RT Journal Article SR Electronic T1 123I-BZA2 as a Melanin-Targeted Radiotracer for the Identification of Melanoma Metastases: Results and Perspectives of a Multicenter Phase III Clinical Trial JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 15 OP 22 DO 10.2967/jnumed.113.123554 VO 55 IS 1 A1 Cachin, Florent A1 Miot-Noirault, Elisabeth A1 Gillet, Brigitte A1 Isnardi, Vanina A1 Labeille, Bruno A1 Payoux, Pierre A1 Meyer, Nicolas A1 Cammilleri, Serge A1 Gaudy, Caroline A1 Razzouk-Cadet, Micheline A1 Lacour, Jean Philippe A1 Granel-Brocard, Florence A1 Tychyj, Christelle A1 Benbouzid, Fathalah A1 Grange, Jean Daniel A1 Baulieu, Françoise A1 Kelly, Antony A1 Merlin, Charles A1 Mestas, Danielle A1 Gachon, Françoise A1 Chezal, Jean Michel A1 Degoul, Françoise A1 D’Incan, Michel YR 2014 UL http://jnm.snmjournals.org/content/55/1/15.abstract AB Our group has developed a new radiopharmaceutical, 123I-N-(2-diethylaminoethyl)-2-iodobenzamide (123I-BZA2), a benzamide derivative able to bind to melanin pigment in melanoma cells. In a prospective and multicentric phase III clinical study, the value of 18F-FDG PET/CT and 123I-BZA2 scintigraphy was compared for melanoma staging. Methods: Patients with a past history of cutaneous or ocular melanoma were included from 8 hospitals. 18F-FDG imaging was performed according to a standard PET protocol. Whole-body, static planar, and SPECT/CT (if available) images were acquired 4 h after injection of a 2 MBq/kg dose of 123I-BZA2. 18F-FDG and 123I-BZA2 sensitivity and specificity for the diagnosis of melanoma metastasis were calculated and compared on both a lesion basis and a patient basis. True-positive and true-negative lesion status was determined after 6 mo of clinical follow-up or according to lesion biopsies (if available). Melanin content in biopsies was evaluated with the standard Fontana–Masson silver method and was correlated with 123I-BZA2 uptake. Based on statistical analysis, the number of inclusions was estimated at 186. Results: In all, 87 patients were enrolled from 2008 to 2010. Of these, 45 (52%) had metastases. A total of 338 imaging abnormalities were analyzed; 86 lesions were considered metastases, and 20 of 25 lesion biopsies found melanoma metastases. In a patient-based analysis, the sensitivity of 18F-FDG for diagnosis of melanoma metastases was higher than that of 123I-BZA2, at 87% and 39%, respectively (P < 0.05). For specificity, 18F-FDG and 123I-BZA2 were not statistically different, at 78% and 94%, respectively. In a lesion-based analysis, the sensitivity of 18F-FDG was statistically higher than that of 123I-BZA2 (80% vs. 23%, P < 0.05). The specificity of 18F-FDG was lower than that of 123I-BZA2 (54% vs. 86%, P < 0.05). According to biopsy analysis, only 9 of 20 metastatic lesions (45%) were pigmented with high melanin content. 123I-BZA2 imaging was positive for 6 of 8 melanin-positive lesions, fairly positive for 3 of 10 melanin-negative lesions, and negative for 7 of 10 melanin-negative lesions. The sensitivity and specificity of 123I-BZA2 for the diagnosis of melanin-positive lesions were 75% and 70%, respectively. Because of a low 123I-BZA2 sensitivity, this clinical trial was prematurely closed after 87 patients had been included. Conclusion: This study confirms the value of 18F-FDG PET/CT for melanoma staging and strengthens the high accuracy of 123I-BZA2 for diagnosis of melanin-positive metastatic melanoma. Moreover, benzamide derivatives radiolabeled with therapeutic radionuclide may offer a new strategy for the treatment of metastatic melanoma patients harboring melanin-positive metastases.