Vol.:(0123456789) 1 3 Annals of Nuclear Medicine https://doi.org/10.1007/s12149-019-01364-7 ORIGINAL ARTICLE Distribution pattern of FDG uptake using ring‑type dedicated breast PET in comparison to whole‑body PET/CT scanning in invasive breast cancer Rena Sakaguchi 1  · Masako Kataoka 1  · Shotaro Kanao 2  · Kanae K. Miyake 1  · Yuji Nakamoto 1  · Tomohatru Sugie 3  · Masakazu Toi 4  · Yoshiki Mikami 5  · Kaori Togashi 1 Received: 11 March 2019 / Accepted: 3 May 2019 © The Japanese Society of Nuclear Medicine 2019 Abstract Purpose This study aimed to investigate the incidence of rim uptake (RU) or multifocal uptake (MU) by invasive breast cancers on a ring-type dedicated breast positron emission tomography (dbPET) scanner compared with whole-body PET (wbPET) scanner imaging and to correlate uptake patterns with pathological features and prognosis. Methods Between 2009 and 2011, 76 lesions in 74 patients with primary invasive breast cancers were included. Each patient underwent dbPET and wbPET scanning on the same day after administration of 18 F-fuorodeoxyglucose (FDG). The images were evaluated to identify specifc uptake patterns (RU and MU). Their association with pathological characteristics and prognosis was analyzed. Results On dbPET, RU and MU patterns were observed in 18 lesions (24%) and 28 lesions (37%), respectively. On wbPET, RU and MU patterns were observed in six lesions (8%) and 17 lesions (22%), respectively. Lesions with RU on dbPET were of higher grade than lesions without RU (P = 0.024) and a higher Ki-67 index (mean; 31% vs. 18%, P = 0.015). They tended to be triple-negative (33% vs. 12%, P = 0.046) and less likely to be luminal A subtype (17% vs. 47%, P = 0.020). On wbPET, however, no signifcant diferences in these markers were seen between RU and non-RU. The MU pattern did not correlate with pathological characteristics in either scanner. Lesions with RU or MU were not signifcantly associated with disease-free survival. Conclusions DbPET can identify detailed FDG distribution patterns of breast cancer better than wbPET. Breast cancer with RU on dbPET was associated with higher grade and triple-negative subtype. Keywords Ring-type dedicated breast PET · PET/CT · Breast cancer · Triple negative subtype · Ki-67 index Introduction Breast cancer is a heterogeneous disease which comprises of different biological characteristics and clinical out- comes. The Nottingham (Elston–Ellis) modification of the Scarf–Bloom–Richardson histopathological grading system, also known as the Nottingham Grading System (NGS), is commonly accepted as a powerful indicator of aggressiveness, useful for prognosis [1]. Gene expression profling is another system linked to prognosis and treatment selection. It uses a simplifed immunohistochemical classi- fcation using estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) oncogene expression and/or amplifcation [2]. Ki-67 [3] is a nuclear protein present in all proliferating cells and its index is used as a proliferation marker [4, 5]. The status of these markers can identify the four main intrinsic subtypes of breast cancer: luminal A, luminal B, HER2-enriched, and triple negative [6]. Positron emission tomography (PET) with 18 F-fuorode- oxyglucose (FDG), often combined with computed tomog- raphy (PET/CT) has been widely used for the evaluation of breast cancer patients, for staging and assessment of This work was supported by Shimadzu Co., Kyoto, Japan, and a Grant-in-Aid for Scientifc Research from the Ministry of Education, Culture, Sports, Science and Technology of Japan (C:22591329). * Masako Kataoka makok@kuhp.kyoto-u.ac.jp Extended author information available on the last page of the article