Article Figures & Data
Figures
- Fig 1.
Average spectra obtained with the dataset of noncensored patients dichotomized into 2 subgroups depending on survival better or worse than the median value (187 days). A, STE spectra. The main differences are seen in the mobile lipid region (all around 0.90 and 1.30 ppm) and in the region between 3.40 and 3.90 ppm. Two representative spectroscopy points were defined in the statistical analysis in the positions 0.98 and 3.67 ppm. B, LTE spectra. Significant differences are found in the mobile lipid region at this TE. Two representative spectroscopy points were defined in the positions 0.98 and 1.25 ppm.
- Fig 2.
Survival curves for patients are dichotomized by the following: the intensity value of the spectroscopy point 0.98 ppm at STE, normalized to unit-length (NI0.98) (A), the intensity value of the point 3.67 ppm at STE, normalized to unit-length (NI3.67) (B), the value of the ratio between the intensities of the points 3.67 and 0.98 ppm at STE (I3.67/I0.98; note that no additional normalization is required for ratios) (C), the intensity value of the point 0.98 ppm at LTE, normalized to unit-length (NI0.98) (D), and the intensity value of the point 1.25 ppm at LTE, normalized to unit-length (NI1.25) (E).
- Fig 3.
Representative cases of the prognostic value of 1H-MRS. A, Axial T1-weighted postcontrast image in a 53-year-old man shows a right frontoparietal necrotic mass. The box shows the VOI used for spectroscopy. The patient’s KPS score after surgical debulking was 80. Treatment with chemoradiotherapy was performed. B, STE spectrum shows the presence of lipids at both 0.90 and 1.30 ppm, a large Cho peak (centered at 3.21 ppm), and various resonances between 3.55 and 4.00 ppm. The elective spectroscopy parameter at this TE was in the range of patients with long survival (NI3.67=0.0623 [>0.0473, good prognosis]) as well as the value of the ratio (ratio I3.67/I0.98 = 0.7425 [>0.5510, good prognosis]). C, LTE spectrum shows no signals of mobile lipids at this TE. The elective spectroscopy parameters at this TE were also in the range of patients with long survival (NI0.98=−0.0316 [<0.0267, good prognosis], NI1.25=−0.1087 [<0.0098, good prognosis]). The patient was alive at the end of the study, after 1004 days of follow-up. D, Axial T1-weighted image in a 59-year-old man shows a right frontal necrotic mass. The patient’s KPS score after surgical debulking was 70. Treatment with chemoradiotherapy was performed. E, The STE spectrum shows prominent lipid peaks with little contribution of other resonances. The elective spectroscopy parameter and the ratio suggest poor prognosis (NI3.67=0.0097 [<0.0473, poor prognosis], and ratio I3.67/I0.98=0.1124 [<0.5510, poor prognosis]). F, The LTE spectrum also shows a clear dominance of lipid peaks. The elective spectroscopy parameters at this TE were also in the poor prognosis range (NI0.98=0.0458 [>0.0267, poor prognosis], NI1.25=0.4452 [>0.0098, poor prognosis]). The patient died after 110 days of follow-up.
Tables
Prognostic Factor No. Survival (median) (95% CI) Agea <50 years 21 330 (34–975) ≥50 years 124 178 (39–927) Sex Men 89 175 (41–924) Women 56 201 (40–954) WHO gradeb Anaplastic astrocytoma (III) 27 254 (43–963) Glioblastoma (IV) 118 178 (39–937) Karnofsky Performance Statusa <70 46 108 (39–472) 70–80 56 197 (59–887) >80 43 278 (57–1238) Extent of surgeryb Biopsy 56 137 (28–849) Partial resection 53 197 (54–839) Complete resection 36 363 (63–1265) Treatmentb Conservative support 55 92 (28–249) Radiotherapy 27 222 (94–461) Chemoradiotherapy 63 330 (109–1154) -
a No significant differences were found when only the noncensored patients were evaluated, but the differences reached significance level when the censored patients were included in the survival analysis.
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b Significant differences were found with the logrank test.
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Variable Value Overall Patients P Patients Treated with Chemoradiotherapy Conservative-Support Treatment P No. Hazard Ratio (95% CI) No. Hazard Ratio (95% CI) P No. Hazard Ratio (95% CI) STEa NI0.98 <0.1024 133 0.568 (0.391–0.826) .003 72 0.424 (0.231–0.778) .006 38 0.575 (0.323–1.026) NS >0.1024 47 1.000 18 1.000 20 1.000 NI3.67 <0.0473 71 1.992 (1.421–2.792) <.001 29 2.080 (1.238–3.495) .006 28 2.038 (1.122–3.699) .018 >0.0473 109 1.000 61 1.000 30 1.000 STEb I3.67/I0.98 <0.5510 76 1.866 (1.329–2.621) <.001 34 2.673 (1.582–4.517) <.001 29 1.960 (1.071–3.586) .029 >0.5510 104 1.000 56 1.000 29 1.000 LTEa NI0.98 <0.0267 103 0.426 (0.304–0.597) <.001 57 0.417 (0.249–0.698) .001 38 0.472 (0.259–0.860) .014 >0.0267 79 1.000 32 1.000 21 1.000 NI1.25 <0.0098 59 0.400 (0.272–0.590) <.001 39 0.434 (0.252–0.748) .003 10 0.412 (0.187–0.905) .027 >0.0098 123 1.000 50 1.000 49 1.000 -
a Intensity values of points normalized to unit-length: NIx.xx
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b Ratio between intensity signals of points: Ix.xx/Ix.xx.
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- Table 3:
Multivariate analysis of prognostic factors using the Cox proportional hazards model with forward stepwise selection in 180 patients with HGA and spectra obtained at STEa
Variable/Value No. Hazard Ratio (95% CI) P Clinical parameters/treatment <.001 Conservative support 58 11.564 (7.242–18.465) Radiotherapy alone 31 1.768 (1.100–2.841) Chemoradiotherapy 91 1.000 Spectroscopy parameters Intensity signals normalized to unit-length (NI) NI3.67 <.001 <0.0473 71 2.132 (1.504–3.023) >0.0473 109 1.000 -
a Age (<50 years vs >50 years), sex, WHO grade, KPS, extent of surgery, the spectroscopic parameters normalized intensity signal at 0.98 ppm, and the ratio between intensity signals at 3.67 and 0.98 ppm were not selected as elective prognostic factors.
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- Table 4:
Multivariate analysis of prognostic factors using the Cox proportional hazards model with forward stepwise selection in 182 patients with HGA and spectra obtained at LTEa
Variable/Value No. Hazard Ratio P Clinical parameters/treatment <.001 Conservative support 58 12.241 (7.556–19.831) Radiotherapy alone 34 1.784 (1.116–2.853) Chemoradiotherapy 90 1.000 Spectroscopy parameters Intensity signals normalized to unit-length (NI) NI0.98 <.001 <0.0267 103 0.499 (0.339–0.736) >0.0267 79 1.000 NI1.25 .015 <0.0098 60 0.574 (0.368–0.897) >0.0098 122 1.000 -
a Age (<50 years vs > 50 years), sex, WHO grade, KPS, and extent of surgery were not selected as elective prognostic factors.
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