PT  - JOURNAL ARTICLE
AU  - Venema, Clasina M.
AU  - Mammatas, Lemonitsa H.
AU  - Schröder, Carolina P.
AU  - van Kruchten, Michel
AU  - Apollonio, Giulia
AU  - Glaudemans, Andor W.J.M.
AU  - Bongaerts, Alfons H.H.
AU  - Hoekstra, Otto S.
AU  - Verheul, Henk M.W.
AU  - Boven, Epi
AU  - van der Vegt, Bert
AU  - de Vries, Erik F.J.
AU  - de Vries, Elisabeth G.E.
AU  - Boellaard, Ronald
AU  - Menke van der Houven van Oordt, Catharina W.
AU  - Hospers, Geke A.P.
TI  - Androgen and Estrogen Receptor Imaging in Metastatic Breast Cancer Patients as a Surrogate for Tissue Biopsies
AID  - 10.2967/jnumed.117.193649
DP  - 2017 Dec 01
TA  - Journal of Nuclear Medicine
PG  - 1906--1912
VI  - 58
IP  - 12
4099  - http://jnm.snmjournals.org/content/58/12/1906.short
4100  - http://jnm.snmjournals.org/content/58/12/1906.full
SO  - J Nucl Med2017 Dec 01; 58
AB  - In addition to the well-known estrogen receptor (ER) and human epidermal growth factor receptor 2, the androgen receptor (AR) is also a potential drug target in breast cancer treatment. Whole-body imaging can provide information across lesions within a patient. ER expression in tumor lesions can be visualized by 18F-fluoroestradiol (18F-FES) PET, and AR expression has been visualized in prostate cancer patients with 18F-fluorodihydrotestosterone (18F-FDHT) PET. Our aim was to assess the concordance between 18F-FDHT and 18F-FES PET and tumor AR and ER expression measured immunohistochemically in patients with metastatic breast cancer. Methods: Patients with ER-positive metastatic breast cancer were eligible for the study, irrespective of tumor AR status. The concordance of 18F-FDHT and 18F-FES uptake on PET with immunohistochemical expression of AR and ER in biopsies of corresponding metastases was analyzed. Patients underwent 18F-FDHT PET and 18F-FES PET. A metastasis was biopsied within 8 wk of the PET procedures. Tumor samples with more than 10% and 1% nuclear tumor cell staining were considered, respectively, AR- and ER-positive. Correlations between PET uptake and semiquantitative immunohistochemical scoring (percentage positive cells × intensity) were calculated. The optimum threshold of SUV to discriminate positive and negative lesions for both AR and ER was determined by receiver-operating-characteristic analysis. Results: In the 13 evaluable patients, correlation (R2) between semiquantitative AR expression and 18F-FDHT uptake was 0.47 (P = 0.01) and between semiquantitative ER expression and 18F-FES uptake 0.78 (P = 0.01). The optimal cutoff for AR-positive lesions was an SUVmax of 1.94 for 18F-FDHT PET, yielding a sensitivity of 91% and a specificity of 100%; the optimal cutoff was an SUVmax of 1.54 for 18F-FES PET, resulting in a sensitivity and specificity of 100% for ER. Conclusion: 18F-FDHT and 18F-FES uptake correlate well with AR and ER expression levels in representative biopsies. These results show the potential use of whole-body imaging for receptor status assessment, particularly in view of biopsy-associated sampling errors and heterogeneous receptor expression in breast cancer metastases.