The role of technetium-99m methoxyisobutyl isonitrile scintigraphy in suspected recurrent breast cancer.

The aim of this study was to determine the role of technetium-99m methoxyisobutyl isonitrile (99mTc-MIBI) scintigraphy in the evaluation of recurrence and metastases in breast cancer patients with mastectomy and/or radiotherapy. A prospective study was designed to assess the accuracy of 99mTc-MIBI scintigraphy in 36 patients (mean age 49 years) with suspected recurrent breast cancer. The scintigraphic studies were correlated with radiological findings and/or with histopathology. At 10-15 min after 740MBq 99mTc-MIBI injection, standard planar images were obtained in prone lateral and anterior supine views and then single-photon emission computed tomography (SPECT) imaging was performed. A whole body imaging was also performed to demonstrate distant metastatic lesions. Totally 52 lesions were evaluated which 19 of them in 9 patients were malignant, while 33 lesions in 27 patients were benign. The sensitivity was 33%, 88% and the specificity was 96%, 93% for planar and SPECT imaging, respectively in loco-regional lesions. Overall, the sensitivity and the specificity of MIBI imaging including whole body were 89%, 81%, in other conventional radiological imaging methods were 95%, 65%, respectively. 99mTc-MIBI scintigraphy using SPECT imaging may provide useful complementary information in patients with suspected recurrence breast cancer.