Association of morphological and quantitative parameters on dedicated breast PET with the expression status of hormone receptors, HER2 and Ki-67 in breast cancers

• Published in: The Journal of nuclear medicine (1978) Vol. 58; p. 1055
• Main Authors: Miyake, Kanae, Ikeda, Debra, Iagaru, Andrei, Quon, Andrew, Daniel, Bruce, Lipson, Jafi, Pal, Sunita, Mittra, Erik, Guo, Haiwei, Nakamoto, Yuji, Nishimatsu, Kayo, Kanao, Shotaro, Kataoka, Masako, Togashi, Kaori
• Format: Journal Article
• Language: English
• Published: New York Society of Nuclear Medicine 01-05-2017
• Subjects: Breast; Breast cancer; ErbB-2 protein; Estrogen receptors; Estrogens; Feature recognition; Females; Heterogeneity; Hormones; Magnetic resonance imaging; Medical imaging; Medical personnel; NMR; Nuclear magnetic resonance; Nuclear medicine; Oncology; Patients; Physical characteristics; Physicians; Positron emission; Positron emission tomography; Progesterone; Progesterone receptors; Prone position; Receptors; Tomography; Tumors
• ISSN: 0161-5505; 1535-5667

Objectives: High-resolution 3D dedicated breast PET (dbPET) allows identification of more detailed morphological characteristics of tumor uptake compared to conventional PET. The aim of this study was to see if tumor uptake features, including morphological and quantitative features, on dbPET has any associations with molecular expression status in breast cancers, with comparison to conventional whole-body PET (WB-PET) and dynamic contrast enhanced (DCE)-MRI. Methods: A total 35 females (32-80 yrs) with histologically proven invasive breast cancers who underwent 18F-fluorodeoxyglucose (FDG) WB-PET, FDG dbPET with a ring-shaped scanner, and DCE-MRI before treatment were included in this study. All imaging studies were performed with patients in the prone position. Each patient had one index tumor that was shown as a mass with a minimal diameter of 1 cm on DCE-MRI and was entirely included within FOV on dbPET. Morphological features, including tumor shape, margin, internal heterogeneity, and presence of rim sign, of index tumors on WB-PET, dbPET, and DCE-MRI were determined based on independent visual assessment by 4 readers (2 nuclear medicine physicians and 2 breast radiologists). Quantitative values, including SUVmax of tumor uptake on WB-PET and dbPET and tumor size on DCE-MRI, were also obtained. The relationships between the morphological and quantitative imaging variables and the expression status of estrogen (ER) and progesterone receptors (PgR), HER2 receptor and Ki-67, that were immunohistochemically determined, were examined using Fisher's exact test and Mann-Whitney's U test. Results: Tumor shape was classified as oval/round vs. irregular in 33 vs. 2 on WB-PET, 17 vs. 18 on dbPET, and 8 vs. 27 on DCE-MRI. Tumor margin was smooth/circumscribed vs. not-smooth/not-circumscribed in 34 vs. 1 on WB-PET, 12 vs. 35 on dbPET, and 7 vs. 28 on DCE-MRI. Internal pattern was homogeneous vs. heterogeneous in 33 vs. 2 on WB-PET, 8 vs. 27 on dbPET, and 1 vs. 34 on DCE-MRI. Rim sign was positive in 0 on WB-PET, 10 on dbPET, and 5 on DCE-MRI. SUVmax ranged from 1.3 to 15.4 on WB-PET and from 2.4 to 26.8 on dbPET. Tumor size was 10 to 57 mm on DCE-MRI. With respect to molecular expression status, ER expression status was significantly and negatively associated with rim sign on dbPET (p=0.043): tumors with rim sign on dbPET were more frequently negative for ER (4/10, 40%) than those without rim sign (2/25, 8%). PgR status had no associations with any imaging variables. HER2-positivity was significantly and positively associated with irregular shape on dbPET (p=0.046) and larger tumor size on DCE-MRI (p=0.005). Ki67 ³ 14% was significantly associated with circumscribed margins on DCE-MRI (p=0.031). There was a tendency that tumors with Ki67 ³ 14% had higher SUVmax on dbPET; however, it was marginally insignificant (p=0.054). None of imaging features on WB-PET were related to the molecular expression status. Conclusion: This study demonstrated that morphological features of tumor uptake recognizable on dbPET, such as rim sign and irregular shape, may be associated with the molecular expression status in breast cancers.