Observation of microvasculatures in athymic nude rat transplanted tumor using synchrotron radiation microangiography system.
OBJECTIVE
The diagnostic potential of tumor microvasculatures with the monochromatic synchrotron radiation microangiography (MSRA) system was examined in an experimental model using athymic nude rats.


METHODS
In the lower abdominal wall in athymic nude rats (male, 120-150 g, 6 weeks old), 1 x 10(7) cells of N-nitrosomethylurea-induced rat mammary adenocarcinoma was transplanted to prepare a lower abdominal wall tumor transplanted model. A microcatheter was inserted in the abdominal aorta in a rat under anesthesia, and microangiographic images of the normal inferior epigastric artery and vein were obtained using an MSRA system. Changes in the tumor microvasculatures were observed using an MSRA system on the day 7 (n = 3), day 14 (n = 3), day 21 (n = 3), and day 28 (n = 3) after transplant. In addition, we measured the microvessel density (MVD) with a computer using the binarization method. These results were compared among the histologic MVDs.


RESULTS
The microvasculatures of tumors measuring 20-30 microm were observable by the MSRA system in the transplanted tumor model using the inferior epigastric artery and vein as the feeding vessels. The tumor microvasculatures were observed for 7-28 days after transplantation. The tumor MVD obtained by the binarization method increased as the tumor volume increased. When histologic MVD was compared with the fixed quantitative results of angiographic MVD, a significant correlation (r = 0.933, P <.01) was observed.


CONCLUSIONS
These preliminary investigations indicate that MSRA proved to be suitable for quantification and appears to be a simple method for clearly imaging tumor microvasculatures.
Tokiya
Ryoji
R
Department of Radiation Oncology, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, Japan. radoncol@med.kawasaki-m.ac
Umetani
Keiji
K
Imai
Shigeki
S
Yamashita
Takenori
T
Hiratsuka
Junichi
J
Imajo
Yoshinari
Y
D000008:Abdominal Neoplasms / Q000473:pathology*; D034861:Abdominal Wall / Q000098:blood supply / Q000473:pathology*; D000230:Adenocarcinoma / Q000473:pathology*; D000792:Angiography; D000818:Animals; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging / Q000473:pathology; D004396:Coloring Agents; D004195:Disease Models, Animal; D004801:Eosine Yellowish-(YS); D006416:Hematoxylin; D008297:Male; D008325:Mammary Neoplasms, Experimental / Q000473:pathology; D009368:Neoplasm Transplantation; D009381:Neoplasms, Radiation-Induced / Q000473:pathology*; D009389:Neovascularization, Pathologic / Q000000981:diagnostic imaging; D051381:Rats; D011923:Rats, Nude; D017356:Synchrotrons; D013997:Time Factors
D004396:Coloring Agents; D004801:Eosine Yellowish-(YS); D006416:Hematoxylin