- Xinhua Bu
- Department of Gynecology and Obstetrics, Taizhou People's Hospital, Taizhou, Jiangsu, China (mainland)
| | - Ji Zhang
- Department of Radiology, Taizhou People's Hospital, Taizhou, Jiangsu, China (mainland)
| | - Fangzheng Tian
- Department of Radiology, Taizhou People's Hospital, Taizhou, Jiangsu, China (mainland)
| | - Xiulan Wang
- Department of Radiology, Taizhou People's Hospital, Taizhou, Jiangsu, China (mainland)
| | - Linyun Wu
- Taizhou Polytechnic College, Taizhou, Jiangsu, China (mainland)
| | - Weizhong Tian
- Department of Radiology, Taizhou People's Hospital, Taizhou, Jiangsu, China (mainland)
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Miao J, Yan H, Tian Y, Ma P, Liu Z, Li M, Ren W, Chen J, Zhang Y, Dai J. Reducing dose to the lungs through loosing target dose homogeneity requirement for radiotherapy of non small cell lung cancer. J Appl Clin Med Phys 2017; 18:169-176. [PMID: 29024297 PMCID: PMC5689922 DOI: 10.1002/acm2.12200] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 08/28/2017] [Accepted: 09/07/2017] [Indexed: 12/25/2022] Open
Abstract
It is important to minimize lung dose during intensity-modulated radiation therapy (IMRT) of nonsmall cell lung cancer (NSCLC). In this study, an approach was proposed to reduce lung dose by relaxing the constraint of target dose homogeneity during treatment planning of IMRT. Ten NSCLC patients with lung tumor on the right side were selected. The total dose for planning target volume (PTV) was 60 Gy (2 Gy/fraction). For each patient, two IMRT plans with six beams were created in Pinnacle treatment planning system. The dose homogeneity of target was controlled by constraints on the maximum and uniform doses of target volume. One IMRT plan was made with homogeneous target dose (the resulting target dose was within 95%-107% of the prescribed dose), while another IMRT plan was made with inhomogeneous target dose (the resulting target dose was more than 95% of the prescribed dose). During plan optimization, the dose of cord and heart in two types of IMRT plans were kept nearly the same. The doses of lungs, PTV and organs at risk (OARs) between two types of IMRT plans were compared and analyzed quantitatively. For all patients, the lung dose was decreased in the IMRT plans with inhomogeneous target dose. On average, the mean dose, V5, V20, and V30 of lung were reduced by 1.4 Gy, 4.8%, 3.7%, and 1.7%, respectively, and the dose to normal tissue was also reduced. These reductions in DVH values were all statistically significant (P < 0.05). There were no significant differences between the two IMRT plans on V25, V30, V40, V50 and mean dose for heart. The maximum doses of cords in two type IMRT plans were nearly the same. IMRT plans with inhomogeneous target dose could protect lungs better and may be considered as a choice for treating NSCLC.
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Affiliation(s)
- Junjie Miao
- Department of Radiation OncologyNational Cancer Center/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
| | - Hui Yan
- Department of Radiation OncologyNational Cancer Center/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
| | - Yuan Tian
- Department of Radiation OncologyNational Cancer Center/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
| | - Pan Ma
- Department of Radiation OncologyNational Cancer Center/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
| | - Zhiqiang Liu
- Department of Radiation OncologyNational Cancer Center/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
| | - Minghui Li
- Department of Radiation OncologyNational Cancer Center/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
| | - Wenting Ren
- Department of Radiation OncologyNational Cancer Center/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
| | - Jiayun Chen
- Department of Radiation OncologyNational Cancer Center/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
| | - Ye Zhang
- Department of Radiation OncologyNational Cancer Center/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
| | - Jianrong Dai
- Department of Radiation OncologyNational Cancer Center/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
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Skórska M, Piotrowski T. Personalized radiotherapy treatment planning based on functional imaging. Rep Pract Oncol Radiother 2017; 22:327-330. [DOI: 10.1016/j.rpor.2017.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 04/19/2017] [Indexed: 11/30/2022] Open
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Wu VW, Epelman MA, Wang H, Edwin Romeijn H, Feng M, Cao Y, Ten Haken RK, Matuszak MM. Optimizing global liver function in radiation therapy treatment planning. Phys Med Biol 2016; 61:6465-84. [PMID: 27518786 PMCID: PMC5237377 DOI: 10.1088/0031-9155/61/17/6465] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Liver stereotactic body radiation therapy (SBRT) patients differ in both pre-treatment liver function (e.g. due to degree of cirrhosis and/or prior treatment) and radiosensitivity, leading to high variability in potential liver toxicity with similar doses. This work investigates three treatment planning optimization models that minimize risk of toxicity: two consider both voxel-based pre-treatment liver function and local-function-based radiosensitivity with dose; one considers only dose. Each model optimizes different objective functions (varying in complexity of capturing the influence of dose on liver function) subject to the same dose constraints and are tested on 2D synthesized and 3D clinical cases. The normal-liver-based objective functions are the linearized equivalent uniform dose ([Formula: see text]) (conventional '[Formula: see text] model'), the so-called perfusion-weighted [Formula: see text] ([Formula: see text]) (proposed 'fEUD model'), and post-treatment global liver function (GLF) (proposed 'GLF model'), predicted by a new liver-perfusion-based dose-response model. The resulting [Formula: see text], fEUD, and GLF plans delivering the same target [Formula: see text] are compared with respect to their post-treatment function and various dose-based metrics. Voxel-based portal venous liver perfusion, used as a measure of local function, is computed using DCE-MRI. In cases used in our experiments, the GLF plan preserves up to [Formula: see text] more liver function than the fEUD ([Formula: see text]) plan does in 2D cases, and up to [Formula: see text] in 3D cases. The GLF and fEUD plans worsen in [Formula: see text] of functional liver on average by 1.0 Gy and 0.5 Gy in 2D and 3D cases, respectively. Liver perfusion information can be used during treatment planning to minimize the risk of toxicity by improving expected GLF; the degree of benefit varies with perfusion pattern. Although fEUD model optimization is computationally inexpensive and often achieves better GLF than [Formula: see text] model optimization does, the GLF model directly optimizes a more clinically relevant metric and can further improve fEUD plan quality.
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Affiliation(s)
- Victor W Wu
- Department of Industrial and Operations Engineering, University of Michigan, Ann Arbor, MI 48109, USA
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Rødal J, Waldeland E, Søvik Å, Malinen E. Dosimetric verification of biologically adapted IMRT. Med Phys 2011; 38:2586-94. [DOI: 10.1118/1.3581406] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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8
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Zhao B, Joiner MC, Orton CG, Burmeister J. “SABER”: A new software tool for radiotherapy treatment plan evaluation. Med Phys 2010; 37:5586-92. [DOI: 10.1118/1.3497152] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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9
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Lambin P, Petit SF, Aerts HJWL, van Elmpt WJC, Oberije CJG, Starmans MHW, van Stiphout RGPM, van Dongen GAMS, Muylle K, Flamen P, Dekker ALAJ, De Ruysscher D. The ESTRO Breur Lecture 2009. From population to voxel-based radiotherapy: exploiting intra-tumour and intra-organ heterogeneity for advanced treatment of non-small cell lung cancer. Radiother Oncol 2010; 96:145-52. [PMID: 20647155 DOI: 10.1016/j.radonc.2010.07.001] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2010] [Revised: 07/07/2010] [Accepted: 07/07/2010] [Indexed: 01/22/2023]
Abstract
Evidence is accumulating that radiotherapy of non-small cell lung cancer patients can be optimized by escalating the tumour dose until the normal tissue tolerances are met. To further improve the therapeutic ratio between tumour control probability and the risk of normal tissue complications, we firstly need to exploit inter patient variation. This variation arises, e.g. from differences in tumour shape and size, lung function and genetic factors. Secondly improvement is achieved by taking into account intra-tumour and intra-organ heterogeneity derived from molecular and functional imaging. Additional radiation dose must be delivered to those parts of the tumour that need it the most, e.g. because of increased radio-resistance or reduced therapeutic drug uptake, and away from regions inside the lung that are most prone to complication. As the delivery of these treatments plans is very sensitive for geometrical uncertainties, probabilistic treatment planning is needed to generate robust treatment plans. The administration of these complicated dose distributions requires a quality assurance procedure that can evaluate the treatment delivery and, if necessary, adapt the treatment plan during radiotherapy.
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Affiliation(s)
- Philippe Lambin
- Department of Radiation Oncology (MAASTRO), GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre, The Netherlands.
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Abstract
Recently, there has been much interest in how to use information on patient-specific tumor biology and normal tissue function to individualize cancer treatment. In radiation therapy, dose may be escalated to radioresistant regions within a tumor, or regions of particular functional importance in normal organs may be preferentially spared. However, tumor and normal tissue biology may change during treatment, and adaptation of therapy may be necessary to ensure that optimal therapy is delivered. Furthermore, changes in tumor and normal tissue biology during early treatment may be predictive for the outcome of radiotherapy, and this information could be used for individual adaptation of the remaining part of the treatment. In the present study, we address variations that may occur in tumor and normal tissue radiobiological properties during radiotherapy, and how these may be related to the response to treatment. Moreover, we discuss the criteria for when to adapt treatment and how this adaptation should be performed. Finally, we discuss to what degree biologically adapted radiotherapy may be expected to improve treatment outcome and which issues need to be resolved for this strategy to reach its full potential.
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Affiliation(s)
- Aste Søvik
- Department of Radiation Biology, Institute for Cancer Research, Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway.
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11
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South CP, Evans PM, Partridge M. Dose prescription complexity versus tumor control probability in biologically conformal radiotherapy. Med Phys 2009; 36:4379-88. [DOI: 10.1118/1.3213519] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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12
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Metabolic control probability in tumour subvolumes or how to guide tumour dose redistribution in non-small cell lung cancer (NSCLC): An exploratory clinical study. Radiother Oncol 2009; 91:393-8. [DOI: 10.1016/j.radonc.2009.02.020] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2008] [Revised: 02/19/2009] [Accepted: 02/27/2009] [Indexed: 11/22/2022]
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13
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Qi XS, Semenenko VA, Li XA. Improved critical structure sparing with biologically based IMRT optimization. Med Phys 2009; 36:1790-9. [DOI: 10.1118/1.3116775] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Cappuccio A, Herrero MA, Nuñez L. Biological optimization of tumor radiosurgery. Med Phys 2009; 36:98-104. [PMID: 19235378 DOI: 10.1118/1.2986141] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
In tumor radiosurgery, a high dose of radiation is delivered in a single session. The question then naturally arises of selecting an irradiation strategy of high biological efficiency. In this study, the authors propose a mathematical framework to investigate the biological effects of heterogeneity and rate of dose delivery in radiosurgery. The authors simulate a target composed by proliferating and hypoxic tumor cells as well as by normal tissue. Treatment outcome is evaluated by a functional of the dose distribution that counts the LQ-surviving fractions of each cell type. Prescriptions on intensity, homogeneity, and duration of radiation delivery are incorporated as constraints. Biological optimization is performed by means of calculus of variation techniques. For a fixed dose, increasing heterogeneity considerably improved the biological performance. The dose peaks progressively concentrated in the hypoxic and proliferating areas, while damage to normal tissue was reduced. The duration of delivery, optimized in the range of 1-30 min and for various tumor/normal characteristic DNA repair time ratios, coincided with the maximum allowed value. It resulted in a poor therapeutic gain, which was positively correlated with the tumor/normal characteristic DNA repair time ratio. The mathematical framework described in this work allows one to design the dose distribution and dose rate of biologically based plans for tumor radiosurgery. It may be thus integrated into the available simulation softwares to assist in treatment planning.
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Affiliation(s)
- Antonio Cappuccio
- Departamento de Matemática Aplicada, Universidad Complutense, Plaza de las Ciencias s/n, 28040 Madrid, Spain.
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Petit SF, Dekker ALAJ, Seigneuric R, Murrer L, van Riel NAW, Nordsmark M, Overgaard J, Lambin P, Wouters BG. Intra-voxel heterogeneity influences the dose prescription for dose-painting with radiotherapy: a modelling study. Phys Med Biol 2009; 54:2179-96. [PMID: 19293465 DOI: 10.1088/0031-9155/54/7/022] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The purpose of this study was to increase the potential of dose redistribution by incorporating estimates of oxygen heterogeneity within imaging voxels for optimal dose determination. Cellular oxygen tension (pO(2)) distributions were estimated for imaging-size-based voxels by solving oxygen diffusion-consumption equations around capillaries placed at random locations. The linear-quadratic model was used to determine cell survival in the voxels as a function of pO(2) and dose. The dose distribution across the tumour was optimized to yield minimal survival after 30 x 2 Gy fractions by redistributing the dose based on differences in oxygen levels. Eppendorf data of a series of 69 tumours were used as a surrogate of what might be expected from oxygen imaging datasets. Dose optimizations were performed both taking into account cellular heterogeneity in oxygenation within voxels and assuming a homogeneous cellular distribution of oxygen. Our simulations show that dose redistribution based on derived cellular oxygen distributions within voxels result in dose distributions that require less total dose to obtain the same degree of cell kill as dose distributions that were optimized with a model that considered voxels as homogeneous with respect to oxygen. Moderately hypoxic tumours are expected to gain most from dose redistribution. Incorporating cellular-based distributions of radiosensitivity into dose-planning algorithms theoretically improves the potential gains from dose redistribution algorithms.
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Affiliation(s)
- Steven F Petit
- Department of Radiation Oncology (Maastro), GROW, U.H. Maastricht, Maastricht, The Netherlands
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Søvik Å, Malinen E, Olsen DR. Strategies for Biologic Image-Guided Dose Escalation: A Review. Int J Radiat Oncol Biol Phys 2009; 73:650-8. [DOI: 10.1016/j.ijrobp.2008.11.001] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2008] [Revised: 10/30/2008] [Accepted: 11/03/2008] [Indexed: 11/17/2022]
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Semenenko VA, Reitz B, Day E, Qi XS, Miften M, Li XA. Evaluation of a commercial biologically based IMRT treatment planning system. Med Phys 2008; 35:5851-60. [DOI: 10.1118/1.3013556] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
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Stewart RD, Li XA. BGRT: biologically guided radiation therapy-the future is fast approaching! Med Phys 2007; 34:3739-51. [PMID: 17985619 DOI: 10.1118/1.2779861] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Rapid advances in functional and biological imaging, predictive assays, and our understanding of the molecular and cellular responses underpinning treatment outcomes herald the coming of the long-sought goal of implementing patient-specific biologically guided radiation therapy (BGRT) in the clinic. Biological imaging and predictive assays have the potential to provide patient-specific, three-dimensional information to characterize the radiation response characteristics of tumor and normal structures. Within the next decade, it will be possible to combine such information with advanced delivery technologies to design and deliver biologically conformed, individualized therapies in the clinic. The full implementation of BGRT in the clinic will require new technologies and additional research. However, even the partial implementation of BGRT treatment planning may have the potential to substantially impact clinical outcomes.
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Affiliation(s)
- Robert D Stewart
- School of Health Sciences, Purdue University, 550 Stadium Mall Drive, West Lafayette, Indiana 47907-2051, USA
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Flynn RT, Barbee DL, Mackie TR, Jeraj R. Comparison of intensity modulated x-ray therapy and intensity modulated proton therapy for selective subvolume boosting: a phantom study. Phys Med Biol 2007; 52:6073-91. [PMID: 17921573 DOI: 10.1088/0031-9155/52/20/001] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Selective subvolume boosting can theoretically improve tumour control probability while maintaining normal tissue complication probabilities similar to those of uniform dose distributions. In this work the abilities of intensity-modulated x-ray therapy (IMXT) and intensity-modulated proton therapy (IMPT) to deliver boosts to multiple subvolumes of varying size and proximities are compared in a thorough phantom study. IMXT plans were created using the step-and-shoot (IMXT-SAS) and helical tomotherapy (IMXT-HT) methods. IMPT plans were created with the spot scanning (IMPT-SS) and distal gradient tracking (IMPT-DGT) methods. IMPT-DGT is a generalization of the distal edge tracking method designed to reduce the number of proton beam spots required to deliver non-uniform dose distributions relative to IMPT-SS. The IMPT methods were delivered over both 180 degrees and 360 degrees arcs. The IMXT-SAS and IMPT-SS methods optimally satisfied the non-uniform dose prescriptions the least and the most, respectively. The IMPT delivery methods reduced the normal tissue integral dose by a factor of about 2 relative to the IMXT delivery methods, regardless of the delivery arc. The IMPT-DGT method reduced the number of proton beam spots by a factor of about 3 relative to the IMPT-SS method.
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Affiliation(s)
- R T Flynn
- Department of Medical Physics, University of Wisconsin, 1300 University Avenue, Madison, WI 53703, USA.
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