phosphocreatine and Soft-Tissue-Neoplasms

Magnetic resonance imaging (MRI) is of restricted value for the in vivo characterization of tumor types. The applicability of phosphorus-31 (31P) magnetic resonance spectroscopy (MRS) in the diagnosis of bone and soft tissue tumors is unknown.. A total of 191 consecutive patients (85 females and 106 males; mean age 41 years, range 1-80) with a well-defined bone or soft tissue tumor on MRI were analyzed for additional 31P spectroscopy. Histology and/or cytology was obtained from all tumors. Because of low sensitivity of the 31P nucleus and the contamination of surrounding tissue, only large, superficially located tumors accessible to the surface coil could be accepted for MRS.. Twenty-one patients (11%) could be included in the study. From this remaining group only 12 studies (57%) produced spectra with well resolved phosphorus peaks and an acceptable signal-to-noise ratio. However, these spectra did not allow differentiation between the benign and malignant nature of the lesions. The other 9 studies showed spectra with poor signal intensities and/or poorly defined peaks, making tumor differentiation impossible.. Only 6% of the bone and soft tissue tumors produced well defined spectra, which implies that localized 31P MRS cannot be considered as a routine technique in the diagnostic and treatment evaluation of bone and soft tissue tumors.

Topics: Adenosine Triphosphate; Adolescent; Adult; Aged; Aged, 80 and over; Bone Neoplasms; Child; Child, Preschool; Female; Humans; Infant; Magnetic Resonance Spectroscopy; Male; Middle Aged; Phosphocreatine; Phosphoric Diester Hydrolases; Phosphoric Monoester Hydrolases; Phosphorus Isotopes; Soft Tissue Neoplasms

To study the characteristic changes of 31P-MR spectroscopy of bone and soft tissue tumors.. 41 patients were examined by phosphorus surface coil of 3 tesla MR machine, including 18 benign tumor foci and 28 malignant foci, and adjacent normal muscles. The areas under the peaks of various metabolites in the spectra were measured, including phosphomonoester (PME), inorganic phosphours (Pi), phosphodiester (PDE), phosphocreatine (Pcr), adenosine triphosphate (ATP) gamma, alpha, beta. The ratios of the metabolites to beta-ATP, NTP and Pcr were calculated. Intracellular pH was calculated according to the chemical shift change of Pi relative to Pcr.. The ratios of Pcr/PME and PME/NTP in benign and malignant tumor groups were significantly different from those of the normal group (P<0.05). Between benign and malignant tumor groups, the ratios of PME/beta-ATP and PME/NTP were significantly different (P<0.05).. Pcr/PME and PME/NTP are potential diagnostic indexes of bone and soft tissue tumors. PME/beta-ATP and PME/NTP are potential indexes of differential diagnosis of bone and soft tissue tumors.

Topics: Adenosine Triphosphate; Adolescent; Adult; Aged; Bone Neoplasms; Child; Diagnosis, Differential; Female; Fibroma; Giant Cell Tumors; Humans; Magnetic Resonance Spectroscopy; Male; Middle Aged; Organophosphates; Osteosarcoma; Phosphocreatine; Phosphorus; Phosphorus Isotopes; Sarcoma, Ewing; Soft Tissue Neoplasms; Young Adult

Metabolite concentrations determined from MR spectra provide more specific information than peak area ratios. This paper presents a method of quantification that allows metabolite concentrations to be determined from in vivo 31P MR spectra acquired using a surface coil and ISIS localization. Corrections for the effects of B1 field inhomogeneity produced by surface coils are based on a measured and calibrated spatial sensitivity field map for the coil. Account is taken of imperfections in pulse performance, coil loading effects and relaxation effects, the latter making use of published metabolite relaxation times. The technique is demonstrated on model solutions. The concentrations of the main 31P metabolites in normal human calf muscle measured using this method are [PCr] = 26.9 +/- 4.1 mM; [Pi] = 3.6 +/- 1.2 mM; [NTP] = 6.8 +/- 1.8 mM. Quantification of spectra acquired from soft-tissue tumours in patients both pre- and post-treatment showed that changes in metabolite concentrations are more sensitive to metabolic changes than changes in peak area ratios.

Topics: Adenosine Triphosphate; Gadolinium; Gadolinium DTPA; Humans; Leg; Magnetic Resonance Spectroscopy; Muscle Neoplasms; Muscle, Skeletal; Neuroendocrine Tumors; Organometallic Compounds; Pentetic Acid; Phosphates; Phosphocreatine; Phosphorus; Reproducibility of Results; Sensitivity and Specificity; Soft Tissue Neoplasms

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.

Topics: Animals; Antineoplastic Agents; Biomarkers, Tumor; Extremities; Female; Humans; Magnetic Resonance Spectroscopy; Male; Mice; Middle Aged; Nucleotides; Phosphocreatine; Phosphoric Diester Hydrolases; Phosphoric Monoester Hydrolases; Phosphorus; Probability; Remission Induction; Sarcoma; Sarcoma, Experimental; Soft Tissue Neoplasms; Tumor Cells, Cultured

The 31P Magnetic Resonance Spectroscopy allows to monitor noninvasively and in vivo the energy and phospholipid metabolism of tissue. At present the high technical demand prevents the application of this new modality in the clinical routine. By means of some cases the advantages and limitations of the 31P-MRS are demonstrated. Recent results show that 31P-MRS monitors effects on the metabolism of tumor cells as early as two days after onset of chemotherapy. Further clinical studies and technical developments are necessary to render 31P-MRS a clinic routine examination.

Topics: Computer Graphics; Energy Metabolism; Follow-Up Studies; Humans; Hydrogen-Ion Concentration; Magnetic Resonance Spectroscopy; Phosphocreatine; Phosphorus; Signal Processing, Computer-Assisted; Soft Tissue Neoplasms; Software