Detection of lung and chest tumours using⁹⁹tc^m-tetrofosmin comparison with ²⁰¹t1

The aim of this study was to assess the usefulness of ⁹⁹Tc^m-tetrofosmin for detecting tumours of the lungs and adjacent structures and to compare the results with those for ²⁰¹T1. In the 18 patients studied, there were 30 lesions in total. Dual-isotope SPET acquisitions were performed 10 min and 3 h after the administration of ⁹⁹Tc^m-tetrofosmin and ²⁰¹T1. Image quality and semi-quantitative parameters were evaluated for both tracers. All lesions were detected by the two radiopharmaceuticals on both the early and delayed images. In seven patients, the image quality of ⁹⁹Tc^m-tetrofosmin was better than that of ²⁰¹T1. For the detection of metastatic lymph nodes, the delayed ²⁰¹T1 and the early ⁹⁹Tc^m-tetrofosmin images were superior. No significant difference was observed between the uptake ratios of the two tracers. ⁹⁹Tc^m-tetrofosmin showed significantly (P < 0.001) higher washout than ²⁰¹T1 from both the lesions and normal lungs, although washout of ²⁰¹T1 from normal lungs was significantly higher than that from the lesions. In conclusion, ⁹⁹Tc^m-tetrofosmin may be helpful for detecting tumours of the lungs and adjacent structures, but has limited applicability in differentiating between malignant and benign tumours and may not be used instead of ²⁰¹T1 to detect malignant tumours of the lungs.