腫瘍内低酸素変動の可視化と放射線生物学における意義

  • 安井 博宣
    北海道大学大学院獣医学研究院応用獣医科学分野放射線学教室
  • 松元 慎吾
    北海道大学大学院情報科学研究院生命人間情報科学専攻磁気共鳴工学研究室
  • 稲波 修
    北海道大学大学院獣医学研究院応用獣医科学分野放射線学教室
  • Murali Cherukuri Krishna
    米国国立衛生研究所NIH/NCI

書誌事項

タイトル別名
  • Imaging of Tumor-Specific Hypoxia Dynamics and Its Significance in Radiation Biology
  • シュヨウ ナイ テイサンソ ヘンドウ ノ カシカ ト ホウシャセン セイブツガク ニ オケル イギ

この論文をさがす

抄録

<p>Hypoxia has been known to be a feature associated with tumor radioresistance. So far, clinical strategies to overcome chronic hypoxia due to the limitation of the oxygen diffusion have been designed. However, intermittent or acute/cycling hypoxia, whose frequency can range between a few cycles per minutes to hours, is receiving increased attention, because this type of hypoxia has been reported to have an influence on tumor malignancy as well as treatment resistance via increased expression of pro-survival pathways. Therefore, a priori information on fluctuating hypoxia can be important in clinical treatment planning, but complicated dynamics makes it difficult to elucidate biological significance of intermittent hypoxia.</p><p>Here, we illustrate the use of pulsed electron spin resonance imaging (ESRI) as a novel imaging method to directly monitor fluctuating oxygenation i.e. cycling hypoxia in transplanted tumors. A common resonator platform for both ESRI and magnetic resonance imaging (MRI) provided pO2 maps with anatomical guidance without positional movement. Oxygen images every 3 min in pO2 could visualize the rapid oxygen fluctuation and distinguish the cycling hypoxia and chronic hypoxia. Furthermore, we have examined the vascular renormalization process by longitudinally pO2 mapping during treatments with a multi-tyrosine kinase inhibitor sunitinib. Transient improvement in tumor oxygenation and the decrease of cycling tumor hypoxia were visualized by ESRI 2 to 4 days following antiangiogenic treatments. Radiation treatment during this time period of improved oxygenation by antiangiogenic therapy resulted in a synergistic delay in tumor growth.</p><p>In conclusion, this ESRI technique combined with MRI, may offer a powerful clinical tool to noninvasively detect variable hypoxic status in tumors and to identify a window of vascular renormalization to maximize the effects of combination therapy with antiangiogenic drugs.</p>

収録刊行物

  • 医学物理

    医学物理 40 (1), 13-18, 2020-03-31

    公益社団法人  日本医学物理学会

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