PET measurements of hyperthermia-induced suppression of protein synthesis in tumors in relation to effects on tumor growth.
Hyperthermia-induced metabolic changes in tumor tissue have been monitored by PET. Uptake of L-[1-11C]tyrosine in rhabdomyosarcoma tissue of Wag/Rij rats was dose-dependently reduced after local hyperthermia treatment at 42, 45, or 47 degrees C. Tumor blood flow, as measured by PET with 13NH3, appeared to be unchanged. The L-[1-11C]tyrosine uptake data were compared to uptake data of L-[1-14C]tyrosine and with data on the incorporation of L-[1-14C]tyrosine into tumor proteins. After intravenous injection, the 14C data were obtained from dissected tumor tissue. Heat-induced inhibition of the incorporation of L-[1-14C]tyrosine into tumor proteins tallied with the L-[1-11C]tyrosine uptake data. Heat-induced inhibition of amino acid uptake in the tumor correlated well with regression of tumor growth. It is concluded that PET using L-[1-11C]tyrosine is eligible for monitoring the effect of hyperthermia on tumor growth.
Daemen
B J
BJ
Department of Nuclear Medicine, University Hospital, Groningen, The Netherlands.
Elsinga
P H
PH
Mooibroek
J
J
Paans
A M
AM
Wieringa
A R
AR
Konings
A W
AW
Vaalburg
W
W
D000641:Ammonia; D000818:Animals; D002250:Carbon Radioisotopes; D005260:Female; D006979:Hyperthermia, Induced; D009363:Neoplasm Proteins / Q000096:biosynthesis*; D009590:Nitrogen Radioisotopes; D051381:Rats; D012208:Rhabdomyosarcoma / Q000000981:diagnostic imaging* / Q000628:therapy; D014055:Tomography, Emission-Computed; D014443:Tyrosine
D002250:Carbon Radioisotopes; D009363:Neoplasm Proteins; D009590:Nitrogen Radioisotopes; D014443:Tyrosine; D000641:Ammonia