Abstract
PURPOSE
To assess the relationship between F-18-fluoro-ethyl-tyrosine positron emission tomography (FET-PET) parameters of relapsing oligodendroglioma and progression-free survival.
MATERIAL AND METHODS
The relationship of clinical parameters, FET-PET parameters (SUV$_{max}$, TBR$_{max}$, BTV$_{,}$ time-activity curves) and progression-free survival was analyzed using univariate and multivariate analysis in 42 adult patients with relapsing oligodendroglioma. Kaplan-Meier analysis was used to assess survival.
RESULTS
Patients who did not undergo surgical resection of their relapsing tumor had significantly lower PFS if the tumor exhibited an SUV$_{max}$ above 3.40 than those with an SUV$_{max}$ below 3.40 (13.1 ± 2.3 months vs. 47.3 ± 6.0 months, respectively, p < .001). Patients who underwent surgery had similar PFS as the aforementioned non-operated patients with low SUV$_{max}$ (53.6 ± 6.7 months, p = .948). The same was true for TBR$_{max}$ using a threshold of 3.03 (PFS 12.5 ± 2.4 months vs. 44.0 ± 6.3 months / 53.6 ± 6.7 months, respectively; p < .001 / p = .825). Also, subjects with BTV below 10 cm$^{3}$ that did not undergo surgery had a similar PFS as subjects who underwent surgery (40.2 ± 6.0 months vs. 52.4 ± 8.9 months, respectively, p = .587). Subjects with BTV above 10 cm$^{3}$ and without surgery had a significantly worse PFS (13.8 ± 3.3 months, p < .001). Multivariate analysis showed that the prognostication by clinical parameters is improved by adding TBR$_{max}$ to the model (AUC 0.945 (95% CI: 0.881-1.000), true classification rate 88.1%).
CONCLUSION
FET-PET may provide added value for the prognostication of relapsing oligodendroglioma in addition to clinical parameters.