Targeting disseminated melanoma with radiolabelled methylene blue: Comparative bio-distribution studies in man and animals.

Abstract

Targeted radiotherapy for pigmented melanoma with 3,7-(dimethylamino) phenazathionium chloride [methylene blue (MTB)] labelled with Astatine-211 (211At; alpha-particle emitter) proved to be very effective in animal model systems. Since the results justified an introduction of the treatment to the clinic, the aim of the bio-distribution studies using [123I]-MTB and [131I]-MTB in patients was to confirm selectiveness of radiolabelled MTB uptake in melanoma lesions. The investigations were carried out using planar and SPECT (single photon emission computed tomography) gamma-cameras. A stable uptake of radioiodinated MTB was found in pigmented melanomas in man, with tumour/surrounding tissue and tumour/blood ratios amounting to 9 at 19 h after a single i.v. injection. A time-dependent kinetics of radioiodinated MTB distribution was similar to that observed in human melanoma-bearing athymic mice. Blood radioactivity decreased by about 90% during the first 2.5 min after i.v. injection of the compound (T1/2biol = 0.58 min). Its retention time in various organs was either the same or very similar to that characteristic of the blood. A rapid uptake of radioiodinated MTB in the liver and kidneys confirmed the importance of these organs in excreting the compound: 25-30% of the radioactivity administered was expelled with urine over the first 24 h after the injection. There was no obvious retention of radioiodinated MTB in the brain over the observation period and in the eyes for at least the first 14 h.

• Authors: E M Link, D C Costa, D Lui, P J Ell, P J Blower, M F Spittle
• Journal: Acta oncologica (Stockholm, Sweden) (Acta Oncol) Vol. 35 Issue 3 Pg. 331-41 ( 1996) ISSN: 0284-186X [Print] England
• PMID: 8679265 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Coloring Agents
• Iodine Radioisotopes
• Methylene Blue

Topics

• Adult
• Aged
• Animals
• Brain (metabolism)
• Coloring Agents (administration & dosage, pharmacokinetics)
• Disease Models, Animal
• Eye (metabolism)
• Female
• Humans
• Injections, Intravenous
• Iodine Radioisotopes (blood, pharmacokinetics, urine)
• Kidney (metabolism)
• Liver (metabolism)
• Male
• Melanoma (diagnostic imaging, radiotherapy)
• Methylene Blue (administration & dosage, pharmacokinetics)
• Mice
• Mice, Nude
• Middle Aged
• Neoplasm Transplantation
• Time Factors
• Tissue Distribution
• Tomography, Emission-Computed, Single-Photon (methods)
• Transplantation, Heterologous