Changes in the Pharmacokinetics of Gd-DTPA in Experimental Tumors after Charged Particle Radiation : Comparison with γ-Ray Radiation

Author(s)

Abstract

We performed dynamic MRI to reveal the characteristic gadopentetate dimeglumine (Gd-DTPA) uptake in carbon-ion irradiated tumor and compare it with photon irradiation. Fibrosarcomas in C3H mice legs were irradiated with either 16 Gy of carbon ions (74 keV/mm) or an equivalent dose (30 Gy) of Cs-137 γ-rays. Dynamic MRI was performed 1 or 6 days after irradiation when the tumors showed an initial growth delay or incipient regrowth, respectively. The enhancement pattern was visualized by mapping the maximum enhanced time (<i>Tmax</i>), relative signal intensity maximum (<i>SImax</i>), and time delay of starting enhancement (<i>Td</i>). Significantly larger <i>Tmax</i> and <i>Td<i> values were observed in the tumors 1 day after carbon-ion irradiation than in the nonradiated tumors (<i>No-R</i>) and tumors 1 day after γ-ray irradiation. Among the selected pixels in the tumors 6 days after carbon irradiation, 77% had <i>Tmax</i> values of less than 120 sec, significantly more than in the <i>No-R</i> group. The <i>Tmax</i> maps for the tumors irradiated with γ-rays showed a similar tendency to the carbon-irradiated ones, and only a significant difference was obtained between tumors 1 and 6 days after irradiation. <i>Tmax</i> and <i>Td</i> in the carbon-ion irradiated tumors were different from those in the γ-ray-irradiated tumors. These treatment-specific kinetics may be useful in predicting the therapeutic efficacy of carbon-ion treatment.<br>

Journal

  • Journal of Radiation Research

    Journal of Radiation Research 45(2), 261-267, 2004-06-15

    Journal of Radiation Research Editorial Committee

References:  22

Codes

  • NII Article ID (NAID)
    110004041025
  • NII NACSIS-CAT ID (NCID)
    AA00705792
  • Text Lang
    ENG
  • Article Type
    ART
  • ISSN
    04493060
  • NDL Article ID
    7014530
  • NDL Source Classification
    ZS45(科学技術--医学--放射線医学)
  • NDL Call No.
    Z53-P232
  • Data Source
    CJP  NDL  NII-ELS  J-STAGE  NDL-Digital 
Page Top