The preliminary study of 16α-[18F]fluoroestradiol PET/CT in assisting the individualized treatment decisions of breast cancer patients.

To evaluate the clinical value of 16α-[18F]fluoroestradiol (18F-FES) PET/CT in assisting the individualized treatment decisions of breast cancer patients.Thirty-three breast cancer patients, who underwent both 18F-FES and 18F-FDG PET/CT from July 2010 to March 2013 in our center, were enrolled in this preliminary study. All the patients used 18F-FES PET/CT as a diagnostic tool with a clinical dilemma. We used the maximum Standardized Uptake Value (SUVmax) to quantify ER expression and a cutoff value of 1.5 to dichotomize results into ER positive and negative lesions. All patients were clinically followed up at least 6 months.In evaluating equivocal lesions on conventional work-up group (n = 4), three lung lesions and another iliac lesion were enrolled. As for three lung lesions, 18F-FES PET/CT showed one lesion with high uptake, which suggested it was an ER positive metastasis. The other two lesions were 18F-FES negative, which meant an ER negative metastasis or secondary primary tumor. Additionally, one iliac lesion was detected by MRI. 18F-FDG uptake was high at the suspected lesion, whereas 18F-FES uptake was absent; In predicting origin of metastasis group (n = 2), two breast cancer patients had secondary primary tumors were collected. They were 18F-FES negative, which showed low possibility of metastasis from breast cancer and they were all confirmed by biopsy. In detecting ER status in metastasis group (n = 27), 18F-FES PET/CT showed increased 18F-FES uptake in all metastatic lesions in 11 patients; absent in all lesions in 13 patients; and the remaining 3 patients had both 18F-FES positive and negative lesions. Totally, on the basis of the 18F-FES PET/CT results, we found changes in the treatment plans in 16 patients (48.5%, 16/33).18F-FES PET/CT could assess the entire tumor volume receptor status; therefore, it may be used to assist the individualized treatment decisions of breast cancer patients

A 65-year-old female breast cancer patient, who also had renal clear cell carcinoma (RCCC), underwent ¹⁸F-FES and ¹⁸F-FDG PET/CT in our center.

<p>We detected a metastasis in mediastinal lymph node (D. CT imaging). The metastasis was no obvious ¹⁸F-FES uptake (A, C), whereas high ¹⁸F-FDG PET/CT uptake was detected (B. SUVmax = 3.9). The patient underwent an EBUS-TBNA after imaging. Histological evidence showed that the metastasis originated from RCCC.</p

A 58-year-old female breast cancer patient.

<p>We detected a mass with irregular margin in left lung (B,D. CT imaging), with a maximum diameter of 4.5cm. It was difficult to differentiate it between metastasis and secondary primary lung cancer in CT imaging. The tumor presented with high uptake of both ¹⁸F-FES and ¹⁸F-FDG PET, SUVmax was 6.3 and 5.5 respectively. It suggested that it was a metastasis (A. ¹⁸F-FES PET/CT, C. ¹⁸F-FDG PET/CT). After operation, it was confirmed to be an ER positive metastasis from breast cancer.</p