Randomized double-blind placebo-controlled trial of bevacizumab therapy for radiation necrosis of the central nervous system

Cost-effectiveness analysis of bevacizumab for cerebral radiation necrosis treatment based on real-world utility value in China

BACKGROUND

Bevacizumab shows superior efficacy in cerebral radiation necrosis (CRN) therapy, but its economic burden remains heavy due to the high drug price. This study aims to evaluate the cost-effectiveness of bevacizumab for CRN treatment from the Chinese payers' perspective.

METHODS

A decision tree model was developed to compare the costs and health outcomes of bevacizumab and corticosteroids for CRN therapy. Efficacy and safety data were derived from the NCT01621880 trial, which compared the effectiveness and safety of bevacizumab monotherapy with corticosteroids for CRN in nasopharyngeal cancer patients, and demonstrated that bevacizumab invoked a significantly higher response than corticosteroids (65.5% vs. 31.5%, P < 0.001) with no significant differences in adverse events between two groups. The utility value of the "non-recurrence" status was derived from real-world data. Costs and other utility values were collected from an authoritative Chinese network database and published literature. The primary outcomes were total costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratio (ICER). The uncertainty of the model was evaluated via one-way and probabilistic sensitivity analyses.

RESULTS

Bevacizumab treatment added 0.12 (0.48 vs. 0.36) QALYs compared to corticosteroid therapy, along with incremental costs of $ 2010 ($ 4260 vs. $ 2160). The resultant ICER was $ 16,866/QALY, which was lower than the willingness-to-pay threshold of $ 38,223/QALY in China. The price of bevacizumab, body weight, and the utility value of recurrence status were the key influential parameters for ICER. Probabilistic sensitivity analysis revealed that the probability of bevacizumab being cost-effectiveness was 84.9%.

CONCLUSION

Compared with corticosteroids, bevacizumab is an economical option for CRN treatment in China.

Neurological complications of modern radiotherapy for head and neck cancer

Radiotherapy is one of the mainstay treatment modalities for the management of non-metastatic head and neck cancer (HNC). Notable improvements in treatment outcomes have been observed in the recent decades. Modern radiotherapy techniques, such as intensity-modulated radiotherapy and charged particle therapy, have significantly improved tumor target conformity and enabled better preservation of normal structures. However, because of the intricate anatomy of the head and neck region, multiple critical neurological structures such as the brain, brainstem, spinal cord, cranial nerves, nerve plexuses, autonomic pathways, brain vasculature, and neurosensory organs, are variably irradiated during treatment, particularly when tumor targets are in close proximity. Consequently, a diverse spectrum of late neurological sequelae may manifest in HNC survivors. These neurological complications commonly result in irreversible symptoms, impair patients' quality of life, and contribute to a substantial proportion of non-cancer deaths. Although the relationship between radiation dose and toxicity has not been fully elucidated for all complications, appropriate application of dosimetric constraints during radiotherapy planning may reduce their incidence. Vigilant surveillance during the course of survivorship also enables early detection and intervention. This article endeavors to provide a comprehensive review of the various neurological complications of modern radiotherapy for HNC, summarize the current incidence data, discuss methods to minimize their risks during radiotherapy planning, and highlight potential strategies for managing these debilitating toxicities.

Comparative analysis of bevacizumab and LITT for treating radiation necrosis in previously radiated CNS neoplasms: a systematic review and meta-analysis

PURPOSE

Radiation necrosis (RN) is a local inflammatory reaction that arises in response to radiation injury and may cause significant morbidity. This study aims to evaluate and compare the efficacy of bevacizumab and laser interstitial thermal therapy (LITT) in treating RN in patients with previously radiated central nervous system (CNS) neoplasms.

METHODS

PubMed, Cochrane, Scopus, and EMBASE databases were screened. Studies of patients with radiation necrosis from primary or secondary brain tumors were included. Indirect meta-analysis with random-effect modeling was performed to compare clinical and radiological outcomes.

RESULTS

Twenty-four studies were included with 210 patients in the bevacizumab group and 337 patients in the LITT group. Bevacizumab demonstrated symptomatic improvement/stability in 87.7% of cases, radiological improvement/stability in 86.2%, and steroid wean-off in 45%. LITT exhibited symptomatic improvement/stability in 71.2%, radiological improvement/stability in 64.7%, and steroid wean-off in 62.4%. Comparative analysis revealed statistically significant differences favoring bevacizumab in symptomatic improvement/stability (p = 0.02), while no significant differences were observed in radiological improvement/stability (p = 0.27) or steroid wean-off (p = 0.90). The rates of adverse reactions were 11.2% for bevacizumab and 14.9% for LITT (p = 0.66), with the majority being grade 2 or lower (72.2% for bevacizumab and 62.5% for LITT).

CONCLUSION

Both bevacizumab and LITT exhibited favorable clinical and radiological outcomes in managing RN. Bevacizumab was found to be associated with better symptomatic control compared to LITT. Patient-, diagnosis- and lesion-related factors should be considered when choosing the ideal treatment modality for RN to enhance overall patient outcomes.

Hypofractionated re-irradiation with bevacizumab for relapsed chemorefractory glioblastoma after prior high dose radiotherapy: a feasible option for patients with large-volume relapse

PURPOSE

There remains no standard of care for patients with recurrent and chemorefractory glioblastoma. Re-irradiation (reRT) provides an additional management option. However, published series predominantly focus on small reRT volumes utilizing stereotactic hypofractionated regimens. Concerns regarding toxicity have limited utilisation of reRT for larger recurrences, however this may be mitigated with use of bevacizumab (BEV).

METHODS AND MATERIALS

A prospective database of patients managed with the EORTC-NCIC (Stupp) protocol 60 Gy chemoradiotherapy protocol for glioblastoma between 2007 and 2021 was reviewed for those patients receiving reRT for chemorefractory relapse. Serial MRI and PET were used to establish true progression and exclude patients with pseudoprogression or radionecrosis from reRT. The primary endpoint was overall survival (OS) from date of reRT. Prognostic factors were also assessed.

RESULTS

447 patients managed for glioblastoma under the Stupp protocol were identified, of which 372 had relapsed and were thus eligible for reRT. 71 patients underwent reRT. Median relapse-free survival from diagnosis for the reRT and overall cohorts were similar at 11.6 months (95%CI:9.4-14.2) and 11.8 months (95%CI:9.4-14.2) respectively. 60/71 (85%) reRT patients had received BEV prior to reRT and continued concurrent BEV during reRT. Of the 11 patients not managed with BEV during reRT, 10 required subsequent salvage BEV. ReRT patients were younger (median 53 vs. 59 years, p < 0.001), had better performance status (86% vs. 69% ECOG 0-1, p = 0.002) and more commonly had MGMT promoter-methylated tumours (54% vs. 40%, p = 0.083) compared to non-reRT patients. Median reRT PTV volume was 135cm3 (IQR: 69-207cm3). Median OS from reRT to death was 7.1 months (95%CI:6.3-7.9). Patients aged < 50, 50-70 and > 70 years had post-reRT median OS of 7.7, 6.4 and 6.0 months respectively (p = 0.021). Median post-reRT survival was longer for patients with ECOG performance status 0-1 compared to 2-3 (8.1 vs. 6.3 months, p = 0.039). PTV volume, site of relapse, MGMT promoter-methylation status and extent of initial surgical resection were not associated with post-reRT survival. ReRT was well-tolerated. Out of the 6 patients (8%) admitted to hospital after reRT, only one was for reRT toxicity. This was a CTCAE grade 3 radiation necrosis event in a patient managed without prior BEV.

CONCLUSION

Patients with recurrent glioblastoma who have been previously treated with 60 Gy radiotherapy have a meaningful survival benefit from large volume re-irradiation which is well tolerated. ReRT should not be ignored as a salvage treatment option in patients with chemorefractory progressive disease.

The addition of chloroquine and bevacizumab to standard radiochemotherapy for recurrent glioblastoma multiforme

INTRODUCTION

Hypoxia-induced autophagy leads to an increase in vasculogenic-mimicry (VM) and the development of resistance of glioblastoma-cells to bevacizumab (BEV). Chloroquine (HCQ) inhibits autophagy, reduces VM and can thus produce a synergistic effect in anti-angiogenic-therapy by delaying the development of resistance to BEV.

PURPOSE

We retrospectively compared the combined addition of HCQ+BEV and adjuvant-radiochemotherapy (aRCT) to aRCT alone for recurrent-glioblastoma (rGBM) in regards of overall survival (OS).

METHODS

Between 2006 and 2016, 134 patients underwent neurosurgery for rGBM at our institution. Forty-two patients (Karnofsky-Performance-Score>60%) with primary-glioblastoma underwent repeat-surgery and aRCT for recurrence. Four patients (9.5%) received aRCT+HCQ+BEV. Five patients received aRCT+BEV.

RESULTS

In rGBM-patients who were treated with aRCT+HCQ+BEV, median OS was 36.57 months and median post-recurrence-survival (PRS) was 23.92 months while median PRS in the control-group was 9.63 months (p=0.022). In patients who received aRCT+BEV, OS and PRS were 26.83 and 12.97 months, respectively.

CONCLUSIONS

Although this study was performed on a small number of highly selected patients, it demonstrates a synergistic effect of HCQ+BEV in the treatment of rGBM which previously could be demonstrated based on experimental data. A significant increase of OS in patients who receive aRCT+HCQ+BEV cannot be ruled out and should be further investigated in randomised-controlled-trials.

Efficacy and toxicity of photon, proton, and carbon ion radiotherapy in the treatment of intracranial solitary fibrous tumor/hemangiopericytoma

BACKGROUND

Solitary fibrous tumors (SFT) of the central nervous system are rare and treatment options are not well established. The aim of this study was to evaluate the clinical outcomes of radiotherapy (RT) and re-radiotherapy (re-RT) for de novo intracranial SFT and recurrent intracranial SFT.

METHODS

This retrospective study analyzed efficacy and toxicity of different RT modalities in patients who received radiotherapy (RT) for intracranial SFT at Heidelberg University Hospital between 2000 and 2020 following initial surgery after de novo diagnosis ("primary group"). We further analyzed the patients of this cohort who suffered from tumor recurrence and received re-RT at our institution ("re-irradiation (re-RT) group"). Median follow-up period was 54.0 months (0-282) in the primary group and 20.5 months (0-72) in the re-RT group. RT modalities included 3D-conformal RT (3D-CRT), intensity-modulated RT (IMRT), stereotactic radiosurgery (SRS), proton RT, and carbon-ion RT (C12-RT). Response rates were analyzed according to RECIST 1.1 criteria.

RESULTS

While the primary group consisted of 34 patients (f: 16; m:18), the re-RT group included 12 patients (f: 9; m: 3). Overall response rate (ORR) for the primary group was 38.3% (N = 11), with 32.4% (N = 11) complete remissions (CR) and 5.9% (N = 2) partial remissions (PR). Stable disease (SD) was confirmed in 5.9% (N = 2), while 41.2% (N = 14) experienced progressive disease (PD). 14% (N = 5) were lost to follow up. The re-RT group had 25.0% CR and 17.0% PR with 58.0% PD. The 1-, 3-, and 5-year progression-free survival rates were 100%, 96%, and 86%, respectively, in the primary group, and 81%, 14%, and 14%, respectively, in the re-RT group. Particle irradiation (N = 11) was associated with a lower likelihood of developing a recurrence in the primary setting than photon therapy (N = 18) (OR = 0.038; p = 0.002), as well as doses ≥ 60.0 Gy (N = 15) versus < 60.0 Gy (N = 14) (OR = 0.145; p = 0.027). Risk for tumor recurrence was higher for women than for men (OR = 8.07; p = 0.014) with men having a median PFS of 136.3 months, compared to women with 66.2 months.

CONCLUSION

The data suggests RT as an effective treatment option for intracranial SFT, with high LPFS and PFS rates. Radiation doses ≥ 60 Gy could be associated with lower tumor recurrence. Particle therapy may be associated with a lower risk of recurrence in the primary setting, likely due to the feasibility of higher RT-dose application.

The dilemma of radiation necrosis from diagnosis to treatment in the management of brain metastases

Radiation therapy with stereotactic radiosurgery (SRS) or whole brain radiation therapy is a mainstay of treatment for patients with brain metastases. The use of SRS in the management of brain metastases is becoming increasingly common and provides excellent local control. Cerebral radiation necrosis (RN) is a late complication of radiation treatment that can be seen months to years following treatment and is often indistinguishable from tumor progression on conventional imaging. In this review article, we explore risk factors associated with the development of radiation necrosis, advanced imaging modalities used to aid in diagnosis, and potential treatment strategies to manage side effects.

Dosimetric feasibility analysis and presentation of an isotoxic dose-escalated radiation therapy concept for glioblastoma used in the PRIDE trial (NOA-28; ARO-2022-12)

Background and purpose

The PRIDE trial (NOA-28; ARO-2022-12; NCT05871021) is scheduled to start recruitment in October 2023. Its primary objective is to enhance median overall survival (OS), compared to historical median OS rates, in patients with methylguanine methlyltransferase (MGMT) promotor unmethylated glioblastoma by incorporating isotoxic dose escalation to 75 Gy in 30 fractions. To achieve isotoxicity and counteract the elevated risk of radiation necrosis (RN) associated with dose-escalated regimens, the addition of protective concurrent bevacizumab (BEV) serves as an innovative approach. The current study aims to assess the dosimetric feasibility of the proposed concept.

Materials and methods

A total of ten patients diagnosed with glioblastoma were included in this dosimetric analysis. Delineation of target volumes for the reference plans adhered to the ESTRO-EANO 2023 guideline. The experimental plans included an additional volume for the integrated boost. Additionally, the 60 Gy-volume was reduced by using a margin of 1.0 cm instead of 1.5 cm. To assess the risk of symptomatic RN, the Normal Tissue Complication Probability (NTCP) was calculated and compared between the reference and experimental plans.

Results

Median NTCP of the reference plan (NTCPref) and of the experimental plan (NTCPex) were 0.24 (range 0.11-0.29) and 0.42 (range 0.18-0.54), respectively. NTCPex was a median of 1.77 (range 1.60-1.99) times as high as the NTXPref. In a logarithmic comparison, the risk of RN is enhanced by a factor of median 2.00 (range 1.66-2.35). The defined constraints for the organs at risk were feasible.

Conclusion

When considering the potential protective effect of BEV, which we hypothesized might reduce the risk of RN by approximately two-fold, achieving isotoxicity with the proposed dose-escalated experimental plan for the PRIDE trial seems feasible.

Hyperbaric Oxygen Therapy as an Alternative Therapeutic Option for Radiation-Induced Necrosis Following Radiotherapy for Intracranial Pathologies

BACKGROUND

Radiotherapy (RT) is a feasible adjuvant therapeutic option for managing intracranial pathologies. One of the late complications of RT that frequently develops within months following RT is radiation necrosis (RN). Corticosteroids are the first-line therapeutic option for RNs; however, in case of unfavorable outcomes or intolerability, several other options, including bevacizumab, laser interstitial thermal therapy, surgery, and hyperbaric oxygen therapy (HBOT). Our goal was to investigate the feasibility and efficacy of the application of HBOT in RNs following RT and help physicians make decisions based on the latest data in the literature.

METHODS

We provide a comprehensive review of the literature on the current issues of utilization of HBOT in RNs.

RESULTS

We included 11 studies with a total of 46 patients who underwent HBOT. Most of the cases were diagnosed with brain tumors or arteriovenous malformations. Improvement was achieved in most of the cases.

DISCUSSION

HBOT is a noninvasive therapeutic intervention that can play a role in adjuvant therapy concurrent with RT and chemotherapy and treating RNs. HBOT resolves the RN through 3 mechanisms, including angiogenesis, anti-inflammatory modulation, and cellular repair. Previous studies demonstrated that HBOT is a feasible and well-tolerated therapeutic option that has shown promising results in improving clinical and radiological outcomes in intracranial RNs. Complications of HBOT are usually mild and reversible.

CONCLUSIONS

HBOT is a feasible and effective therapeutic option in steroid-refractory RNs and is associated with favorable outcomes and a low rate of side effects.

Metabolic and Toxic Myelopathies

OBJECTIVE

This article reviews the clinical presentation, diagnostic evaluation, and treatment of metabolic and toxic myelopathies resulting from nutritional deficiencies, environmental and dietary toxins, drugs of abuse, systemic medical illnesses, and oncologic treatments.

LATEST DEVELOPMENTS

Increased use of bariatric surgery for obesity has led to higher incidences of deficiencies in nutrients such as vitamin B12 and copper, which can cause subacute combined degeneration. Myelopathies secondary to dietary toxins including konzo and lathyrism are likely to become more prevalent in the setting of climate change leading to drought and flooding. Although modern advances in radiation therapy techniques have reduced the incidence of radiation myelopathy, patients with cancer are living longer due to improved treatments and may require reirradiation that can increase the risk of this condition. Immune checkpoint inhibitors are increasingly used for the treatment of cancer and are associated with a wide variety of immune-mediated neurologic syndromes including myelitis.

ESSENTIAL POINTS

Metabolic and toxic causes should be considered in the diagnosis of myelopathy in patients with particular clinical syndromes, risk factors, and neuroimaging findings. Some of these conditions may be reversible if identified and treated early, requiring careful history, examination, and laboratory and radiologic evaluation for prompt diagnosis.

Can low-dose intravenous bevacizumab be as effective as high-dose bevacizumab for cerebral radiation necrosis?

Although intravenous bevacizumab (IVBEV) is the most promising treatment for cerebral radiation necrosis (CRN), there is no conclusion on the optimal dosage. Our retrospective study aimed to compare the efficacy and safety of high-dose with low-dose IVBEV in treating CRN associated with radiotherapy for brain metastases (BMs). This paper describes 75 patients who were diagnosed with CRN secondary to radiotherapy for BMs, treated with low-dose or high-dose IVBEV and followed up for a minimum of 6 months. The clinical data collected for this study include changes in brain MRI, clinical symptoms, and corticosteroid usage before, during, and after IVBEV treatment. At the 3-month mark following administration of IVBEV, a comparison of two groups revealed that the median percentage decreases in CRN volume on T2-weighted fluid-attenuated inversion recovery and T1-weighted gadolinium contrast-enhanced image (T1CE), as well as the signal ratio reduction on T1CE, were 65.8% versus 64.8% (p = 0.860), 41.2% versus 51.9% (p = 0.396), and 37.4% versus 35.1% (p = 0.271), respectively. Similarly, at 6 months post-IVBEV, the median percentage reductions of the aforementioned parameters were 59.5% versus 62.0% (p = 0.757), 39.1% versus 31.3% (p = 0.851), and 35.4% versus 28.2% (p = 0.083), respectively. Notably, the incidence of grade ≥3 adverse events was higher in the high-dose group (n = 4, 9.8%) than in the low-dose group (n = 0). Among patients with CRN secondary to radiotherapy for BMs, the administration of high-dose IVBEV did not demonstrate superiority over low-dose IVBEV. Moreover, the use of high-dose IVBEV was associated with a higher incidence of grade ≥3 adverse events compared with low-dose IVBEV.

Prospective Randomized Phase 2 Trial of Hypofractionated Stereotactic Radiation Therapy of 25 Gy in 5 Fractions Compared With 35 Gy in 5 Fractions in the Reirradiation of Recurrent Glioblastoma

PURPOSE

The aim of this work was to investigate whether reirradiation of recurrent glioblastoma with hypofractionated stereotactic radiation therapy (HSRT) consisting of 35 Gy in 5 fractions (35 Gy/5 fx) compared with 25 Gy in 5 fractions (25 Gy/5 fx) improves outcomes while maintaining acceptable toxicity.

METHODS AND MATERIALS

We conducted a prospective randomized phase 2 trial involving patients with recurrent glioblastoma (per the 2007 and 2016 World Health Organization classification). A minimum interval from first radiation therapy of 5 months and gross tumor volume of 150 cc were required. Patients were randomized 1:1 to receive HSRT alone in 25 Gy/5 fx or 35 Gy/5 fx. The primary endpoint was progression-free survival (PFS). We used a randomized phase 2 screening design with a 2-sided α of 0.15 for the primary endpoint.

RESULTS

From 2011 to 2019, 40 patients were randomized and received HSRT, with 20 patients in each group. The median age was 50 years (range, 27-71); a new resection before HSRT was performed in 75% of patients. The median PFS was 4.9 months in the 25 Gy/5 fx group and 5.2 months in the 35 Gy/5 fx group (P = .23). Six-month PFS was similar at 40% (85% CI, 24%-55%) for both groups. The median overall survival (OS) was 9.2 months in the 25 Gy/5 fx group and 10 months in the 35 Gy/5 fx group (P = .201). Grade ≥3 necrosis was numerically higher in the 35 Gy/5 fx group (3 [16%] vs 1 [5%]), but the difference was not statistically significant (P = .267). In an exploratory analysis, median OS of patients who developed treatment-related necrosis was 14.1 months, and that of patients who did not was 8.7 months (P = .003).

CONCLUSIONS

HSRT alone with 35 Gy/5 fx was not superior to 25 Gy/5 fx in terms of PFS or OS. Due to a potential increase in the rate of clinically meaningful treatment-related necrosis, we suggest 25 Gy/5 fx as the standard dose in HSRT alone. During follow-up, attention should be given to differentiating tumor progression from potentially manageable complications.

Potent in vivo efficacy of oral gallium maltolate in treatment-resistant glioblastoma

Background

Treatment-resistant glioblastoma (trGBM) is an aggressive brain tumor with a dismal prognosis, underscoring the need for better treatment options. Emerging data indicate that trGBM iron metabolism is an attractive therapeutic target. The novel iron mimetic, gallium maltolate (GaM), inhibits mitochondrial function via iron-dependent and -independent pathways.

Methods

In vitro irradiated adult GBM U-87 MG cells were tested for cell viability and allowed to reach confluence prior to stereotactic implantation into the right striatum of male and female athymic rats. Advanced MRI at 9.4T was carried out weekly starting two weeks after implantation. Daily oral GaM (50mg/kg) or vehicle were provided on tumor confirmation. Longitudinal MRI parameters were processed for enhancing tumor ROIs in OsiriX 8.5.1 (lite) with Imaging Biometrics Software (Imaging Biometrics LLC). Statistical analyses included Cox proportional hazards regression models, Kaplan-Meier survival plots, linear mixed model comparisons, and t-statistic for slopes comparison as indicator of tumor growth rate.

Results

In this study we demonstrate non-invasively, using longitudinal MRI surveillance, the potent antineoplastic effects of GaM in a novel rat xenograft model of trGBM, as evidenced by extended suppression of tumor growth (23.56 mm3/week untreated, 5.76 mm3/week treated, P < 0.001), a blunting of tumor perfusion, and a significant survival benefit (median overall survival: 30 days untreated, 56 days treated; P < 0.001). The therapeutic effect was confirmed histologically by the presence of abundant cytotoxic cellular swelling, a significant reduction in proliferation markers (P < 0.01), and vessel normalization characterized by prominent vessel pruning, loss of branching, and uniformity of vessel lumina. Xenograft tumors in the treatment group were further characterized by an absence of an invasive edge and a significant reduction in both, MIB-1% and mitotic index (P < 0.01 each). Transferrin receptor and ferroportin expression in GaM-treated tumors illustrated cellular iron deprivation. Additionally, treatment with GaM decreased the expression of pro-angiogenic markers (von Willebrand Factor and VEGF) and increased the expression of anti-angiogenic markers, such as Angiopoietin-2.

Conclusion

Monotherapy with the iron-mimetic GaM profoundly inhibits trGBM growth and significantly extends disease-specific survival in vivo.

Bevacizumab in the Treatment of Refractory Brain Edema in High-grade Glioma

We report the case of a 14-year-old boy with a steroid-dependent refractory tumor whose longstanding dexamethasone treatment was successfully discontinued after a course of bevacizumab. The use of bevacizumab despite the absence of clear evidence of radionecrosis allowed a significant decrease in the amount of the brain edema.

A Systematic Review Informing the Management of Symptomatic Brain Radiation Necrosis After Stereotactic Radiosurgery and International Stereotactic Radiosurgery Society Recommendations

Radiation necrosis (RN) secondary to stereotactic radiosurgery is a significant cause of morbidity. The optimal management of corticosteroid-refractory brain RN remains unclear. Our objective was to summarize the literature specific to efficacy and toxicity of treatment paradigms for patients with symptomatic corticosteroid-refractory RN and to provide consensus guidelines for grading and management of RN on behalf of the International Stereotactic Radiosurgery Society. A systematic review of articles pertaining to treatment of RN with bevacizumab, laser interstitial thermal therapy (LITT), surgical resection, or hyperbaric oxygen therapy was performed. The primary composite outcome was clinical and/or radiologic stability/improvement (ie, proportion of patients achieving improvement or stability with the given intervention). Proportions of patients achieving the primary outcome were pooled using random weighted-effects analysis but not directly compared between interventions. Twenty-one articles were included, of which only 2 were prospective studies. Thirteen reports were relevant for bevacizumab, 5 for LITT, 5 for surgical resection and 1 for hyperbaric oxygen therapy. Weighted effects analysis revealed that bevacizumab had a pooled symptom improvement/stability rate of 86% (95% CI 77%-92%), pooled T2 imaging improvement/stability rate of 93% (95% CI 87%-98%), and pooled T1 postcontrast improvement/stability rate of 94% (95% CI 87%-98%). Subgroup analysis showed a statistically significant improvement favoring treatment with low-dose (below median, ≤7.5 mg/kg every 3 weeks) versus high-dose bevacizumab with regards to symptom improvement/stability rate (P = .02) but not for radiologic T1 or T2 changes. The pooled T1 postcontrast improvement/stability rate for LITT was 88% (95% CI 82%-93%), and pooled symptom improvement/stability rate for surgery was 89% (95% CI 81%-96%). Toxicity was inconsistently reported but was generally low for all treatment paradigms. Corticosteroid-refractory RN that does not require urgent surgical intervention, with sufficient noninvasive diagnostic testing that favors RN, can be treated medically with bevacizumab in carefully selected patients as a strong recommendation. The role of LITT is evolving as a less invasive image guided surgical modality; however, the overall evidence for each modality is of low quality. Prospective head-to-head comparisons are needed to evaluate the relative efficacy and toxicity profile among treatment approaches.

Incidence and Clinical Presentation of Pre- and Postoperative Seizures in Patients With Posterior Fossa Meningiomas

INTRODUCTION

Seizures are a common symptom of supratentorial meningiomas with pre- and postoperative seizure rates of approximately 30% and 12%, respectively, especially in parasagittal and convexity meningiomas. Less is known about the association between seizures and posterior fossa meningiomas. This study evaluates the prevalence, potential causes, and outcomes of seizures in patients who have undergone surgery for posterior fossa meningioma.

METHODS

This is a retrospective, observational, single-center study of consecutive patients who underwent surgical resection of posterior fossa meningiomas between 2009 and 2017. We retrospectively identified patients with seizures and analyzed patient demographics, tumor characteristics, and procedural characteristics.

RESULTS

A total of 44 patients (mean age: 59.8 ± 13.5 years) were included. Twenty-six tumors were located at the cerebellar convexity and tentorium (59.1%), 12 at the cerebellopontine angle (27.3%), four at the clivus (9.1%), and two at the foramen magnum (4.5%). Seizures were the presenting symptom of cerebellar meningioma in two patients. Patients were seizure-free after surgery. Three patients had their first seizure after surgery (interval between surgery and first seizure: two days to 17 months). Analysis of these three patients revealed possible causes of postoperative seizures: radiation necrosis and edema, hyponatremia, and preoperative hydrocephalus. In all patients with postoperative seizures, long-term seizure control was achieved with the administration of antiepileptic drugs.

CONCLUSIONS

The incidence of seizures in patients with posterior fossa meningiomas is relatively low. Antiepileptic drugs can help to achieve seizure control.

Perfusion MRI in the evaluation of brain metastases: current practice review and rationale for study of baseline MR perfusion imaging prior to stereotactic radiosurgery (STARBEAM-X)

Stereotactic radiosurgery is an established focal treatment for brain metastases with high local control rates. An important side-effect of stereotactic radiosurgery is the development of radionecrosis. On conventional MR imaging, radionecrosis and tumour progression often have similar appearances, but have contrasting management approaches. Perfusion MR imaging is often used in the post-treatment setting in order to help distinguish between the two, but image interpretation can be fraught with challenges.Perfusion MR plays an established role in the baseline and post-treatment evaluation of primary brain tumours and a number of studies have concentrated on the value of perfusion imaging in brain metastases. Of the parameters generated, relative cerebral blood volume is the most widely used variable in terms of its clinical value in differentiating between radionecrosis and tumour progression. Although it has been suggested that the relative cerebral blood volume tends to be elevated in active metastatic disease following treatment with radiosurgery, but not with treatment-related changes, the literature available on interpretation of the ratios provided in the context of defining tumour progression is not consistent.This article aims to provide an overview of the role perfusion MRI plays in the assessment of brain metastases and introduces the rationale for the STARBEAM-X study (Study of assessment of radionecrosis in brain metastases using MR perfusion extra imaging), which will prospectively evaluate baseline perfusion imaging in brain metastases. We hope this will allow insight into the vascular appearance of metastases from different primary sites, and aid in the interpretation of post-treatment perfusion imaging.

Management of Complications in Neuro-oncology Patients

OBJECTIVE

The purpose of this article is to familiarize the reader with the spectrum of neurologic and medical complications relevant to the care of patients with neurologic cancer while highlighting best practices to prevent morbidity and mortality. Topics include tumor-related epilepsy, vasogenic edema, complications of corticosteroid use, disruption of the hypothalamic-pituitary axis, venous thromboembolism, and opportunistic infection.

LATEST DEVELOPMENTS

In 2021, a joint guideline from the Society for Neuro-Oncology and the European Association of Neuro-Oncology reaffirmed recommendations first established in 2000 that patients with newly diagnosed brain tumors should not be prescribed an antiseizure medication prophylactically. For those with tumor-related epilepsy, monotherapy with a non-enzyme-inducing anticonvulsant is the preferred initial treatment, and levetiracetam remains the preferred first choice. Surveys of physician practice continue to demonstrate excessive use of glucocorticoids in the management of patients with both primary and metastatic central nervous system malignancy. This is particularly concerning among patients who require checkpoint inhibitors as the efficacy of these agents is blunted by concomitant glucocorticoid use, resulting in a reduction in overall survival. Finally, direct oral anticoagulants have been shown to be safe in patients with brain tumors and are now favored as first-line treatment among those who require treatment for venous thromboembolism.

ESSENTIAL POINTS

Medical care for patients impacted by primary and secondary central nervous system malignancy is complex and requires a committed team-based approach that routinely calls upon the expertise of physicians across multiple fields. Neurologists have an important role to play and should be familiar with the spectrum of complications impacting these patients as well as the latest recommendations for management.

Neurologic Complications of Conventional Chemotherapy and Radiation Therapy

OBJECTIVE

Neurologic complications are among the most common and feared outcomes of cancer treatments. This review discusses the signs and symptoms, mechanisms, and management of the most common peripheral and central neurologic complications of chemotherapy, radiation therapy, and antiangiogenic therapy during cancer treatment and in survivors.

LATEST DEVELOPMENTS

The landscape of cancer treatments is evolving to include more targeted and biologic therapies, in addition to more traditional cytotoxic therapies and radiation therapy. With increasingly complex regimens and longer survival for patients with cancer, the early recognition and management of neurologic complications is key to improving the morbidity and mortality of patients living with cancer.

ESSENTIAL POINTS

Neurologists should be familiar with acute central and peripheral toxicities that can occur during cancer treatment and delayed toxicities that can occur years after exposure. Neurologists should be familiar with the clinical and radiologic presentations of these complications and strategies for management.

Tumor Location Impacts the Development of Radiation Necrosis in Benign Intracranial Tumors

BACKGROUND

Radiation necrosis (RN) is a possible late complication of stereotactic radiosurgery (SRS), but only a few risk factors are known. The aim of this study was to assess tumor location in correlation to the development of radiation necrosis for skull base (SB) and non-skull base tumors.

METHODS

All patients treated with radiosurgery for benign neoplasms (2004-2020) were retrospectively evaluated. The clinical, imaging and medication data were obtained and the largest axial tumor diameter was determined using MRI scans in T1-weighted imaging with gadolinium. The diagnosis of RN was established using imaging parameters. Patients with tumors located at the skull base were compared to patients with tumors in non-skull base locations.

RESULTS

205 patients could be included. Overall, 157 tumors (76.6%) were located at the SB and compared to 48 (23.4%) non-SB tumors. Among SB tumors, the most common were vestibular schwannomas (125 cases) and meningiomas (21 cases). In total, 32 (15.6%) patients developed RN after a median of 10 (IqR 5-12) months. Moreover, 62 patients (30.2%) had already undergone at least one surgical resection. In multivariate Cox regression, SB tumors showed a significantly lower risk of radiation necrosis with a Hazard Ratio (HR) of 0.252, p < 0.001, independently of the applied radiation dose. Furthermore, higher radiation doses had a significant impact on the occurrence of RN (HR 1.372, p = 0.002).

CONCLUSIONS

The risk for the development of RN for SB tumors appears to be low but should not be underestimated. No difference was found between recurrent tumors and newly diagnosed tumors, which may support the value of radiosurgical treatment for patients with recurrent SB tumors.

Bevacizumab-Irinotecan combination therapy in recurrent low-grade glioma, previously treated with chemo-radiotherapy: a case report

Low grade gliomas (LGGs) of pineal region are usually difficult to remove and they frequently relapse or progress after front line chemotherapy. Bevacizumab-Irinotecan (BEVIRI) combination has been successfully attempted in children with recurrent LGGs, in most cases not previously irradiated. The efficacy of bevacizumab has also been described in radiation necrosis. Considering the possible overlapping of radiation treatment effect and disease progression and difficulty in differentiating, we report on the use of BEVIRI in a case of a recurrent relapsing low-grade glioma of the pineal region, subjected to multiple neurosurgical interventions, also treated with a carboplatin-etoposide regimen and a radiation course, at present at one-year follow-up showing a stable response, with no adverse events.

Research trends of radiation induced temporal lobe injury in patients with nasopharyngeal carcinoma from 2000 to 2022: a bibliometric analysis

BACKGROUND

In patients with nasopharyngeal cancer (NPC), radiation-induced temporal lobe injury (TLI) is the most dreaded late-stage complication following radiation therapy (RT). We currently lack a definitive algorithmic administration for this entity. In the meantime, the pathogenesis of TLI and the mechanism-based interventions to prevent or treat this adverse effect remain unknown. To better answer the aforementioned questions, it is necessary to comprehend the intellectual foundations and prospective trends of this field through bibliometric analysis.

METHODS

Articles were gathered from the Web of Science Core Collection (WoSCC) database between 2000 and 2022. CiteSpace was utilized to create a country/institutional co-authorship network, perform dual-map analysis, and find keywords with citation bursts. VOSviewer was used to build networks based on author co-authorship, journal citation, co-citation analysis of authors, references, and journals, and keyword co-occurrence.

RESULTS

A total of 140 articles and reviews were included in the final analysis. The number of publications has steadily increased with some fluctuations over the years. The country and institution contributing most to this field are the China and Sun Yat-Sen University. Han Fei was the most prolific author, while Lee Awm was the most frequently cited. The analysis of co-occurrence revealed three clusters, including: "radiation-induced injury or necrosis in NPC," "clinical studies on chemotherapy/radiotherapy complications and survival in recurrent NPC," and "IMRT/chemotherapy outcomes and toxicities in head and neck cancer"). Most recent keyword bursts were "volume," "temporal lobe injury," "toxicities," "model," "survival," "intensity modulated radiotherapy," "induced brain injury," "head and neck cancer," and "temporal lobe."

CONCLUSION

This study provides some insights of the major areas of interest in the field of radiation-induced TLI in patients with NPC by bibliometric analyses. This study assists scholars in locating collaborators and significant literature in this field, provides guidance for publishing journals, and identifies research hotspots. This analysis acknowledges significant contributions to the discipline and encourages the scientific community to conduct additional research.

Pseudoprogression versus true progression in glioblastoma: what neurosurgeons need to know

Management of patients with glioblastoma (GBM) is complex and involves implementing standard therapies including resection, radiation therapy, and chemotherapy, as well as novel immunotherapies and targeted small-molecule inhibitors through clinical trials and precision medicine approaches. As treatments have advanced, the radiological and clinical assessment of patients with GBM has become even more challenging and nuanced. Advances in spatial resolution and both anatomical and physiological information that can be derived from MRI have greatly improved the noninvasive assessment of GBM before, during, and after therapy. Identification of pseudoprogression (PsP), defined as changes concerning for tumor progression that are, in fact, transient and related to treatment response, is critical for successful patient management. These temporary changes can produce new clinical symptoms due to mass effect and edema. Differentiating this entity from true tumor progression is a major decision point in the patient's management and prognosis. Providers may choose to start an alternative therapy, transition to a clinical trial, consider repeat resection, or continue with the current therapy in hopes of resolution. In this review, the authors describe the invasive and noninvasive techniques neurosurgeons need to be aware of to identify PsP and facilitate surgical decision-making.

Reirradiation versus systemic therapy versus combination therapy for recurrent high-grade glioma: a systematic review and meta-analysis of survival and toxicity

PURPOSE

This review compares reirradiation (reRT), systemic therapy and combination therapy (reRT & systemic therapy) with regards to overall survival (OS), progression-free survival (PFS), adverse effects (AEs) and quality of life (QoL) in patients with recurrent high-grade glioma (rHGG).

METHODS

A search was performed on PubMed, Scopus, Embase and CENTRAL. Studies reporting OS, PFS, AEs and/or QoL and encompassing the following groups were included; reirradiation vs systemic therapy, combination therapy vs systemic therapy, combination therapy vs reRT, and bevacizumab-based combination therapy vs reRT with/without non-bevacizumab-based systemic therapy. Meta-analyses were performed utilising a random effects model. Certainty of evidence was assessed using GRADE.

RESULTS

Thirty-one studies (three randomised, twenty-eight non-randomised) comprising 2084 participants were included. In the combination therapy vs systemic therapy group, combination therapy improved PFS (HR 0.57 (95% CI 0.41-0.79); low certainty) and OS (HR 0.73 (95% CI 0.56-0.95); low certainty) and there was no difference in grade 3 + AEs (RR 1.03 (95% CI 0.57-1.86); very low certainty). In the combination therapy vs reRT group, combination therapy improved PFS (HR 0.52 (95% CI 0.38-0.72); low certainty) and OS (HR 0.69 (95% CI 0.52-0.93); low certainty). In the bevacizumab-based combination therapy vs reRT with/without non-bevacizumab-based systemic therapy group, adding bevacizumab improved PFS (HR 0.46 (95% CI 0.27-0.77); low certainty) and OS (HR 0.42 (95% CI 0.24-0.72; low certainty) and reduced radionecrosis (RR 0.17 (95% CI 0.06-0.48); low certainty).

CONCLUSIONS

Combination therapy may improve OS and PFS with acceptable toxicities in patients with rHGG compared to reRT or systemic therapy alone. Particularly, combining bevacizumab with reRT prophylactically reduces radionecrosis.

REGISTRATION

CRD42022291741.

High-dose bevacizumab for radiation-induced brain necrosis: a case report

Radiation-induced brain necrosis (RIBN) is a common adverse event from radiation therapy. We present a case of a 56-year-old man, diagnosed with non-small-cell lung cancer with brain metastases 2 years prior, for which he had received whole brain radiotherapy and brain stereotactic radiosurgery, who presented to the oncology unit with headache, dizziness and abnormal gait. MRI of the brain revealed radiological worsening of a cerebellar mass, including edema and mass effect. After a multidisciplinary tumor board meeting, the patient was diagnosed with RIBN and received 4 cycles of high-dose bevacizumab, with complete symptom resolution and significant radiological response. We report the successful use of a high-dose, shorter-duration treatment protocol of bevacizumab for RIBN.

Effect of Bevacizumab Treatment in Cerebral Radiation Necrosis : Investigation of Response Predictors in a Single-Center Experience

OBJECTIVE

Bevacizumab is a feasible option for treating cerebral radiation necrosis (RN). We investigated the clinical outcome of RN after treatment with bevacizumab and factors related to the initial response and the sustained effect.

METHODS

Clinical data of 45 patients treated for symptomatic RN between September 2019 and February 2021 were retrospectively collected. Bevacizumab (7.5 mg/kg) was administered at 3-week intervals with a maximum four-cycle schedule. Changes in the lesions magnetic resonance image (MRI) scans were examined for the response evaluation. The subgroup analysis was performed based on the initial response and the long-term maintenance of the effect.

RESULTS

Of the 45 patients, 36 patients (80.0%) showed an initial response, and eight patients (17.8%) showed delayed worsening of the corresponding lesion. The non-responders showed a significantly higher incidence of diffusion restriction on MRI than the responders (100.0% vs. 25.0%, p<0.001). The delayed worsening group showed a significantly higher proportion of glioma pathology than the maintenance group (87.5% vs. 28.6%, p=0.005). Cumulative survival rates with sustained effect were significantly higher in the groups with non-glioma pathology (p=0.019) and the absence of diffusion restriction (p<0.001). Pathology of glioma and diffusion restriction in MRI were the independent risk factors for non-response or delayed worsening after initial response.

CONCLUSION

The initial response of RN to bevacizumab was favorable, with improvement in four-fifths of the patients. However, a certain proportion of patients showed non-responsiveness or delayed exacerbations. Bevacizumab may be more effective in treating RN in patients with non-glioma pathology and without diffusion restriction in the MRI.

Radionecrosis mimicking pseudo‑progression in a patient with lung cancer and brain metastasis following the combination of anti‑PD‑1 therapy and stereotactic radiosurgery: A case report

Brain metastases (BMs) usually develop in patients with non-small cell lung cancer. In addition to systemic therapy, radiation therapy and surgery, anti-programmed cell death-ligand 1 (PD-L1) therapy is another promising clinical anticancer treatment modality. However, the optimal timing and drug-drug interactions of anti-PD-L1 therapy with other combined treatments remain to be elucidated. Treatment with anti-PD-L1 therapy is associated with an increased risk of radionecrosis (RN) regardless of tumor histology. The present study described a case of RN in a patient with lung adenocarcinoma and with BM who received anti-PD-L1 therapy. Before anti-PD-L1 treatment, the patient received whole brain radiotherapy. During durvalumab treatment, the intracranial metastases regressed. The progression of intracranial lesions 9 months later prompted a second-line of therapy with PD-L1 inhibitor durvalumab and stereotactic radiotherapy (SRT). Despite stereotactic irradiation, the lesions progressed further, leading to surgical resection. On examination, RN was detected, but there was no evidence of metastatic lung cancer. The aim of the present study was to present the longitudinal change in magnetic resonance imaging in RN following STR and anti-PD-L1 combined therapy. The atypical image of RN is conditionally important for making an accurate preoperative diagnosis.

Phase II study of border zone stereotactic radiosurgery with bevacizumab in patients with recurrent or progressive glioblastoma multiforme

PURPOSE

Recurrent glioblastoma is universally fatal with limited effective treatment options. The aim of this phase 2 study of Border Zone SRS plus bevacizumab was to evaluate OS in patients with recurrent GBM.

METHODS

Patients with histologically confirmed GBM with recurrent disease who had received prior first-line treatment with fractionated radiotherapy and chemotherapy and eligible for SRS were enrolled. Bevacizumab 10 mg/kg was given day -1, day 14, and then every 14 days until disease progression. 1-14 days before BZ-SRS procedure, patients underwent brain MRI /MRS. MRS with measurement of choline-to-N-acetyl aspartate index (CNI) area ≥ 3 was targeted for SRS.

RESULTS

From 2015-2017, sixteen of planned 40 patients were enrolled. The median age was 62 (range, 48-74Y). 3/16 (0.188) participants experienced grade 2 toxicity. No AREs were reported. The mOS was 11.73 months compared to 8.74 months (P = 0.324) from date of SRS for the BZ-SRS and institutional historical controls, respectively. PFS-6 and OS-6 were 31.2% (p = 0.00294) and 81.2%(p = 0.058), respectively. Of 13 evaluable for best response: 1 CR (p = 0.077), 4 PR (p = 0.308), 7 SD (p = 0.538), and 1 PD (p = 0.077). 11/16 participants had MRS scans with an estimated probability that MRS changes a treatment plan of 0 (0, 0.285).

CONCLUSION

BZ-SRS with bevacizumab was feasible and well tolerated. There is no significant survival benefit using BZ-SRS with bevacizumab compared to institutional historical controls. Secondary analysis revealed a trend toward improved PFS-6, but not OS-6 after BZ-SRS. MRS scans did not result in changes to SRS treatment plans.

Diagnosis and management of complications from the treatment of primary central nervous system tumors in adults

Central nervous system (CNS) tumor patients commonly undergo multimodality treatment in the course of their disease. Adverse effects and complications from these interventions have not been systematically studied, but pose significant challenges in clinical practice and impact function and quality of life, especially in the management of long-term brain tumor survivors. Here, the European Association of Neuro-Oncology (EANO) has developed recommendations to prevent, diagnose, and manage adverse effects and complications in the adult primary brain CNS tumor (except lymphomas) patient population with a specific focus on surgery, radiotherapy, and pharmacotherapy. Specifically, we also provide recommendations for dose adaptations, interruptions, and reexposure for pharmacotherapy that may serve as a reference for the management of standard of care in clinical trials. We also summarize which interventions are unnecessary, inactive or contraindicated. This consensus paper should serve as a reference for the conduct of standard therapy within and outside of clinical trials.

Radiation Myelopathy: A Case Report and Literature Review

Proton beam therapy is a common type of radiation treatment that delivers a beam of proton particles to treat cancer and minimize damage to nearby healthy tissue. In this paper, we describe a case of a 20-year-old male patient with osteosarcoma of the distal right femur that eventually metastasized to his thoracic cavity. The patient underwent radiation beam therapy treatment that was directed at his left thorax and nine months later presented with clinical and radiographic findings of delayed radiation myelopathy (RM).

Recognition and Management of the Long-term Effects of Cranial Radiation

OPINION STATEMENT

Cranial radiation is ubiquitous in the treatment of primary malignant and benign brain tumors as well as brain metastases. Improvement in radiotherapy targeting and delivery has led to prolongation of survival outcomes. As long-term survivorship improves, we also focus on prevention of permanent side effects of radiation and mitigating the impact when they do occur. Such chronic treatment-related morbidity is a major concern with significant negative impact on patient's and caregiver's respective quality of life. The actual mechanisms responsible for radiation-induced brain injury remain incompletely understood. Multiple interventions have been introduced to potentially prevent, minimize, or reverse the cognitive deterioration. Hippocampal-sparing intensity modulated radiotherapy and memantine represent effective interventions to avoid damage to regions of adult neurogenesis. Radiation necrosis frequently develops in the high radiation dose region encompassing the tumor and surrounding normal tissue. The radiographic findings in addition to the clinical course of the patients' symptoms are taken into consideration to differentiate between tissue necrosis and tumor recurrence. Radiation-induced neuroendocrine dysfunction becomes more pronounced when the hypothalamo-pituitary (HP) axis is included in the radiation treatment field. Baseline and post-treatment evaluation of hormonal profile is warranted. Radiation-induced injury of the cataract and optic system can develop when these structures receive an amount of radiation that exceeds their tolerance. Special attention should always be paid to avoid irradiation of these sensitive structures, if possible, or minimize their dose to the lowest limit.

Neurotoxicity from Old and New Radiation Treatments for Brain Tumors

Research regarding the mechanisms of brain damage following radiation treatments for brain tumors has increased over the years, thus providing a deeper insight into the pathobiological mechanisms and suggesting new approaches to minimize this damage. This review has discussed the different factors that are known to influence the risk of damage to the brain (mainly cognitive disturbances) from radiation. These include patient and tumor characteristics, the use of whole-brain radiotherapy versus particle therapy (protons, carbon ions), and stereotactic radiotherapy in various modalities. Additionally, biological mechanisms behind neuroprotection have been elucidated.

Stereotactic Radiosurgery as Treatment for Brain Metastases: An Update

Stereotactic radiosurgery (SRS) is a mainstay treatment option for brain metastasis (BM). While guidelines for SRS use have been outlined by professional societies, consideration of these guidelines should be weighed in the context of emerging literature, novel technology platforms, and contemporary treatment paradigms. Here, we review recent advances in prognostic scale development for SRS-treated BM patients and survival outcomes as a function of the number of BM and cumulative intracranial tumor volume. Focus is placed on the role of stereotactic laser thermal ablation in the management of BM that recur after SRS and the management of radiation necrosis. Neoadjuvant SRS prior to surgical resection as a means of minimizing leptomeningeal spread is also discussed.

Outcomes of systemic bevacizumab in radiation-induced optic neuropathy, case series

PURPOSE

Optic neuropathy is a rare, delayed complication after radiation with no universally accepted treatment modality. We report the outcomes of 6 patients with radiation-induced optic neuropathy (RION) who were treated with systemic bevacizumab.

METHODS

This is a retrospective series of 6 cases of RION, treated with intravenous (IV) bevacizumab. "Improved" or "worse" visual outcomes were defined as a change in best corrected visual acuity of ≥ 3 Snellen lines. Otherwise, the visual outcome was noted as "stable".

RESULTS

In our series, RION was diagnosed 8 to 36 months after radiotherapy. IV bevacizumab was initiated as treatment within 6 weeks of the onset of visual symptoms in 3 cases and after 3 months in the other cases. Although no improvement in visual function was observed, stabilization of vision was noted in 4 of the 6 cases. In the other 2 cases, the level of vision declined from counting fingers to no light perception. In 2 cases, bevacizumab treatment was discontinued prior to completion of the planned course due to renal stone formation or worsening of renal disease. One patient developed ischemic stroke 4 months after bevacizumab completion.

CONCLUSION

Systemic bevacizumab may stabilize vision in some patients with RION, though the limitations of our study do not allow us to draw this conclusion definitively. Therefore, the risks and potential benefits of using IV bevacizumab should be considered in each individual case.

[Limits of dose constraint definition for organs at risk specific to stereotactic radiotherapy]

Stereotactic radiotherapy is a very hypofractionated radiotherapy (>7.5Gy per fraction), and therefore is more likely to induce late toxicities than conventional normofractionated irradiations. The present study examines four frequent and potentially serious late toxicities: brain radionecrosis, radiation pneumonitis, radiation myelitis, and radiation-induced pelvic toxicities. The critical review focuses on the toxicity scales, the definition of the dose constrained volume, the dosimetric parameters, and the non-dosimetric risk factors. The most commonly used toxicity scales remain: RTOG/EORTC or common terminology criteria for adverse events (CTCAE). The definition of organ-at-risk volume requiring protection is often controversial, which limits the comparability of studies and the possibility of accurate dose constraints. Nevertheless, for the brain, whatever the indication (arteriovenous malformation, benign tumor, metastasis of solid tumors...), the association between the volume of brain receiving 12Gy (V12Gy) and the risk of cerebral radionecrosis is well established for both single and multi-fraction stereotactic irradiation. For the lung, the average dose received by both lungs and the V20 seem to correlate well with the risk of radiation-induced pneumonitis. For the spinal cord, the maximum dose is the most consensual parameter. Clinical trial protocols are useful for nonconsensual dose constraints. Non-dosimetric risk factors should be considered when validating the treatment plan.

Low-Dose Bevacizumab for the Treatment of Focal Radiation Necrosis of the Brain (fRNB): A Single-Center Case Series

Focal radiation necrosis of the brain (fRNB) is a late adverse event that can occur following the treatment of benign or malignant brain lesions with stereotactic radiation therapy (SRT) or stereotactic radiosurgery (SRS). Recent studies have shown that the incidence of fRNB is higher in cancer patients who received immune checkpoint inhibitors. The use of bevacizumab (BEV), a monoclonal antibody that targets the vascular endothelial growth factor (VEGF), is an effective treatment for fRNB when given at a dose of 5-7.5 mg/kg every two weeks. In this single-center retrospective case series, we investigated the effectiveness of a low-dose regimen of BEV (400 mg loading dose followed by 100 mg every 4 weeks) in patients diagnosed with fRNB. A total of 13 patients were included in the study; twelve of them experienced improvement in their existing clinical symptoms, and all patients had a decrease in the volume of edema on MRI scans. No clinically significant treatment-related adverse effects were observed. Our preliminary findings suggest that this fixed low-dose regimen of BEV can be a well-tolerated and cost-effective alternative treatment option for patients diagnosed with fRNB, and it is deserving of further investigation.

Novel Mechanisms and Future Opportunities for the Management of Radiation Necrosis in Patients Treated for Brain Metastases in the Era of Immunotherapy

Radiation necrosis, also known as treatment-induced necrosis, has emerged as an important adverse effect following stereotactic radiotherapy (SRS) for brain metastases. The improved survival of patients with brain metastases and increased use of combined systemic therapy and SRS have contributed to a growing incidence of necrosis. The cyclic GMP-AMP (cGAMP) synthase (cGAS) and stimulator of interferon genes (STING) pathway (cGAS-STING) represents a key biological mechanism linking radiation-induced DNA damage to pro-inflammatory effects and innate immunity. By recognizing cytosolic double-stranded DNA, cGAS induces a signaling cascade that results in the upregulation of type 1 interferons and dendritic cell activation. This pathway could play a key role in the pathogenesis of necrosis and provides attractive targets for therapeutic development. Immunotherapy and other novel systemic agents may potentiate activation of cGAS-STING signaling following radiotherapy and increase necrosis risk. Advancements in dosimetric strategies, novel imaging modalities, artificial intelligence, and circulating biomarkers could improve the management of necrosis. This review provides new insights into the pathophysiology of necrosis and synthesizes our current understanding regarding the diagnosis, risk factors, and management options of necrosis while highlighting novel avenues for discovery.

Advances in treatments of patients with classical and emergent neurological toxicities of anticancer agents

The neurotoxicity associated to the anticancer treatments has received a growing body of interest in the recent years. The development of innovating therapies over the last 20years has led to the emergence of new toxicities. Their diagnosis and management can be challenging in the clinical practice and further research is warranted to improve the understanding of their pathogenic mechanisms. Conventional treatments as radiation therapy and chemotherapy are associated to well-known and under exploration emerging central nervous system (CNS) and peripheral nervous system (PNS) toxicities. The identification of the risk factors and a better understanding of their pathogeny through a "bench to bedside and back again" approach, are the first steps towards the development of toxicity mitigation strategies. New imaging techniques and biological explorations are invaluable for their diagnosis. Immunotherapies have changed the cancer treatment paradigm from tumor cell centered to immune modulation towards an efficient anticancer immune response. The use of the immune checkpoints inhibitors (ICI) and chimeric antigen receptor (CAR-T cells) lead to an increase in the incidence of immune-mediated toxicities and new challenges in the neurological patient's management. The neurological ICI-related adverse events (n-irAE) are rare but potentially severe and may present with both CNS and PNS involvement. The most frequent and well characterized, from a clinical and biological standpoint, are the PNS phenotypes: myositis and polyradiculoneuropathy, but the knowledge on CNS phenotypes and their treatments is expanding. The n-irAE management requires a good balance between dampening the autoimmune toxicity without impairing the anticancer immunity. The adoptive cell therapies as CAR-T cells, a promising anticancer strategy, trigger cellular activation and massive production of proinflammatory cytokines inducing frequent and sometime severe toxicity known as cytokine release syndrome and immune effector cell-associated neurologic syndrome. Their management requires a close partnership between oncologist-hematologists, neurologists, and intensivists. The oncological patient's management requires a multidisciplinary clinical team (oncologist, neurologist and paramedical) as well as a research team leading towards a better understanding and a better management of the neurological toxicities.

Advances in Radiotherapy for Brain Metastases

Radiotherapy remains a cornerstone treatment of brain metastases. With new treatment advances, patients with brain metastases are living longer, and finding solutions for mitigating treatment-related neurotoxicity and improving quality of life is important. Historically, whole-brain radiation therapy (WBRT) was widely used but treatment options such as hippocampal sparing WBRT and stereotactic radiosurgery (SRS) have emerged as promising alternatives. Herein, we discuss the recent advances in radiotherapy for brain metastases including the sparing of critical structures that may improve long-term neurocognitive outcomes (eg, hippocampus, fornix) that may improve long-term neurocognitive outcome, evidence supporting preoperative and fractionated-SRS, and treatment strategies for managing radiation necrosis.

Management of initial and recurrent radiation-induced contrast enhancements following radiotherapy for brain metastases: Clinical and radiological impact of bevacizumab and corticosteroids

Purpose

The appearance of radiation-induced contrast enhancements (RICE) after radiotherapy for brain metastases can go along with severe neurological impairments. The aim of our analysis was to evaluate radiological changes, the course and recurrence of RICE and identify associated prognostic factors.

Methods

We retrospectively identified patients diagnosed with brain metastases, who were treated with radiotherapy and subsequently developed RICE. Patient demographic and clinical data, radiation-, cancer-, and RICE-treatment, radiological results, and oncological outcomes were reviewed in detail.

Results

A total of 95 patients with a median follow-up of 28.8 months were identified. RICE appeared after a median time of 8.0 months after first radiotherapy and 6.4 months after re-irradiation. Bevacizumab in combination with corticosteroids achieved an improvement of clinical symptoms and imaging features in 65.9% and 75.6% of cases, respectively, both significantly superior compared to treatment with corticosteroids only, and further significantly prolonged RICE-progression-free survival to a median of 5.6 months. Recurrence of RICE after initially improved or stable imaging occurred in 63.1% of cases, significantly more often in patients after re-irradiation and was associated with high mortality of 36.6% after the diagnosis of flare-up. Response of recurrence significantly depended on the applied treatment and multiple courses of bevacizumab achieved good response.

Conclusion

Our results suggest that bevacizumab in combination with corticosteroids is superior in achieving short-term imaging and symptom improvement of RICE and prolongs the progression-free time compared to corticosteroids alone. Long-term RICE flare-up rates after bevacizumab discontinuation are high, but repeated treatments achieved effective symptomatic control.

The role of the neurologist in the diagnosis and treatment of brain metastases and carcinomatous meningitis

Traditionally, in the past, most of central nervous system metastases from solid tumors were associated with an advanced phase of the disease needing palliation only, while to date they increasingly develop as an early and/or solitary relapse in patients with the systemic disease under control. This review will cover all the aspects of a modern management of brain and leptomeningeal metastases from diagnosis to the different therapeutic options, either local (surgery, stereotactic radiosurgery, whole-brain radiotherapy with hippocampal avoidance) or systemic. Particular emphasis is reserved to the new-targeted drugs, that allow to target specifically driver molecular alterations. These new compounds pose new problems in terms of monitoring efficacy and adverse events, but increasingly they allow improvement of outcome in comparison to historical controls.

Delineation of recurrent glioblastoma by whole brain spectroscopic magnetic resonance imaging

BACKGROUND

Glioblastoma (GBM) cellularity correlates with whole brain spectroscopic MRI (sMRI) generated relative choline to N-Acetyl-Aspartate ratio (rChoNAA) mapping. In recurrent GBM (rGBM), tumor volume (TV) delineation is challenging and rChoNAA maps may assist with re-RT targeting.

METHODS

Fourteen rGBM patients underwent sMRI in a prospective study. Whole brain sMRI was performed to generate rChoNAA maps. TVs were delineated by the union of rChoNAA ratio over 2 (rChoNAA > 2) on sMRI and T1PC. rChoNAA > 2 volumes were compared with multiparametric MRI sequences including T1PC, T2/FLAIR, diffusion-restriction on apparent diffusion coefficient (ADC) maps, and perfusion relative cerebral blood volume (rCBV).

RESULTS

rChoNAA > 2 (mean 27.6 cc, range 6.6-79.1 cc) was different from other imaging modalities (P ≤ 0.05). Mean T1PC volumes were 10.7 cc (range 1.2-31.4 cc). The mean non-overlapping volume of rChoNAA > 2 and T1PC was 29.2 cm³. rChoNAA > 2 was 287% larger (range 23% smaller-873% larger) than T1PC. T2/FLAIR volumes (mean 111.7 cc, range 19.0-232.7 cc) were much larger than other modalities. rCBV volumes (mean 6.2 cc, range 0.2-19.1 cc) and ADC volumes were tiny (mean 0.8 cc, range 0-3.7 cc). Eight in-field failures were observed. Three patients failed outside T1PC but within rChoNAA > 2. No grade 3 toxicities attributable to re-RT were observed. Median progression-free and overall survival for re-RT patients were 6.5 and 7.1 months, respectively.

CONCLUSIONS

Treatment of rGBM may be optimized by sMRI, and failure patterns suggest benefit for dose-escalation within sMRI-delineated volumes. Dose-escalation and radiologic-pathologic studies are underway to confirm the utility of sMRI in rGBM.

A phase 2 study of thalidomide for the treatment of radiation-induced blood-brain barrier injury

Radiation-induced brain injury (RIBI) is a debilitating sequela after radiotherapy to treat head and neck cancer, and 20 to 30% of patients with RIBI fail to respond to or have contraindications to the first-line treatments of bevacizumab and corticosteroids. Here, we reported a Simon's minmax two-stage, single-arm, phase 2 clinical trial (NCT03208413) to assess the efficacy of thalidomide in patients with RIBI who were unresponsive to or had contraindications to bevacizumab and corticosteroid therapies. The trial met its primary endpoint, with 27 of 58 patients enrolled showing ≥25% reduction in the volume of cerebral edema on fluid-attenuated inversion recovery-magnetic resonance imaging (FLAIR-MRI) after treatment (overall response rate, 46.6%; 95% CI, 33.3 to 60.1%). Twenty-five (43.1%) patients demonstrated a clinical improvement based on the Late Effects Normal Tissues-Subjective, Objective, Management, Analytic (LENT/SOMA) scale, and 36 (62.1%) experienced cognitive improvement based on the Montreal Cognitive Assessment (MoCA) scores. In a mouse model of RIBI, thalidomide restored the blood-brain barrier and cerebral perfusion, which were attributed to the functional rescue of pericytes secondary to elevation of platelet-derived growth factor receptor β (PDGFRβ) expression by thalidomide. Our data thus demonstrate the therapeutic potential of thalidomide for the treatment of radiation-induced cerebral vasculature impairment.

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.

Neurologic complications of breast cancer

Breast cancer is a heterogeneous disease with unique neurologic complications that can arise from central nervous system (CNS) involvement or secondary to treatments themselves. As progress is made, with more targeted therapies and combinations available, particularly in the realm of human epidermal growth factor receptor 2 (HER2)-positive disease, the role of these new agents in patients with CNS disease is gradually evolving, although intracranial efficacy itself is lagging. At the same time, both systemic and local standard therapies pose clinical challenges regarding neurologic complications, such as peripheral neuropathy and cognitive changes. The development of new agents, such as immunotherapy, and new strategies, such as incorporating systemic therapies into local therapy, unveil new presentations of neurological complications.

Combination toripalimab and bevacizumab for an elderly urothelial carcinoma patient with brain metastasis who failed rapidly after radiotherapy: a case report and literature review

Brain metastasis is a rare refractory event in patients with urothelial carcinoma. Platinum-based chemotherapy is the recommended first-line standard therapy for all metastasis urothelial carcinoma patients eligible for cisplatin or carboplatin. Patients ineligible for platinum may receive immunotherapy. No clear evidence exists that UC with brain metastasis is sensitive to immunotherapy, and the optimal treatment for patients with BM is uncertain. We evaluated the safety and efficacy of combined immunotherapy and antivascular therapy in an elderly patient with urothelial carcinoma with brain metastasis, and summarize the currently available evidence. First, she underwent a left nephrectomy and left ureterectomy and recovered well postoperatively. The postoperative pathologic findings were consistent with urothelial carcinoma. Approximately 2 years later, the patient developed impaired limb movement on the right side and underwent MRI, which revealed lesions in the left frontal lobe and suggested brain metastasis. The brain metastasis responded to local radiotherapy but progressed again in a short time. Then, the patient was administered toripalimab at 240 mg combined with bevacizumab at 300 mg every 3 weeks. After 1cycle of treatment, the patient achieved a quick response, and symptoms improved significantly. Repeat evaluation imaging demonstrated that the lesions in the brain and lung were significantly smaller and evaluation showed partial response. The treatment was well tolerated and the patient remained in partial response until the last follow-up by July 2022, 6 months after the initiation of treatment. This case suggests that immune checkpoint blockade combined with antivascular therapy might be a new possibility for patients with metastatic urothelial carcinoma, including brain metastases.

Treatment of adverse radiation effects with Boswellia serrata after failure of pentoxifylline and vitamin E: illustrative cases

BACKGROUND

Adverse radiation effects (AREs) can occur after stereotactic radiosurgery (SRS), and symptomatic cases are often treated with corticosteroids, pentoxifylline, and vitamin E. The supplement 5-Loxin (Boswellia serrata) is an extract of Indian frankincense that inhibits vascular endothelial growth factor expression and has been shown to reduce perilesional edema in brain tumor patients undergoing fractionated radiation.

OBSERVATIONS

Three patients underwent SRS for meningioma or metastasis and developed symptomatic AREs at 4 to 8 months. They were initially treated with corticosteroids, pentoxifylline, and vitamin E with transient improvement followed by recurrent neurological symptoms and imaging findings as steroids were tapered off. All patients were rescued by the administration of 5-Loxin with resolution of neurological symptoms and imaging changes, discontinuation of steroids, and no medication side effects.

LESSONS

The author's early experience with 5-Loxin has been encouraging, and this supplement has become the author's first-line treatment for acute radiation effects after SRS. The author reserves bevacizumab for significant mass effect or failure of oral therapy. 5-Loxin has many advantages including low cost, ease of use, and patient tolerability. More experience is needed to confirm the role of 5-Loxin in the upfront treatment of AREs.

Advances in the Management of Central Nervous System Metastases in Non-Small Cell Lung Cancer

Central nervous system (CNS) metastases are common among patients with non-small cell lung cancer (NSCLC). While the presence of brain metastases has historically portended poor prognosis, recent advances in local and systemic therapies have greatly improved outcomes for NSCLC patients with CNS involvement. Stereotactic radiology surgery (SRS) has emerged as an effective radiotherapy technique with fewer toxicities compared to whole brain radiotherapy (WBRT). Furthermore, multi-generation tyrosine kinase inhibitors (TKIs) with CNS overall response rates (ORR) of up to 70-80% are now an accepted first-line approach for a subset of advanced NSCLC patients with targetable molecular alterations. In addition, while the CNS was once considered an immunologic sanctuary site, growing evidence shows that immune checkpoint inhibitors (ICIs) can induce durable responses in brain metastases as well. Ongoing efforts to optimize CNS metastases management are necessary to refine multimodal treatment approaches and develop new therapeutics with better CNS penetrance.