|
41. Relationship between HL91 Uptake and Blood Flow in Tumor
Tsunehiko Nishimura1, Mitsuaki Tatsumi1, Kenji Yutani1, Takayuki Nakano1, Osamu Inoue2, Kyosan Yoshikawa3
(1 Tracer Kinetics, Osaka University Graduate School of Medicine, 2 Medical Physics, School of Allied Health Sciences, Osaka University Faculty of Medicine, 3 National Institute of Radiological Sciences)
Keywords: Tumor hypoxia, HL91, IAP, GLUT1, DG
Technetium-99m-HL91 (HL91) is a potential agent for imaging hypoxic tissue in vivo. Last year we reported that the HL91 uptake, the C-14-deoxyglucose (DG) uptake, and the expression of glucose transporter type 1 (GLUT1) in the hxpoxic area significantly higher than those in the normoxic area. This year, to elucidate the relationship between hypoxia and blood flow in a tumor, dual-tracer autoradiography with HL91 and C-14-iodoantipyrine, a blood flow tracer, (IAP) was performed in a tumor [Walker 256 (rat mammary carcinoma) cell] bearing rat model. The distribution of each tracer was analyzed visually and semi-quantitatively. In the tumors with central necrotic areas, HL91 uptake was marked around the necrotic areas. IAP uptake was marked at the periphery of the tumors, around the areas of marked HL91 uptake. Normalized HL91 uptake (%HL91) was highest in the low-normalized IAP uptake (%IAP) fraction in the non-necrotic areas. There was a weak negative correlation between %HL91 and %IAP in the non-necrotic areas (r = -0.322, p< 0.0001). In tumors with few or no necrotic areas, HL91 uptake was observed heterogeneously throughout the tumors, while IAP uptake was predominant at the periphery of the tumors. %HL91 was higher in the inner two-thirds of the tumor than in the outer third. There was also a weak negative correlation between %HL91 and %IAP (r = -0.354, p< 0.0001). This study confirmed that high HL91 uptake is related to low blood flow. The marked HL91 uptake around the necrotic region suggests the presence of chronic hypoxia in a tumor.
Publications:
M. Tatsumi et al. Eur. J. Nucl. Med. (1999) 26:91-94
