TY - JOUR T1 - Assessment of SPECT-CT fusion images and semi-quantitative evaluation using SUV parameter of I-123 IMP SPECT in patients with ocular choroidal melanoma. JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1271 LP - 1271 VL - 60 IS - supplement 1 AU - Kana Yamazaki AU - Ryuichi Nishii AU - Tatsuya Higashi AU - Hirokazu Makishima AU - Goro Kasuya AU - Tachen Chang AU - Hiroshi Tsuji AU - Koji Murakami AU - Keiichiro Yoshinaga AU - Tadashi Kamada Y1 - 2019/05/01 UR - http://jnm.snmjournals.org/content/60/supplement_1/1271.abstract N2 - 1271Objectives: Choroidal melanoma is the most common primary ocular malignant tumor. I-123 IMP SPECT imaging was reported to be useful diagnostic imaging tool, however the semi-quantitative diagnostic values in terms of assessment of fused image with CT and the semi-quantitative evaluation of the IMP-SPECT are still left to be discussed. Recently researchers have developed a novel method to assess semi-quantitative uptake value using SUV in evaluation of bone SPECT scan. The aim of this study is to assess the usefulness SPECT-CT fusion images and to assess an unique semi-quantitative evaluation applying SUV parameter to IMP-SPECT in patients with ocular choroidal melanoma. Methods: Among patients who were diagnosed ocular choroidal melanoma histopathologically and visited our institution for carbon-ion radiotherapy, 14 patients (10 males, 4 females) who received IMP-SPECT imaging were enrolled in this investigation. The mean age of patients is 57.1+/- 11.9 (ranged from 33 to 74) years old. Fifteen min and 6 or 24 hours after intravenous injection of 205 +/- 14 MBq of I-123 IMP, SPECT imaging was performed using a gamma camera. All acquired SPECT images were fused with CT images using an image-analysis software. Volume of interests (VOIs) of the tumor and the contralateral normal choroidal tissue referring to CT image were analyzed, followed by semi-quantitative evaluations by SUV measurement such as SUV max, SUV mean and SUV peak were assessed. And the correlation between SUV value of the tumor and the size categories of the tumors according to UICC criteria was also assessed. Results: All tumors were visualized clearly in the 6 or 24h-SPECT image than those in 15min-SPECT image. SUV max of the tumor and the contralateral choroidal tissue were 5.10 +/- 1.43 and 2.17 +/- 0.54, respectively (non-parametric Wilcoxon rank sum test, p < 0.001). SUV value was significantly higher in the tumor. According to the size categories of UICC, patients were classified into category 1 to 4. In the assessment of the correlation between SUV value and size categories, significant correlation was found in SUV max of the tumor by size category 1-4 tumor; 3.06 +/- 2.23, 5.23 +/- 0.77, 5.06 +/- 1.44 and 6.41 +/- 0.91, respectively (p < 0.05, between category 1 and 4). SUV max of the normal choroidal tissue of each category were 2.38 +/- 0.53, 2.47 +/- 0.30, 2.23 +/- 0.63 and 1.60 +/- 0.20, respectively (n.s.). Conclusions: I-123 IMP SPECT imaging performed 6h or 24h after injection of the radiotracer and fusion-image-analysis with CT were useful for detection of the ocular choroidal melanoma. And semi-quantitative evaluation using the fused images assessed by SUV is considered to be a valuable imaging technique for diagnosing ocular choroidal melanoma. ER -