2002 Fiscal Year Final Research Report Summary
An experimental study to seek the feasibility of manganese porphyrin contrast media in diagnosing pancreatic cancer
| Project/Area Number |
13670927
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Radiation science
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| Research Institution | HAMAMATSU UNIVERSITY SCHOOL OF MEDICINE |
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Principal Investigator |
TAKEHARA Yasuo Hamamatsu University Hospital, associate professor, 医学部附属病院, 講師 (70188217)
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| Co-Investigator(Kenkyū-buntansha) |
SAKAHARA Harumi Hamamatsu University School of Medicine, professor, 医学部, 教授 (10187031)
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| Project Period (FY) |
2001 – 2002
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| Keywords | magnetic resonance imaging / contrast media / metalloporphyrin / neoplasia / pancreas / pancreatic cancer / animal study / mice |
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| Research Abstract |
Biodistribution analysis and in-vivo contrast enhanced MR imaging were done on nude mice bearing a human pancreas cancer (panc-1) of 1-2 cm in diameter. Biodistribution analysis was done using 38 mice according to a timetable, I.e. pre-contrast, 5 min, 2 hrs and 24 hrs after the I.v, -either of HOP-9P (0.1mmol/kg) or HOP-8P (0.1mmol/kg). Mn concentrations in the blood, tumor, muscle, liver, kidneys and pancreas were measured with optical emission spectrometer. MRI was performed on a 3.0 T imager with a head coil using 7 nude mice. Coronal T1-weighted spin echo images (TR/TE=600/14) were acquired before and 2 hours and 24 hours after I.v. injection of HOP-9P (0.1mmol/kg). Mean signal intensities of the tumor and a standard phantom (1 mM CuSO4) were measured and the signal intensity ratios (SIR) were calculated. After the imaging, animals were sacrificed and frozen at -20℃ and sliced, fixed and stained with H&E.
The tissue concentration of Mn in the tumor showed nine-fold increase at 2 hrs post injection of HOP-9P. Tumor/pancreas tissue concentraion was also highest at 2 hours post-injection with mean value^^+__-SD of 0.86^^+__-0.66 as compared to precontrast value of 0.18^^+__-01.6 (p<0.05). Biodistribution data with HOP-8P showed similar trend, but less specificity to the tumor.
Since the biodistribution data of HOP-9P seemed to be more promising, in-vivo MR imaging was done with HOP-9P. The MR images demonstrated progressive and sustained enhancement of the tumor until 24 hrs (p<0.05) after HOP-9P administration (precontrast ; 0.18^^+__-0.01 (mean^^+__-SE), 30min ; 0.21 ^^+__-0.01, 2 hrs ; 0.22^^+__-0.01 and 24 hrs ; 0.23^^+__-0.01).
Imaging and Histological correlation showed that the contrast media can enhance both viable and necrotic portions of the tumor.
Our data suggest HOP-9P may be a promising contrast media to detect pancreatic cancer.
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