19F-magnetic resonance spectroscopy in patients with liver metastases of colorectal cancer treated with 5-fluorouracil.

The purpose of this study was to examine the uptake and metabolism of 5-fluorouracil (5-FU) in human liver metastases. Patients with liver metastases of colorectal cancer were treated with 5-FU (500/600 mg/m)+folinic acid with or without trimetrexate. The clinical application of F-magnetic resonance spectroscopy (MRS) of 5-FU in a random group of patients (n=17) was investigated. MR spectra of all patients showed 5-FU and catabolite resonances, and fluoronucleotides were also seen in seven patients. A correlation was found between maximum levels of 5-FU catabolites as measured by F-MRS and response in a group with larger metastases. However, such correlation was not observed in a group with smaller metastases, probably because of a significant contribution of normal liver tissue to the MR spectra.