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The 'stealth-bomber' paradigm for deciphering the tumour response to carbon-ion irradiation. Br J Cancer 2023; 128:1429-1438. [PMID: 36639527 PMCID: PMC10070470 DOI: 10.1038/s41416-022-02117-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 12/01/2022] [Accepted: 12/08/2022] [Indexed: 01/14/2023] Open
Abstract
Numerous studies have demonstrated the higher biological efficacy of carbon-ion irradiation (C-ions) and their ballistic precision compared with photons. At the nanometre scale, the reactive oxygen species (ROS) produced by radiation and responsible for the indirect effects are differentially distributed according to the type of radiation. Photon irradiation induces a homogeneous ROS distribution, whereas ROS remain condensed in clusters in the C-ions tracks. Based on this linear energy transfer-dependent differential nanometric ROS distribution, we propose that the higher biological efficacy and specificities of the molecular response to C-ions rely on a 'stealth-bomber' effect. When biological targets are on the trajectories of the particles, the clustered radicals in the tracks are responsible for a 'bomber' effect. Furthermore, the low proportion of ROS outside the tracks is not able to trigger the cellular mechanisms of defence and proliferation. The ability of C-ions to deceive the cellular defence of the cancer cells is then categorised as a 'stealth' effect. This review aims to classify the biological arguments supporting the paradigm of the 'stealth-bomber' as responsible for the biological superiority of C-ions compared with photons. It also explains how and why C-ions will always be more efficient for treating patients with radioresistant cancers than conventional radiotherapy.
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Glowa C, Peschke P, Brons S, Neels OC, Kopka K, Debus J, Karger CP. Carbon ion radiotherapy: impact of tumor differentiation on local control in experimental prostate carcinomas. Radiat Oncol 2017; 12:174. [PMID: 29121984 PMCID: PMC5679331 DOI: 10.1186/s13014-017-0914-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 10/27/2017] [Indexed: 11/30/2022] Open
Abstract
Background To summarize the research activities of the “clinical research group heavy ion therapy”, funded by the German Research Foundation (DFG, KFO 214), on the impact of intrinsic tumor characteristics (grading, hypoxia) on local tumor control after carbon (12C-) ion- and photon irradiations. Methods Three sublines of syngeneic rat prostate tumors (R3327) with various differentiation levels (highly (-H), moderately (-HI) or anaplastic (-AT1), (diameter 10 mm) were irradiated with 1, 2 and 6 fractions of either 12C-ions or 6 MV photons using increasing dose levels. Primary endpoint was local tumor control at 300 days. The relative biological effectiveness (RBE) of 12C-ions was calculated from TCD50-values (dose at 50% tumor control probability) of photons and 12C-ions and correlated with intrinsic tumor parameters. For the HI-subline, larger tumors (diameter 18 mm) were irradiated with either carbon ions, oxygen ions or photons under ambient as well as hypoxic conditions to determine the variability of the RBE under different oxygenation levels. In addition, imaging, histology and molecular analyses were performed to decipher the underlying mechanisms. Results Experimental results revealed (i) a smaller variation of the TCD50-values between the three tumor sublines for 12C-ions (23.6 - 32.9 Gy) than for photons (38.2 - 75.7 Gy), (ii) steeper dose-response curves for 12C-ions, and (iii) an RBE that increased with tumor grading (1.62 ± 0.11 (H) vs 2.08 ± 0.13 (HI) vs 2.30 ± 0.08 (AT1)). Large HI-tumors resulted in a marked increase of TCD50, which was increased further by 15% under hypoxic relative to oxic conditions. Noninvasive imaging, histology and molecular analyses identified hypoxia as an important radioresistance factor in photon therapy. Conclusions The dose-response studies revealed a higher efficacy of 12C-ions relative to photon therapy in the investigated syngeneic tumor model. Hypoxia turned out to be at least one important radioresistance factor, which can be partly overridden by high-LET ion beams. This might be used to increase treatment effectiveness also in patients. The results of this project served as a starting point for several ongoing research projects.
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Affiliation(s)
- Christin Glowa
- Department of Radiation Oncology, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany. .,Department of Medical Physics in Radiation Oncology (E040), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany. .,National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.
| | - Peter Peschke
- Department of Medical Physics in Radiation Oncology (E040), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany.,National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Im Neuenheimer Feld 400, 69120, Heidelberg, Germany
| | - Stephan Brons
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.,Heidelberg Ion Beam Therapy Center (HIT), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany
| | - Oliver C Neels
- Division of Radiopharmaceutical Chemistry, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany.,German Cancer Consortium (DKTK), Im Neuenheimer Feld 400, 69120, Heidelberg, Germany
| | - Klaus Kopka
- Division of Radiopharmaceutical Chemistry, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany.,German Cancer Consortium (DKTK), Im Neuenheimer Feld 400, 69120, Heidelberg, Germany
| | - Jürgen Debus
- Department of Radiation Oncology, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.,National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Im Neuenheimer Feld 400, 69120, Heidelberg, Germany
| | - Christian P Karger
- Department of Medical Physics in Radiation Oncology (E040), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany.,National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Im Neuenheimer Feld 400, 69120, Heidelberg, Germany
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Walenta S, Mueller-Klieser W. Differential Superiority of Heavy Charged-Particle Irradiation to X-Rays: Studies on Biological Effectiveness and Side Effect Mechanisms in Multicellular Tumor and Normal Tissue Models. Front Oncol 2016; 6:30. [PMID: 26942125 PMCID: PMC4766872 DOI: 10.3389/fonc.2016.00030] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 01/28/2016] [Indexed: 01/31/2023] Open
Abstract
This review is focused on the radiobiology of carbon ions compared to X-rays using multicellular models of tumors and normal mucosa. The first part summarizes basic radiobiological effects, as observed in cancer cells. The second, more clinically oriented part of the review, deals with radiation-induced cell migration and mucositis. Multicellular spheroids from V79 hamster cells were irradiated with X-rays or carbon ions under ambient or restricted oxygen supply conditions. Reliable oxygen enhancement ratios could be derived to be 2.9, 2.8, and 1.4 for irradiation with photons, 12C+6 in the plateau region, and 12C+6 in the Bragg peak, respectively. Similarly, a relative biological effectiveness of 4.3 and 2.1 for ambient pO2 and hypoxia was obtained, respectively. The high effectiveness of carbon ions was reflected by an enhanced accumulation of cells in G2/M and a dose-dependent massive induction of apoptosis. These data clearly show that heavy charged particles are more efficient in sterilizing tumor cells than conventional irradiation even under hypoxic conditions. Clinically relevant doses (3 Gy) of X-rays induced an increase in migratory activity of U87 but not of LN229 or HCT116 tumor cells. Such an increase in cell motility following irradiation in situ could be the source of recurrence. In contrast, carbon ion treatment was associated with a dose-dependent decrease in migration with all cell lines and under all conditions investigated. The radiation-induced loss of cell motility was correlated, in most cases, with corresponding changes in β1 integrin expression. The photon-induced increase in cell migration was paralleled by an elevated phosphorylation status of the epidermal growth factor receptor and AKT-ERK1/2 pathway. Such a hyperphosphorylation did not occur during 12C+6 irradiation under all conditions registered. Comparing the gene toxicity of X-rays with that of particles using the γH2AX technique in organotypic cultures of the oral mucosa, the superior effectiveness of heavy ions was confirmed by a twofold higher number of foci per nucleus. However, proinflammatory signs were similar for both treatment modalities, e.g., the activation of NFκB and the release of IL6 and IL8. The presence of peripheral blood mononuclear cell increased the radiation-induced release of the proinflammatory cytokines by factors of 2–3. Carbon ions are part of the cosmic radiation. Long-term exposure to such particles during extended space flights, as planned by international space agencies, may thus impose a medical and safety risk on the astronauts by a potential induction of mucositis. In summary, particle irradiation is superior to gamma-rays due to a higher radiobiological effectiveness, a reduced hypoxia-induced radioresistance, a multicellular radiosensitization, and the absence of a radiation-induced cell motility. However, the potential of inducing mucositis is similar for both radiation types.
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Affiliation(s)
- Stefan Walenta
- Institute of Pathophysiology, University Medical Center, University of Mainz , Mainz , Germany
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Held KD, Kawamura H, Kaminuma T, Paz AES, Yoshida Y, Liu Q, Willers H, Takahashi A. Effects of Charged Particles on Human Tumor Cells. Front Oncol 2016; 6:23. [PMID: 26904502 PMCID: PMC4751258 DOI: 10.3389/fonc.2016.00023] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 01/21/2016] [Indexed: 12/22/2022] Open
Abstract
The use of charged particle therapy in cancer treatment is growing rapidly, in large part because the exquisite dose localization of charged particles allows for higher radiation doses to be given to tumor tissue while normal tissues are exposed to lower doses and decreased volumes of normal tissues are irradiated. In addition, charged particles heavier than protons have substantial potential clinical advantages because of their additional biological effects, including greater cell killing effectiveness, decreased radiation resistance of hypoxic cells in tumors, and reduced cell cycle dependence of radiation response. These biological advantages depend on many factors, such as endpoint, cell or tissue type, dose, dose rate or fractionation, charged particle type and energy, and oxygen concentration. This review summarizes the unique biological advantages of charged particle therapy and highlights recent research and areas of particular research needs, such as quantification of relative biological effectiveness (RBE) for various tumor types and radiation qualities, role of genetic background of tumor cells in determining response to charged particles, sensitivity of cancer stem-like cells to charged particles, role of charged particles in tumors with hypoxic fractions, and importance of fractionation, including use of hypofractionation, with charged particles.
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Affiliation(s)
- Kathryn D Held
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School , Boston, MA , USA
| | - Hidemasa Kawamura
- Gunma University Heavy Ion Medical Center, Gunma, Japan; Department of Radiation Oncology, Gunma University Graduate School of Medicine, Gunma, Japan
| | - Takuya Kaminuma
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; Gunma University Heavy Ion Medical Center, Gunma, Japan; Department of Radiation Oncology, Gunma University Graduate School of Medicine, Gunma, Japan
| | | | - Yukari Yoshida
- Gunma University Heavy Ion Medical Center , Gunma , Japan
| | - Qi Liu
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School , Boston, MA , USA
| | - Henning Willers
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School , Boston, MA , USA
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