Tumor imaging with carbon-11 labeled alpha-aminoisobutyric acid (AIB) in a patient with advanced malignant melanoma

Abstract

A 29 year-old-man presenting with advanced metastatic malignant melanoma was successfully imaged using carbon-11 (11C) labeled alpha-aminoisobutyric acid (AIB), a synthetic, non-metabolized amino acid transported into viable cells by the A-type, or alanine-preferring, amino acid transport system. Tumor located in the hilum of the lung was well visualized with 11C-AIB prior to chemotherapy. A gallium image with liver subtraction using 99mTc-sulfur colloid demonstrated regions of increased activity in liver which correlated with regions of increased activity on the 11C-AIB liver image.

Radiohalogenated nonnatural amino acids as PET and SPECT tumor imaging agents

“…In these studies, AIB generally demonstrated good tumor imaging properties, although the uptake in the spontaneous canine tumors was variable. PET studies performed with [ 11 C]AIB in a small number of patients with melanoma demonstrated increased uptake in tumor relative to normal tissues in most but not all of the melanoma tumors . Similarly, in two patients with soft tissue sarcomas, [ 11 C]AIB demonstrated good tumor visualization .…”

“…To date, the majority of radiolabeled amino acids for tumor imaging target system L transporters, and many of these tracers are derivatives of the natural amino acids L ‐phenylalanine and L ‐tyrosine, including L ‐3‐[ 123 I]iodo‐α‐methyl tyrosine (IMT), O ‐(2‐[ 18 F]fluoroethyl)‐ L ‐tyrosine (FET), and L ‐3,4‐dihydroxy‐6‐[ 18 F]fluorophenylalanine (FDOPA) . To a lesser extent, radiolabeled amino acids targeting system A amino acid transport, such as α‐aminoisobutyric acid (AIB) and its N ‐methyl analog MeAIB have been evaluated for tumor imaging …”

Non-natural amino acids for tumor imaging using positron emission tomography and single photon emission computed tomography

“…Initial studies with radiolabeled AIB in animals including murine melanoma xenograft and canine spontaneous tumor models demonstrated uptake in some but not all tumors [187,188]. Studies of [ 11 C]AIB in a small number of patients with soft tissue sarcomas and melanoma showed good uptake in the majority of the known tumors [177,178,189]. The high degree of regulation of system A transport by factors such as amino acid availability [51,[63][64][65]190] has been proposed as a major source of this observed variability.…”

Synthesis and biological properties of radiohalogenated α,α‐disubstituted amino acids for PET and SPECT imaging of amino acid transporters (AATs)

“…The syn-and anti-3-IVACBC and gem-3-IVACBC stannylated precursors (68)(69)(70) were obtained from the corresponding iodo-derivatives (56,57,59), respectively, as shown in Scheme 14. 47 There are several advantages to using organotin precursors.…”

“…For use in PET studies, AIB has been labeled with carbon-11 at the carboxylic acid position ([1-11 C]AIB), [52][53][54][55][56] at the α-carbon position ([2-11 C]AIB), 57,58 and at the αmethyl position ([3-11 C]AIB). 59,60 Similarly, MeAIB has been labeled at the α-carbon position ([2-11 C]MeAIB) 57 and at the N-methyl position ([N-methyl-11 C]MeAIB). 61 Preliminary evaluation of [2-11 C]AIB and [N-methyl- 11 C] MeAIB has shown promise for PET tumor imaging in patients with chest and other malignancies.…”