Two Cases of Primary Malignant Melanoma Treated by Selective Melanoma Thermal Neutron Capture Therapy

Abstract

In 1972, the study of Selective Melanoma Thermal Neutron Capture Therapy (Selective-Melanoma NCT) was initiated by Mishima’s group¹⁾. In order to apply the theory that reaction products between ¹⁰B and neutrons can destroy cells containing ¹⁰B ²⁾, ¹⁰B had to be transported into malignant melanoma (Mm) cells. For that purpose, ¹⁰B₁-para-borono-phenylalanine (¹⁰B₁-BPA) was synthesized. It is a precursor dopa analogue and accumulates in melanosomes within Mm cells (Fig 1) ^3,4). ¹⁰B₁-BPA was complexed with fructose so that it could be soluble at pH near 7.4 (almost equal to blood pH) and be suitable for Selective-Melanoma NCT ⁵⁾. The first clinical application to metastatic Mm was performed successfully in 1987 ^{1, 6–8)}. Since then 16 cases of Mm have been treated. Here we report a case of lentigo maligna melanoma on the right face and a case of acral lentiginous melanoma on the right sole, treated by Selective-Melanoma NCT.