Experimental Brain Tumor Response to Hyperthermia Evaluated by in vivo 31P Magnetic Resonance Spectoscopy

Experimental Brain Tumor Response to Hyperthermia Evaluated by in vivo 31P Magnetic Resonance Spectoscopy

Creators Kin Shigenari

In vivo 31P-MR spectroscopy was employed to measure the energy metabolism and pH of T9 gliosarcomas in the flank of Fisher rats before and serially up to 24 h after hyperthermia at various temperatures. Water bath hyperthermia was used to heat tumors at 41℃, 43℃ and 45℃ for 30 min. Following hyperthermia at 41℃ , the ratio of β-nucleoside triphosphate to inorganic phosphate (β-NTP/Pi) significantly decreased at 1 h and 3 h (p<0.05), but recovered at 6 h. The-β-NTP/Pi ratio after hyperthermia at 43℃ and 45℃ decreased significantly up to 24 h (p<0.05). The intracellular pH significantly decreased from the pretreatment level at 6 h after hyperthermia at 45℃. Histological comparison of tumors with and without hyperthermia 24 h posttreatment showed the loss of the endothelial lining and enlargement of the interstitial space in tumors with hyperthermia at 43℃ and 45℃. Thrombosis in vessele and pyknosis were also demonstrated in tumors treated at 43℃ and 45℃. But these changes were more marked in tumors with hyperthermia at 45℃. Our data suggest that in vivo 31P-MR spectroscopy provides useful information about the therapeutic effects of hyperthermia within 6 h after the treatment.

[ISSN]0513-1812

[NCID]AA00594272