UNLABELLED: The purpose of this study was to evaluate the relationship between 99mTc-sestamibi (MIBI) accumulation by tumor and response to chemotherapy in small cell lung cancer patients compared with 201TI-chloride. METHODS: There were 19 patients with small cell lung cancer just before chemotherapy initiation. The patients were classified by a follow-up CT into complete remission, partial remission and no change groups. All patients underwent dual-isotope imaging with 201TI-chloride and 99mTc-MIBI. Regions of interest were placed over the tumors and contralateral normal lung tissue on one coronal view with a clearly defined lesion, and the tumor-to-normal (T/N) ratio and retention index were calculated. RESULTS: Early and delayed T/N ratios for 99mTc-MIBI in complete remission and partial remission groups were significantly higher (p < 0.05) than in the no change group. There was no significant correlation between T/N ratio and tumor response using 201TI-chloride. There were no significant differences in the retention index with respect to the tumor response in both 201TI-chloride and 99mTc-MIBI SPECT images. CONCLUSION: Technetium-99m-MIBI SPECT may be more effective than 201TI-chloride SPECT for evaluating response to chemotherapy in patients with small cell lung cancer.
UNLABELLED: The purpose of this study was to evaluate the relationship between 99mTc-sestamibi (MIBI) accumulation by tumor and response to chemotherapy in small cell lung cancerpatients compared with 201TI-chloride. METHODS: There were 19 patients with small cell lung cancer just before chemotherapy initiation. The patients were classified by a follow-up CT into complete remission, partial remission and no change groups. All patients underwent dual-isotope imaging with 201TI-chloride and 99mTc-MIBI. Regions of interest were placed over the tumors and contralateral normal lung tissue on one coronal view with a clearly defined lesion, and the tumor-to-normal (T/N) ratio and retention index were calculated. RESULTS: Early and delayed T/N ratios for 99mTc-MIBI in complete remission and partial remission groups were significantly higher (p < 0.05) than in the no change group. There was no significant correlation between T/N ratio and tumor response using 201TI-chloride. There were no significant differences in the retention index with respect to the tumor response in both 201TI-chloride and 99mTc-MIBI SPECT images. CONCLUSION:Technetium-99m-MIBI SPECT may be more effective than 201TI-chloride SPECT for evaluating response to chemotherapy in patients with small cell lung cancer.