Background
Standard treatment for glioblastoma is radiation with concomitant and adjuvant temozolomide for 6 cycles, although the optimal number of cycles of adjuvant temozolomide has long been a subject of debate. We performed a phase II randomized trial investigating whether extending adjuvant temozolomide for more than 6 cycles improved outcome.
Methods
Glioblastoma patients treated at 20 Spanish hospitals who had not progressed after 6 cycles of adjuvant temozolomide were centrally randomized to stop (control arm) or continue (experimental arm) temozolomide up to a total of 12 cycles at the same doses they were receiving in cycle 6. Patients were stratified by MGMT methylation and measurable disease. The primary endpoint was differences in 6-month progression-free survival (PFS). Secondary endpoints were PFS, overall survival (OS), and safety (Clinicaltrials.gov NCT02209948).
Results
From August 2014 to November 2018, 166 patients were screened, 7 of whom were ineligible. Seventy-nine patients were included in the stop arm and 80 in the experimental arm. All patients were included in the analyses of outcomes and of safety. There were no differences in 6-month PFS (control 55.7%; experimental 61.3%), PFS, or OS between arms. MGMT methylation and absence of measurable disease were independent factors of better outcome. Patients in the experimental arm had more lymphopenia (P < 0.001), thrombocytopenia (P < 0.001), and nausea and vomiting (P = 0.001).
Conclusions
Continuing temozolomide after 6 adjuvant cycles is associated with greater toxicity but confers no additional benefit in 6-month PFS.
Key Points
1. Extending adjuvant temozolomide to 12 cycles did not improve 6-month PFS.
2. Extending adjuvant temozolomide did not improve PFS or OS in any patient subset.
3. Extending adjuvant temozolomide was linked to increased toxicities.
Background
Glioblastoma (GBM) is the most aggressive primary brain tumor, characterized by a heterogeneous and abnormal vascularity. Subtypes of vascular habitats within the tumor and edema can be distinguished: high angiogenic tumor (HAT), low angiogenic tumor (LAT), infiltrated peripheral edema (IPE), and vasogenic peripheral edema (VPE).
Purpose
To validate the association between hemodynamic markers from vascular habitats and overall survival (OS) in glioblastoma patients, considering the intercenter variability of acquisition protocols.
Study Type
Multicenter retrospective study.
Population
In all, 184 glioblastoma patients from seven European centers participating in the NCT03439332 clinical study.
Field Strength/Sequence
1.5T (for 54 patients) or 3.0T (for 130 patients). Pregadolinium and postgadolinium‐based contrast agent‐enhanced T1‐weighted MRI, T2‐ and FLAIR T2‐weighted, and dynamic susceptibility contrast (DSC) T2* perfusion.
Assessment
We analyzed preoperative MRIs to establish the association between the maximum relative cerebral blood volume (rCBVmax) at each habitat with OS. Moreover, the stratification capabilities of the markers to divide patients into "vascular" groups were tested. The variability in the markers between individual centers was also assessed.
Statistical Tests
Uniparametric Cox regression; Kaplan–Meier test; Mann–Whitney test.
Results
The rCBVmax derived from the HAT, LAT, and IPE habitats were significantly associated with patient OS (P < 0.05; hazard ratio [HR]: 1.05, 1.11, 1.28, respectively). Moreover, these markers can stratify patients into "moderate‐" and "high‐vascular" groups (P < 0.05). The Mann–Whitney test did not find significant differences among most of the centers in markers (HAT: P = 0.02–0.685; LAT: P = 0.010–0.769; IPE: P = 0.093–0.939; VPE: P = 0.016–1.000).
Data Conclusion
The rCBVmax calculated in HAT, LAT, and IPE habitats have been validated as clinically relevant prognostic biomarkers for glioblastoma patients in the pretreatment stage. This study demonstrates the robustness of the hemodynamic tissue signature (HTS) habitats to assess the GBM vascular heterogeneity and their association with patient prognosis independently of intercenter variability.
Level of Evidence: 3
Technical Efficacy Stage: 2
J. Magn. Reson. Imaging 2020;51:1478–1486.
This study shows that compliance to bandages during CDT is one of the most important predictors of response. Moreover, data support the idea that more severe lymphedemas have a worse response to treatment, and it should be recommended in early stages. The association between the season of treatment and response was also very strong, so weather conditions are an additional factor that must be taken into account in further studies.
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