Background:Bone marrow transplantation (BMT) is one of the most efficient methods for the treatment of hematological neoplasms. Its successful application requires previous complete remission (CR) and exclusion of residual disease.Material/Methods: This 31P MRS study reports data collected during several years of observation of nineteen patients. Duration of observation varied from 1 to 8.5 years from the time of diagnosis. Data collected after BMT covered periods ranging from 1.5 months to 6.5 years.Results: 31P MRS spectra of normal sera showed four peaks, that at the lowest field due to Pi and the other three to phospholipids (PL), i.e. phosphatidylethanolamine + sphingomyelin (PE + SM), lysophosphatidylcholine (LPC), and phosphatidylcholine (PC). Long-term follow-up studies showed good correlation between the [sup]31[/sup]P MR spectral features of sera and disease response to therapy. In particular, at the time of diagnosis spectra showed significant decreases in the levels of all detected phospholipids (PC, LPC, PE and SM). These decreases, dependent upon disease severity, changed during chemotherapy according to the individual response of the patient. During chemotherapy and after BMT, the spectral profile changed in responding patients to resemble that of normal serum with the typical, higher peak intensities.Conclusions: Longitudinal analysis of in vitro [sup]31[/sup]P spectra of sera of patients with hematological malignancies represents a reliable method to evaluate the susceptibility of the neoplasm to a cytostatic treatment. The same approach seems to be useful in evaluating the effectiveness and outcome of bone marrow transplantation over time.

Keywords: Phosphorus Isotopes - chemistry, Adolescent, Bone Marrow Transplantation, Follow-Up Studies, Hematologic Neoplasms - metabolism, Magnetic Resonance Spectroscopy - methods, Phospholipids - blood, Phosphorus Isotopes - chemistry