Tc-99m MIBI, Tc-99m Tetrofosmin, 그리고 Tc-99m (V) DMSA 스캔에 의해 발견된 재발성 악성 흉선종

Recurrent Malignant Thymoma Detected by Tc-99m MIBI, Tc-99m Tetrofosmin and Tc-99m (V) DMSA Scan

Thymoma is the most common primary tumor of anterior mediastinum, accounting for 20% to 30% of all mediastinal tumors. The recurrence rate after total resection of the thymoma ranges 8% to 18%. We reported one patient of recurrent malignant thymoma imaged with Tc-99m MIBI, Tc-99m Tetrofosmin and Tc-99m (V) DMSA. Early and delayed Tc-99m MIBI and Tc-99m Tetrofosmin scintigraphies showed an increased uptake in the mediastinal area. Also, Tc-99m (V) DMSA scintigraphy revealed an increased uptake tn the corresponding area. Coronal SPECT images of Tc-99m MIBI, Tc-99m Tetrofosmin and Tc-99m (V) DMSA revealed increased uptake of each radiopharmaceutical in the tumor lesion corresponding to the mediastinal lesion on the chest CT. However, the normal blood pool activities of the heart and great vessels of Tc-99m (V) DMSA obscured the recurrent malignant thymoma. Although Tc-99m (V) DMSA is a useful tumor seeking agent, we recommend Tc-99m MIBI and Tc-99m Tetrofosmin SPECT rather than Tc-99m (V) DMSA to detect primary and recurrent malignant thymoma.