A nomogram to predict symptomatic epilepsy in patients with radiation-induced brain necrosis

Asparagine endopeptidase deficiency mitigates radiation-induced brain injury by suppressing microglia-mediated neuronal senescence

Mounting evidence supports the role of neuroinflammation in radiation-induced brain injury (RIBI), a chronic disease characterized by delayed and progressive neurological impairment. Asparagine endopeptidase (AEP), also known as legumain (LGMN), participates in multiple malignancies and neurodegenerative diseases and may potentially be involved in RIBI. Here, we found AEP expression was substantially elevated in the cortex and hippocampus of wild-type (Lgmn+/+) mice following whole-brain irradiation. Lgmn knockout (Lgmn-/-) alleviated neurological impairment caused by whole-brain irradiation by suppressing neuronal senescence. Bulk RNA and metabolomic sequencing revealed AEP's involvement in the antigen processing and presentation pathway and neuroinflammation. This was further confirmed by co-culturing Lgmn+/+ primary neurons with the conditioned media derived from irradiated Lgmn+/+ or Lgmn-/- primary microglia. Furthermore, esomeprazole inhibited the enzymatic activity of AEP and RIBI. These findings identified AEP as a critical factor of neuroinflammation in RIBI, highlighting the prospect of targeting AEP as a therapeutic approach.

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.

Risk of temporal lobe necrosis between proton beam and volumetric modulated arc therapies in patients with different head and neck cancers

BACKGROUND

To investigate the frequency of temporal lobe necrosis (TLN) soon after radiotherapy (RT) and identify differences among patients with various types of head and neck cancer (HNC) and between different RT methods.

METHODS

We retrospectively reviewed 483 patients with HNC who had completed RT in our hospital after January, 2015. These patients were followed-up at the radio-oncology department and received contrast-enhanced magnetic resonance imaging (MRI) or computed tomography (CT) to identify metastases or recurrence of cancer at regular intervals. Meanwhile, the occurrence of TLN, graded according to the Common Terminology Criteria for Adverse Events V5.0, was recorded. We categorized the patients into nasopharyngeal carcinoma (NPC) and non-NPC groups and compared the cumulative occurrence of TLN between the groups using Kaplan-Meier and Cox regression analyses. We further compared the cumulative occurrence of TLN between proton beam therapy (PBT) and volumetric modulated arc therapy (VMAT) in patients with any HNC, NPC, and non-NPC HNC.

RESULTS

Compared with the non-NPC group, the NPC group had a higher frequency of TLN (5.6% vs. 0.4%,  p < 0.01) and were more commonly associated with TLN in the Kaplan-Meier analysis (p < 0.01) and the Cox regression model after covariates were adjusted for (adjusted hazard ratio: 13.35, 95% confidence interval: 1.37-130.61) during the follow-up period. Furthermore, the frequency of TLN was similar between patients receiving PBT and those receiving VMAT (PBT vs. VMAT: 4.7% vs. 6.3%, p = 0.76). Kaplan-Meier analysis revealed that the accumulated risks of TLN were similar between PBT and VMAT in patients with any HNC (p = 0.44), NPC (p = 0.84), and non-NPC HNC (p = 0.70).

CONCLUSION

Our study demonstrated that patients with NPC are susceptible to TLN during the early period after RT. In addition, PBT may be associated with an equivalent risk of TLN when compared with VMAT in patients with NPC or other HNCs.

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.

Recurrent Brain Metastasis Versus Radiation-Induced Necrosis: A Case Report and Literature Review

Radiotherapy is the cornerstone of brain metastasis management. With the advancement of therapies, patients are living longer, exposing them to the long-term effects of radiotherapy. Using concurrent or sequential chemotherapy, targeted agents, and immune checkpoint inhibitors may increase the incidence and severity of radiation-induced toxicity. Recurrent metastasis and radiation necrosis (RN) appear indistinguishable on neuroimaging, making it a diagnostic dilemma for clinicians. Here, we present a case of RN in a 65-year-old male patient who previously had brain metastasis (BM) from primary lung cancer, misdiagnosed initially as recurrent BM.

Radiation necrosis or tumor progression? A review of the radiographic modalities used in the diagnosis of cerebral radiation necrosis

PURPOSE

Cerebral radiation necrosis is a complication of radiation therapy that can be seen months to years following radiation treatment. Differentiating radiation necrosis from tumor progression on standard magnetic resonance imaging (MRI) is often difficult and advanced imaging techniques may be needed to make an accurate diagnosis. The purpose of this article is to review the imaging modalities used in differentiating radiation necrosis from tumor progression following radiation therapy for brain metastases.

METHODS

We performed a review of the literature addressing the radiographic modalities used in the diagnosis of radiation necrosis.

RESULTS

Differentiating radiation necrosis from tumor progression remains a diagnostic challenge and advanced imaging modalities are often required to make a definitive diagnosis. If diagnostic uncertainty remains following conventional imaging, a multi-modality diagnostic approach with perfusion MRI, magnetic resonance spectroscopy (MRS), positron emission tomography (PET), single photon emission spectroscopy (SPECT), and radiomics may be used to improve diagnosis.

CONCLUSION

Several imaging modalities exist to aid in the diagnosis of radiation necrosis. Future studies developing advanced imaging techniques are needed.

Efficacy and safety of apatinib in radiation-induced brain injury among head and neck cancer: an open-label, single-arm, phase 2 study

BACKGROUND

The treatment of radiation-induced brain injury (RI) caused by radiotherapy for head and neck cancer is challenging. Antiangiogenic therapy is a promising treatment. Apatinib is an oral tyrosine kinase inhibitor (TKI) that selectively inhibits vascular endothelial growth factor receptor (VEGFR) 2. We aimed to assess the efficacy and safety of apatinib in patients with RI.

PATIENTS AND METHODS

In this phase 2, open-label, single-arm, prospective study, we recruited patients aged 35-80 years with prior radiotherapy history for head and neck cancer who had newly diagnosed RI at the Sun Yat-sen Memorial Hospital, China. Apatinib was administered at a dosage of 250 mg once daily orally for 4 weeks. A Simon's mini-max two-stage design was performed. The primary outcome was the proportion of patients with an overall clinical efficacy defined as radiographic response ≥ 25% reduction in baseline brain edema volume on magnetic resonance (MR) fluid attenuated inversion recovery (FLAIR) images at week 4. Secondary endpoints were overall improvement rate of brain necrosis, neurological function, and safety.

RESULTS

We screened 37 patients, 36 of whom were enrolled between October 17, 2019 and August 3, 2020. At the cutoff date, 36 patients were assessed for efficacy and safety (19 to stage 1 and 17 to stage 2). Of the 36 patients evaluated for overall clinical efficacy, 22 patients (61.1%; 95%CI 43.5-76.9%) achieved the primary endpoint at week 4. Among the 31 patients with brain necrosis lesions, 19 patients (61.3%; 95%CI 42.2%-78.2%) showed improvement of brain necrosis. The most common grade 1 to 2 adverse events were hand-foot syndrome, fatigue and hypertension There were no treatment-related grade 4-5 toxicities.

CONCLUSION

Oral apatinib shows promising efficacy and is well-tolerated in patients with RI. Further randomized controlled studies are warranted.

TRIAL REGISTRATION

ClinicalTrials.gov (ID: NCT04152681).

A novel nomogram to predict overall survival in head and neck cancer survivors with radiation-induced brain necrosis

BACKGROUND AND PURPOSE

The study aimed to develop and validate a novel nomogram to predict overall survival in head and neck cancer survivors following the diagnosis of radiation-induced brain necrosis (RN).

MATERIALS AND METHODS

We included head and neck cancer survivors with RN from a radiation complications registry study. A total of 495 eligible patients were 7:3 randomly allocated to a training cohort and an internal validation cohort. The Least Absolute Shrinkage and Selection Operator (LASSO) regression was applied to select significant predictors of post-RN survival in the training cohort, and a multivariable Cox model was used to develop the nomogram. The performance of the nomogram was assessed using the internal validation cohort and externally validated using additional 88 RN patients.

RESULTS

We identified five predictors of post-RN survival using the training data: age, tumor progression before RN, lower cranial nerves injury, bilateral necrosis, and history of stroke. The nomogram showed favorable performance in the internal validation cohort (C-index 0.761, 95% CI 0.676 to 0.847) and in the external validation cohort (C-index 0.795, 95% CI 0.717 to 0.874). The decision curve analysis indicated that the nomogram was clinically useful when the probabilities of death ranging from 1% to 48% at 1 year, from 3% to 50% at 3 years, and exceeding 2% at 5 years after being diagnosed with RN.

CONCLUSION

In this LASSO-Cox model-based nomogram study, we developed and validated an easily applied model to predict overall survival in head and neck cancer survivors following an RN diagnosis.

Refractory Epilepsy as a Late Effect of Chemoradiation in Childhood Cancer: A Case Series

BACKGROUND

Seizures are a common complication of both primary central nervous system (CNS) tumors and other oncologic processes with CNS involvement. They occur most frequently during induction or consolidation therapy, but there is a growing body of evidence that they can also develop later in life. Refractory epilepsy can develop as a late complication for survivors of pediatric cancer with CNS involvement who undergo chemoradiation therapy.

PATIENT DESCRIPTIONS

We report three patients who presented with atypical nonconvulsive seizures (behavioral arrest, falls, nonsensical speech) up to 14 years after cancer diagnosis. All underwent whole-brain radiation in addition to chemotherapy. None had a prior epilepsy diagnosis or known prior seizures. One patient suddenly passed away of unclear causes five months after diagnosis, and the other two continued to have EEG findings consistent with cerebral dysfunction and epileptogenicity years after diagnosis.

CONCLUSION

We hypothesize that the development of refractory epilepsy may be a late effect of radiation treatment. Given the high morbidity and mortality associated with epilepsy, early identification is crucial to improve outcomes and quality of life for this vulnerable population. This is especially true for patients with medication-refractory epilepsy as there is an increasing breadth of effective surgical options.

Predicting the occurrence of early seizures after cerebral venous thrombosis using a comprehensive nomogram

BACKGROUND

Seizure is a common clinical manifestation of cerebral venous thrombosis (CVT). The mortality rate of patients with CVT with seizure is three times higher than that of patients without seizure. The aim of this study was to develop a nomogram to predict the individual probability of acute seizure events in patients with CVT.

METHOD

This was a single-center, retrospective cohort study. We analyzed and compared demographic variables, epidemiological risk factors, clinical presentation, laboratory results and imaging data in a cohort of 142 patients who were diagnosed with CVT in our hospital from January 2013 to December 2018. A nomogram was constructed to predict the risk of early seizure (ES) in these patients according to the multivariable logistic regression analysis results. The concordance index, GiViTi calibration belt and decision curve analysis (DCA) were used to assess nomogram performance.

RESULTS

Forty-three (30.28%) patients experienced seizure within 2 weeks after a CVT diagnosis. Multivariate analysis identified focal neurologic deficit, Glasgow Coma Scale (GCS) scores ≤ 8 on admission, hemorrhagic lesions, superior sagittal sinus thrombosis (SSST) and frontal lobe lesions as independent predictive factors for ES occurrence after CVT. A nomogram was generated based on these predictive factors with the concordance index reaching 0.82, indicating that the clinical tool was well calibrated. DCA showed that the model was useful with a threshold probability in the range of 0-77%.

CONCLUSIONS

We developed the first nomogram that could predict the risk of ES in CVT patients. This effective and convenient tool has shown promising clinical benefit and will assist clinicians in making treatment decisions.

Under-recognized toxicities of cranial irradiation

Cranial irradiation of primary or metastatic lesions is frequent, historically with 3D-conformal radiation therapy and now with stereotactic radiosurgery and intensity modulation. Evolution of radiotherapy technique is concomitant to systemic treatment evolution permitting long time survival. Thus, physicians have to face underestimated toxicities on long-survivor patients and unknown toxicities from combination of cranial radiotherapy to new therapeutics as targeted therapies and immunotherapies. This article proposes to develop these toxicities, without being exhaustive, to allow a better apprehension of cranial irradiation in current context.

Prognostic Value of Eight-Gene Signature in Head and Neck Squamous Carcinoma

Head and neck cancer (HNC) is the fifth most common cancer worldwide. In this study, we performed an integrative analysis of the discovery set and established an eight-gene signature for the prediction of prognosis in patients with head and neck squamous cell carcinoma (HNSCC). Univariate Cox analysis was used to identify prognosis-related genes (with P < 0.05) in the GSE41613, GSE65858, and TCGA-HNSC RNA-Seq datasets after data collection. We performed LASSO Cox regression analysis and identified eight genes (CBX3, GNA12, P4HA1, PLAU, PPL, RAB25, EPHX3, and HLF) with non-zero regression coefficients in TCGA-HNSC datasets. Survival analysis revealed that the overall survival (OS) of GSE41613 and GSE65858 datasets and the progression-free survival(DFS)of GSE27020 and GSE42743 datasets in the low-risk group exhibited better survival outcomes compared with the high-risk group. To verify that the eight-mRNA prognostic model was independent of other clinical features, KM survival analysis of the specific subtypes with different clinical characteristics was performed. Univariate and multivariate Cox regression analyses were used to identify three independent prognostic factors to construct a prognostic nomogram. Finally, the GSVA algorithm identified six pathways that were activated in the intersection of the TCGA-HNSC, GSE65858, and GSE41613 datasets, including early estrogen response, cholesterol homeostasis, oxidative phosphorylation, fatty acid metabolism, bile acid metabolism, and Kras signaling. However, the epithelial–mesenchymal transition pathway was inhibited at the intersection of the three datasets. In conclusion, the eight-gene prognostic signature proved to be a useful tool in the prognostic evaluation and facilitate personalized treatment of HNSCC patients.