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Shen H, Wang H, Mo J, Zhang J, Xu C, Sun F, Ou X, Zhu X, Du L, Ju H, Ye R, Shi G, Kwok RT, Lam JW, Sun J, Zhang T, Ning S, Tang BZ. Unrestricted molecular motions enable mild photothermy for recurrence-resistant FLASH antitumor radiotherapy. Bioact Mater 2024; 37:299-312. [PMID: 38694765 PMCID: PMC11061705 DOI: 10.1016/j.bioactmat.2024.03.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 03/05/2024] [Accepted: 03/15/2024] [Indexed: 05/04/2024] Open
Abstract
Ultrahigh dose-rate (FLASH) radiotherapy is an emerging technology with excellent therapeutic effects and low biological toxicity. However, tumor recurrence largely impede the effectiveness of FLASH therapy. Overcoming tumor recurrence is crucial for practical FLASH applications. Here, we prepared an agarose-based thermosensitive hydrogel containing a mild photothermal agent (TPE-BBT) and a glutaminase inhibitor (CB-839). Within nanoparticles, TPE-BBT exhibits aggregation-induced emission peaked at 900 nm, while the unrestricted molecular motions endow TPE-BBT with a mild photothermy generation ability. The balanced photothermal effect and photoluminescence are ideal for phototheranostics. Upon 660-nm laser irradiation, the temperature-rising effect softens and hydrolyzes the hydrogel to release TPE-BBT and CB-839 into the tumor site for concurrent mild photothermal therapy and chemotherapy, jointly inhibiting homologous recombination repair of DNA. The enhanced FLASH radiotherapy efficiently kills the tumor tissue without recurrence and obvious systematic toxicity. This work deciphers the unrestricted molecular motions in bright organic fluorophores as a source of photothermy, and provides novel recurrence-resistant radiotherapy without adverse side effects.
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Affiliation(s)
- Hanchen Shen
- Affiliated Cancer Hospital & Institute of Guangzhou Medical University, School of Biomedical Engineering, Guangzhou Medical University, Guangzhou, China
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Division of Life Science, and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
| | - Hongbin Wang
- The Second Ward of Breast Surgery, Cancer Hospital Affiliated to Harbin Medical University, Heilongjiang, 150081, China
| | - Jianlan Mo
- Department of Anesthesiology, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Jianyu Zhang
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Division of Life Science, and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
| | - Changhuo Xu
- MOE Frontiers Science Center for Precision Oncology, Faculty of Health Sciences, University of Macau, Macao, China
| | - Feiyi Sun
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Division of Life Science, and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
| | - Xinwen Ou
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Division of Life Science, and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
| | - Xinyan Zhu
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Division of Life Science, and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
| | - Lidong Du
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Division of Life Science, and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
- MOE Frontiers Science Center for Precision Oncology, Faculty of Health Sciences, University of Macau, Macao, China
| | - Huaqiang Ju
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Division of Life Science, and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
| | - Ruquan Ye
- Department of Chemistry, State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong, China
| | - Guangfu Shi
- Department of Breast Surgery, The Second Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Ryan T.K. Kwok
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Division of Life Science, and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
| | - Jacky W.Y. Lam
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Division of Life Science, and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
| | - Jianwei Sun
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Division of Life Science, and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
| | - Tianfu Zhang
- Affiliated Cancer Hospital & Institute of Guangzhou Medical University, School of Biomedical Engineering, Guangzhou Medical University, Guangzhou, China
| | - Shipeng Ning
- Department of Breast Surgery, The Second Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Ben Zhong Tang
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Division of Life Science, and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
- School of Science and Engineering, Shenzhen Institute of Aggregate Science and Technology, The Chinese University of Hong Kong, Shenzhen (CUHK-Shenzhen), Guangdong, 518172, China
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Orobeti S, Sima LE, Porosnicu I, Diplasu C, Giubega G, Cojocaru G, Ungureanu R, Dobrea C, Serbanescu M, Mihalcea A, Stancu E, Staicu CE, Jipa F, Bran A, Axente E, Sandel S, Zamfirescu M, Tiseanu I, Sima F. First in vitro cell co-culture experiments using laser-induced high-energy electron FLASH irradiation for the development of anti-cancer therapeutic strategies. Sci Rep 2024; 14:14866. [PMID: 38937505 PMCID: PMC11211417 DOI: 10.1038/s41598-024-65137-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Accepted: 06/17/2024] [Indexed: 06/29/2024] Open
Abstract
Radiation delivery at ultrahigh dose rates (UHDRs) has potential for use as a new anticancer therapeutic strategy. The FLASH effect induced by UHDR irradiation has been shown to maintain antitumour efficacy with a reduction in normal tissue toxicity; however, the FLASH effect has been difficult to demonstrate in vitro. The objective to demonstrate the FLASH effect in vitro is challenging, aiming to reveal a differential response between cancer and normal cells to further identify cell molecular mechanisms. New high-intensity petawatt laser-driven accelerators can deliver very high-energy electrons (VHEEs) at dose rates as high as 1013 Gy/s in very short pulses (10-13 s). Here, we present the first in vitro experiments carried out on cancer cells and normal non-transformed cells concurrently exposed to laser-plasma accelerated (LPA) electrons. Specifically, melanoma cancer cells and normal melanocyte co-cultures grown on chamber slides were simultaneously irradiated with LPA electrons. A non-uniform dose distribution on the cell cultures was revealed by Gafchromic films placed behind the chamber slide supporting the cells. In parallel experiments, cell co-cultures were exposed to pulsed X-ray irradiation, which served as positive controls for radiation-induced nuclear DNA double-strand breaks. By measuring the impact on discrete areas of the cell monolayers, the greatest proportion of the damaged DNA-containing nuclei was attained by the LPA electrons at a cumulative dose one order of magnitude lower than the dose obtained by pulsed X-ray irradiation. Interestingly, in certain discrete areas, we observed that LPA electron exposure had a different effect on the DNA damage in healthy normal human epidermal melanocyte (NHEM) cells than in A375 melanoma cells; here, the normal cells were less affected by the LPA exposure than cancer cells. This result is the first in vitro demonstration of a differential response of tumour and normal cells exposed to FLASH irradiation and may contribute to the development of new cell culture strategies to explore fundamental understanding of FLASH-induced cell effect.
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Affiliation(s)
- Stefana Orobeti
- National Institute for Laser, Plasma and Radiation Physics (INFLPR), 409 Atomistilor Street, RO-077125, Magurele, Romania
- Department of Molecular Cell Biology, Institute of Biochemistry of the Romanian Academy, 296 Splaiul Independentei, 060031, Bucharest, Romania
| | - Livia Elena Sima
- Department of Molecular Cell Biology, Institute of Biochemistry of the Romanian Academy, 296 Splaiul Independentei, 060031, Bucharest, Romania
| | - Ioana Porosnicu
- National Institute for Laser, Plasma and Radiation Physics (INFLPR), 409 Atomistilor Street, RO-077125, Magurele, Romania
| | - Constantin Diplasu
- National Institute for Laser, Plasma and Radiation Physics (INFLPR), 409 Atomistilor Street, RO-077125, Magurele, Romania
| | - Georgiana Giubega
- National Institute for Laser, Plasma and Radiation Physics (INFLPR), 409 Atomistilor Street, RO-077125, Magurele, Romania
| | - Gabriel Cojocaru
- National Institute for Laser, Plasma and Radiation Physics (INFLPR), 409 Atomistilor Street, RO-077125, Magurele, Romania
| | - Razvan Ungureanu
- National Institute for Laser, Plasma and Radiation Physics (INFLPR), 409 Atomistilor Street, RO-077125, Magurele, Romania
| | - Cosmin Dobrea
- National Institute for Laser, Plasma and Radiation Physics (INFLPR), 409 Atomistilor Street, RO-077125, Magurele, Romania
| | - Mihai Serbanescu
- National Institute for Laser, Plasma and Radiation Physics (INFLPR), 409 Atomistilor Street, RO-077125, Magurele, Romania
| | - Alexandru Mihalcea
- National Institute for Laser, Plasma and Radiation Physics (INFLPR), 409 Atomistilor Street, RO-077125, Magurele, Romania
| | - Elena Stancu
- National Institute for Laser, Plasma and Radiation Physics (INFLPR), 409 Atomistilor Street, RO-077125, Magurele, Romania
| | - Cristina Elena Staicu
- National Institute for Laser, Plasma and Radiation Physics (INFLPR), 409 Atomistilor Street, RO-077125, Magurele, Romania
| | - Florin Jipa
- National Institute for Laser, Plasma and Radiation Physics (INFLPR), 409 Atomistilor Street, RO-077125, Magurele, Romania
| | - Alexandra Bran
- National Institute for Laser, Plasma and Radiation Physics (INFLPR), 409 Atomistilor Street, RO-077125, Magurele, Romania
| | - Emanuel Axente
- National Institute for Laser, Plasma and Radiation Physics (INFLPR), 409 Atomistilor Street, RO-077125, Magurele, Romania
| | - Simion Sandel
- National Institute for Laser, Plasma and Radiation Physics (INFLPR), 409 Atomistilor Street, RO-077125, Magurele, Romania
| | - Marian Zamfirescu
- National Institute for Laser, Plasma and Radiation Physics (INFLPR), 409 Atomistilor Street, RO-077125, Magurele, Romania
| | - Ion Tiseanu
- National Institute for Laser, Plasma and Radiation Physics (INFLPR), 409 Atomistilor Street, RO-077125, Magurele, Romania
| | - Felix Sima
- National Institute for Laser, Plasma and Radiation Physics (INFLPR), 409 Atomistilor Street, RO-077125, Magurele, Romania.
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Yan O, Wang S, Wang Q, Wang X. FLASH Radiotherapy: Mechanisms of Biological Effects and the Therapeutic Potential in Cancer. Biomolecules 2024; 14:754. [PMID: 39062469 PMCID: PMC11275005 DOI: 10.3390/biom14070754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2024] [Revised: 06/11/2024] [Accepted: 06/15/2024] [Indexed: 07/28/2024] Open
Abstract
Radiotherapy is an important treatment for many unresectable advanced malignant tumors, and radiotherapy-associated inflammatory reactions to radiation and other toxic side effects are significant reasons which reduce the quality of life and survival of patients. FLASH-radiotherapy (FLASH-RT), a prominent topic in recent radiation therapy research, is an ultra-high dose rate treatment known for significantly reducing therapy time while effectively targeting tumors. This approach minimizes radiation side effects on at-risk organs and maximally protects surrounding healthy tissues. Despite decades of preclinical exploration and some notable achievements, the mechanisms behind FLASH effects remain debated. Standardization is still required for the type of FLASH-RT rays and dose patterns. This review addresses the current state of FLASH-RT research, summarizing the biological mechanisms behind the FLASH effect. Additionally, it examines the impact of FLASH-RT on immune cells, cytokines, and the tumor immune microenvironment. Lastly, this review will discuss beam characteristics, potential clinical applications, and the relevance and applicability of FLASH-RT in treating advanced cancers.
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Affiliation(s)
| | | | | | - Xin Wang
- Division of Abdominal Tumor Multimodality Treatment, Department of Radiation Oncology, Cancer Center, West China Hospital of Sichuan University, Chengdu 610041, China; (O.Y.); (S.W.); (Q.W.)
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Cengel KA, Kim MM, Diffenderfer ES, Busch TM. FLASH Radiotherapy: What Can FLASH's Ultra High Dose Rate Offer to the Treatment of Patients With Sarcoma? Semin Radiat Oncol 2024; 34:218-228. [PMID: 38508786 DOI: 10.1016/j.semradonc.2024.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/22/2024]
Abstract
FLASH is an emerging treatment paradigm in radiotherapy (RT) that utilizes ultra-high dose rates (UHDR; >40 Gy)/s) of radiation delivery. Developing advances in technology support the delivery of UHDR using electron and proton systems, as well as some ion beam units (eg, carbon ions), while methods to achieve UHDR with photons are under investigation. The major advantage of FLASH RT is its ability to increase the therapeutic index for RT by shifting the dose response curve for normal tissue toxicity to higher doses. Numerous preclinical studies have been conducted to date on FLASH RT for murine sarcomas, alongside the investigation of its effects on relevant normal tissues of skin, muscle, and bone. The tumor control achieved by FLASH RT of sarcoma models is indistinguishable from that attained by treatment with standard RT to the same total dose. FLASH's high dose rates are able to mitigate the severity or incidence of RT side effects on normal tissues as evaluated by endpoints ranging from functional sparing to histological damage. Large animal studies and clinical trials of canine patients show evidence of skin sparing by FLASH vs. standard RT, but also caution against delivery of high single doses with FLASH that exceed those safely applied with standard RT. Also, a human clinical trial has shown that FLASH RT can be delivered safely to bone metastasis. Thus, data to date support continued investigations of clinical translation of FLASH RT for the treatment of patients with sarcoma. Toward this purpose, hypofractionated irradiation schemes are being investigated for FLASH effects on sarcoma and relevant normal tissues.
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Affiliation(s)
- Keith A Cengel
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania..
| | - Michele M Kim
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Eric S Diffenderfer
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Theresa M Busch
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
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Ramesh P, Ruan D, Liu SJ, Seo Y, Braunstein S, Sheng K. Hypoxia-informed RBE-weighted beam orientation optimization for intensity modulated proton therapy. Med Phys 2024; 51:2320-2333. [PMID: 38345134 PMCID: PMC10940223 DOI: 10.1002/mp.16978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 01/30/2024] [Accepted: 01/30/2024] [Indexed: 03/13/2024] Open
Abstract
BACKGROUND Variable relative biological effectiveness (RBE) models in treatment planning have been proposed to optimize the therapeutic ratio of proton therapy. It has been reported that proton RBE decreases with increasing tumor oxygen level, offering an opportunity to address hypoxia-related radioresistance with RBE-weighted optimization. PURPOSE Here, we obtain a voxel-level estimation of partial oxygen pressure to weigh RBE values in a single biologically informed beam orientation optimization (BOO) algorithm. METHODS Three glioblastoma patients with [18 F]-fluoromisonidazole (FMISO)-PET/CT images were selected from the institutional database. Oxygen values were derived from tracer uptake using a nonlinear least squares curve fitting. McNamara RBE, calculated from proton dose, was then weighed using oxygen enhancement ratios (OER) for each voxel and incorporated into the dose fidelity term of the BOO algorithm. The nonlinear optimization problem was solved using a split-Bregman approach, with FISTA as the solver. The proposed hypoxia informed RBE-weighted method (HypRBE) was compared to dose fidelity terms using the constant RBE of 1.1 (cRBE) and the normoxic McNamara RBE model (RegRBE). Tumor homogeneity index (HI), maximum biological dose (Dmax), and D95%, as well as OAR therapeutic index (TI = gEUDCTV /gEUDOAR ) were evaluated along with worst-case statistics after normalization to normal tissue isotoxicity. RESULTS Compared to [cRBE, RegRBE], HypRBE increased tumor HI, Dmax, and D95% across all plans by on average [31.3%, 31.8%], [48.6%, 27.1%], and [50.4%, 23.8%], respectively. In the worst-case scenario, the parameters increase on average by [12.5%, 14.7%], [7.3%,-8.9%], and [22.3%, 2.1%]. Despite increased OAR Dmean and Dmax by [8.0%, 3.0%] and [13.1%, -0.1%], HypRBE increased average TI by [22.0%, 21.1%]. Worst-case OAR Dmean, Dmax, and TI worsened by [17.9%, 4.3%], [24.5%, -1.2%], and [9.6%, 10.5%], but in the best cases, HypRBE escalates tumor coverage significantly without compromising OAR dose, increasing the therapeutic ratio. CONCLUSIONS We have developed an optimization algorithm whose dose fidelity term accounts for hypoxia-informed RBE values. We have shown that HypRBE selects bE:\Alok\aaeams better suited to deliver high physical dose to low RBE, hypoxic tumor regions while sparing the radiosensitive normal tissue.
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Affiliation(s)
- Pavitra Ramesh
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Dan Ruan
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - S. John Liu
- Department of Radiation Oncology, University of California San Francisco, San Francisco, CA 94143, USA
| | - Youngho Seo
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA 94143, USA
| | - Steve Braunstein
- Department of Radiation Oncology, University of California San Francisco, San Francisco, CA 94143, USA
| | - Ke Sheng
- Department of Radiation Oncology, University of California San Francisco, San Francisco, CA 94143, USA
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Borghini A, Labate L, Piccinini S, Panaino CMV, Andreassi MG, Gizzi LA. FLASH Radiotherapy: Expectations, Challenges, and Current Knowledge. Int J Mol Sci 2024; 25:2546. [PMID: 38473799 DOI: 10.3390/ijms25052546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Revised: 02/12/2024] [Accepted: 02/19/2024] [Indexed: 03/14/2024] Open
Abstract
Major strides have been made in the development of FLASH radiotherapy (FLASH RT) in the last ten years, but there are still many obstacles to overcome for transfer to the clinic to become a reality. Although preclinical and first-in-human clinical evidence suggests that ultra-high dose rates (UHDRs) induce a sparing effect in normal tissue without modifying the therapeutic effect on the tumor, successful clinical translation of FLASH-RT depends on a better understanding of the biological mechanisms underpinning the sparing effect. Suitable in vitro studies are required to fully understand the radiobiological mechanisms associated with UHDRs. From a technical point of view, it is also crucial to develop optimal technologies in terms of beam irradiation parameters for producing FLASH conditions. This review provides an overview of the research progress of FLASH RT and discusses the potential challenges to be faced before its clinical application. We critically summarize the preclinical evidence and in vitro studies on DNA damage following UHDR irradiation. We also highlight the ongoing developments of technologies for delivering FLASH-compliant beams, with a focus on laser-driven plasma accelerators suitable for performing basic radiobiological research on the UHDR effects.
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Affiliation(s)
| | - Luca Labate
- Intense Laser Irradiation Laboratory (ILIL), CNR Istituto Nazionale di Ottica, 56124 Pisa, Italy
| | - Simona Piccinini
- Intense Laser Irradiation Laboratory (ILIL), CNR Istituto Nazionale di Ottica, 56124 Pisa, Italy
| | | | | | - Leonida Antonio Gizzi
- Intense Laser Irradiation Laboratory (ILIL), CNR Istituto Nazionale di Ottica, 56124 Pisa, Italy
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Byrne KE, Poirier Y, Xu J, Gerry A, Foley MJ, Jackson IL, Sawant A, Jiang K. Technical note: A small animal irradiation platform for investigating the dependence of the FLASH effect on electron beam parameters. Med Phys 2024; 51:1421-1432. [PMID: 38207016 DOI: 10.1002/mp.16909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 10/30/2023] [Accepted: 12/12/2023] [Indexed: 01/13/2024] Open
Abstract
BACKGROUND The recent rediscovery of the FLASH effect, a normal tissue sparing phenomenon observed in ultra-high dose rate (UHDR) irradiations, has instigated a surge of research endeavors aiming to close the gap between experimental observation and clinical treatment. However, the dependences of the FLASH effect and its underpinning mechanisms on beam parameters are not well known, and large-scale in vivo studies using murine models of human cancer are needed for these investigations. PURPOSE To commission a high-throughput, variable dose rate platform providing uniform electron fields (≥15 cm diameter) at conventional (CONV) and UHDRs for in vivo investigations of the FLASH effect and its dependences on pulsed electron beam parameters. METHODS A murine whole-thoracic lung irradiation (WTLI) platform was constructed using a 1.3 cm thick Cerrobend collimator forming a 15 × 1.6 cm2 slit. Control of dose and dose rate were realized by adjusting the number of monitor units and couch vertical position, respectively. Achievable doses and dose rates were investigated using Gafchromic EBT-XD film at 1 cm depth in solid water and lung-density phantoms. Percent depth dose (PDD) and dose profiles at CONV and various UHDRs were also measured at depths from 0 to 2 cm. A radiation survey was performed to assess radioactivation of the Cerrobend collimator by the UHDR electron beam in comparison to a precision-machined copper alternative. RESULTS This platform allows for the simultaneous thoracic irradiation of at least three mice. A linear relationship between dose and number of monitor units at a given UHDR was established to guide the selection of dose, and an inverse-square relationship between dose rate and source distance was established to guide the selection of dose rate between 20 and 120 Gy·s-1 . At depths of 0.5 to 1.5 cm, the depth range relevant to murine lung irradiation, measured PDDs varied within ±1.5%. Similar lateral dose profiles were observed at CONV and UHDRs with the dose penumbrae widening from 0.3 mm at 0 cm depth to 5.1 mm at 2.0 cm. The presence of lung-density plastic slabs had minimal effect on dose distributions as compared to measurements made with only solid water slabs. Instantaneous dose rate measurements of the activated copper collimator were up to two orders of magnitude higher than that of the Cerrobend collimator. CONCLUSIONS A high-throughput, variable dose rate platform has been developed and commissioned for murine WTLI electron FLASH radiotherapy. The wide field of our UHDR-enabled linac allows for the simultaneous WTLI of at least three mice, and for the average dose rate to be modified by changing the source distance, without affecting dose distribution. The platform exhibits uniform, and comparable dose distributions at CONV and UHDRs up to 120 Gy·s-1 , owing to matched and flattened 16 MeV CONV and UHDR electron beams. Considering radioactivation and exposure to staff, Cerrobend collimators are recommended above copper alternatives for electron FLASH research. This platform enables high-throughput animal irradiation, which is preferred for experiments using a large number of animals, which are required to effectively determine UHDR treatment efficacies.
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Affiliation(s)
- Kevin E Byrne
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Department of Physics, School of Natural Sciences, University of Galway, Galway, Ireland
| | - Yannick Poirier
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Junliang Xu
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Andrew Gerry
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Mark J Foley
- Department of Physics, School of Natural Sciences, University of Galway, Galway, Ireland
| | - Isabel Lauren Jackson
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Amit Sawant
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Kai Jiang
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA
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Swamy K. Therapeutic In Situ Cancer Vaccine Using Pulsed Stereotactic Body Radiotherapy-A Translational Model. Vaccines (Basel) 2023; 12:7. [PMID: 38276666 PMCID: PMC10819354 DOI: 10.3390/vaccines12010007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 12/12/2023] [Accepted: 12/19/2023] [Indexed: 01/27/2024] Open
Abstract
Both radiation and cancer therapeutic vaccine research are more than 100 years old, and their potential is likely underexplored. Antiangiogenics, nanoparticle targeting, and immune modulators are some other established anticancer therapies. In the meantime, immunotherapy usage is gaining momentum in clinical applications. This article proposes the concept of a pulsed/intermittent/cyclical endothelial-sparing single-dose in situ vaccination (ISVRT) schedule distinguishable from the standard therapeutic stereotactic body radiotherapy (SBRT) and stereotactic radiosurgery (SRS) plans. This ISVRT schedule can repeatedly generate tumor-specific neoantigens and epitopes for primary and immune modulation effects, augment supplementary immune enhancement techniques, activate long-term memory cells, avoid extracellular matrix fibrosis, and essentially synchronize with the vascular normalized immunity cycle. The core mechanisms of ISVRT impacting in situ vaccination would be optimizing cascading antigenicity and adjuvanticity. The present proposed hypothesis can be validated using the algorithm presented. The indications for the proposed concept are locally progressing/metastatic cancers that have failed standard therapies. Immunotherapy/targeted therapy, chemotherapy, antiangiogenics, and vascular-lymphatic normalization are integral to such an approach.
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Lin B, Fan M, Niu T, Liang Y, Xu H, Tang W, Du X. Key changes in the future clinical application of ultra-high dose rate radiotherapy. Front Oncol 2023; 13:1244488. [PMID: 37941555 PMCID: PMC10628486 DOI: 10.3389/fonc.2023.1244488] [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: 06/22/2023] [Accepted: 10/09/2023] [Indexed: 11/10/2023] Open
Abstract
Ultra-high dose rate radiotherapy (FLASH-RT) is an external beam radiotherapy strategy that uses an extremely high dose rate (≥40 Gy/s). Compared with conventional dose rate radiotherapy (≤0.1 Gy/s), the main advantage of FLASH-RT is that it can reduce damage of organs at risk surrounding the cancer and retain the anti-tumor effect. An important feature of FLASH-RT is that an extremely high dose rate leads to an extremely short treatment time; therefore, in clinical applications, the steps of radiotherapy may need to be adjusted. In this review, we discuss the selection of indications, simulations, target delineation, selection of radiotherapy technologies, and treatment plan evaluation for FLASH-RT to provide a theoretical basis for future research.
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Affiliation(s)
- Binwei Lin
- Department of Oncology, National Health Commission (NHC) Key Laboratory of Nuclear Technology Medical Transformation (Mianyang Central Hospital), Mianyang Central Hospital, School of Medicine, University of Electronic Science and Technology, Mianyang, China
| | - Mi Fan
- Department of Oncology, Affiliated Hospital of North Sichuan Medical College, Nanchong, China
| | - Tingting Niu
- Department of Oncology, Affiliated Hospital of North Sichuan Medical College, Nanchong, China
| | - Yuwen Liang
- Department of Oncology, Affiliated Hospital of North Sichuan Medical College, Nanchong, China
| | - Haonan Xu
- Department of Oncology, Affiliated Hospital of North Sichuan Medical College, Nanchong, China
| | - Wenqiang Tang
- Department of Oncology, Affiliated Hospital of North Sichuan Medical College, Nanchong, China
| | - Xiaobo Du
- Department of Oncology, National Health Commission (NHC) Key Laboratory of Nuclear Technology Medical Transformation (Mianyang Central Hospital), Mianyang Central Hospital, School of Medicine, University of Electronic Science and Technology, Mianyang, China
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Lattery G, Kaulfers T, Cheng C, Zhao X, Selvaraj B, Lin H, Simone CB, Choi JI, Chang J, Kang M. Pencil Beam Scanning Bragg Peak FLASH Technique for Ultra-High Dose Rate Intensity-Modulated Proton Therapy in Early-Stage Breast Cancer Treatment. Cancers (Basel) 2023; 15:4560. [PMID: 37760528 PMCID: PMC10527307 DOI: 10.3390/cancers15184560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 09/06/2023] [Accepted: 09/08/2023] [Indexed: 09/29/2023] Open
Abstract
Bragg peak FLASH-RT can deliver highly conformal treatment and potentially offer improved normal tissue protection for radiotherapy patients. This study focused on developing ultra-high dose rate (≥40 Gy × RBE/s) intensity-modulated proton therapy (IMPT) for hypofractionated treatment of early-stage breast cancer. A novel tracking technique was developed to enable pencil beaming scanning (PBS) of single-energy protons to adapt the Bragg peak (BP) to the target distally. Standard-of-care PBS treatment plans of consecutively treated early-stage breast cancer patients using multiple energy layers were reoptimized using this technique, and dose metrics were compared between single-energy layer BP FLASH and conventional IMPT plans. FLASH dose rate coverage by volume (V40Gy/s) was also evaluated for the FLASH sparing effect. Distal tracking can precisely stop BP at the target distal edge. All plans (n = 10) achieved conformal IMPT-like dose distributions under clinical machine parameters. No statistically significant differences were observed in any dose metrics for heart, ipsilateral lung, most ipsilateral breast, and CTV metrics (p > 0.05 for all). Conventional plans yielded slightly superior target and skin dose uniformities with 4.5% and 12.9% lower dose maxes, respectively. FLASH-RT plans reached 46.7% and 61.9% average-dose rate FLASH coverage for tissues receiving more than 1 and 5 Gy plan dose total under the 250 minimum MU condition. Bragg peak FLASH-RT techniques achieved comparable plan quality to conventional IMPT while reaching adequate dose rate ratios, demonstrating the feasibility of early-stage breast cancer clinical applications.
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Affiliation(s)
- Grant Lattery
- Department of Physics and Astronomy, Hofstra University, 1000 Hempstead Turnpike, Hempstead, NY 11549, USA; (G.L.); (T.K.)
| | - Tyler Kaulfers
- Department of Physics and Astronomy, Hofstra University, 1000 Hempstead Turnpike, Hempstead, NY 11549, USA; (G.L.); (T.K.)
| | - Chingyun Cheng
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, 195 Little Albany Street, New Brunswick, NJ 08901, USA;
| | - Xingyi Zhao
- Beijing Key Laboratory of Medical Physics and Engineering, Peking University, Beijing 100871, China;
- New York Proton Center, 225 E 126th Street, New York, NY 10035, USA; (B.S.); (H.L.); (C.B.S.II); (J.I.C.)
| | - Balaji Selvaraj
- New York Proton Center, 225 E 126th Street, New York, NY 10035, USA; (B.S.); (H.L.); (C.B.S.II); (J.I.C.)
| | - Haibo Lin
- New York Proton Center, 225 E 126th Street, New York, NY 10035, USA; (B.S.); (H.L.); (C.B.S.II); (J.I.C.)
| | - Charles B. Simone
- New York Proton Center, 225 E 126th Street, New York, NY 10035, USA; (B.S.); (H.L.); (C.B.S.II); (J.I.C.)
| | - J. Isabelle Choi
- New York Proton Center, 225 E 126th Street, New York, NY 10035, USA; (B.S.); (H.L.); (C.B.S.II); (J.I.C.)
| | - Jenghwa Chang
- Department of Physics and Astronomy, Hofstra University, 1000 Hempstead Turnpike, Hempstead, NY 11549, USA; (G.L.); (T.K.)
- Radiation Medicine, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, 450 Lakeville Road, Lake Success, NY 11042, USA
| | - Minglei Kang
- New York Proton Center, 225 E 126th Street, New York, NY 10035, USA; (B.S.); (H.L.); (C.B.S.II); (J.I.C.)
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11
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Hu S, Lan X, Zheng J, Bi Y, Ye Y, Si M, Fang Y, Wang J, Liu J, Chen Y, Chen Y, Xiang P, Niu T, Huang Y. The dose-related plateau effect of surviving fraction in normal tissue during the ultra-high-dose-rate radiotherapy. Phys Med Biol 2023; 68:185004. [PMID: 37586385 DOI: 10.1088/1361-6560/acf112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 08/16/2023] [Indexed: 08/18/2023]
Abstract
Objective.Ultra-high-dose-rate radiotherapy, referred to as FLASH therapy, has been demonstrated to reduce the damage of normal tissue as well as inhibiting tumor growth compared with conventional dose-rate radiotherapy. The transient hypoxia may be a vital explanation for sparing the normal tissue. The heterogeneity of oxygen distribution for different doses and dose rates in the different radiotherapy schemes are analyzed. With these results, the influence of doses and dose rates on cell survival are evaluated in this work.Approach.The two-dimensional reaction-diffusion equations are used to describe the heterogeneity of the oxygen distribution in capillaries and tissue. A modified linear quadratic model is employed to characterize the surviving fraction at different doses and dose rates.Main results.The reduction of the damage to the normal tissue can be observed if the doses exceeds a minimum dose threshold under the ultra-high-dose-rate radiation. Also, the surviving fraction exhibits the 'plateau effect' under the ultra-high dose rates radiation, which signifies that within a specific range of doses, the surviving fraction either exhibits minimal variation or increases with the dose. For a given dose, the surviving fraction increases with the dose rate until tending to a stable value, which means that the protection in normal tissue reaches saturation.Significance.The emergence of the 'plateau effect' allows delivering the higher doses while minimizing damage to normal tissue. It is necessary to develop appropriate program of doses and dose rates for different irradiated tissue to achieve more efficient protection.
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Affiliation(s)
- Shuai Hu
- School of Physics and Astronomy, China West Normal University, Nanchong 637009, People's Republic of China
- School of Science, Sun Yat-Sen University, Shenzhen 518107, People's Republic of China
| | - Xiaofei Lan
- School of Physics and Astronomy, China West Normal University, Nanchong 637009, People's Republic of China
| | - Jinfen Zheng
- Dermatology, Center for Chronic Disease Prevention of Shenzhen, Guangdong Shenzhen 518020, People's Republic of China
| | - Yuanjie Bi
- School of Science, Sun Yat-Sen University, Shenzhen 518107, People's Republic of China
| | - Yuanchun Ye
- Department of Hematology, Oncology and Cancer Immunology Campus Benjamin Franklin Charité-Universitätsmedizin Berlin Corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin Hindenburgdamm, 30,12203, Berlin Germany
| | - Meiyu Si
- School of Science, Sun Yat-Sen University, Shenzhen 518107, People's Republic of China
- Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Yuhong Fang
- School of Science, Sun Yat-Sen University, Shenzhen 518107, People's Republic of China
| | - Jinghui Wang
- Varian Medical Systems, Palo Alto, CA 94304, United States of America
| | - Junyan Liu
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94304, United States of America
| | - Yuan Chen
- The Institute for Advanced Studies of Wuhan University, 299, Bayi Road, Wuhan, 430072, People's Republic of China
| | - Yuling Chen
- Department of Rheumatology and Immunology, The Seventh Affiliated Hospital Sun Yat-sen University, Shenzhen 518107, People's Republic of China
| | - Pai Xiang
- The Institute for Advanced Studies of Wuhan University, 299, Bayi Road, Wuhan, 430072, People's Republic of China
| | - Tianye Niu
- Shenzhen Bay Laboratory, Shenzhen 518107, People's Republic of China
| | - Yongsheng Huang
- School of Science, Sun Yat-Sen University, Shenzhen 518107, People's Republic of China
- Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of China
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12
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Mali SB, Dahivelkar S. Flash radiotherapy-gateway to promised land or another mirage. Oral Oncol 2023; 139:106342. [PMID: 36821983 DOI: 10.1016/j.oraloncology.2023.106342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 02/15/2023] [Indexed: 02/23/2023]
Abstract
Radiation therapy damages cancer cells with ionizing radiation, leading to their death. However, radiation‑induced toxicity limits the dose delivered to the tumor, thereby constraining the control effect of radiotherapy n tumor growth. In addition, the delayed toxicity caused by radiotherapy significantly harms the physical and mental health of patients. FLASH‑RT, an emerging class of radiotherapy, causes a phenomenon known as the 'FLASH effect', which delivers radiotherapy at an ultra‑high dose rate with lower toxicity to normal tissue than conventional radiotherapy to achieve local tumor control.
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Affiliation(s)
- Shrikant B Mali
- MDS Oral and Maxillofacial Surgery Mahatma Gandhi Vidya Mandir's Dental College and Hospital Nashik, India.
| | - Sachinkumar Dahivelkar
- MDS Oral and Maxillofacial Surgery Mahatma Gandhi Vidya Mandir's Dental College and Hospital Nashik, India.
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McMillan MT, Kang M, Shepherd AF, Liu W, Lin L, Lin H, Simone CB. Stereotactic body proton therapy for non-small cell lung cancer: Clinical indications and recommendations. JOURNAL OF RADIOSURGERY AND SBRT 2023; 9:17-32. [PMID: 38029014 PMCID: PMC10681144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 08/11/2023] [Indexed: 12/01/2023]
Abstract
Stereotactic body radiation therapy (SBRT) has emerged as a standard treatment approach for early-stage lung cancer and intrathoracic oligometastatic or oligoprogressive disease. While local control is often excellent with this modality when delivered with photon therapy, toxicities for select patients can be significant. Proton therapy offers a unique opportunity to widen the therapeutic window when treating patients with thoracic malignancies requiring or benefitting from ultra-high doses per fraction. Thoracic proton SBRT may be particularly beneficial in cases requiring dose escalation, for tumors >5 cm, for central or ultra-central tumors, for reirradiation, in patients with interstitial lung diseases, and when combining radiation with immunotherapy. These clinical indications are detailed, along with supporting literature and clinical recommendations. Other considerations, future directions and potential benefits of proton SBRT, including sparing lymphocytes, when delivered as intensity-modulated proton therapy or as FLASH, and for the treatment of locally advanced non-small cell lung cancer or in patients with homologous recombination repair deficiencies, are also discussed.
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Affiliation(s)
- Matthew T. McMillan
- Memorial Sloan Kettering Cancer Center, Department of Radiation Oncology, New York, NY, USA
| | | | - Annemarie F. Shepherd
- Memorial Sloan Kettering Cancer Center, Department of Radiation Oncology, New York, NY, USA
- New York Proton Center, New York, NY, USA
| | - Wei Liu
- Mayo Clinic, Department of Radiation Oncology, Phoenix, AZ, USA
| | - Liyong Lin
- Emory University, Department of Radiation Oncology, Atlanta, GA, USA
| | - Haibo Lin
- Memorial Sloan Kettering Cancer Center, Department of Radiation Oncology, New York, NY, USA
- New York Proton Center, New York, NY, USA
| | - Charles B. Simone
- Memorial Sloan Kettering Cancer Center, Department of Radiation Oncology, New York, NY, USA
- New York Proton Center, New York, NY, USA
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