Efficacy and Safety of Temozolomide Combined with Radiotherapy in the Treatment of Malignant Glioma

Application of preoperative advanced diffusion magnetic resonance imaging in evaluating the postoperative recurrence of lower grade gliomas

BACKGROUND

Recurrence of lower grade glioma (LrGG) appeared to be unavoidable despite considerable research performed in last decades. Thus, we evaluated the postoperative recurrence within two years after the surgery in patients with LrGG by preoperative advanced diffusion magnetic resonance imaging (dMRI).

MATERIALS AND METHODS

48 patients with lower-grade gliomas (23 recurrence, 25 nonrecurrence) were recruited into this study. Different models of dMRI were reconstructed, including apparent fiber density (AFD), white matter tract integrity (WMTI), diffusion tensor imaging (DTI), diffusion kurtosis imaging (DKI), neurite orientation dispersion and density imaging (NODDI), Bingham NODDI and standard model imaging (SMI). Orthogonal Partial Least Squares-Discriminant Analysis (OPLS-DA) was used to construct a multiparametric prediction model for the diagnosis of postoperative recurrence.

RESULTS

The parameters derived from each dMRI model, including AFD, axon water fraction (AWF), mean diffusivity (MD), mean kurtosis (MK), fractional anisotropy (FA), intracellular volume fraction (ICVF), extra-axonal perpendicular diffusivity (De⊥), extra-axonal parallel diffusivity (De∥) and free water fraction (fw), showed significant differences between nonrecurrence group and recurrence group. The extra-axonal perpendicular diffusivity (De⊥) had the highest area under curve (AUC = 0.885), which was significantly higher than others. The variable importance for the projection (VIP) value of De⊥ was also the highest. The AUC value of the multiparametric prediction model merging AFD, WMTI, DTI, DKI, NODDI, Bingham NODDI and SMI was up to 0.96.

CONCLUSION

Preoperative advanced dMRI showed great efficacy in evaluating postoperative recurrence of LrGG and De⊥ of SMI might be a valuable marker.

Radiotherapy of high-grade gliomas: dealing with a stalemate

This article discusses the studies on radiotherapy of high-grade gliomas published between January 1, 2022, and June 30, 2022, with special reference to their molecular biology basis. The focus was on advances in radioresistance, radiosensitization and the toxicity of radiotherapy treatments. In the first half of 2022, several important advances have been made in understanding resistance mechanisms in high-grade gliomas. Furthermore, the development of several radiosensitization procedures for these deadly tumors, including studies with small molecule radiosensitizers, new fractionation protocols, and new immunostimulatory agents, has progressed in both the preclinical and clinical settings, reflecting the frantic research effort in the field. However, since 2005 our research efforts fail to produce significant improvements to treatment guidelines for high-grade gliomas. Possible reasons for this stalemate and measures to overcome it are discussed.

Surface-Modified Biobased Polymeric Nanoparticles for Dual Delivery of Doxorubicin and Gefitinib in Glioma Cell Lines

Glioma is a malignant form of brain cancer that is challenging to treat due to the progressive growth of glial cells. To target overexpressed folate receptors in glioma brain tumors, we designed and investigated doxorubicin-gefitinib nanoparticles (Dox-Gefit NPs) and folate conjugated Dox-Gefit NPs (Dox-Gefit NPs-F). Dox-Gefit NPs and Dox-Gefit NPs-F were characterized by multiple techniques including Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), proton nuclear magnetic resonance (1H NMR), and transmission electron microscopy (TEM). In vitro release profiles were measured at both physiological and tumor endosomal pH. The cytotoxicity of the Dox-Gefit NP formulations was measured against C6 and U87 glioma cell lines. A hemolysis assay was performed to investigate biocompatibility of the formulations, and distribution of the drugs in different organs was also estimated. The Dox-Gefit NPs and Dox-Gefit NPs-F were 109.45 ± 7.26 and 120.35 ± 3.65 nm in size and had surface charges of -18.0 ± 3.27 and -20.0 ± 8.23 mV, respectively. Dox-Gefit NPs and Dox-Gefit NPs-F significantly reduced the growth of U87 cells, with IC50 values of 9.9 and 3.2 μM. Similarly, growth of the C6 cell line was significantly reduced, with IC50 values of 8.43 and 3.31 μM after a 24 h incubation, in Dox-Gefit NPs and Dox-Gefit NPs-F, respectively. The percentage drug releases of Dox and Gefit from Dox-Gefit NPs at pH 7.4 were 60.87 ± 0.59 and 68.23 ± 0.1%, respectively. Similarly, at pH 5.4, Dox and Gefit releases from NPs were 70.87 ± 0.28 and 69.24 ± 0.12%, respectively. Biodistribution analysis revealed that more Dox and Gefit were present in the brain than in the other organs. The functionalized NPs inhibited the growth of glioma cells due to high drug concentrations in the brain. Folate conjugated NPs of Dox-Gefit could be a treatment option in glioma therapy.

Retracted: Efficacy and Safety of Temozolomide Combined with Radiotherapy in the Treatment of Malignant Glioma

[This retracts the article DOI: 10.1155/2022/3477918.].