³¹P NMR spectra of extremity sarcomas: Diversity of metabolic profiles and changes in response to chemotherapy

Abstract

We have used 31P NMR spectroscopy to study 22 patients with suspected sarcomas prior to any treatment. The spectra are characterized by the same peaks noted in murine tumors. The mean pH was 7.14 +/- 0.08 and PCr/Pi was 1.18 +/- 0.83. Comparison of pH and PCr/Pi ratios in human and a murine tumor with a low hypoxic cell fraction revealed no significant differences. Six patients subsequently received chemotherapy and three responded to therapy (based on pathologic examination and/or tumor reduction greater than 50%). The three responding patients were noted to have significantly lower PDE/PME in their pretreatment spectra than the three nonresponding patients. The three responding patients with sarcomas also showed a rise of greater than 100% in PDE/PME during the first cycle of therapy. Two of the responding patients had an increase of 0.37 pH units during this interval, which was not detected in the nonresponding patients. These data suggest that 31P NMR spectroscopy may be a useful prognostic indicator in conjunction with other clinical parameters.

Multinuclear MR investigation of the metabolic response of the murine RIF‐1 tumor to 5‐fluorouracil chemotherapy

“…Stevens et al ( 4 ) demonstrated that in the Lewis lung tumor in C57 mice, within 3 h after iv administration the initially intense 5FU signal was replaced by an F-nucleotide (Fnuc) signal (the Fnuc's FUTP and FdUMP cannot be discriminated by in vivo 19F MRS). More recent 19F MR studies confirmed the quick metabolic conversion of 5FU, although for different tumors widely divergent 5FU half-lives ( tl,2) have been reported, that is 20 min to 6 h in murine tumors (5-9) and 8 min to 2 h in human tumors in situ (9)(10)(11)(12). Some murine and human tumors showed a rapid rise in the level of FBAL (6)(7)(8)13).…”

Early detection of treatment response by diffusion-weighted 1H-NMR spectroscopy in a murine tumour in vivo

“…Non-invasive methods, including magnetic resonance spectroscopy (e.g. Koutcher et al, 1990;Presant et al, 1994;Sostman et al, 1994) and positron emission tomography (e.g. Ichiya et Wahl et al, 1993;Berlangieri et al, 1994), are being evaluated for their ability to provide such information.…”

Are cancer cells acidic?

“…(Arnold et al, 1990;Koutcher et al, 1990;Redmond et (Moon & Richards, 1973;Prichard et al, 1983). Absolute pHi can be determined by MRS with a precision of 0.06pH (Smith et al, 1989); smaller relative changes are also reproducibly detectable.…”