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Chen ZJ, Li XA, Brenner DJ, Hellebust TP, Hoskin P, Joiner MC, Kirisits C, Nath R, Rivard MJ, Thomadsen BR, Zaider M. AAPM Task Group Report 267: A joint AAPM GEC-ESTRO report on biophysical models and tools for the planning and evaluation of brachytherapy. Med Phys 2024; 51:3850-3923. [PMID: 38721942 DOI: 10.1002/mp.17062] [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: 12/05/2023] [Revised: 02/28/2024] [Accepted: 03/08/2024] [Indexed: 06/05/2024] Open
Abstract
Brachytherapy utilizes a multitude of radioactive sources and treatment techniques that often exhibit widely different spatial and temporal dose delivery patterns. Biophysical models, capable of modeling the key interacting effects of dose delivery patterns with the underlying cellular processes of the irradiated tissues, can be a potentially useful tool for elucidating the radiobiological effects of complex brachytherapy dose delivery patterns and for comparing their relative clinical effectiveness. While the biophysical models have been used largely in research settings by experts, it has also been used increasingly by clinical medical physicists over the last two decades. A good understanding of the potentials and limitations of the biophysical models and their intended use is critically important in the widespread use of these models. To facilitate meaningful and consistent use of biophysical models in brachytherapy, Task Group 267 (TG-267) was formed jointly with the American Association of Physics in Medicine (AAPM) and The Groupe Européen de Curiethérapie and the European Society for Radiotherapy & Oncology (GEC-ESTRO) to review the existing biophysical models, model parameters, and their use in selected brachytherapy modalities and to develop practice guidelines for clinical medical physicists regarding the selection, use, and interpretation of biophysical models. The report provides an overview of the clinical background and the rationale for the development of biophysical models in radiation oncology and, particularly, in brachytherapy; a summary of the results of literature review of the existing biophysical models that have been used in brachytherapy; a focused discussion of the applications of relevant biophysical models for five selected brachytherapy modalities; and the task group recommendations on the use, reporting, and implementation of biophysical models for brachytherapy treatment planning and evaluation. The report concludes with discussions on the challenges and opportunities in using biophysical models for brachytherapy and with an outlook for future developments.
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Affiliation(s)
- Zhe Jay Chen
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - X Allen Li
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - David J Brenner
- Center for Radiological Research, Columbia University Medical Center, New York, New York, USA
| | - Taran P Hellebust
- Department of Oncology, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
| | - Peter Hoskin
- Mount Vernon Cancer Center, Mount Vernon Hospital, Northwood, UK
- University of Manchester, Manchester, UK
| | - Michael C Joiner
- Department of Radiation Oncology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Christian Kirisits
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
| | - Ravinder Nath
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Mark J Rivard
- Department of Radiation Oncology, Brown University School of Medicine, Providence, Rhode Island, USA
| | - Bruce R Thomadsen
- Department of Medical Physics, University of Wisconsin, Madison, Wisconsin, USA
| | - Marco Zaider
- Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York, USA
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Peng H, Deng J, Jiang S, Timmerman R. Rethinking the potential role of dose painting in personalized ultra-fractionated stereotactic adaptive radiotherapy. Front Oncol 2024; 14:1357790. [PMID: 38571510 PMCID: PMC10987838 DOI: 10.3389/fonc.2024.1357790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 02/21/2024] [Indexed: 04/05/2024] Open
Abstract
Fractionated radiotherapy was established in the 1920s based upon two principles: (1) delivering daily treatments of equal quantity, unless the clinical situation requires adjustment, and (2) defining a specific treatment period to deliver a total dosage. Modern fractionated radiotherapy continues to adhere to these century-old principles, despite significant advancements in our understanding of radiobiology. At UT Southwestern, we are exploring a novel treatment approach called PULSAR (Personalized Ultra-Fractionated Stereotactic Adaptive Radiotherapy). This method involves administering tumoricidal doses in a pulse mode with extended intervals, typically spanning weeks or even a month. Extended intervals permit substantial recovery of normal tissues and afford the tumor and tumor microenvironment ample time to undergo significant changes, enabling more meaningful adaptation in response to the evolving characteristics of the tumor. The notion of dose painting in the realm of radiation therapy has long been a subject of contention. The debate primarily revolves around its clinical effectiveness and optimal methods of implementation. In this perspective, we discuss two facets concerning the potential integration of dose painting with PULSAR, along with several practical considerations. If successful, the combination of the two may not only provide another level of personal adaptation ("adaptive dose painting"), but also contribute to the establishment of a timely feedback loop throughout the treatment process. To substantiate our perspective, we conducted a fundamental modeling study focusing on PET-guided dose painting, incorporating tumor heterogeneity and tumor control probability (TCP).
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Affiliation(s)
- Hao Peng
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX, United States
- Medical Artificial Intelligence and Automation Laboratory, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Jie Deng
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX, United States
- Medical Artificial Intelligence and Automation Laboratory, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Steve Jiang
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX, United States
- Medical Artificial Intelligence and Automation Laboratory, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Robert Timmerman
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX, United States
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Marcu LG, Dell’Oro M, Bezak E. Opportunities in Cancer Therapies: Deciphering the Role of Cancer Stem Cells in Tumour Repopulation. Int J Mol Sci 2023; 24:17258. [PMID: 38139085 PMCID: PMC10744048 DOI: 10.3390/ijms242417258] [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: 11/18/2023] [Revised: 12/06/2023] [Accepted: 12/06/2023] [Indexed: 12/24/2023] Open
Abstract
Tumour repopulation during treatment is a well acknowledged yet still challenging aspect of cancer management. The latest research results show clear evidence towards the existence of cancer stem cells (CSCs) that are responsible for tumour repopulation, dissemination, and distant metastases in most solid cancers. Cancer stem cell quiescence and the loss of asymmetrical division are two powerful mechanisms behind repopulation. Another important aspect in the context of cancer stem cells is cell plasticity, which was shown to be triggered during fractionated radiotherapy, leading to cell dedifferentiation and thus reactivation of stem-like properties. Repopulation during treatment is not limited to radiotherapy, as there is clinical proof for repopulation mechanisms to be activated through other conventional treatment techniques, such as chemotherapy. The dynamic nature of stem-like cancer cells often elicits resistance to treatment by escaping drug-induced cell death. The aims of this scoping review are (1) to describe the main mechanisms used by cancer stem cells to initiate tumour repopulation during therapy; (2) to present clinical evidence for tumour repopulation during radio- and chemotherapy; (3) to illustrate current trends in the identification of CSCs using specific imaging techniques; and (4) to highlight novel technologies that show potential in the eradication of CSCs.
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Affiliation(s)
- Loredana G. Marcu
- UniSA Allied Health & Human Performance, University of South Australia, Adelaide, SA 5001, Australia;
- Faculty of Informatics and Science, University of Oradea, 410087 Oradea, Romania
| | - Mikaela Dell’Oro
- Australian Centre for Quantitative Imaging, School of Medicine, The University of Western Australia, Perth, WA 6009, Australia;
| | - Eva Bezak
- UniSA Allied Health & Human Performance, University of South Australia, Adelaide, SA 5001, Australia;
- Faculty of Chemistry & Physics, University of Adelaide, Adelaide, SA 5000, Australia
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Tien CJ, Chen Z. Radiobiological evaluation of the stepping-source effect in single-fraction monotherapy high-dose-rate prostate brachytherapy. Brachytherapy 2023; 22:593-606. [PMID: 37263898 DOI: 10.1016/j.brachy.2023.03.003] [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: 09/15/2022] [Revised: 02/19/2023] [Accepted: 03/17/2023] [Indexed: 06/03/2023]
Abstract
INTRODUCTION The continued reliance upon the traditional biologically effective dose (BEDT) formalism of BEDT=nd(1+d/(α/β)) may be one possible contributor to the poor clinical outcomes observed with single-fraction 19-20 Gy prescriptions in prostate high-dose-rate (HDR) brachytherapy because BEDT does not consider intrafraction sublethal damage repair (iSLDR). This, along with low α/β and repair half-times comparable to delivery time, could reduce the biological effect predicted using BEDT. METHODS AND MATERIALS BED was recalculated with a model accounting for iSLDR, using time-averaged uniform dose rate (BEDg1) patterns and time-variable dose rate (BEDgss) patterns inherent to stepping-source delivery. An assortment of two-pulse delivery sequences assuming 19 Gy in 972 s was analyzed. Calculations were repeated for 17470 and 61050 U to investigate source strength dependence. RESULTS BEDg1 and BEDgss was/were lower than BEDT by 16.9% and 11.1%-21.1%, respectively, for 40700 U. For 17470 U, BEDg1 and BEDgss was/were lower than BEDT by 32.5% and 21.5%-37.1%, respectively. For 61050 U, BEDg1 and BEDgss was/were lower than BEDT by 11.9% and 7.8%-15.3%, respectively. BEDgss was most dependent on pulse spacing with milder dependence on pulse onset time. BEDg1 served as a lower bound approximation of BEDgss for fast effective delivery time. CONCLUSIONS Even for points with the same calculated dose, the biological dose was significantly reduced by iSLDR (as much as 37.1%). While BEDgss explicitly addressed the temporally-variable dose rate inherent to a stepping-source delivery, calculations were cumbersome. Under certain conditions, BEDg1 may serve as an approachable method to quickly assess "worst-case scenario" BED.
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Affiliation(s)
- Christopher J Tien
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT.
| | - Zhe Chen
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT
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Lorenzo G, di Muzio N, Deantoni CL, Cozzarini C, Fodor A, Briganti A, Montorsi F, Pérez-García VM, Gomez H, Reali A. Patient-specific forecasting of postradiotherapy prostate-specific antigen kinetics enables early prediction of biochemical relapse. iScience 2022; 25:105430. [DOI: 10.1016/j.isci.2022.105430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Revised: 09/04/2022] [Accepted: 10/19/2022] [Indexed: 11/06/2022] Open
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Cui T, Weiner J, Danish S, Chundury A, Ohri N, Yue N, Wang X, Nie K. Evaluation of Biological Effective Dose in Gamma Knife Staged Stereotactic Radiosurgery for Large Brain Metastases. Front Oncol 2022; 12:892139. [PMID: 35847934 PMCID: PMC9280470 DOI: 10.3389/fonc.2022.892139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 05/31/2022] [Indexed: 11/16/2022] Open
Abstract
Objective Gamma knife (GK) staged stereotactic radiosurgery (Staged-SRS) has become an effective treatment option for large brain metastases (BMs); however, it has been challenging to evaluate the total dose because of tumor shrinkage between two staged sessions. This study aims to evaluate total biological effective dose (BED) in Staged-SRS, and to compare the BED with those in single-fraction SRS (SF-SRS) and hypo-fractionated SRS (HF-SRS). Methods Patients treated with GK Staged-SRS at a single institution were retrospectively included. The dose delivered in two sessions of Staged-SRS was summed using the deformable image registration. Each patient was replanned for SF-SRS and HF-SRS. The total BEDs were computed using the linear-quadratic model. Tumor BED98% and brain V84Gy2, equivalent to V12Gy in SF-SRS, were compared between SF-SRS, HF-SRS, and Staged-SRS plans with the Wilcoxon test. Results Twelve patients with 24 BMs treated with GK Staged-SRS were identified. We observed significant differences (p < 0.05) in tumor BED98% but comparable brain V84Gy2 (p = 0.677) between the Staged-SRS and SF-SRS plans. No dosimetric advantages of Staged-SRS over HF-SRS were observed. Tumor BED98% in the HF-SRS plans were significantly higher than those in the Staged-SRS plans (p < 0.05). Despite the larger PTVs, brain V84Gy2 in the HF-SRS plans remained lower (p < 0.05). Conclusion We presented an approach to calculate the composite BEDs delivered to both tumor and normal brain tissue in Staged-SRS. Compared to SF-SRS, Staged-SRS delivers a higher dose to tumor but maintains a comparable dose to normal brain tissue. Our results did not show any dosimetric advantages of Staged-SRS over HF-SRS.
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Affiliation(s)
- Taoran Cui
- Rutgers Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, New Brunswick, NJ, United States
- *Correspondence: Taoran Cui,
| | - Joseph Weiner
- Rutgers Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, New Brunswick, NJ, United States
| | - Shabbar Danish
- Jersey Shore University Medical Center (JSUMC), Neptune, NJ, United States
| | - Anupama Chundury
- Rutgers Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, New Brunswick, NJ, United States
| | - Nisha Ohri
- Rutgers Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, New Brunswick, NJ, United States
| | - Ning Yue
- Rutgers Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, New Brunswick, NJ, United States
| | - Xiao Wang
- Rutgers Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, New Brunswick, NJ, United States
| | - Ke Nie
- Rutgers Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, New Brunswick, NJ, United States
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Ghaderi N, Jung J, Brüningk SC, Subramanian A, Nassour L, Peacock J. A Century of Fractionated Radiotherapy: How Mathematical Oncology Can Break the Rules. Int J Mol Sci 2022; 23:ijms23031316. [PMID: 35163240 PMCID: PMC8836217 DOI: 10.3390/ijms23031316] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/17/2022] [Accepted: 01/18/2022] [Indexed: 02/07/2023] Open
Abstract
Radiotherapy is involved in 50% of all cancer treatments and 40% of cancer cures. Most of these treatments are delivered in fractions of equal doses of radiation (Fractional Equivalent Dosing (FED)) in days to weeks. This treatment paradigm has remained unchanged in the past century and does not account for the development of radioresistance during treatment. Even if under-optimized, deviating from a century of successful therapy delivered in FED can be difficult. One way of exploring the infinite space of fraction size and scheduling to identify optimal fractionation schedules is through mathematical oncology simulations that allow for in silico evaluation. This review article explores the evidence that current fractionation promotes the development of radioresistance, summarizes mathematical solutions to account for radioresistance, both in the curative and non-curative setting, and reviews current clinical data investigating non-FED fractionated radiotherapy.
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Affiliation(s)
- Nima Ghaderi
- Department of Biomedical Engineering, University of Minnesota Twin Cities, Minneapolis, MN 55455, USA; (N.G.); (J.J.)
| | - Joseph Jung
- Department of Biomedical Engineering, University of Minnesota Twin Cities, Minneapolis, MN 55455, USA; (N.G.); (J.J.)
| | - Sarah C. Brüningk
- Machine Learning & Computational Biology Lab, Department of Biosystems Science and Engineering, ETH Zurich, 4058 Basel, Switzerland;
- Swiss Institute for Bioinformatics (SIB), 1015 Lausanne, Switzerland
| | - Ajay Subramanian
- Department of Radiation Oncology, Stanford University, Stanford, CA 94305, USA;
| | - Lauren Nassour
- Department of Radiation Oncology, University of Alabama Birmingham, Birmingham, AL 35205, USA;
| | - Jeffrey Peacock
- Department of Radiation Oncology, University of Alabama Birmingham, Birmingham, AL 35205, USA;
- Correspondence:
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Chan CC, Hsiao YY. The Effects of Dimethylsulfoxide and Oxygen on DNA Damage Induction and Repair Outcomes for Cells Irradiated by 62 MeV Proton and 3.31 MeV Helium Ions. J Pers Med 2021; 11:jpm11040286. [PMID: 33917956 PMCID: PMC8068342 DOI: 10.3390/jpm11040286] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 04/06/2021] [Indexed: 12/12/2022] Open
Abstract
Reactive oxygen species (ROS) play an essential role in radiation-induced indirect actions. In terms of DNA damage, double strand breaks (DSBs) have the greatest effects on the repair of DNA damage, cell survival and transformation. This study evaluated the biological effects of the presence of ROS and oxygen on DSB induction and mutation frequency. The relative biological effectiveness (RBE) and oxygen enhancement ratio (OER) of 62 MeV therapeutic proton beams and 3.31 MeV helium ions were calculated using Monte Carlo damage simulation (MCDS) software. Monte Carlo excision repair (MCER) simulations were used to calculate the repair outcomes (mutation frequency). The RBE values of proton beams decreased to 0.75 in the presence of 0.4 M dimethylsulfoxide (DMSO) and then increases to 0.9 in the presence of 2 M DMSO while the RBE values of 3.31 MeV helium ions increased from 2.9 to 5.7 (0–2 M). The mutation frequency of proton beams also decreased from 0.008–0.065 to 0.004–0.034 per cell per Gy by the addition of 2 M DMSO, indicating that ROS affects both DSB induction and repair outcomes. These results show that the combined use of DMSO in normal tissues and an increased dose in tumor regions increases treatment efficiency.
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Affiliation(s)
- Chun-Chieh Chan
- Department of Electrical Engineering, National Chung Hsing University, Taichung 40227, Taiwan;
| | - Ya-Yun Hsiao
- Department of Radiology, Chung Shan Medical University Hospital, Taichung 40201, Taiwan
- Department of Medical Imaging and Radiological Sciences, Chung Shan Medical University, Taichung 40201, Taiwan
- Correspondence: ; Tel.: +886-4-24730022 (ext. 12010)
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Sosa-Marrero C, de Crevoisier R, Hernandez A, Fontaine P, Rioux-Leclercq N, Mathieu R, Fautrel A, Paris F, Acosta O. Towards a Reduced In Silico Model Predicting Biochemical Recurrence After Radiotherapy in Prostate Cancer. IEEE Trans Biomed Eng 2021; 68:2718-2729. [PMID: 33460366 DOI: 10.1109/tbme.2021.3052345] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
OBJECTIVE Purposes of this work were i) to develop an in silico model of tumor response to radiotherapy, ii) to perform an exhaustive sensitivity analysis in order to iii) propose a simplified version and iv) to predict biochemical recurrence with both the comprehensive and the reduced model. METHODS A multiscale computational model of tumor response to radiotherapy was developed. It integrated the following radiobiological mechanisms: oxygenation, including hypoxic death; division of tumor cells; VEGF diffusion driving angiogenesis; division of healthy cells and oxygen-dependent response to irradiation, considering, cycle arrest and mitotic catastrophe. A thorough sensitivity analysis using the Morris screening method was performed on 21 prostate computational tissues. Tumor control probability (TCP) curves of the comprehensive model and 15 reduced versions were compared. Logistic regression was performed to predict biochemical recurrence after radiotherapy on 76 localized prostate cancer patients using an output of the comprehensive and the reduced models. RESULTS No significant difference was found between the TCP curves of the comprehensive and a simplified version which only considered oxygenation, division of tumor cells and their response to irradiation. Biochemical recurrence predictions using the comprehensive and the reduced models improved those made from pre-treatment imaging parameters (AUC = 0.81 ± 0.02 and 0.82 ± 0.02 vs. 0.75 ± 0.03, respectively). CONCLUSION A reduced model of tumor response to radiotherapy able to predict biochemical recurrence in prostate cancer was obtained. SIGNIFICANCE This reduced model may be used in the future to optimize personalized fractionation schedules.
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Guo L, Li X, Chen Y, Liu R, Ren C, Du S. The efficacy of hypofractionated radiotherapy (HFRT) with concurrent and adjuvant temozolomide in newly diagnosed glioblastoma: A meta-analysis. Cancer Radiother 2021; 25:182-190. [PMID: 33436285 DOI: 10.1016/j.canrad.2020.08.049] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 08/06/2020] [Accepted: 08/28/2020] [Indexed: 12/28/2022]
Abstract
PURPOSE The efficacy of hypofractionated radiotherapy (HFRT) in glioblastoma (GBM) without age restrictions remains unclear. The aim of this meta-analysis is to access the survival outcomes of HFRT in these patients. METHODS A comprehensive electronic literature search of PubMed, Web of Science and Cochrane Library was conducted up to June 1, 2020. The main evaluation data were the overall survival (OS) rate at 12 months and 24 months and the progression-free survival (PFS) rate at 6 and 12 months. The secondary evaluation data was the incidence of radionecrosis and adverse events. The study was performed using R "meta" package. RESULTS Eleven studies met the inclusion criteria, which totally contained 484 participants. The 12-month OS and 24-month OS rate of HFRT in GBM were 71.3% and 34.8%, while the 6-month PFS and 12-month rate were 74.0% and 40.8%. Compared to low-BED (biological equivalent dose) schedules (<78Gy), high-BED schedules may increase survival benefit both in PFS-6 (P=0.003) and PFS-12 (P=0.011), while the difference did not show on OS. Different dose per fraction had no significant effect on both OS and PFS. Incidence of radionecrosis was 14.2%. Although the overall incidence of adverse reactions cannot be quantified, the toxicity of HFRT was acceptable. CONCLUSIONS Compared with survival data for standard treatment, HFRT seemed to improve overall survival and progression-free survival, while high BED schedules may future increase benefit on PFS. Meanwhile, the toxicity of HFRT was tolerable. Further randomised controlled clinical studies are needed to confirm these findings.
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Affiliation(s)
- Longbin Guo
- Department of radiation oncology, Nanfang hospital, Southern medical university, 1838, North Guangzhou avenue, 510515 Guangzhou, China
| | - Xuanzi Li
- Department of radiation oncology, Nanfang hospital, Southern medical university, 1838, North Guangzhou avenue, 510515 Guangzhou, China
| | - Yulei Chen
- Department of radiation oncology, Nanfang hospital, Southern medical university, 1838, North Guangzhou avenue, 510515 Guangzhou, China
| | - Rongping Liu
- Department of radiation oncology, Nanfang hospital, Southern medical university, 1838, North Guangzhou avenue, 510515 Guangzhou, China
| | - Chen Ren
- Department of radiation oncology, Nanfang hospital, Southern medical university, 1838, North Guangzhou avenue, 510515 Guangzhou, China.
| | - Shasha Du
- Department of radiation oncology, Nanfang hospital, Southern medical university, 1838, North Guangzhou avenue, 510515 Guangzhou, China.
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Applications of Nonlinear Programming to the Optimization of Fractionated Protocols in Cancer Radiotherapy. INFORMATION 2020. [DOI: 10.3390/info11060313] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The present work of review collects and evidences the main results of our previous papers on the optimization of fractionated radiotherapy protocols. The problem under investigation is presented here in a unitary framework as a nonlinear programming application that aims to determine the optimal schemes of dose fractionation commonly used in external beam radiotherapy. The radiation responses of tumor and normal tissues are described by means of the linear quadratic model. We formulate a nonlinear, non-convex optimization problem including two quadratic constraints to limit the collateral normal tissue damages and linear box constraints on the fractional dose sizes. The general problem is decomposed into two subproblems: (1) analytical determination of the optimal fraction dose sizes as a function of the model parameters for arbitrarily fixed treatment lengths; and (2) numerical determination of the optimal fraction number, and of the optimal treatment time, in different parameter settings. After establishing the boundedness of the optimal number of fractions, we investigate by numerical simulation the optimal solution behavior for experimentally meaningful parameter ranges, recognizing the crucial role of some parameters, such as the radiosensitivity ratio, in determining the optimality of hypo- or equi-fractionated treatments. Our results agree with findings of the theoretical and clinical literature.
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Giaj-Levra N, Borghetti P, Bruni A, Ciammella P, Cuccia F, Fozza A, Franceschini D, Scotti V, Vagge S, Alongi F. Current radiotherapy techniques in NSCLC: challenges and potential solutions. Expert Rev Anticancer Ther 2020; 20:387-402. [PMID: 32321330 DOI: 10.1080/14737140.2020.1760094] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Introduction: Radiotherapy is an important therapeutic strategy in the management of non-small cell lung cancer (NSCLC). In recent decades, technological implementations and the introduction of image guided radiotherapy (IGRT) have significantly increased the accuracy and tolerability of radiation therapy.Area covered: In this review, we provide an overview of technological opportunities and future prospects in NSCLC management.Expert opinion: Stereotactic body radiotherapy (SBRT) is now considered the standard approach in patients ineligible for surgery, while in operable cases, it is still under debate. Additionally, in combination with systemic treatment, SBRT is an innovative option for managing oligometastatic patients and features encouraging initial results in clinical outcomes. To date, in inoperable locally advanced NSCLC, the radical dose prescription has not changed (60 Gy in 30 fractions), despite the median overall survival progressively increasing. These results arise from technological improvements in precisely hitting target treatment volumes and organ at risk sparing, which are associated with better treatment qualities. Finally, for the management of NSCLC, proton and carbon ion therapies and the recent development of MR-Linac are new, intriguing technological approaches under investigation.
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Affiliation(s)
- Niccolò Giaj-Levra
- Advanced Radiation Oncology Department, IRCCS Sacro Cuore Don Calabria Hospital, Negrar di Valpolicella, Italy
| | - Paolo Borghetti
- Dipartimento di Radioterapia Oncologica, Università e ASST Spedali Civili di Brescia, Brescia, Italy
| | - Alessio Bruni
- Radiotherapy Unit, Department of Oncology and Hematology, University Hospital of Modena, Modena, Italy
| | - Patrizia Ciammella
- Radiation Therapy Unit, Department of Oncology and Advanced Technology, AUSL-IRCCS, Reggio, Emilia, Italy
| | - Francesco Cuccia
- Advanced Radiation Oncology Department, IRCCS Sacro Cuore Don Calabria Hospital, Negrar di Valpolicella, Italy
| | - Alessandra Fozza
- Department of Radiation Oncology, SS.Antonio e Biagio e C.Arrigo Hospital Alessandria, Alessandria, Italy
| | - Davide Franceschini
- Department of Radiotherapy and Radiosurgery, Humanitas Clinical and Research Center- IRCCS - Rozzano (MI), Milano, Italy
| | - Vieri Scotti
- Radiation Therapy Unit, Department of Oncology, Careggi University Hospital, Firenze, Italy
| | - Stefano Vagge
- Radiation oncology Department, IRCCS Ospedale Policlinico San Martino, Genova, Italy
| | - Filippo Alongi
- Advanced Radiation Oncology Department, IRCCS Sacro Cuore Don Calabria Hospital, Negrar di Valpolicella, Italy.,University of Brescia, Italy
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Lorenzo G, Pérez-García VM, Mariño A, Pérez-Romasanta LA, Reali A, Gomez H. Mechanistic modelling of prostate-specific antigen dynamics shows potential for personalized prediction of radiation therapy outcome. J R Soc Interface 2019; 16:20190195. [PMID: 31409240 DOI: 10.1098/rsif.2019.0195] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
External beam radiation therapy is a widespread treatment for prostate cancer. The ensuing patient follow-up is based on the evolution of the prostate-specific antigen (PSA). Serum levels of PSA decay due to the radiation-induced death of tumour cells and cancer recurrence usually manifest as a rising PSA. The current definition of biochemical relapse requires that PSA reaches nadir and starts increasing, which delays the use of further treatments. Also, these methods do not account for the post-radiation tumour dynamics that may contain early information on cancer recurrence. Here, we develop three mechanistic models of post-radiation PSA evolution. Our models render superior fits of PSA data in a patient cohort and provide a biological justification for the most common empirical formulation of PSA dynamics. We also found three model-based prognostic variables: the proliferation rate of the survival fraction, the ratio of radiation-induced cell death rate to the survival proliferation rate, and the time to PSA nadir since treatment termination. We argue that these markers may enable the early identification of biochemical relapse, which would permit physicians to subsequently adapt patient monitoring to optimize the detection and treatment of cancer recurrence.
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Affiliation(s)
- Guillermo Lorenzo
- Dipartimento di Ingegneria Civile e Architettura, Università degli Studi di Pavia, Via Ferrata 3, 27100 Pavia, Italy.,Departamento de Matemáticas, Universidade da Coruña, Campus de Elviña s/n, 15071 A Coruña, Spain
| | - Víctor M Pérez-García
- Mathematical Oncology Laboratory, Universidad de Castilla-La Mancha, Edificio Politécnico, Avenida Camilo José Cela 3, 13071 Ciudad Real, Spain
| | - Alfonso Mariño
- Servicio de Oncología Radioterápica, Centro Oncológico de Galicia, Calle Doctor Camilo Veiras 1, 15009 A Coruña, Spain
| | - Luis A Pérez-Romasanta
- Servicio de Oncología Radioterápica, Hospital Universitario de Salamanca, Paseo de San Vicente 58-182, 37007 Salamanca, Spain
| | - Alessandro Reali
- Dipartimento di Ingegneria Civile e Architettura, Università degli Studi di Pavia, Via Ferrata 3, 27100 Pavia, Italy
| | - Hector Gomez
- School of Mechanical Engineering, Purdue University, 585 Purdue Mall, West Lafayette, IN 47907, USA.,Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, IN 47907, USA.,Purdue Center for Cancer Research, Purdue University, 201 S. University Street, West Lafayette, IN 47907, USA
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14
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Zhong L, Chen L, Lv S, Li Q, Chen G, Luo W, Zhou P, Li G. Efficacy of moderately hypofractionated simultaneous integrated boost intensity-modulated radiotherapy combined with temozolomide for the postoperative treatment of glioblastoma multiforme: a single-institution experience. Radiat Oncol 2019; 14:104. [PMID: 31196126 PMCID: PMC6567425 DOI: 10.1186/s13014-019-1305-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 05/24/2019] [Indexed: 11/10/2022] Open
Abstract
PURPOSE Despite recent advances in multimodal treatments, the prognosis of patients with glioblastoma multiforme (GBM) remains poor. The aim of this study was to evaluate the efficacy of moderately hypofractionated simultaneous integrated boost intensity-modulated radiotherapy (SIB-IMRT) combined with temozolomide (TMZ) for the postoperative treatment of GBM. MATERIALS AND METHODS From February 2012 to February 2018, 80 patients with newly diagnosed and histologically confirmed GBM in our institute were reviewed retrospectively. All patients underwent complete resection or partial resection surgery and then received hypofractionated SIB-IMRT with concomitant TMZ followed by adjuvant TMZ. A total dose of 64 Gy over 27 fractions was delivered to the gross tumor volume (GTV), clinical target volume 1 (CTV1) received 60 Gy over 27 fractions, and CTV2 received 54 Gy over 27 fractions. The progression-free survival (PFS) and overall survival (OS) rates and the toxicities were evaluated. Prognostic factors were analyzed using univariate and multivariate Cox models. RESULTS The median follow-up was 16 months (range, 5~72 months). The median PFS was 15 months, and the 1-, 2-, and 3-year PFS rates were 56.0, 27.6, and 19.5%, respectively. The median OS was 21 months, and the 1-, 2-, 3-, and 5-year OS rates were 77.6, 41.6, 32.8, and 13.4%, respectively. The toxicities were mild and acceptable. Age, KPS scores and the total number of TMZ cycles were significant factors influencing patient survival. CONCLUSION Moderately hypofractionated SIB-IMRT combined with TMZ is a feasible and safe treatment option with mild toxicity and good PFS and OS.
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Affiliation(s)
- Liangzhi Zhong
- Cancer Research Institute of the Chinese People's Liberation Army, Xinqiao Hospital, Army Medical University, Chongqing, 400037, China
| | - Lu Chen
- Cancer Research Institute of the Chinese People's Liberation Army, Xinqiao Hospital, Army Medical University, Chongqing, 400037, China
| | - Shengqing Lv
- Department of neurosurgery, Xinqiao Hospital, Army Medical University, Chongqing, 400037, China
| | - Qingrui Li
- Biobank, Southwest Hospital, Army Medical University, Chongqing, 400038, China
| | - Guangpeng Chen
- Cancer Research Institute of the Chinese People's Liberation Army, Xinqiao Hospital, Army Medical University, Chongqing, 400037, China
| | - Wen Luo
- Cancer Research Institute of the Chinese People's Liberation Army, Xinqiao Hospital, Army Medical University, Chongqing, 400037, China
| | - Pu Zhou
- Cancer Research Institute of the Chinese People's Liberation Army, Xinqiao Hospital, Army Medical University, Chongqing, 400037, China
| | - Guanghui Li
- Cancer Research Institute of the Chinese People's Liberation Army, Xinqiao Hospital, Army Medical University, Chongqing, 400037, China.
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15
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Tien CJ, Carlson DJ, Nath R, Chen ZJ. High-dose-rate brachytherapy as monotherapy for prostate cancer: The impact of cellular repair and source decay. Brachytherapy 2019; 18:701-710. [PMID: 31109870 DOI: 10.1016/j.brachy.2019.04.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 04/02/2019] [Accepted: 04/12/2019] [Indexed: 11/19/2022]
Abstract
PURPOSE This work quantifies the influence of intrafraction DNA damage repair and cellular repopulation on biologically effective dose (BED) in Ir-192 high-dose-rate brachytherapy for prostate cancer. In addition, it examines the effect of source-decay-induced BED variation for patients treated at different time points in a source exchange cycle. MATERIALS AND METHODS Current fractionation schemes are based on simplified-form BED = nd(1 + d/(α/β)), which assumes that intrafraction repair, interfraction repair, and repopulation are negligible. We took accepted radiobiological parameters of Tk, Tp, and α from the recommendations of the AAPM TG-137, and recalculated the full-form BED. Fraction times were normalized to require 15 min for 20 Gy at 10 Ci. Calculations were carried out for both α/β = 1.5 and 3 Gy. RESULTS After accounting for intrafraction repair, interfraction repair, and/or repopulation, full-form BED calculations showed significant values, as compared with simplified-form BED. For 1-fraction 20 Gy fractionation, the full-form BED was only 64-82% of the simplified-form BED. Dose protraction effects were milder for smaller prescriptions (6 Gy/Fx), where full form was 87-94%. With regard to source decay, BED varied >20% for patients treated at the beginning and the end of a source exchange cycle for 20 Gy single-fraction prescription. CONCLUSIONS Repair and repopulation can be significant in monotherapy high-dose-rate for prostate cancer. As fractionation schemes are established, the simplified BED calculation may not be appropriate. Investigators should consider evaluating BED as a range rather than a discrete value when presenting results unless source activity is explicitly incorporated as well.
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Affiliation(s)
- Christopher J Tien
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT.
| | - David J Carlson
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT; Department of Radiation Oncology, University of Pennsylvania Perelman Center for Advanced Medicine, Philadelphia, PA
| | - Ravinder Nath
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT
| | - Zhe Jay Chen
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT
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16
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Abu-Gheida I, Reddy CA, Kotecha R, Weller MA, Shah C, Kupelian PA, Mian O, Ciezki JP, Stephans KL, Tendulkar RD. Ten-Year Outcomes of Moderately Hypofractionated (70 Gy in 28 fractions) Intensity Modulated Radiation Therapy for Localized Prostate Cancer. Int J Radiat Oncol Biol Phys 2019; 104:325-333. [PMID: 30721720 DOI: 10.1016/j.ijrobp.2019.01.091] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 01/24/2019] [Accepted: 01/28/2019] [Indexed: 02/07/2023]
Abstract
PURPOSE Long-term outcomes with hypofractionated radiation therapy for prostate cancer are limited. We report 10-year outcomes for patients treated with intensity modulated radiation therapy (IMRT) for localized prostate cancer with 70 Gy in 28 fractions at 2.5 Gy per fraction. METHODS AND MATERIALS The study included 854 consecutive patients with localized prostate cancer treated with moderately hypofractionated IMRT and daily image guidance at a single institution between 1998 and 2012. Patients with a single intermediate risk factor were considered to have favorable intermediate-risk (FIR) disease, and those with multiple intermediate risk factors were considered unfavorable (UIR). Biochemical relapse-free survival, clinical relapse-free survival, and overall survival were analyzed using Kaplan-Meier analysis. Prostate cancer-specific mortality (PCSM) was analyzed using competing risk regression. All grade ≥3 genitourinary (GU) and gastrointestinal (GI) toxicities were recorded using Common Terminology Criteria for Adverse Event version 4.03, and cumulative incidence rates of GU and GI toxicity were calculated. RESULTS The median follow-up was 11.3 years (maximum, 19 years). For patients with low-risk (LR), FIR, UIR, and high-risk (HR) disease, the 10-year biochemical relapse free survival rates were 88%, 78%, 71%, and 42%, respectively, (P < .0001). The 10-year clinical relapse free survival were 95%, 91%, 85%, and 72% for patients with LR, FIR, UIR, and HR, respectively, (P < .0001). For all patients, the 10-year actuarial overall survival rate was 69% (95% confidence interval, 66%-73%), and the 10-year PCSM was 6.8% (95% confidence interval, 5.1%-8.6%) overall. For patients with LR, FIR, UIR and HR disease, the 10-year PCSM rates were 2%, 5%, 5%, and 15%. Long-term grade ≥3 GU or GI toxicity remained low with 10-year cumulative incidences of 2% and 1%, respectively. CONCLUSIONS High-dose moderately hypofractionated IMRT with daily image guidance for localized prostate cancer demonstrates favorable 10-year oncologic outcomes with a low incidence of toxicity. This fractionation schedule appears to be acceptable for patients across all risk groups.
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Affiliation(s)
- Ibrahim Abu-Gheida
- Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio
| | - Chandana A Reddy
- Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio
| | - Rupesh Kotecha
- Department of Radiation Oncology, Miami Cancer Institute, Baptist Health South Florida, Miami, Florida; Herbert Wertheim College of Medicine, Florida International University, Miami, Florida
| | - Michael A Weller
- Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio
| | - Chirag Shah
- Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio
| | | | - Omar Mian
- Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio
| | - Jay P Ciezki
- Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio
| | - Kevin L Stephans
- Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio
| | - Rahul D Tendulkar
- Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio.
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17
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Bruni C, Conte F, Papa F, Sinisgalli C. Optimal number and sizes of the doses in fractionated radiotherapy according to the LQ model. MATHEMATICAL MEDICINE AND BIOLOGY-A JOURNAL OF THE IMA 2018; 36:1-53. [DOI: 10.1093/imammb/dqx020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2017] [Accepted: 12/10/2017] [Indexed: 01/18/2023]
Affiliation(s)
- C Bruni
- Istituto di Analisi dei Sistemi ed Informatica “A. Ruberti” – CNR, Via dei Taurini 19, Rome, Italy
| | - F Conte
- Istituto di Analisi dei Sistemi ed Informatica “A. Ruberti” – CNR, Via dei Taurini 19, Rome, Italy
| | - F Papa
- Istituto di Analisi dei Sistemi ed Informatica “A. Ruberti” – CNR, Via dei Taurini 19, Rome, Italy
| | - C Sinisgalli
- Istituto di Analisi dei Sistemi ed Informatica “A. Ruberti” – CNR, Via dei Taurini 19, Rome, Italy
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18
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Moderate hypofractionated radiotherapy with volumetric modulated arc therapy and simultaneous integrated boost for pelvic irradiation in prostate cancer. J Cancer Res Clin Oncol 2017; 143:1301-1309. [DOI: 10.1007/s00432-017-2375-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 02/13/2017] [Indexed: 10/20/2022]
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19
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Casares-Magaz O, van der Heide UA, Rørvik J, Steenbergen P, Muren LP. A tumour control probability model for radiotherapy of prostate cancer using magnetic resonance imaging-based apparent diffusion coefficient maps. Radiother Oncol 2016; 119:111-6. [DOI: 10.1016/j.radonc.2016.02.030] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 01/13/2016] [Accepted: 02/12/2016] [Indexed: 11/26/2022]
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20
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Prestwich R, Vaidyanathan S, Scarsbrook A. Functional Imaging Biomarkers: Potential to Guide an Individualised Approach to Radiotherapy. Clin Oncol (R Coll Radiol) 2015; 27:588-600. [DOI: 10.1016/j.clon.2015.06.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Revised: 06/02/2015] [Accepted: 06/08/2015] [Indexed: 02/03/2023]
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21
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Yeung TPC, Kurdi M, Wang Y, Al-Khazraji B, Morrison L, Hoffman L, Jackson D, Crukley C, Lee TY, Bauman G, Yartsev S. CT perfusion imaging as an early biomarker of differential response to stereotactic radiosurgery in C6 rat gliomas. PLoS One 2014; 9:e109781. [PMID: 25329655 PMCID: PMC4201465 DOI: 10.1371/journal.pone.0109781] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Accepted: 09/02/2014] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND The therapeutic efficacy of stereotactic radiosurgery for glioblastoma is not well understood, and there needs to be an effective biomarker to identify patients who might benefit from this treatment. This study investigated the efficacy of computed tomography (CT) perfusion imaging as an early imaging biomarker of response to stereotactic radiosurgery in a malignant rat glioma model. METHODS Rats with orthotopic C6 glioma tumors received either mock irradiation (controls, N = 8) or stereotactic radiosurgery (N = 25, 12 Gy in one fraction) delivered by Helical Tomotherapy. Twelve irradiated animals were sacrificed four days after stereotactic radiosurgery to assess acute CT perfusion and histological changes, and 13 irradiated animals were used to study survival. Irradiated animals with survival >15 days were designated as responders while those with survival ≤15 days were non-responders. Longitudinal CT perfusion imaging was performed at baseline and regularly for eight weeks post-baseline. RESULTS Early signs of radiation-induced injury were observed on histology. There was an overall survival benefit following stereotactic radiosurgery when compared to the controls (log-rank P<0.04). Responders to stereotactic radiosurgery showed lower relative blood volume (rBV), and permeability-surface area (PS) product on day 7 post-stereotactic radiosurgery when compared to controls and non-responders (P<0.05). rBV and PS on day 7 showed correlations with overall survival (P<0.05), and were predictive of survival with 92% accuracy. CONCLUSIONS Response to stereotactic radiosurgery was heterogeneous, and early selection of responders and non-responders was possible using CT perfusion imaging. Validation of CT perfusion indices for response assessment is necessary before clinical implementation.
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Affiliation(s)
- Timothy Pok Chi Yeung
- Department of Medical Biophysics, Western University, London, Ontario, Canada
- Robarts Research Institute, Western University, London, Ontario, Canada
- London Regional Cancer Program, London, Ontario, Canada
- * E-mail:
| | - Maher Kurdi
- Department of Pathology, Western University, London, Ontario, Canada
- Department of Pathology, King Abdulaziz University, Jeddah, Makkah, Saudi Arabia
| | - Yong Wang
- Robarts Research Institute, Western University, London, Ontario, Canada
| | - Baraa Al-Khazraji
- Department of Medical Biophysics, Western University, London, Ontario, Canada
| | - Laura Morrison
- Lawson Imaging, Lawson Health Research Institute, London, Ontario, Canada
| | - Lisa Hoffman
- Department of Medical Biophysics, Western University, London, Ontario, Canada
- Department of Anatomy and Cell Biology, Western University, London, Ontario, Canada
- Lawson Imaging, Lawson Health Research Institute, London, Ontario, Canada
| | - Dwayne Jackson
- Department of Medical Biophysics, Western University, London, Ontario, Canada
| | - Cathie Crukley
- Robarts Research Institute, Western University, London, Ontario, Canada
| | - Ting-Yim Lee
- Department of Medical Biophysics, Western University, London, Ontario, Canada
- Robarts Research Institute, Western University, London, Ontario, Canada
- Lawson Imaging, Lawson Health Research Institute, London, Ontario, Canada
- Department of Medical Imaging, Western University, London, Ontario, Canada
- Department of Oncology, Western University, London, Ontario, Canada
| | - Glenn Bauman
- Department of Medical Biophysics, Western University, London, Ontario, Canada
- Department of Oncology, Western University, London, Ontario, Canada
- London Regional Cancer Program, London, Ontario, Canada
| | - Slav Yartsev
- Department of Medical Biophysics, Western University, London, Ontario, Canada
- Department of Oncology, Western University, London, Ontario, Canada
- London Regional Cancer Program, London, Ontario, Canada
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22
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Zaorsky NG, Doyle LA, Hurwitz MD, Dicker AP, Den RB. Do theoretical potential and advanced technology justify the use of high-dose rate brachytherapy as monotherapy for prostate cancer? Expert Rev Anticancer Ther 2014; 14:39-50. [PMID: 24124755 DOI: 10.1586/14737140.2013.836303] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Low-dose rate brachytherapy (LDR-BT), involving implantation of radioactive seeds into the prostate, is an established monotherapy for most low-risk and select intermediate- and high-risk prostate cancer patients. High-dose rate brachytherapy (HDR-BT) is an advanced technology theorized to be more advantageous than LDR-BT from a radiobiological and radiophysics perspective, to the patient himself, and in terms of resource allocation. Studies of HDR-BT monotherapy have encouraging results in terms of biochemical control, patient survival, treatment toxicity and erectile preservation. However, there are still certain limitations that preclude recommending HDR-BT monotherapy for prostate cancer outside the setting of a clinical trial. HDR-BT monotherapy should be considered experimental at present.
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Affiliation(s)
- Nicholas G Zaorsky
- Department of Radiation Oncology Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA, 19111, USA
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23
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Lee CD. Recent developments and best practice in brachytherapy treatment planning. Br J Radiol 2014; 87:20140146. [PMID: 24734939 PMCID: PMC4453147 DOI: 10.1259/bjr.20140146] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Revised: 04/10/2014] [Accepted: 04/14/2014] [Indexed: 12/20/2022] Open
Abstract
Brachytherapy has evolved over many decades, but more recently, there have been significant changes in the way that brachytherapy is used for different treatment sites. This has been due to the development of new, technologically advanced computer planning systems and treatment delivery techniques. Modern, three-dimensional (3D) imaging modalities have been incorporated into treatment planning methods, allowing full 3D dose distributions to be computed. Treatment techniques involving online planning have emerged, allowing dose distributions to be calculated and updated in real time based on the actual clinical situation. In the case of early stage breast cancer treatment, for example, electronic brachytherapy treatment techniques are being used in which the radiation dose is delivered during the same procedure as the surgery. There have also been significant advances in treatment applicator design, which allow the use of modern 3D imaging techniques for planning, and manufacturers have begun to implement new dose calculation algorithms that will correct for applicator shielding and tissue inhomogeneities. This article aims to review the recent developments and best practice in brachytherapy techniques and treatments. It will look at how imaging developments have been incorporated into current brachytherapy treatment and how these developments have played an integral role in the modern brachytherapy era. The planning requirements for different treatments sites are reviewed as well as the future developments of brachytherapy in radiobiology and treatment planning dose calculation.
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Affiliation(s)
- C D Lee
- Physics Department, Clatterbridge Cancer Centre, Bebington, Wirral, UK
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24
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Konijnenberg MW, Breeman WAP, de Blois E, Chan HS, Boerman OC, Laverman P, Kolenc-Peitl P, Melis M, de Jong M. Therapeutic application of CCK2R-targeting PP-F11: influence of particle range, activity and peptide amount. EJNMMI Res 2014; 4:47. [PMID: 26116111 PMCID: PMC4452684 DOI: 10.1186/s13550-014-0047-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Accepted: 08/15/2014] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Targeted radionuclide therapy with high-energy beta-emitters is generally considered suboptimal to cure small tumours (<300 mg). Tumour targeting of the CCK2 receptor-binding minigastrin analogue PP-F11 was determined in a tumour-bearing mouse model at increasing peptide amounts. The optimal therapy was analysed for PP-F11 labelled with (90)Y, (177)Lu or (213)Bi, accounting for the radionuclide specific activities (SAs), the tumour absorbed doses and tumour (radio) biology. METHODS Tumour uptake of (111)In-PP-F11 was determined in nude mice bearing CCK2 receptor-transfected A431 xenografts at 1 and 4 h post-injection for escalating peptide masses of 0.03 to 15 nmol/mouse. The absorbed tumour dose was estimated, assuming comparable biodistributions of the (90)Y, (177)Lu or (213)Bi radiolabelled peptides. The linear-quadratic (LQ) model was used to calculate the tumour control probabilities (TCP) as a function of tumour mass and growth. RESULTS Practically achievable maximum SAs for PP-F11 labelled with (90)Y and (177)Lu were 400 MBq (90)Y/nmol and 120 MBq(177)Lu/nmol. Both the large elution volume from the 220 MBq (225)Ac generator used and reaction kinetics diminished the maximum achieved (213)Bi SA in practice: 40 MBq (213)Bi/nmol. Tumour uptakes decreased rapidly with increasing peptide amounts, following a logarithmic curve with ED50 = 0.5 nmol. At 0.03 nmol peptide, the (300 mg) tumour dose was 9 Gy after 12 MBq (90)Y-PP-F11, and for (111)In and (177)Lu, this was 1 Gy. A curative dose of 60 Gy could be achieved with a single administration of 111 MBq (90)Y labelled to 0.28 nmol PP-F11 or with 4 × 17 MBq (213)Bi (0.41 nmol) when its α-radiation relative biological effectiveness (RBE) was assumed to be 3.4. Repeated dosing is preferable to avoid complete tumour receptor saturation. Tumours larger than 200 mg are curable with (90)Y-PP-F11; the other radionuclides perform better in smaller tumours. Furthermore, (177)Lu is not optimal for curing fast-growing tumours. CONCLUSIONS Receptor saturation, specific radiopharmaceutical activities and absorbed doses in the tumour together favour therapy with the CCK2 receptor-binding peptide PP-F11 labelled with (90)Y, despite its longer β-particle range in tissue, certainly for tumours larger than 300 mg. The predicted TCPs are of theoretical nature and need to be compared with the outcome of targeted radionuclide experiments.
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Affiliation(s)
- Mark W Konijnenberg
- Department of Nuclear Medicine, Erasmus MC, PO Box 2040, 3000, CA, Rotterdam, The Netherlands,
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25
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Zaorsky NG, Den RB, Doyle LA, Dicker AP, Hurwitz MD. Combining theoretical potential and advanced technology in high-dose rate brachytherapy boost therapy for prostate cancer. Expert Rev Med Devices 2014; 10:751-63. [PMID: 24195459 DOI: 10.1586/17434440.2013.841347] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
External beam radiation therapy (EBRT) combined with brachytherapy (BT) is an attractive treatment option for select patients with clinically localized prostate cancer. Either low- or high-dose rate BT may be combined with EBRT ('LDR-BT boost,' 'HDR-BT boost,' respectively). HDR-BT boost has potential theoretical benefits over LDR-BT boost or external beam radiation therapy monotherapy in terms of radiobiology, radiophysics and patient convenience. Based on prospective studies in this review, freedom from biochemical failure (FFBF) rates at 5 years for low-, intermediate- and high-risk patients have generally been 85-100%, 68-97%, 63-85%, respectively; late Radiotherapy and Oncology Group Grades 3 and 4 genitourinary and gastrointestinal toxicities are seen in <8% of patients. HDR-BT boost is now a relatively well-established treatment modality for certain intermediate-risk and high-risk prostate cancer patients, though limitations exist in drawing conclusions from the currently published studies.
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Affiliation(s)
- Nicholas G Zaorsky
- Department of Radiation Oncology, Kimmel Cancer Center, Jefferson Medical College of Thomas Jefferson University, Philadelphia, PA, USA
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26
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Zimmerman MA, Huang Q, Li F, Liu X, Li CY. Cell death-stimulated cell proliferation: a tissue regeneration mechanism usurped by tumors during radiotherapy. Semin Radiat Oncol 2014; 23:288-95. [PMID: 24012343 DOI: 10.1016/j.semradonc.2013.05.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The death of all the cancer cells in a tumor is the ultimate goal of cancer therapy. Therefore, much of the current effort in cancer research is focused on activating cellular machinery that facilitates cell death such as factors involved in causing apoptosis. However, recently, a number of studies point to some counterintuitive roles for apoptotic caspases in radiation therapy as well as in tissue regeneration. It appears that a major function of apoptotic caspases is to facilitate tissue regeneration and tumor cell repopulation during cancer therapy. Because tumor cell repopulation has been shown to be important for local tumor relapse, understanding the molecular mechanisms behind tumor repopulation would be important to enhance cancer radiotherapy. In this review, we discuss our current knowledge of these potentially paradigm-changing phenomena and mechanisms in various organisms and their implications on the development of novel cancer therapeutics and strategies.
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Affiliation(s)
- Mary A Zimmerman
- Department of Dermatology, Duke University Medical Center, Durham, NC
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High dose rate brachytherapy boost for prostate cancer: A systematic review. Cancer Treat Rev 2014; 40:414-25. [DOI: 10.1016/j.ctrv.2013.10.006] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Revised: 10/10/2013] [Accepted: 10/16/2013] [Indexed: 11/22/2022]
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Yang J, Yue JB, Liu J, Yu JM. Repopulation of tumor cells during fractionated radiotherapy and detection methods (Review). Oncol Lett 2014; 7:1755-1760. [PMID: 24932228 PMCID: PMC4049693 DOI: 10.3892/ol.2014.1990] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Accepted: 02/26/2014] [Indexed: 12/18/2022] Open
Abstract
Repopulation of tumor cells during radiotherapy is believed to be a significant cause for treatment failure. The phenomenon of tumor repopulation during fractionated radiotherapy was found from clinical observations that identified that the local control rate decreased with a prolonged treatment time. A series of animal experiments with varied overall treatment time and fractionated doses were performed to demonstrate tumor cell repopulation during radiotherapy in various mouse xenograft models. However, conventional detection methods are challenging, as it is difficult to separate viable cells from those destined for apoptosis during fractionated radiotherapy. In essence, the mechanism of tumor repopulation involves the continuing proliferation of clonogenic tumor cells. In vivo imaging, tracking and targeting of the repopulation of these cells has been of clinical interest so as to administer a higher dose to the tumor repopulation regions. Currently, functional imaging methods, including 3'-deoxy-3'-18F-fluorothymidine positron emission tomography (18F-FLT PET), are showing promise in assessing the proliferation activity of tumors in vivo. This review mainly focuses on the phenomenon of tumor repopulation during radiotherapy and its conventional and novel detection methods, particularly on the feasibility of 18F-FLT PET for the detection of tumor-cell repopulation.
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Affiliation(s)
- Jia Yang
- Shandong Cancer Hospital and Institute, Jinan University, Shandong Academy of Medical Sciences, Jinan, Shandong 250117, P.R. China
| | - Jin-Bo Yue
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Jinan, Shandong 250117, P.R. China
| | - Jing Liu
- Graduate Education Centre of Shandong Academy of Medical Sciences, Jinan, Shandong 250117, P.R. China
| | - Jin-Ming Yu
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Jinan, Shandong 250117, P.R. China
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Iuchi T, Hatano K, Kodama T, Sakaida T, Yokoi S, Kawasaki K, Hasegawa Y, Hara R. Phase 2 trial of hypofractionated high-dose intensity modulated radiation therapy with concurrent and adjuvant temozolomide for newly diagnosed glioblastoma. Int J Radiat Oncol Biol Phys 2014; 88:793-800. [PMID: 24495592 DOI: 10.1016/j.ijrobp.2013.12.011] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2013] [Revised: 12/05/2013] [Accepted: 12/10/2013] [Indexed: 01/10/2023]
Abstract
PURPOSE/OBJECTIVES To assess the effect and toxicity of hypofractionated high-dose intensity modulated radiation therapy (IMRT) with concurrent and adjuvant temozolomide (TMZ) in 46 patients with newly diagnosed glioblastoma multiforme (GBM). METHODS AND MATERIALS All patients underwent postsurgical hypofractionated high-dose IMRT. Three layered planning target volumes (PTVs) were contoured. PTV1 was the surgical cavity and residual tumor on T1-weighted magnetic resonance images with 5-mm margins, PTV2 was the area with 15-mm margins surrounding the PTV1, and PTV3 was the high-intensity area on fluid-attenuated inversion recovery images. Irradiation was performed in 8 fractions at total doses of 68, 40, and 32 Gy for PTV1, PTV2, and PTV3, respectively. Concurrent TMZ was given at 75 mg/m(2)/day for 42 consecutive days. Adjuvant TMZ was given at 150 to 200 mg/m(2)/day for 5 days every 28 days. Overall and progression-free survivals were evaluated. RESULTS No acute IMRT-related toxicity was observed. The dominant posttreatment failure pattern was dissemination. During a median follow-up time of 16.3 months (range, 4.3-80.8 months) for all patients and 23.7 months (range, 12.4-80.8 months) for living patients, the median overall survival was 20.0 months after treatment. Radiation necrosis was diagnosed in 20 patients and was observed not only in the high-dose field but also in the subventricular zone (SVZ). Necrosis in the SVZ was significantly correlated with prolonged survival (hazard ratio, 4.08; P=.007) but caused deterioration in the performance status of long-term survivors. CONCLUSIONS Hypofractionated high-dose IMRT with concurrent and adjuvant TMZ altered the dominant failure pattern from localized to disseminated and prolonged the survival of patients with GBM. Necrosis in the SVZ was associated with better patient survival, but the benefit of radiation to this area remains controversial.
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Affiliation(s)
- Toshihiko Iuchi
- Division of Neurological Surgery, Chiba Cancer Center, Chiba, Japan.
| | - Kazuo Hatano
- Division of Radiation Oncology, Chiba Cancer Center, Chiba, Japan
| | - Takashi Kodama
- Division of Radiation Oncology, Chiba Cancer Center, Chiba, Japan
| | - Tsukasa Sakaida
- Division of Neurological Surgery, Chiba Cancer Center, Chiba, Japan
| | - Sana Yokoi
- Division of Gene Diagnosis, Chiba Cancer Center, Chiba, Japan
| | | | - Yuzo Hasegawa
- Division of Neurological Surgery, Chiba Cancer Center, Chiba, Japan
| | - Ryusuke Hara
- Division of Radiation Oncology, Chiba Cancer Center, Chiba, Japan
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Afsharpour H, Walsh S, Collins Fekete CA, Vigneault E, Verhaegen F, Beaulieu L. On the sensitivity of α/β prediction to dose calculation methodology in prostate brachytherapy. Int J Radiat Oncol Biol Phys 2014; 88:345-50. [PMID: 24411607 DOI: 10.1016/j.ijrobp.2013.11.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2013] [Revised: 09/16/2013] [Accepted: 11/01/2013] [Indexed: 01/13/2023]
Abstract
PURPOSE To study the relationship between the accuracy of the dose calculation in brachytherapy and the estimations of the radiosensitivity parameter, α/β, for prostate cancer. METHODS AND MATERIALS In this study, Monte Carlo methods and more specifically the code ALGEBRA was used to produce accurate dose calculations in the case of prostate brachytherapy. Equivalent uniform biologically effective dose was calculated for these dose distributions and was used in an iso-effectiveness relationship with external beam radiation therapy. RESULTS By considering different levels of detail in the calculations, the estimation for the α/β parameter varied from 1.9 to 6.3 Gy, compared with a value of 3.0 Gy suggested by the American Association of Physicists in Medicine Task Group 137. CONCLUSIONS Large variations of the α/β show the sensitivity of this parameter to dose calculation modality. The use of accurate dose calculation engines is critical for better evaluating the biological outcomes of treatments.
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Affiliation(s)
- Hossein Afsharpour
- Centre de Recherche sur le Cancer, Université Laval and Département de Radio-Oncologie, Centre Hospitalier Universitaire de Québec, Québec, QC, Canada; Centre Intégré de Cancérologie de la Montérégie, Hôpital Charles-LeMoyne, Greenfield Park, QC, Canada
| | - Sean Walsh
- Department of Radiation Oncology Maastricht Radiation Oncology (MAASTRO), GROW, University Hospital Maastricht, Maastricht, The Netherlands; Gray Institute for Radiation Oncology and Biology, The University of Oxford, The United Kingdom
| | - Charles-Antoine Collins Fekete
- Centre de Recherche sur le Cancer, Université Laval and Département de Radio-Oncologie, Centre Hospitalier Universitaire de Québec, Québec, QC, Canada
| | - Eric Vigneault
- Centre de Recherche sur le Cancer, Université Laval and Département de Radio-Oncologie, Centre Hospitalier Universitaire de Québec, Québec, QC, Canada
| | - Frank Verhaegen
- Department of Radiation Oncology Maastricht Radiation Oncology (MAASTRO), GROW, University Hospital Maastricht, Maastricht, The Netherlands; Medical Physics Unit, Department of Oncology, McGill University, Montréal, Québec, Canada
| | - Luc Beaulieu
- Centre de Recherche sur le Cancer, Université Laval and Département de Radio-Oncologie, Centre Hospitalier Universitaire de Québec, Québec, QC, Canada.
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Mavroidis P, Ferreira BC, Papanikolaou N, Lopes MDC. Analysis of fractionation correction methodologies for multiple phase treatment plans in radiation therapy. Med Phys 2013; 40:031715. [PMID: 23464310 DOI: 10.1118/1.4792636] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Radiation therapy is often delivered by multiple sequential treatment plans. For an accurate radiobiological evaluation of the overall treatment, fractionation corrections to each dose distribution must be applied before summing the three-dimensional dose matrix of each plan since the simpler approach of performing the fractionation correction to the total dose-volume histograms, obtained by the arithmetical sum of the different plans, becomes inaccurate for more heterogeneous dose patterns. In this study, the differences between these two fractionation correction methods, named here as exact (corrected before) and approximate (after summation), respectively, are assessed for different cancer types. METHODS Prostate, breast, and head and neck (HN) tumor patients were selected to quantify the differences between two fractionation correction methods (the exact vs the approximate). For each cancer type, two different treatment plans were developed using uniform (CRT) and intensity modulated beams (IMRT), respectively. The responses of the target and normal tissue were calculated using the Poisson linear-quadratic-time model and the relative seriality model, respectively. All treatments were radiobiologically evaluated and compared using the complication-free tumor control probability (P+), the biologically effective uniform dose (D) together with common dosimetric criteria. RESULTS For the prostate cancer patient, an underestimation of around 14%-15% in P+ was obtained when the fractionation correction was applied after summation compared to the exact approach due to significant biological and dosimetric variations obtained between the two fractionation correction methods in the involved lymph nodes. For the breast cancer patient, an underestimation of around 3%-4% in the maximum dose in the heart was obtained. Despite the dosimetric differences in this organ, no significant variations were obtained in treatment outcome. For the HN tumor patient, an underestimation of about 5% in treatment outcome was obtained for the CRT plan as a result of an underestimation of the planning target volume control probability by about 10%. An underestimation of about 6% in the complication probability of the right parotid was also obtained. For all the other organs at risk, dosimetric differences of up to 4% were obtained but with no significant impact in the expected clinical outcome. However, for the IMRT plan, an overestimation in P+ of 4.3% was obtained mainly due to an underestimation of the complication probability of the left and right parotids (2.9% and 5.8%, respectively). CONCLUSIONS The use of the exact fractionation correction method, which is applying fractionation correction on the separate dose distributions of a multiple phase treatment before their summation was found to have a significant expected clinical impact. For regions of interest that are irradiated with very heterogeneous dose distributions and significantly different doses per fraction in the different treatment phases, the exact fractionation correction method needs to be applied since a significant underestimation of the true patient outcome can be introduced otherwise.
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Affiliation(s)
- Panayiotis Mavroidis
- Department of Radiation Oncology, University of Texas Health Sciences Center, San Antonio, Texas 78229, USA.
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Zaorsky NG, Ohri N, Showalter TN, Dicker AP, Den RB. Systematic review of hypofractionated radiation therapy for prostate cancer. Cancer Treat Rev 2013; 39:728-36. [PMID: 23453861 DOI: 10.1016/j.ctrv.2013.01.008] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2012] [Revised: 01/28/2013] [Accepted: 01/29/2013] [Indexed: 01/11/2023]
Abstract
Prostate cancer is the second most prevalent solid tumor diagnosed in men in the United States and Western Europe. Conventionally fractionated external beam radiation therapy (1.8-2.0 Gy/fraction) is an established treatment modality for men in all disease risk groups. Emerging evidence from experimental and clinical studies suggests that the α/β ratio for prostate cancer may be as low as 1.5 Gy, which has prompted investigators around the world to explore moderately hypofractionated radiation therapy (2.1-3.5 Gy/fraction). We review the impetus behind moderate hypofractionation and the current clinical evidence supporting moderate hypofractionated radiation therapy for prostate cancer. Although hypofractionated radiation therapy has many theoretical advantages, there is no clear evidence from prospective, randomized, controlled trials showing that hypofractionated schedules have improved outcomes or lower toxicity than conventionally fractionated regimens. Currently, hypofractionated schedules should only be used in the context of clinical trials. High dose rate brachytherapy and stereotactic body radiation therapy (fraction size 3.5 Gy and greater) are alternative approaches to hypofractionation, but are beyond the scope of this report.
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Affiliation(s)
- Nicholas G Zaorsky
- Department of Radiation Oncology, Jefferson Medical College & Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107, USA.
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Zaorsky NG, Studenski MT, Dicker AP, Gomella L, Den RB. Stereotactic body radiation therapy for prostate cancer: is the technology ready to be the standard of care? Cancer Treat Rev 2012; 39:212-8. [PMID: 23218442 DOI: 10.1016/j.ctrv.2012.10.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Revised: 10/19/2012] [Accepted: 10/22/2012] [Indexed: 11/17/2022]
Abstract
Prostate cancer is the second most prevalent solid tumor diagnosed in men in the United States and Western Europe. Stereotactic body radiation therapy (SBRT) is touted as a superior type of external beam radiation therapy (EBRT) for the treatment of various tumors. SBRT developed from the theory that high doses of radiation from brachytherapy implant seeds could be recapitulated from advanced technology of radiation treatment planning and delivery. Moreover, SBRT has been theorized to be advantageous compared to other RT techniques because it has a treatment course shorter than that of conventionally fractionated EBRT (a single session, five days per week, for about two weeks vs. eight weeks), is non-invasive, is more effective at killing tumor cells, and is less likely to cause damage to normal tissue. In areas of the US and Europe where there is limited access to RT centers, SBRT is frequently being used to treat prostate cancer, even though long-term data about its efficacy and safety are not well established. We review the impetus behind SBRT and the current clinical evidence supporting its use for prostate cancer, thus providing oncologists and primary care physicians with an understanding of the continually evolving field of prostate radiation therapy. Studies of SBRT provide encouraging results of biochemical control and late toxicity. However, they are limited by a number of factors, including short follow-up, exclusion of intermediate- and high-risk patients, and relatively small number of patients treated. Currently, SBRT regimens should only be used in the context of clinical trials.
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Affiliation(s)
- Nicholas G Zaorsky
- Department of Radiation Oncology, Kimmel Cancer Center, Jefferson Medical College of Thomas Jefferson University, Philadelphia, PA 19107, USA.
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Diot Q, Kavanagh B, Timmerman R, Miften M. Biological-based optimization and volumetric modulated arc therapy delivery for stereotactic body radiation therapy. Med Phys 2011; 39:237-45. [DOI: 10.1118/1.3668059] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
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Lohse I, Lang S, Hrbacek J, Scheidegger S, Bodis S, Macedo NS, Feng J, Lütolf UM, Zaugg K. Effect of high dose per pulse flattening filter-free beams on cancer cell survival. Radiother Oncol 2011; 101:226-32. [DOI: 10.1016/j.radonc.2011.05.072] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2011] [Revised: 05/22/2011] [Accepted: 05/26/2011] [Indexed: 11/25/2022]
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Wahl RL, Herman JM, Ford E. The promise and pitfalls of positron emission tomography and single-photon emission computed tomography molecular imaging-guided radiation therapy. Semin Radiat Oncol 2011; 21:88-100. [PMID: 21356477 PMCID: PMC4337868 DOI: 10.1016/j.semradonc.2010.11.004] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
External beam radiation therapy procedures have, until recently, been planned almost exclusively using anatomic imaging methods. Molecular imaging using hybrid positron emission tomography (PET)/computed tomography scanning or single-photon emission computed tomography (SPECT) imaging has provided new insights into the precise location of tumors (staging) and the extent and character of the biologically active tumor volume (BTV) and has provided differential response information during and after therapy. In addition to the commonly used radiotracer (18)F-fluoro- 2-deoxyD-glucose (FDG), additional radiopharmaceuticals are being explored to image major physiological processes as well as tumor biological properties, such as hypoxia, proliferation, amino acid accumulation, apoptosis, and receptor expression, providing the potential to target or boost the radiation dose to a biologically relevant region within a tumor, such as the most hypoxic or most proliferative area. Imaging using SPECT agents has furthered the possibility of limiting dose to functional normal tissues. PET can also portray the distribution of particle therapy by displaying activated species in situ. With both PET and SPECT imaging, fundamental physical issues of limited spatial resolution relative to the biological process, partial volume effects for quantification of small volumes, image misregistration, motion, and edge delineation must be carefully considered and can differ by agent or the method applied. Molecular imaging-guided radiation therapy (MIGRT) is a rapidly evolving and promising area of investigation and clinical translation. As MIGRT evolves, evidence must continue to be gathered to support improved clinical outcomes using MIGRT versus purely anatomic approaches.
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Affiliation(s)
- Richard L Wahl
- Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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Preclinical animal research on therapy dosimetry with dual isotopes. Eur J Nucl Med Mol Imaging 2011; 38 Suppl 1:S19-27. [PMID: 21484379 PMCID: PMC3098995 DOI: 10.1007/s00259-011-1774-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2011] [Accepted: 02/22/2011] [Indexed: 11/17/2022]
Abstract
Preclinical research into radionuclide therapies based on radiation dosimetry will enable the use of any LET-equivalent radionuclide. Radiation dose and dose rate have significant influence on dose effects in the tumour depending on its radiation sensitivity, possibilities for repair of sublethal damage, and repopulation during or after the therapy. Models for radiation response of preclinical tumour models after peptide receptor radionuclide therapy based on the linear quadratic model are presented. The accuracy of the radiation dose is very important for observation of dose-effects. Uncertainties in the radiation dose estimation arise from incomplete assay of the kinetics, low accuracy in volume measurements and absorbed dose S-values for stylized models instead of the actual animal geometry. Normal dose uncertainties in the order of 20% might easily make the difference between seeing a dose-effect or missing it altogether. This is true for the theoretical case of a homogeneous tumour type behaving in vivo in the same way as its cells do in vitro. Heterogeneity of tumours induces variations in clonogenic cell density, radiation sensitivity, repopulation capacity and repair kinetics. The influence of these aspects are analysed within the linear quadratic model for tumour response to radionuclide therapy. Preclinical tumour models tend to be less heterogenic than the clinical conditions they should represent. The results of various preclinical radionuclide therapy experiments for peptide receptor radionuclide therapy are compared to the outcome of theoretical models and the influence of increased heterogeneity is analysed when the results of preclinical research is transferred to the clinic. When the radiation dose and radiobiology of the tumour response is known well enough it may be possible to leave the current phenomenological approach in preclinical radionuclide therapy and start basing these experiments on radiation dose. Then the use of a gamma ray-emitting radionuclides for a chemically comparable beta-particle-emitting paired isotope for therapy evaluation would be feasible.
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Nickers P, Hermesse J, Deneufbourg JM, Vanbelle S, Lartigau E. Which α/β ratio and half-time of repair are useful for predicting outcomes in prostate cancer? Radiother Oncol 2010; 97:462-6. [DOI: 10.1016/j.radonc.2010.06.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2009] [Revised: 06/21/2010] [Accepted: 06/22/2010] [Indexed: 11/30/2022]
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Gao M, Mayr NA, Huang Z, Zhang H, Wang JZ. When tumor repopulation starts? The onset time of prostate cancer during radiation therapy. Acta Oncol 2010; 49:1269-75. [PMID: 20712432 DOI: 10.3109/0284186x.2010.509737] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE To analyze published clinical data and provide a preliminary estimate of tumor repopulation rate and its onset time during radiation therapy for prostate cancer. METHODS Data on prostate cancer treated with external beam radiotherapy (EBRT) by Perez et al. (2004), Amdur et al. (1990) and Lai et al. (1991) were analyzed in this study. The stage-combined pelvic control rate from Perez et al. was calculated to be 0.95±0.01, 0.87±0.02, and 0.72±0.04 for patients treated ≤7 weeks, 7.1-9 weeks, and >9 weeks respectively. Based on the Linear-Quadratic model, extended to account for tumor repopulation, the least χ² method was used to fit the clinical data and derive the onset time (T(k)) and effective doubling time (T(d)) for prostate cancer. Similar analysis was performed for the other two datasets. RESULTS Best fit was achieved with onset time T(k)=34±7 days and doubling time T(d)=12±2 days. These parameters were independent of the choice of the α/β values currently published in the literature. Analyses of the other two datasets showed T(k)=42±7 days with T(d)=9 ± 3 days, and T(k)=34±6 days with T(d)=34±5 days, respectively. T(k) was found to be dependent on tumor stage. CONCLUSIONS Consistent values for onset time T(k) were obtained from different datasets, while the range of doubling time T(d) was large. Tumor repopulation starts no later than 58 days (at 90% confidence level) in the course of EBRT for prostate cancer.
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Affiliation(s)
- Mingcheng Gao
- Department of Radiation Oncology, James Cancer Hospital & Solove Research Institute, The Ohio State University, Columbus, 43210, USA.
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Radiobiological evaluation of the influence of dwell time modulation restriction in HIPO optimized HDR prostate brachytherapy implants. J Contemp Brachytherapy 2010; 2:117-128. [PMID: 27853473 PMCID: PMC5104831 DOI: 10.5114/jcb.2010.16923] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2010] [Accepted: 09/01/2010] [Indexed: 12/25/2022] Open
Abstract
Purpose One of the issues that a planner is often facing in HDR brachytherapy is the selective existence of high dose volumes around some few dominating dwell positions. If there is no information available about its necessity (e.g. location of a GTV), then it is reasonable to investigate whether this can be avoided. This effect can be eliminated by limiting the free modulation of the dwell times. HIPO, an inverse treatment plan optimization algorithm, offers this option. In treatment plan optimization there are various methods that try to regularize the variation of dose non-uniformity using purely dosimetric measures. However, although these methods can help in finding a good dose distribution they do not provide any information regarding the expected treatment outcome as described by radiobiology based indices. Material and methods The quality of 12 clinical HDR brachytherapy implants for prostate utilizing HIPO and modulation restriction (MR) has been compared to alternative plans with HIPO and free modulation (without MR). All common dose-volume indices for the prostate and the organs at risk have been considered together with radiobiological measures. The clinical effectiveness of the different dose distributions was investigated by calculating the response probabilities of the tumors and organs-at-risk (OARs) involved in these prostate cancer cases. The radiobiological models used are the Poisson and the relative seriality models. Furthermore, the complication-free tumor control probability, P+ and the biologically effective uniform dose (D¯¯) were used for treatment plan evaluation and comparison. Results Our results demonstrate that HIPO with a modulation restriction value of 0.1-0.2 delivers high quality plans which are practically equivalent to those achieved with free modulation regarding the clinically used dosimetric indices. In the comparison, many of the dosimetric and radiobiological indices showed significantly different results. The modulation restricted clinical plans demonstrated a lower total dwell time by a mean of 1.4% that was proved to be statistically significant (p = 0.002). The HIPO with MR treatment plans produced a higher P+ by 0.5%, which stemmed from a better sparing of the OARs by 1.0%. Conclusions Both the dosimetric and radiobiological comparison shows that the modulation restricted optimization gives on average similar results with the optimization without modulation restriction in the examined clinical cases. Concluding, based on our results, it appears that the applied dwell time regularization technique is expected to introduce a minor improvement in the effectiveness of the optimized HDR dose distributions.
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Marcu L, Bezak E. Modelling of tumour repopulation after chemotherapy. AUSTRALASIAN PHYSICAL & ENGINEERING SCIENCES IN MEDICINE 2010; 33:265-70. [PMID: 20652783 DOI: 10.1007/s13246-010-0026-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2010] [Accepted: 07/12/2010] [Indexed: 11/29/2022]
Abstract
While repopulation is a clinically observed phenomenon after radiotherapy, repopulation of tumour cells between cycles of chemotherapy is usually a neglected factor in cancer treatment. As the effect of both radiotherapy and chemotherapy on tumour cells is the same (attack on cancer cells), the response of the tumour to injury and cell loss from the two treatment methods should be similar, including repopulation. Cell recruitment is known to be a possible mechanism responsible for tumour regrowth after radiotherapy. The literature data regarding mechanisms of repopulation after chemotherapy is very limited. The current paper employs a Monte Carlo modelling approach to implement the pharmacokinetics of a widely used drug (cisplatin) into a previously developed virtual head and neck tumour and to study the effect of cisplatin on tumour regression and regrowth during treatment. The mechanism of cell recruitment was modelled by releasing various percentages (5-50%) of quiescent cells into the mitotic cycle after each chemotherapy cell kill. The onset of repopulation was also simulated, with both immediate onset and late onset of cell recruitment. Repopulation during chemotherapy, if occurring, is a highly potent phenomenon, similar to drug resistance, therefore it should not be neglected during treatment.
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Affiliation(s)
- Loredana Marcu
- School of Chemistry and Physics, University of Adelaide, Adelaide, Australia.
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Biologically Effective Dose (BED) Correlation With Biochemical Control After Low–Dose Rate Prostate Brachytherapy for Clinically Low-Risk Prostate Cancer. Int J Radiat Oncol Biol Phys 2010; 77:139-46. [DOI: 10.1016/j.ijrobp.2009.04.052] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2009] [Revised: 04/08/2009] [Accepted: 04/22/2009] [Indexed: 11/23/2022]
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Altman MB, Stinauer MA, Javier D, Smith BD, Herman LC, Pytynia ML, Aydogan B, Pelizzari CA, Chmura SJ, Roeske JC. Validation of temporal optimization effects for a single fraction of radiation in vitro. Int J Radiat Oncol Biol Phys 2009; 75:1240-6. [PMID: 19857787 DOI: 10.1016/j.ijrobp.2009.06.076] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2009] [Revised: 05/06/2009] [Accepted: 06/18/2009] [Indexed: 10/20/2022]
Abstract
PURPOSE To experimentally validate how temporal modification of the applied dose pattern within a single fraction of radiation therapy affects cell survival. METHOD AND MATERIALS Using the linear-quadratic model, we have previously demonstrated that the greatest difference in cell survival results from comparing a temporal dose pattern delivering the highest doses during the middle of a fraction and the lowest at the beginning and end ("Triangle") to one with the lowest doses at the middle and the highest at the beginning and end ("V-shaped"). Also, these differences would be greatest in situations with low alpha/beta and large dose/fraction and fraction length. Two low (WiDr, PC-3) and one high (SQ-20B) alpha/beta cell lines were irradiated in six-well plates with 900 cGy over 20 min (900 cGy/20 min), one each with a Triangle and V-shaped dose pattern. WiDr cells were subjected to the same experiments with first 180 cGy/20 min, then 900 cGy/5 min. Cell survival was assessed using the clonogenic assay. RESULTS At 900 cGy/20 min, irradiation with a V-shaped pattern resulted in an increased survival compared with use of a Triangle pattern of 21.2% for WiDr (p < 0.01), 18.6% for PC-3 (p < 0.025), and 4.7% for SQ-20B cells (p > 0.05). For WiDr cells at 180 cGy/20 min, this increase reduced to 2.7% (p > 0.05) and to -0.8% (p > 0.05) at 900 cGy/5 min. CONCLUSIONS These results verify the assertions of the modeling study in vitro, and imply that the temporal pattern of applied dose should be considered in treatment planning and delivery.
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Affiliation(s)
- Michael B Altman
- Department of Radiation and Cellular Oncology, University of Chicago, Chicago, IL 60657, USA.
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Røe K, Muren LP, Rørvik J, Olsen DR, Dahl O, Bakke A, Malinen E. Dynamic contrast enhanced magnetic resonance imaging of bladder cancer and implications for biological image-adapted radiotherapy. Acta Oncol 2009; 47:1257-64. [PMID: 18618299 DOI: 10.1080/02841860802244174] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
PURPOSE To assess the role of image parameters derived from dynamic contrast enhanced magnetic resonance imaging (DCEMRI) in bladder cancer staging, and to investigate the potential use of such parameter images in biological image-adapted radiotherapy (RT). MATERIALS AND METHODS High-resolution volumetric interpolated breath-hold (VIBE) DCEMRI of 26 patients diagnosed with bladder cancer was performed. DCEMRI parameters derived from tumor and muscle contrast uptake curves were extracted and subjected to correlation analysis with tumor volume as well as clinical, pathological, histological and T2-weighted MR tumor stage. For parameters showing a significant correlation with tumor stage, 3D malignancy maps were generated. As an initial step towards delivery of biologically adapted intensity modulated radiotherapy (IMRT) it was hypothesized that the malignancy map could be used as a RT dose prescription map. Simulating IMRT delivery with multi-leaf collimators (MLCs), idealized dose distributions, constituted by dose cubes, were adapted to the prescription map. The size of the dose cubes were varied to mimic MLCs of varying leaf width. The difference between the adapted and prescribed dose distributions was quantified by the root mean square deviation (RMSD). RESULTS No significant relationships were found between tumor volume and extracted DCEMRI parameters. The normalized area between tumor and muscle contrast uptake curves (nABC) evaluated from 0-180 seconds (nABC(180)) and 0-480 s (nABC(480)) correlated significantly with tumor stage (p=0.047 and p=0.035, respectively). Dose prescription maps for 10 patients were generated from the nABC(480). The RMSD between the prescribed and adapted dose distribution decreased with decreasing size of the dose cubes. Large interpatient variations in the RMSD and in the dependence of the RMSD on different dose cube sizes were found. CONCLUSIONS The nABC(180) and nABC(480) may provide added value in staging of bladder cancer. High-resolution IMRT is required for some patients for optimal adapted RT.
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Chen GP, Ahunbay E, Schultz C, Li XA. Development of an inverse optimization package to plan nonuniform dose distributions based on spatially inhomogeneous radiosensitivity extracted from biological images. Med Phys 2007; 34:1198-205. [PMID: 17500451 DOI: 10.1118/1.2710948] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
An inverse optimization package which is capable of generating nonuniform dose distribution with subregional dose escalation is developed to achieve maximum equivalent uniform dose (EUD) for target while keeping the critical structure doses as low as possible. Relative cerebral blood volume (rCBV) maps obtained with a dynamic susceptibility contrast-enhanced MRI technique were used to delineate spatial radiosensitivity distributions. The voxel rCBV was converted to voxel radiosensitivity parameters (e.g., alpha and alpha/beta) based on previously reported correlations between rCBV, tumor grade, and radiosensitivity. A software package, DOSEPAINT, developed using MATLAB, optimizes the beamlet weights to achieve maximum EUD for target while limiting doses to critical structures. Using DOSEPAINT, we have generated nonuniform 3D-dose distributions for selected patient cases. Depending on the variation of the pixel radiosensitivity, the subregional dose escalation can be as high as 35% of the uniform dose as planned conventionally. The target dose escalation comes from both the inhomogeneous radiosensitivities and the elimination of integral target dose constraint. The target EUDs are found to be higher than those for the uniform dose planned ignoring the spatial inhomogeneous radiosensitivity. The EUDs for organs at risk are found to be approximately equal to or lower than those for the uniform dose plans. In conclusion, we have developed a package that is capable of generating nonuniform dose distributions optimized for spatially inhomogeneous radiosensitivity. Subregional dose escalation may lead to increased treatment effectiveness as indicated by higher EUDs. The current development will impact biological image guided radiotherapy.
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Affiliation(s)
- Guang-Pei Chen
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
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Koukourakis MI, Abatzoglou I, Touloupidis S, Manavis I. Biological dose volume histograms during conformal hypofractionated accelerated radiotherapy for prostate cancer. Med Phys 2006; 34:76-80. [PMID: 17278492 DOI: 10.1118/1.2401655] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Radiobiological data suggest that prostate cancer has a low alpha/beta ratio. Large radiotherapy fractions may, therefore, prove more efficacious than standard radiotherapy, while radiotherapy acceleration should further improve control rates. This study describes the radiobiology of a conformal hypofractionated accelerated radiotherapy scheme for the treatment of high risk prostate cancer. Anteroposterior fields to the pelvis deliver a daily dose of 2.7 Gy, while lateral fields confined to the prostate and seminal vesicles deliver an additional daily dose of 0.7 Gy. Radiotherapy is accomplished within 19 days (15 fractions). Dose volume histograms, calculated for tissue specific alpha/beta ratios and time factors, predict a high biological dose to the prostate and seminal vesicles (77-93 Gy). The biological dose to normal pelvic tissues is maintained at standard levels. Radiobiological dosimetry suggests that, using hypofractionated and accelerated radiotherapy, high biological radiation dose can be given to the prostate without overdosing normal tissues.
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Affiliation(s)
- Michael I Koukourakis
- Department of Radiotherapy-Oncology, Democritus University of Thrace, University Hospital of Alexandroupolis, Alexandroupolis, 68100 Greece.
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Altman MB, Chmura SJ, Deasy JO, Roeske JC. Optimization of the temporal pattern of radiation: An IMRT based study. Int J Radiat Oncol Biol Phys 2006; 66:898-905. [PMID: 17011463 DOI: 10.1016/j.ijrobp.2006.07.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2006] [Revised: 07/07/2006] [Accepted: 07/10/2006] [Indexed: 10/24/2022]
Abstract
PURPOSE To investigate how the temporal pattern of dose applied during a single-intensity modulated radiation therapy (IMRT) fraction can be arranged to maximize or minimize cell kill. METHODS AND MATERIALS Using the linear-quadratic repair-time model and a simplified IMRT delivery pattern model, the surviving fraction of cells for a single fraction was calculated for all permutations of the dose delivery pattern for an array of clinically based IMRT cases. Maximization of cell kill was achieved by concentrating the highest doses in the middle of a fraction, while minimization was achieved by spreading the highest doses between the beginning and end. The percent difference between maximum and minimum cell kill (%Diff(min/max)) and the difference between maximum and minimum total doses normalized to 2 Gy/fx (deltaNTD(2 Gy)) was calculated for varying fraction durations (T), alpha/beta ratios, and doses/fx. RESULTS %Diff(min/max) and deltaNTD(2 Gy) both increased with increasing T and with decreasing alpha/beta. The largest increases occurred with dose/fx. With alpha/beta = 3 Gy and 30 min/fx, %Diff(min/max) ranged from 2.7-5.3% for 2 Gy/fx to 48.6-74.1% for 10 Gy/fx, whereas deltaNTD(2 Gy) ranged from 1.2 Gy-2.4 Gy for 30 fractions of 2 Gy/fx to 2.3-4.8 Gy for 2 fractions of 10.84 Gy/fx. Using alpha/beta = 1.5 Gy, an analysis of prostate hypofractionation schemes yielded differences in clinical outcome based on the pattern of applied dose ranging from 3.2%-6.1% of the treated population. CONCLUSIONS Rearrangement of the temporal pattern of dose for a single IMRT fraction could be used to optimize cell kill and to directly, though modestly, affect treatment outcome.
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Affiliation(s)
- Michael B Altman
- Department of Radiation and Cellular Oncology, University of Chicago, Chicago, IL 60637, USA
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Chen J, Morin O, Aubin M, Bucci MK, Chuang CF, Pouliot J. Dose-guided radiation therapy with megavoltage cone-beam CT. Br J Radiol 2006; 79 Spec No 1:S87-98. [PMID: 16980688 DOI: 10.1259/bjr/60612178] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Recent advances in fractionated external beam radiation therapy have increased our ability to deliver radiation doses that conform more tightly to the tumour volume. The steeper dose gradients delivered in these treatments make it increasingly important to set precisely the positions of the patient and the internal organs. For this reason, considerable research now focuses on methods using three-dimensional images of the patient on the treatment table to adapt either the patient position or the treatment plan, to account for variable organ locations. In this article, we briefly review the different adaptive methods being explored and discuss a proposed dose-guided radiation therapy strategy that adapts the treatment for future fractions to compensate for dosimetric errors from past fractions. The main component of this strategy is a procedure to reconstruct the dose delivered to the patient based on treatment-time portal images and pre-treatment megavoltage cone-beam computed tomography (MV CBCT) images of the patient. We describe the work to date performed to develop our dose reconstruction procedure, including the implementation of a MV CBCT system for clinical use, experiments performed to calibrate MV CBCT for electron density and to use the calibrated MV CBCT for dose calculations, and the dosimetric calibration of the portal imager. We also present an example of a reconstructed patient dose using a preliminary reconstruction program and discuss the technical challenges that remain to full implementation of dose reconstruction and dose-guided therapy.
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Affiliation(s)
- J Chen
- UCSF Comprehensive Cancer Center, Department of Radiation Oncology, University of California San Francisco, 1600 Divisadero Street, Suite H1031, San Francisco, CA 94143, USA
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Wang JZ, Mayr NA, Nag S, Montebello J, Gupta N, Samsami N, Kanellitsas C. Effect of edema, relative biological effectiveness, and dose heterogeneity on prostate brachytherapya). Med Phys 2006; 33:1025-32. [PMID: 16696479 DOI: 10.1118/1.2181294] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Many factors influence response in low-dose-rate (LDR) brachytherapy of prostate cancer. Among them, edema, relative biological effectiveness (RBE), and dose heterogeneity have not been fully modeled previously. In this work, the generalized linear-quadratic (LQ) model, extended to account for the effects of edema, RBE, and dose heterogeneity, was used to assess these factors and their combination effect. Published clinical data have shown that prostate edema after seed implant has a magnitude (ratio of post- to preimplant volume) of 1.3-2.0 and resolves exponentially with a half-life of 4-25 days over the duration of the implant dose delivery. Based on these parameters and a representative dose-volume histogram (DVH), we investigated the influence of edema on the implant dose distribution. The LQ parameters (alpha=0.15 Gy(-1) and alpha/beta=3.1 Gy) determined in earlier studies were used to calculate the equivalent uniform dose in 2 Gy fractions (EUD2) with respect to three effects: edema, RBE, and dose heterogeneity for 125I and 103Pd implants. The EUD2 analysis shows a negative effect of edema and dose heterogeneity on tumor cell killing because the prostate edema degrades the dose coverage to tumor target. For the representative DVH, the V100 (volume covered by 100% of prescription dose) decreases from 93% to 91% and 86%, and the D90 (dose covering 90% of target volume) decrease from 107% to 102% and 94% of prescription dose for 125I and 103Pd implants, respectively. Conversely, the RBE effect of LDR brachytherapy [versus external-beam radiotherapy (EBRT) and high-dose-rate (HDR) brachytherapy] enhances dose effect on tumor cell kill. In order to balance the negative effects of edema and dose heterogeneity, the RBE of prostate brachytherapy was determined to be approximately 1.2-1.4 for 125I and 1.3-1.6 for 103Pd implants. These RBE values are consistent with the RBE data published in the literature. These results may explain why in earlier modeling studies, when the effects of edema, dose heterogeneity, and RBE were all ignored simultaneously, prostate LDR brachytherapy was reported to show an overall similar dose effect as EBRT and HDR brachytherapy, which are independent of edema and RBE effects and have a better dose coverage.
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Affiliation(s)
- Jian Z Wang
- Department of Radiation Medicine, The Ohio State University, Columbus, Ohio 43210, USA.
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Stock RG, Stone NN, Cesaretti JA, Rosenstein BS. Biologically effective dose values for prostate brachytherapy: Effects on PSA failure and posttreatment biopsy results. Int J Radiat Oncol Biol Phys 2006; 64:527-33. [PMID: 16242258 DOI: 10.1016/j.ijrobp.2005.07.981] [Citation(s) in RCA: 206] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2005] [Revised: 07/18/2005] [Accepted: 07/19/2005] [Indexed: 11/24/2022]
Abstract
PURPOSE To analyze the effect of biologically effective dose (BED) values on prostate-specific antigen (PSA) failure and posttreatment biopsy. METHODS AND MATERIALS From 1990 to 2003, 1,377 patients had prostate brachytherapy alone (I-125 or Pd-103) (571), hormonal and brachytherapy (371), and trimodality therapy (hormonal, implant, and external beam) (435). Dose was defined as the D90 (dose delivered to 90% of the gland from the dose-volume histogram). RESULTS Freedom from PSA failure (FFPF) at 10 years was 87%. The 10-year FFPF for BED<100, >100-120, >120-140, >140-160, <160-180, >180-200, and >200 were 46%, 68%, 81%, 85.5%, 90%, 90%, and 92%, respectively (p<0.0001). BED and Gleason score had the greatest effect, with p values of p<0.0001 in multivariate analysis. Posttreatment positive biopsy rate was 7% (31/446). The positive biopsy rates for BED<or=100, >100-120, >120-140, >140-160, >160-180, >180-200, and >200 were 24% (8/33), 15% (3/20), 6% (2/33), 6% (3/52), 7% (6/82), 1% (1/72), and 3% (4/131), respectively (p<0.0001). BED was the most significant predictor of biopsy outcome in multivariate analysis (p=0.006). CONCLUSIONS Biologically effective dose equations provide a method of comparing different isotopes and combined therapies in the brachytherapy management of prostate cancer. The effects of BED on FFPF and posttreatment biopsy demonstrate a strong dose-response relationship.
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Affiliation(s)
- Richard G Stock
- Department of Radiation Oncology, Mount Sinai School of Medicine, New York, NY 10029, USA.
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