PT  - JOURNAL ARTICLE
AU  - Chang, Chih-Chao
AU  - Lin, Ming-Hsien
AU  - Shen, Chih-Chieh
AU  - Chen, Chuan-Lin
AU  - Liu, Ren-Shyan
AU  - Wang, Hsin-Ell
TI  - Synthesis and evaluation of a novel radioiodinated phenylacetamide as a SPECT probe for malignant melanoma
DP  - 2014 May 01
TA  - Journal of Nuclear Medicine
PG  - 501--501
VI  - 55
IP  - supplement 1
4099  - http://jnm.snmjournals.org/content/55/supplement_1/501.short
4100  - http://jnm.snmjournals.org/content/55/supplement_1/501.full
SO  - J Nucl Med2014 May 01; 55
AB  - 501 Objectives Melanoma is one of the most deadly cancers around the world. Melanin is an attractive target of malignant melanoma for diagnosis and treatment. This study reports N-(2-(diethylamino)ethyl)-2-(4-hydroxy-3-123/131I-iodophenyl)acetamide (123/131I-IPA) as a novel SPECT probe for imaging malignant melanoma. Methods 123/131I-IPA can be prepared from a self-synthesized precursor via oxidative radioiodination with high radiochemical yield (>70%) and high radiochemical purity (>95%). Biological characterizations including cellular uptake, biodistribution and microSPECT imaging were performed in mice bearing various melanomas. Results 123/131I-IPA is hydrophilic (log P = -0.76±0.04) and exhibited good in vitro stability (radiochemical purity >95% after a 24-h incubation) in human serum. 123/131I-IPA exhibited a high affinity (88.78±0.66 %AD) to synthetic melanin (0.5 mg/10 mL) after 1 h of incubation. A rapid and high uptake of 123/131I-IPA by B16F0 melanoma cells after 0.25, 1 and 4 h of incubation was observed (10.07±0.45, 15.62±0.72 and 19.22±0.62 %AD/106 cells, respectively), while that by amelanonic A375 cells was much lower (1.62±0.13, 1.30±0.11 and 0.90±0.05 %AD/106 cells, respectively). A remarkable accumulation in melanoma and eyeballs of C57BL6 mice post intravenous injection (p.i.) was noticed. The tumor-to-muscle ratio was 17.5, 26.3 and 62.0 at 1, 4 and 24 h p.i., respectively, consistent with those observed in microSPECT imaging which displayed a high contrast B16F0 melanoma lesion. Conclusions Our studies demonstrated that 123/131I-IPA, a novel phenylacetamide derivative, is a melanin-specific agent for imaging malignant melanoma with SPECT. Research Support This study was supported by grants from National Science Council, Taiwan (NSC 100-2314-B-010-013 and NSC 101-2314-B-010-044-MY3) and Cheng Hsin General Hospital, Taiwan (102F218C08)