Calibration of methylene-referenced lipid-dissolved xenon frequency for absolute MR temperature measurements.

PURPOSE: Absolute MR temperature measurements are currently difficult because they require precalibration procedures specific for tissue types and conditions. Reference of the lipid-dissolved 129 Xe resonance frequency to temperature-insensitive methylene protons (rLDX) has been proposed to remove the effect of macro- and microscopic susceptibility gradients to obtain absolute temperature information. The scope of this work is to evaluate the rLDX chemical shift (CS) dependence on lipid composition to estimate the precision of absolute temperature measurements in lipids. METHODS: Neat triglycerides, vegetable oils, and samples of freshly excised human and rodent adipose tissue (AT) are prepared under 129 Xe atmosphere and studied using high-resolution NMR. The rLDX CS is measured as a function of temperature. 1 H spectra are also acquired and the consistency of methylene-referenced water proton and rLDX CS values are compared in human AT. RESULTS: Although rLDX CS shows a dependence on lipid composition, in human and rodent AT samples the rLDX shows consistent CS values with a similar temperature dependence (-0.2058 ± 0.0010) ppm/°C × T (°C) + (200.15 ± 0.03) ppm, enabling absolute temperature measurements with an accuracy of 0.3°C. Methylene-referenced water CS values present variations of up to 4°C, even under well-controlled conditions. CONCLUSIONS: The rLDX can be used to obtain accurate absolute temperature measurements in AT, opening new opportunities for hyperpolarized 129 Xe MR to measure tissue absolute temperature.

Outcomes of allogeneic stem cell transplantation among patients with acute myeloid leukemia presenting active disease: Experience of a single European Comprehensive Cancer Center.

INTRODUCTION:: Allogeneic hematopoietic stem cell transplantation (ASCT) representes a potentially curative approach for patients with relapsed or refractory acute myeloid leukemia (AML). We report the outcome of relapsed/refractory AML patients treated with ASCT. METHOD:: A retrospective cohort from 1994 to 2013 that included 61 patients with diagnosis of relapsed/refractory AML. Outcomes of interest were transplant-related mortality (TRM), incidence of acute and chronic graft-versus-host disease (GVHD), relapse incidence, progression-free survival (PFS) and overall survival (OS). Statistical significance was set at p<0.05. RESULTS:: The median age was 61 years (range 1 to 65). The cumulative incidence of 90 days, 1 year, and 3 years TRM were 60%, 26.7%, and 13.3%, respectively (p<0.001). The incidence of relapse was 21.7% at 1 year, 13% at 3 years, and 8.7% at 5 years. Median OS was estimated to be 8 months (95CI 3.266-12.734) and median PFS, 3 months (95CI 1.835-4.165). CONCLUSION:: In our cohort, TRM in first years after ASCT remains considerable, but ASCT in this setting seems to be a good choice for AML patients with active disease. However, novel approaches are needed to reduce TRM and relapse in this set of patients.

Outcomes of allogeneic stem cell transplantation among patients with acute myeloid leukemia presenting active disease: Experience of a single European Comprehensive Cancer Center / Resultados do transplante alogênico de células-tronco em doentes com leucemia mieloide aguda com doença ativa: experiência de um único Centro Oncológico Europeu

Summary Introduction: Allogeneic hematopoietic stem cell transplantation (ASCT) representes a potentially curative approach for patients with relapsed or refractory acute myeloid leukemia (AML). We report the outcome of relapsed/refractory AML patients treated with ASCT. Method: A retrospective cohort from 1994 to 2013 that included 61 patients with diagnosis of relapsed/refractory AML. Outcomes of interest were transplant-related mortality (TRM), incidence of acute and chronic graft-versus-host disease (GVHD), relapse incidence, progression-free survival (PFS) and overall survival (OS). Statistical significance was set at p<0.05. Results: The median age was 61 years (range 1 to 65). The cumulative incidence of 90 days, 1 year, and 3 years TRM were 60%, 26.7%, and 13.3%, respectively (p<0.001). The incidence of relapse was 21.7% at 1 year, 13% at 3 years, and 8.7% at 5 years. Median OS was estimated to be 8 months (95CI 3.266-12.734) and median PFS, 3 months (95CI 1.835-4.165). Conclusion: In our cohort, TRM in first years after ASCT remains considerable, but ASCT in this setting seems to be a good choice for AML patients with active disease. However, novel approaches are needed to reduce TRM and relapse in this set of patients.

Resumo Introdução: o transplante alogênico de células-tronco hematopoiéticas (TCTH-alo) representa uma abordagem potencialmente curativa para pacientes com leucemia mieloide aguda (LMA) recorrente ou refratária. Nosso trabalho apresenta o resultado de pacientes com recaída ou doença refratária tratados com TCTH-alo. Método: coorte retrospectiva incluindo 61 pacientes de 1994 a 2013 com diagnóstico de recidiva/LMA refratária. Os desfechos de interesse foram mortalidade relacionada ao transplante (MRT), incidência da doença aguda e crônica do enxerto contra hospedeiro (DECH), incidência de recaídas, sobrevida livre de progressão (PFS - progression-free survival) e sobrevida global (SG). A significância estatística foi considerada para p<0,05. Resultados: a média de idade foi de 61 anos (variação de 1 a 65). A incidência cumulativa de 90 dias, 1 ano e 3 anos de MRT foram de 60%, 26,7% e 13,3%, respectivamente (p<0,001). A incidência de recaída foi de 21,7% em 1 ano, 13% em 3 anos e 8,7% em 5 anos. A SG mediana foi estimada em 8 meses (IC 95% 3,266-12,734) e a mediana de PFS, em 3 meses (IC 95% 1,835-4,165). Conclusão: em nossa coorte, MRT no primeiro ano após o transplante permanece considerável, mas TCTH-alo nesse cenário parece ser uma boa opção para pacientes com LMA ativa. No entanto, novas abordagens são necessárias para reduzir MRT e recaída nesse conjunto de pacientes.

In vivo NMR detection of diet-induced changes in adipose tissue composition.

We introduce an in vivo spectroscopic method to assess the effects of diet on fatty acid composition of the predominant chemical constituent of adipocytes in mice. To do this, we make use of a nonlinear NMR signal that, unlike a standard NMR signal, is intrinsically insensitive to local magnetic field inhomogeneities and which naturally suppresses the large water signal from nonfatty tissues. Our method yields fat composition information from fat depots distributed over large sample volumes in a single experiment, without requiring the use of tedious shimming procedures, voxel selection, or water suppression. Our results suggest that this method can reveal clear differences in adipose tissue composition of mice fed a standard chow diet compared with mice fed a diet rich in polyunsaturated fatty acids. With further developments this method could be used to obtain information on human lipid composition noninvasively and to track changes in lipid composition induced by diet intervention, pharmaceutical drugs, and exercise.