Association of intratumoral pharmacokinetics of fluorouracil with clinical response.
In-vivo fluorine-19 nuclear magnetic resonance spectroscopy (NMRS) allows non-invasive, real-time, chemical identification of specific fluorinated compounds inside human tumours after administration of fluorouracil (5-fluorouracil). Kinetic measures of the administered drug and metabolites allow estimation of the tumoral half-life of fluorouracil. We studied 57 patients by 19F NMRS immediately after they had received 600 mg/m2 fluorouracil intravenously. Serial spectra were acquired with the surface coil positioned on the skin above the tumour. We defined an intratumoral half-life of fluorouracil of 20 min or more as indicating trapping of the drug, based on the blood half-life of 8-12 min. 19 patients had intratumoral half-lives indicating trapping of fluorouracil, 27 had half-lives less than 20 min, and 11 had no detectable fluorouracil in their tumours. 8 of 9 evaluable patients whose tumours showed trapping had partial responses to chemotherapy that included fluorouracil compared with only 2 of 25 patients whose tumours did not trap the drug (p = 0.000021). 19F NMRS can identify patients likely to respond to chemotherapy with fluorouracil and could be used clinically to tailor optimum treatment.
Presant
C A
CA
Center for Noninvasive Pharmacology, Los Angeles Oncologic Institute, St Vincent Medical Center, CA 90057.
Wolf
W
W
Waluch
V
V
Wiseman
C
C
Kennedy
P
P
Blayney
D
D
Brechner
R R
RR
D005472:Fluorouracil / Q000493:pharmacokinetics* / Q000627:therapeutic use; D006207:Half-Life; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D009369:Neoplasms / Q000188:drug therapy / Q000378:metabolism*; D016896:Treatment Outcome
D005472:Fluorouracil