technetium-tc-99m-exametazime and Carcinoma--Squamous-Cell

Tumor perfusion and oxygenation status have been suggested as factors which may influence treatment outcome in cancer patients. Nuclear medicine assays of tumor perfusion [99mTc-hexamethylpropylenamine oxime (HMPAO)] and tumor hypoxia [123I-iodoazomycin arabinoside (IAZA)] have recently been developed and described. We report on measurements of perfusion and oxygenation status of 27 tumors in 22 patients using these probes. An inverse correlation between tumor uptake of HMPAO and IAZA was measured (p < 0.05), with severe perfusion deficit usually associated with an increased uptake of the hypoxic marker. This trend was observed for limited stage small-cell lung carcinoma, squamous-cell carcinoma of the head and neck, soft-tissue sarcoma, brain metastases from small-cell lung carcinoma and adenocarcinoma of the prostate as a group, but not for glioblastoma multiforme. Whereas each imaging agent can yield information about the physiological status of tumor and normal tissue, the information resulting from their combined use could be important in cancer therapy.

Topics: Brain Neoplasms; Carcinoma, Small Cell; Carcinoma, Squamous Cell; Cell Hypoxia; Female; Glioblastoma; Head and Neck Neoplasms; Humans; Iodine Radioisotopes; Lung Neoplasms; Male; Nitroimidazoles; Organotechnetium Compounds; Oximes; Sarcoma; Soft Tissue Neoplasms; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

99mTc-labelled hexamethylpropylene amine oxime (HMPAO) is a lipophilic compound with a neutral charge which reflects tumor blood flow and has been previously investigated to estimate brain blood flow. In this study, we attempted to use 99mTc-HMPAO for the evaluation of 18 patients with histologically proven primary lung carcinoma. The eight surgical specimens revealed that viable carcinoma cells were present when the 99mTc-HMPAO accumulated in the tumor, however, extensive tumor necrosis was observed when defective or ring like uptake was seen in the tumor. Qualitative study revealed that when perfusion defects were observed corresponding to the tumor, the possibility of squamous cell carcinoma or large cell carcinoma was high instead of adenocarcinoma. Quantitative analysis revealed that the uptake ratio was statistically different between adenocarcinoma (1.6 +/- 0.1) and squamous cell carcinoma (1.2 +/- 0.4) (P less than 0.05), between squamous cell carcinoma and large cell carcinoma (0.9 +/- 0.1) (P less than 0.05), and also between adenocarcinoma and large cell carcinoma (P less than 0.01). In conclusion, 99mTc-HMPAO may be useful for the evaluation of patients with primary lung carcinoma.

Topics: Adenocarcinoma; Aged; Carcinoma, Non-Small-Cell Lung; Carcinoma, Squamous Cell; Female; Humans; Lung Neoplasms; Male; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

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.

Topics: Carcinoma, Non-Small-Cell Lung; Carcinoma, Squamous Cell; Female; Glutathione; Humans; Lung Neoplasms; Male; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon