99Tcm-labelled meso-HMPAO and glutathione content of human lung tumours.
Levels of reduced glutathione (GSH) are increased in some types of malignant tumours and are known to influence the response to radio- and chemotherapy. In vitro studies suggest a correlation between cellular GSH concentration and retention of the meso form of hexamethyl propyleneamineoxime (HMPAO). This study investigates the relationship between in vivo tissue retention of 99Tcm-labelled HMPAO and GSH concentration in ten patients referred for thoracotomy for possible lung cancer. Retention of 99Tcm-HMPAO was measured using single photon emission computed tomography (SPECT). The tumour and normal lung concentration of reduced glutathione (GSH) was measured in tissue specimens collected peroperatively. Malignancy was confirmed in eight patients. Of seven patients undergoing curative resection for carcinoma, tumour GSH concentration was higher (mean 2.76 mM) than normal lung (mean 1.04 mM). In one neurofibroma, the GSH concentration was 1.80 mM. No correlation was found between 99Tcm meso-HMPAO retention and either the tumour GSH concentration or the tumour:lung GSH ratio. The results from this small series demonstrate that the intracellular GSH concentration of malignant lung tumours is generally higher than that in normal lung but that meso-HMPAO retention could not be used to predict these levels.
Rowell
N P
NP
Department of Radiotherapy, Royal Marsden Hospital, Sutton, Surrey, UK.
McCready
V R
VR
Cronin
B
B
Pepper
J
J
Higley
B
B
Burke
J F
JF
Tyrrell
D A
DA
D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging* / Q000378:metabolism; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging* / Q000378:metabolism; D005260:Female; D005978:Glutathione / Q000378:metabolism*; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D015609:Organotechnetium Compounds; D010091:Oximes; D019690:Technetium Tc 99m Exametazime; D015899:Tomography, Emission-Computed, Single-Photon
D015609:Organotechnetium Compounds; D010091:Oximes; D019690:Technetium Tc 99m Exametazime; D005978:Glutathione