RT Journal Article SR Electronic T1 SiPM-based vs LYSO-based 68Ga-DOTA-TATE PET/CT: Comparison of Semi-Quantitative Measurements in Normal Tissues and Lesions JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 430 OP 430 VO 59 IS supplement 1 A1 Lucia Baratto A1 Akira Toriihara A1 Negin Hatami A1 Guido Davidzon A1 Shyam Srinivas A1 Sanjiv Gambhir A1 Andrei Iagaru YR 2018 UL http://jnm.snmjournals.org/content/59/supplement_1/430.abstract AB 430Purpose: To compare the performance of a silicon photomultiplier (SiPM)-based PET/CT scanner (DMI) and a LYSO-based PET/CT scanner (D690) used in our clinic and to determine any differences in semi-quantitative measurements. Methods: We prospectively enrolled patients referred for 68Ga-DOTA-TATE PET/CT. All patients underwent a single 68Ga-DOTA-TATE injection dual imaging protocol: they were randomly scanned first on the D690 or the DMI scanner. SUVmax of different normal tissues and all detectable lesions from data acquired using both scanners were measured and recorded. RESULTS: Data from 21 patients (35-79 year-old; 21 women, 6 men) was analyzed. The mean±SD 68Ga-DOTA-TATE dosage was 5.9 ± 0.8 mCi (range 4 - 7 mCi). Eleven patients out of 21 (52%) underwent DMI as first scan and a total of 42 lesions were detected on both scanners; 10 patients out of 21 (48%) performed D690 PET/CT as first scan and a total of 33 lesions were seen on both scanners. Regardless of whether DMI was performed first or second, average SUVmax of lesions measured on DMI was higher. The agreement analysis for different normal tissues indicated that these measurements from the two scanners were similar regardless of scan order, except for pituitary and parotid (Table 1). CONCLUSIONS: We observed higher SUVmax values for lesions measured from DMI compared to D690 regardless of the order of the scan, while the measurements were similar for normal tissues. While delayed imaging can lead to higher SUVmax values in cancer lesions, in the series of lesions identified when DMI was performed as first scan this was not seen; therefore, the data suggests superior performance of the DMI scanner.