Magnetic resonance spectroscopic detection of lactate is predictive of a poor prognosis in patients with diffuse intrinsic pontine glioma

Abstract

Diffuse brainstem glioma has a poor prognosis, and there are few long-term survivors. We looked for clinical, conventional magnetic resonance (MR), and MR spectroscopic (MRS) findings predictive of the prognosis of patients with brainstem glioma. Our institutional review board approved this retrospective study of 23 patients with diffuse intrinsic pontine or diffuse medullary brainstem glioma treated during the period 2000-2009. To evaluate prognostic values, we performed a Kaplan-Meier survival analysis (log-rank test) that incorporated the patients' age and sex, symptom duration, the presence or absence of cranial nerve palsy, long tract sign, ataxia, and cysts, the chemotherapeutic regimen, Gd enhancement, longitudinal and cerebellar extension, basilar artery encasement, and MRS parameters. Of the 23 diffuse brainstem gliomas, 19 were located at the pons (ratio of male to female patients, 1.1:1). The mean age of the 23 patients was 15.9 years (range, 4-50 years); 16 were aged <20 years. The duration of overall survival was 19.7 months; in patients with diffuse intrinsic pontine glioma, it was 16.6 months, and in patients aged <20 years, it was 11.8 months. Clinical and conventional MR findings at presentation were not predictive of the prognosis in children with diffuse intrinsic pontine glioma. In addition, a patient age <20 years and the detection of lactate by MRS were poor prognostic factors. The MRS detection of lactate is a prognostic factor in patients with diffuse intrinsic pontine glioma. Additional studies of larger patient populations using other imaging modalities are needed.

Iterative averaging of spectra as a powerful way of suppressing spurious resonances in signal processing

“…Assessment of this spectral region has also been helpful for distinguishing cancerous from non-malignant pathology from the brain [5,[7][8][9], and from other organs, such as the ovary [52] and the breast [53,54]. However, in vivo proton MRS studies [24,52] indicate that much uncertainty arises in attempts to assess this chemical shift region. We have seen from the Padé-reconstructed "ersatz" component spectra that in addition to the Lac doublet, a number of other resonances are closely overlapping even at a long TE of 272 ms, when the broad lipid resonances have already decayed.…”

“…At short echo times, Lac and Lip overlap since they both resonate in the chemical shift region of ∼1.3 ppm. Difficulties in identifying these two diagnostically important resonances are frequently encountered at short TEs [23,24]. The accurate assessment of Lac and Lip is recognized to be tenuous, due to the overlap of these resonances.…”

“…The accurate assessment of Lac and Lip is recognized to be tenuous, due to the overlap of these resonances. On the other hand, the use of long TEs causes attenuation of the magnitude of all resonances [24].…”

Analysis of plasma free amino acid profiles in canine brain tumors

“…An MRS study in humans has suggested that the levels of several metabolites, such as lactic acid and choline, are elevated in malignant gliomas (12). Another MRS study demonstrated no difference in glycine levels between glioblastoma and meningioma patients, although these levels were altered according to the grade of the glioma (22).…”

“…Various metabolites, such as amino acids and choline, have been analyzed in human glioma patients by means of proton magnetic resonance spectroscopy (MRS) or from tissue specimens obtained during surgery or autopsy (12,13). However, there have been few reports on PFAA analysis in intracranial disorders (14).…”