F-18 fluoro-deoxy-glucose and F-18 sodium fluoride cocktail PET/CT scan in patients with breast cancer having equivocal bone SPECT/CT.
BACKGROUND
Although single-photon emission computed tomography (SPECT)/computed tomography (CT) plays a major role in the characterization of equivocal lesions on bone scintigraphy, it remains equivocal in a fraction of these patients. We evaluated the additional value of cocktail F-18 sodium fluoride (18F-NaF) and F-18 fluorodeoxyglucose (18F-FDG) co-injection positron emission tomography (PET) (cocktail PET) in these patients.


METHODS
Fifteen breast cancer patients, who had equivocal findings on the whole body bone scan (WBS) and SPECT/CT, were subjected to a cocktail PET/CT scan. The cocktail PET/CT was performed by co-administration of 18F-FDG and 18F-NaF in a ratio of about 2.4, with the total administered activity kept at approximately 10 mCi.


RESULTS
Of the 15 patients, seven were with locally advanced breast cancer (LABC) and the other eight were referred because of suspicion of recurrent disease on follow-up. Of the seven patients with LABC, the cocktail PET scan was positive for all the lesions suspicious on WBS and SPECT/CT. Additionally, it showed uptake in the primary tumor and ipsilateral axillary lymph nodes as well as identified additional osseous, lymph nodal, and solid organ metastases in these patients. Similarly, of the eight patients studied for suspicion of recurrence, the cocktail PET scan was found to be positive in seven patients. In three patients, additional osseous lesions were noted.


CONCLUSIONS
The cocktail PET/CT scan can characterize almost all the suspicious equivocal lesions on the bone scan and SPECT/CT. The distinct advantage of identifying lymph nodal and solid organ metastases allows it to be considered as a useful imaging modality in patients with equivocal bone SPECT/CT.
Department of Nuclear Medicine and PET, Postgraduate Institute of Medical Education and Research, Chandigarh, U.T., India.
Chidambaram Natrajan Balasubramanian
CN
Harisankar
Department of Nuclear Medicine and PET, Postgraduate Institute of Medical Education and Research, Chandigarh, U.T., India.
Kanhaiyalal
K
Agrawal
Department of Nuclear Medicine and PET, Postgraduate Institute of Medical Education and Research, Chandigarh, U.T., India.
Anish
A
Bhattacharya
Department of Nuclear Medicine and PET, Postgraduate Institute of Medical Education and Research, Chandigarh, U.T., India.
Bhagwant Rai
BR
Mittal
Breast cancer; F-18 fluorodeoxyglucose positron emission tomography/computed tomography; F-18 sodium fluoride; bone single-photon emission computed tomography/computed tomography; cocktail scan