Efficacy of Whole-Ventricular Radiotherapy in Patients Undergoing Maximal Tumor Resection for Glioblastomas Involving the Ventricle.

Kyung Hwan Kim,Chang-Ok Suh,Jihwan Yoo,Seok-Gu Kang,Hwa Kyung Byun,Nalee Kim,Jong Hee Chang,Ju Hyung Moon,Hong In Yoon

doi:10.3389/fonc.2021.736482

Kyung Hwan Kim, Chang-Ok Suh + Show 7 more

Open Access

https://doi.org/10.3389/fonc.2021.736482

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Abstract

Background and PurposePatients with glioblastoma (GBM) involving the ventricles are at high risk of ventricle opening during surgery and potential ventricular tumor spread. We evaluated the effectiveness of whole-ventricular radiotherapy (WVRT) in reducing intraventricular seeding in patients with GBM and identified patients who could benefit from this approach.Methods and MaterialsWe retrospectively reviewed the data of 382 patients with GBM who underwent surgical resection and temozolomide-based chemoradiotherapy. Propensity score matching was performed to compensate for imbalances in characteristics between patients who did [WVRT (+); n=59] and did not [WVRT (–); n=323] receive WVRT. Local, outfield, intraventricular, and leptomeningeal failure rates were compared.ResultsAll patients in the WVRT (+) group had tumor ventricular involvement and ventricle opening during surgery. In the matched cohort, the WVRT (+) group exhibited a significantly lower 2-year intraventricular failure rate than the WVRT (–) group (2.1% vs. 11.8%; P=0.045), with no difference in other outcomes. Recursive partitioning analysis stratified the patients in the WVRT (–) group at higher intraventricular failure risk (2-year survival, 14.2%) due to tumor ventricular involvement, MGMT unmethylation, and ventricle opening. WVRT reduced the intraventricular failure rate only in high-risk patients (0% vs. 14.2%; P=0.054) or those with MGMT-unmethylated GBM in the matched cohort (0% vs. 17.3%; P=0.036).ConclusionsWVRT reduced the intraventricular failure rate in patients with tumor ventricular involvement and ventricle opening during surgery. The MGMT-methylation status may further stratify patients who could benefit from WVRT. Further prospective evaluation of WVRT in GBM is warranted.

Highlights

Glioblastoma (GBM) is the most common type of malignant primary brain tumor in adults and accounts for most deaths due to primary brain tumors [1]
Gross total resection (GTR) was performed in 66.5% of patients, and the extent of resection was similar in the two groups (Table 1)
Peritumoral edema was included in the radiotherapy field in most patients, but the rate was significantly lower in the whole-ventricular radiotherapy (WVRT) (–) group than in the WVRT (+) group

Summary

Introduction

Glioblastoma (GBM) is the most common type of malignant primary brain tumor in adults and accounts for most deaths due to primary brain tumors [1]. GBM commonly involves the ventricular wall in 40–50% of cases [11,12,13]. In such cases, surgeons are reluctant to surpass the ventricular wall due to a risk of iatrogenic tumor spread occurring through the ventricular system. Patients with leptomeningeal and intraventricular tumor seeding in high grade gliomas are known to exhibit a dismal prognosis with a median survival of 2 to 6 months after being diagnosed with seeding metastases [14, 15, 17,18,19]. Patients with glioblastoma (GBM) involving the ventricles are at high risk of ventricle opening during surgery and potential ventricular tumor spread. We evaluated the effectiveness of whole-ventricular radiotherapy (WVRT) in reducing intraventricular seeding in patients with GBM and identified patients who could benefit from this approach

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Results

Conclusion