The evolving role for re-irradiation in the management of recurrent grade 4 glioma

NRG Oncology/RTOG1205: A Randomized Phase II Trial of Concurrent Bevacizumab and Reirradiation Versus Bevacizumab Alone as Treatment for Recurrent Glioblastoma

PURPOSE

To assess whether reirradiation (re-RT) and concurrent bevacizumab (BEV) improve overall survival (OS) and/or progression-free survival (PFS), compared with BEV alone in recurrent glioblastoma (GBM). The primary objective was OS, and secondary objectives included PFS, response rate, and treatment adverse events (AEs) including delayed CNS toxicities.

METHODS

NRG Oncology/RTOG1205 is a prospective, phase II, randomized trial of re-RT and BEV versus BEV alone. Stratification factors included age, resection, and Karnofsky performance status (KPS). Patients with recurrent GBM with imaging evidence of tumor progression ≥ 6 months from completion of prior chemo-RT were eligible. Patients were randomly assigned 1:1 to re-RT, 35 Gy in 10 fractions, with concurrent BEV IV 10 mg/kg once in every 2 weeks or BEV alone until progression.

RESULTS

From December 2012 to April 2016, 182 patients were randomly assigned, of whom 170 were eligible. Patient characteristics were well balanced between arms. The median follow-up for censored patients was 12.8 months. There was no improvement in OS for BEV + RT, hazard ratio, 0.98; 80% CI, 0.79 to 1.23; P = .46; the median survival time was 10.1 versus 9.7 months for BEV + RT versus BEV alone. The median PFS for BEV + RT was 7.1 versus 3.8 months for BEV, hazard ratio, 0.73; 95% CI, 0.53 to 1.0; P = .05. The 6-month PFS rate improved from 29.1% (95% CI, 19.1 to 39.1) for BEV to 54.3% (95% CI, 43.5 to 65.1) for BEV + RT, P = .001. Treatment was well tolerated. There were a 5% rate of acute grade 3+ treatment-related AEs and no delayed high-grade AEs. Most patients died of recurrent GBM.

CONCLUSION

To our knowledge, NRG Oncology/RTOG1205 is the first prospective, randomized multi-institutional study to evaluate the safety and efficacy of re-RT in recurrent GBM using modern RT techniques. Overall, re-RT was shown to be safe and well tolerated. BEV + RT demonstrated a clinically meaningful improvement in PFS, specifically the 6-month PFS rate but no difference in OS.

A Prospective Study of Conventionally Fractionated Dose Constraints for Reirradiation of Primary Brain Tumors in Adults

PURPOSE

Dose constraints for reirradiation of recurrent primary brain tumors are not well-established. This study was conducted to prospectively evaluate composite dose constraints for conventionally fractionated brain reirradiation.

METHODS AND MATERIALS

A single-institution, prospective study of adults with previously irradiated, recurrent brain tumors was performed. For 95% of patients, electronic dosimetry records from the first course of radiation (RT1) were obtained and deformed onto the simulation computed tomography for the second course of radiation (RT2). Conventionally fractionated treatment plans for RT2 were developed that met protocol-assigned dose constraints for RT2 alone and the composite dose of RT1 + RT2. Prospective composite dose constraints were based on histology, interval since RT1, and concurrent bevacizumab. Patients were followed with magnetic resonance imaging including spectroscopy and perfusion studies. Primary endpoint was the rate of symptomatic brain necrosis at 6 months after RT2.

RESULTS

Patients were enrolled from March 2017 to May 2018; 20 were evaluable. Eighteen had glioma, 1 had atypical choroid plexus papilloma, and 1 had hemangiopericytoma. Nineteen patients were treated with volumetric modulated arc therapy, and one was treated with protons. Median RT1 dose was 57 Gy (range, 50-60 Gy). Median RT1-RT2 interval was 49 months (range, 9-141 months). Median RT2 dose was 42.4 Gy (range, 36-60 Gy). Median planning target volume was 186 cc (range, 8-468 cc). Nineteen of 20 patients (95%) were free of grade 3+ central nervous system necrosis. One patient had grade 3+ necrosis 2 months after RT2; the patient recovered fully and lived another 18 months until dying of disease progression. Median overall survival from RT2 start for all patients was 13.3 months (95% credible interval, 6.3-20.7); for patients with glioblastoma, 11.5 months (95% credible interval, 6.1-20.1).

CONCLUSIONS

Brain reirradiation can be safely performed with conventionally fractionated regimens tailored to previous dose distributions. The prospective composite dose constraints described here are a starting point for future studies of conventionally fractionated reirradiation.

Clinical Outcomes of Dose Escalated Re-Irradiation in Patients with Recurrent High Grade Glioma

Background

Reirradiation for recurrent gliomas is a controversial treatment option with no clear standard dose or concurrent systemic therapy.

Methods

This series represents a single institution retrospective review of patients treated with re-irradiation for recurrent high grade glioma. After 2012, patients were commonly offered concurrent bevacizumab as a cytoprotective agent against radiation necrosis. Kaplan Meier method was used to estimate overall and progression-free survival. Cox proportional hazards regression was used to identify factors associated with overall and progression-free survival.

Results

Between 2001 and 2021, 52 patients underwent re-irradiation for a diagnosis of recurrent high grade glioma. 36 patients (69.2%) had a histologic diagnosis of glioblastoma at time of re-irradiation. The median BED10 (biologic equivalent dose 10 Gy) of re-irradiation was 53.1 Gy . Twenty-one patients (40.4%) received concurrent bevacizumab with re-irradiation. Median survival for the entire cohort and for glioblastoma at time of recurrence patients was 6.7 months and 6.0 months , respectively. For patients with glioblastoma at time of recurrence, completing re-irradiation (HR 0.03, p < 0.001), use of concurrent bevacizumab (HR 0.3, p=0.009), and the BED10 (HR 0.9, p=0.005) were predictive of overall survival. Nine patients developed Grade 3-5 toxicity; of these, 2 received concurrent bevacizumab and 7 did not (p=0.15).

Conclusion

High dose re-irradiation with concurrent bevacizumab is feasible in patients with recurrent gliomas. Concurrent bevacizumab and increasing radiation dose may improve survival in recurrent glioblastoma patients.

High-dose re-irradiation of intracranial lesions - Efficacy and safety including dosimetric analysis based on accumulated EQD2Gy dose EQD calculation

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Re-irradiation of the brain is feasible with an encouraging overall survival.

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Treatment related toxicity was low within the reported dose range.

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EQD2 cumulative dose distributions were calculated using rigid registration.

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Dose-Response-Modelling with logistic regression showed a correlation of the D1cc brain with any grade of acute toxicity.

Introduction

The use of cranial re-irradiation is growing with improving overall survival and the advent of high-precision radiotherapy techniques. Still the value of re-irradiation needs careful evaluation regarding safety and efficacy. We analyzed dosimetric and clinical data of patients receiving cranial re-irradiation using EQD2 sum plans.

Methods and material

We retrospectively analyzed the data of 76 patients who received repeated cranial radiotherapy from 02/2013 to 09/2016. 34 patients suffered from recurrent primary brain tumors, 42 from brain metastases. Dosimetric analysis was performed accumulating EQD2 dose distributions based on rigid image registration. Clinical and radiological data was collected at follow-ups including toxicity, local control and overall survival.

Results

In total 76 patients had at least 2 courses of intracranial radiotherapy. The median accumulated prescription EQD2 dose was 96.5 Gy₂ for all radiation courses combined. The median D(0.1 cc) of the brain for patients receiving more than 100 Gy₂ was 114 Gy₂ with a highest dose of 161.5 Gy₂. 74% of patients suffered from low grade (G1–G2) acute toxicity, only two high grade (>G3) toxicities were recorded.

Median overall survival from the time of first re-irradiation was 57 weeks (range 4–186 weeks). The median time to local failure for patients with a primary brain tumor was not reached and 24 weeks (range 1–77 weeks) for patients with brain metastases.

Conclusion

Repeated radiotherapy appears both safe and efficient in patients with recurrent primary or secondary brain tumors with doses to the brain up to 120 Gy₂ EQD2, doses below 100 Gy₂ for brainstem and doses below 75 Gy₂ EQD2 to chiasm and optic nerves.

Carbon irradiation overcomes glioma radioresistance by eradicating stem cells and forming an antiangiogenic and immunopermissive niche

Tumor radioresistance leading to local therapy failure remains a major obstacle for successful treatment of high-grade glioma. We hypothesized that distinct radiobiological features of particle therapy with carbon ions may circumvent glioma radioresistance. We demonstrate that carbon irradiation (CIR) efficiently eradicates radioresistant patient-derived glioma stem cells (GSCs), leading to growth inhibition and prolonged survival. The impact of CIR at the tumor-stroma interface was further investigated in 2 syngeneic mouse and 2 orthotopic GSC xenograft models. Intriguingly, tumor regressions and long-term local controls were observed at doses greater than or equal to 15-Gy CIR. Fractionated CIR further prolonged survival. The enhanced relative biological effectiveness of CIR in vivo was attributed to its potent antiangiogenic effects and eradication of radioresistant hypoxic tumor cells. Blockade of the HIF1-α/stromal cell-derived factor 1/CXCR4 axis by CIR reduced the recruitment of microglia and myeloid-derived suppressor cells (CD11b+Gr1+). Consequently, CIR abrogated M2-like immune polarization and enhanced the influx of CD8+ cells, generating an immunopermissive niche. We report that radiotherapy with carbon ions could surmount several central glioma resistance mechanisms by eradicating hypoxic and stem cell-like tumor cells, as well as modulating the glioma niche toward an antiangiogenic and less immunosuppressive state. Conclusively, potentially novel rationales for CIR in conquering glioma radioresistance are provided.

Multimodal treatment for local recurrent malignant gliomas: Resurgery and/or reirradiation followed by chemotherapy

The therapeutic management of recurrent malignant gliomas (MGs) is not determined. Therefore, the efficacy of a multimodal approach and a combination systemic therapy was investigated. A retrospective analysis of 26 MGs patients at first relapse treated with multimodal therapy (chemotherapy plus surgery and/or reirradiation) or chemotherapy alone was performed. Second-line chemotherapy consisted of fotemustine (FTM) in combination with bevacizumab (BEV) (cFTM/BEV) or followed by third-line BEV (sFTM/BEV). Subgroup analyses were performed. Multimodal therapy provided a higher overall response rate (ORR) (73 vs. 47%), disease control rate (DCR) (82 vs. 67%), median progression-free survival (mPFS) (11 vs. 7 months; P=0.08) and median overall survival (mOS) (13 vs. 8 months; P=0.04) compared with chemotherapy. Concomitant FTM/BEV resulted in higher ORR (84 vs. 36%), DCR (92 vs. 57%), mPFS (10 vs. 5 months; P=0.22) and mOS (11 vs. 5.2 months; P=0.15) compared with sFTM/BEV. Methylated patients did not experience additional survival benefits with multimodality treatment but had higher mPFS (10 vs 7.1 months; P=0.33) and mOS (11 vs. 8 months; P=0.33) with cFTM/BEV. Unmethylated patients experienced the greatest survival benefit with the multimodal approach (mPFS: 10 vs. 5 months; mOS 11 vs 6 months; both P=0.02) and cFTM/BEV (mPFS: 5 vs. 2 months; mOS 6 vs. 3.2 months; both P=0.01). In conclusion, in recurrent MGs, multimodal therapy and cFTM/BEV provide survival and response benefits. Methylated patients benefit from a cFTM/BEV but not from a multimodal approach. Notably, unmethylated patients had the highest survival benefit with the two strategies.

Re-irradiation for malignant glioma: Toward patient selection and defining treatment parameters for salvage

Purpose

Reirradiation for recurrent glioma remains controversial without knowledge of optimal patient selection, dose, fractionation, and normal tissue tolerances. We retrospectively evaluated outcomes and toxicity after conventionally fractionated reirradiation for recurrent high-grade glioma, along with the impact of concurrent chemotherapy.

Methods and materials

We conducted a retrospective review of patients reirradiated for high-grade glioma recurrence between 2007 and 2016 (including patients with initial low-grade glioma). Outcome metrics included overall survival (OS), prognostic factors for survival, and treatment-related toxicity.

Results

Patients (n = 118; median age 47 years; median Karnofsky performance status score: 80) were re-treated at a median of 28 months (range, 5-214 months) after initial radiation therapy. The median reirradiation dose was 41.4 Gy (range, 12.6-54.0 Gy) to a median lesion volume of 202 cm³ (range, 20-901 cm³). The median cumulative (initial radiation and reirradiation combined) potential maximum brainstem dose was 76.9 Gy (range, 5.0-108.3 Gy) and optic apparatus dose was 56.0 Gy (range, 4.5-90.9 Gy). Of the patients, 56% received concurrent temozolomide, 14%, bevacizumab, and 11%, temozolomide plus bevacizumab; 19% had no chemotherapy. The planned reirradiation was completed by 90% of patients. Median OS from the completion of reirradiation was 9.6 months (95% confidence interval [CI], 7.5-11.7 months) for all patients and 14.0, 11.5, and 6.7 months for patients with initial grade 2, 3, and 4 glioma, respectively. On multivariate analysis, better OS was observed with a >24-month interval between radiation treatments (hazard ratio [HR]: 0.3; 95% CI, 0.2-0.5; P < .001), reirradiation dose >41.4 Gy (HR: 0.6; 95% CI, 0.4-0.9; P = .03), and gross total resection before reirradiation (HR: 0.6, 95% CI, 0.3-0.9; P = .02). Radiation necrosis and grade ≥3 late neurotoxicity were both minimal (<5%). No symptomatic persistent brainstem or optic nerve/chiasm injury was identified.

Conclusions

Salvage reirradiation, even at doses >41.4 Gy in conventional fractionation, along with chemotherapy, was safe and well tolerated with meaningful survival duration. These data provide information that may be useful in implementing safe reirradiation treatments for appropriately selected patients and guiding future studies to define optimal reirradiation doses, maximal safe doses to critical structures, and the role of systemic therapy.

Nucleolar and spindle-associated protein 1 is a tumor grade correlated prognosis marker for glioma patients

AIMS

Despite therapeutic advances in glioma management including surgery, radiation, and chemotherapy, the improvement of patient outcome is far from satisfactory. Nucleolar and spindle-associated protein 1 (NUSAP1) is an important functional protein during mitosis, and its abnormal expression is implicated in progression of different types of tumors. However, the role of NUSAP1 in gliomas remains unclear.

METHODS

NUSAP1 expression in gliomas with different grades was investigated based on GEO glioma datasets. Kaplan-Meier survival analysis was used to evaluate its prognostic significance. In vitro assays were also performed to evaluate effects of NUSAP1 on malignant phenotypes of glioma cells by silencing NUSAP1.

RESULTS

NUSAP1 expression was correlated not only with glioma grade but also with prognosis of glioma patients. NUSAP1 depletion suppressed proliferation of U251 cells by inducing cell cycle arrest at G2/M phase and apoptosis. NUSAP1 depletion rendered U251 cells impaired migratory ability as well.

CONCLUSION

NUSAP1 is a potential prognosis marker for glioma patients and therapeutic strategies targeting NUSAP1 might hold promise in improving glioma treatment.