Gastrin-Releasing Peptide Receptor Imaging in Human Breast Carcinoma Versus Immunohistochemistry

¹ Department of Nuclear Medicine, Ghent University Hospital, Ghent, Belgium; Department of Nuclear Medicine and Molecular Imaging, University Medical Centre, Groningen, The Netherlands
² Department of Anatomopathology, Ghent University Hospital, Ghent, Belgium
³ Department of Nuclear Medicine, Ghent University Hospital, Ghent, Belgium
⁴ Division of Gynaecological Oncology, Ghent University Hospital, Ghent, Belgium
⁵ Department of Medical Oncology, Ghent University Hospital, Ghent, Belgium

^* To whom correspondence should be addressed. E-mail: christophe.vandewiele{at}ugent.be.

	Abstract

This study reports on the uptake of ^99mTc-RP527 by human breast carcinoma and its relationship to gastrin-releasing peptide receptor (GRP-R) expression as measured by immunohistochemistry (IHC). Methods: Nine patients referred because of a clinical diagnosis suggestive of breast carcinoma and 5 patients with tamoxifen-resistant bone-mestastasized breast carcinoma underwent ^99mTc-RP527 scintigraphy. The findings were compared with routine staging examinations in all patients and with routine histology and IHC GRP-R staining in the first 9 patients. All 9 patients with suspected breast lesions were tumor positive. Results: The uptake of ^99mTc-RP527 was evident in the primary tumor in 8 of 9 patients and in involved lymph nodes and part of the distant metastasis limited to the bone when present. ^99mTc-RP527 uptake was not found in any of the tamoxifen-resistant patients. Conclusion: Uptake by primary breast carcinoma was significantly correlated with the presence of GRP-Rs as assessed by means of IHC.