Background: Melanin-targeting radiotracers are interesting tools for imaging and treatment of pigmented melanoma metastases. However, variation of the pigment concentration may alter the efficiency of such targeting.
Objectives: A clear assessment of both tumor melanin status and dosimetry are therefore prerequisites for internal radiotherapy of disseminated melanoma.
Materials & methods: The melanin tracer ICF01012 was labelled with iodine-123 for melanoma imaging in pigmented murine B16F0 and human SK-Mel 3 melanomas.
Results: In vivo imaging showed that the uptake of [(123)I]ICF01012 to melanomas correlated significantly with melanin content. Schedule treatment of 3 × 25 MBq [(131)I]ICF01012 significantly reduced SK-Mel 3 tumor growth and significantly increased the median survival in treated mice. For this protocol, the calculated delivered dose was 53.2 Gy.
Conclusion: Radio-iodinated ICF01012 is a good candidate for both imaging and therapeutic purposes for patients with metastatic pigmented melanomas.
Keywords: dosimetry; imaging; melanin; melanoma; radiotracer; targeted radionuclide therapy.