Incidence of Leukoencephalopathy After Whole-Brain Radiation Therapy for Brain Metastases

Optimal sequence of LT for symptomatic BM in EGFR-mutant NSCLC: a comparative study of first-line EGFR-TKIs with/without upfront LT

BACKGROUND

The third-generation epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) can penetrate blood-brain barrier and are effective for brain metastases (BMs). There is no consensus on the optimal sequence of local therapy (LT) and EGFR-TKIs for symptomatic BM patients because patients suffering neurological symptoms were not enrolled in most clinical trials.

METHODS

Non-small cell lung cancer (NSCLC) patients with EGFR mutation (EGFRm) and symptomatic BM receiving first-line osimertinib and aumolertinib from two medical centers were collected. All participants were allocated into the third-generation EGFR-TKIs (TKIs) group and the upfront LT (uLT) plus third-generation EGFR-TKIs (TKIs + uLT) group. Demographic data, survival outcomes, treatment failure patterns, and adverse events were evaluated between the two groups. We also conducted subgroup analyses to explore the impact of BM number on survival outcomes.

RESULTS

86 patients were enrolled, 44 in the TKIs group and 42 in the TKIs + uLT group. There were no significant differences in the short-term response between the groups. TKIs + uLT was associated with significantly longer overall survival (OS) (43 vs. 28 months; hazard ratio [HR], 0.36, 95% confidence interval [CI], 0.17-0.77; p = .011). No differences in progression-free survival (PFS), intracranial PFS (iPFS), failure patterns, or safety were observed. In subgroup analyses of oligo-BM patients, TKIs + uLT could prolong OS (43 vs. 31 months; HR 0.22; 95% CI 0.05-0.92; p = .015).

CONCLUSIONS

EGFRm NSCLC patients with symptomatic BM might benefit from uLT, particularly oligo-BM patients. However, larger prospective cohort studies should be carried out to confirm the responses of the TKIs + uLT scheme.

Comparison of Staged Stereotactic Radiosurgery and Fractionated Stereotactic Radiotherapy in Patients with Brain Metastases > 2 cm without Prior Whole Brain Radiotherapy: A Systematic Review and Meta-Analysis

OBJECTIVE

To compare fractionated stereotactic radiotherapy (FSRT) with staged stereotactic radiosurgery (SSRS) in patients with brain metastases >2 cm without prior whole brain radiotherapy.

METHODS

In this systematic review and meta-analysis, PubMed, Scopus, Web of Science, Embase, and Cochrane were searched to include studies that evaluated FSRT and/or SSRS for brain metastases >2 cm or 4 cm3 in adult patients with a known primary malignancy and no prior history of whole brain radiotherapy. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed and an indirect random-effect meta-analyses was conducted to compare treatment outcomes between the two modalities.

RESULTS

A total of 10 studies were included, comprising 612 (778 metastases) and 250 patients (265 metastases) in the SSRS and FSRT groups, respectively. The SSRS group had significantly older patients (66.6 ± 17.51 years vs. 62.37 ± 37.89 years; P = 0.029) with lower rate of control of primary disease (11.59% vs. 78.7%, P < 0.00001), and more patients with Karnofsky performance status ≥70 at baseline (92.81% vs. 88.56%; P = 0.045). FSRT was associated with a statistically nonsignificant but clinically important lower 12-month overall survival (44.75% [95% confidence interval [CI]: 30.48%-59.95%] vs. 53.25% [95%CI: 45.15%-61.19%], P = 0.1615) and higher rate of salvage radiotherapy (18.18% [95%CI: 8.75%-34%] vs. 12.27% [95%CI: 5.98%-23.53%], P = 0.0841). Both groups had comparable rates of local tumor control, mortality, tumor progression, recurrence, neurological death, and 6-month overall survival.

CONCLUSIONS

SSRS and FSRT were found to be comparable for treating brain metastases >2 cm not previously irradiated. Given the paucity of such studies, trials directly comparing the two treatment strategies are warranted to support these findings.

Therapeutic effect of osimertinib plus cranial radiotherapy compared to osimertinib alone in NSCLC patients with EGFR-activating mutations and brain metastases: a retrospective study

BACKGROUND

The study aimed to compare the efficacy of osimertinib plus cranial radiotherapy (RT) with osimertinib alone in advanced non-small-cell lung cancer (NSCLC) patients harboring epidermal growth factor receptor (EGFR) mutations and brain metastases (BMs).

METHODS

The clinical data of advanced NSCLC patients with BMs who received osimertinib were retrospectively collected. The patients were assigned to one of the two groups according to the therapeutic modality used: the osimertinib monotherapy group or the osimertinib plus RT group.

RESULTS

This was a retrospective study and 61 patients were included from December 2015 to August 2020. Forty patients received osimertinib monotherapy, and twenty-one patients received osimertinib plus RT. Radiotherapy included whole-brain radiation therapy (WBRT, n = 14), WBRT with simultaneous integrated boost (WBRT-SIB, n = 5) and stereotactic radiosurgery (SRS, n = 2). The median number of prior systemic therapies in the two groups was one. Intracranial and systemic ORR and DCR were not significantly different between the two groups. No difference in iPFS was observed between the two groups (median iPFS: 16.67 vs. 13.50 months, P = 0.836). The median OS was 29.20 months in the osimertinib plus RT group compared with 26.13 months in the osimertinib group (HR = 0.895, P = 0.826). In the L858R mutational subgroup of 31 patients, the osimertinib plus RT group had a longer OS (P = 0.046). In the exon 19 deletion mutational subgroup of 30 patients, OS in the osimertinib alone group was longer than that in the osimertinib plus RT group (P = 0.011). The incidence of any-grade adverse events was not significantly different between the osimertinib plus RT group and the osimertinib alone group (47.6% vs. 32.5%, P = 0.762). However, six patients (28.5%) experienced leukoencephalopathy in the osimertinib plus RT group, and 50% (3/6) of the leukoencephalopathy was greater than or equal to grade 3.

CONCLUSION

The therapeutic effect of osimertinib with RT was similar to that of osimertinib alone in EGFR-positive NSCLC patients with BM. However, for patients with the L858R mutation, osimertinib plus RT could provide more benefit than osimertinib alone.

Management of brain metastases in elderly patients with lung cancer

The incidence of brain metastases (BM) is continuing to grow in the elderly population with lung cancer, but these patients are seriously under-represented in clinical trials. Thus, their treatment is not based on the evidence from randomized prospective studies. Age is a well recognized poor prognostic factor for survival in patients with BM from lung cancer, which is reflected in prognostic scales, but its impact on the patients' prognosis reflected by its value in gradually updated grading indices seems to decrease. The reason for poorer outcomes in the elderly is unknown—it may result from the influence of the age per se, simplified staging work-up and suboptimal treatment in this patient subgroup or the excess toxicity of the aggressive anticancer treatment secondary to the impaired physiological regulation mechanisms and comorbidities. The main goal of treatment of BM is to ameliorate neurological symptoms and delay neurological progression, with the focus on the improvement and maintenance of the patients’ quality of life. The possible treatment options for BM from lung cancer are whole-brain radiotherapy, stereotactic radiosurgery, surgery, chemotherapy, targeted therapies and best supportive care. The aim of this review is to summarize the problems related to the management of BM in elderly patients with lung cancer, to analyze the value of the above mentioned treatment options, and to provide an insight into the influence of age-related clinical factors on the patients’ outcomes.

Unexpected Benefits of Multiport Synchrotron Microbeam Radiation Therapy for Brain Tumors

Simple Summary

We unveiled the potential of an innovative irradiation technique that ablates brain cancer while sparing normal tissues. Spatially fractionating the incident beam into arrays of micrometer-wide beamlets of X-rays (MRT for Microbeam Radiation Therapy) has led to significantly increased survival and tumor control in preclinical studies. Multiport MRT versus conventional irradiations, for the same background continuous dose, resulted in unexpectedly high equivalent biological effects in rats that have not been achieved with any other radiotherapeutic method. These hallmarks of multiport MRT, i.e., minimal impact on normal tissues and exceptional tumor control, may promote this method towards clinical applications, possibly increasing survival and improving long-term outcomes in neuro-oncology patients.

Abstract

Delivery of high-radiation doses to brain tumors via multiple arrays of synchrotron X-ray microbeams permits huge therapeutic advantages. Brain tumor (9LGS)-bearing and normal rats were irradiated using a conventional, homogeneous Broad Beam (BB), or Microbeam Radiation Therapy (MRT), then studied by behavioral tests, MRI, and histopathology. A valley dose of 10 Gy deposited between microbeams, delivered by a single port, improved tumor control and median survival time of tumor-bearing rats better than a BB isodose. An increased number of ports and an accumulated valley dose maintained at 10 Gy delayed tumor growth and improved survival. Histopathologically, cell death, vascular damage, and inflammatory response increased in tumors. At identical valley isodose, each additional MRT port extended survival, resulting in an exponential correlation between port numbers and animal lifespan (r² = 0.9928). A 10 Gy valley dose, in MRT mode, delivered through 5 ports, achieved the same survival as a 25 Gy BB irradiation because of tumor dose hot spots created by intersecting microbeams. Conversely, normal tissue damage remained minimal in all the single converging extratumoral arrays. Multiport MRT reached exceptional ~2.5-fold biological equivalent tumor doses. The unique normal tissue sparing and therapeutic index are eminent prerequisites for clinical translation.

Impact of breast cancer subtype on clinical outcomes after Gamma Knife radiosurgery for brain metastases from breast cancer: a multi-institutional retrospective study (JLGK1702)

INTRODUCTION

Brain metastasis (BM) is one of the most important issues in the management of breast cancer (BC), since BMs are associated with neurological deficits. However, the importance of BC subtypes remains unclear for BM treated with Gamma Knife radiosurgery (GKS). Thus, we conducted a multicenter retrospective study to compare clinical outcomes based on BC subtypes, with the aim of developing an optimal treatment strategy.

METHODS

We studied 439 patients with breast cancer and 1-10 BM from 16 GKS facilities in Japan. Overall survival (OS) was analyzed by the Kaplan-Meier method, and cumulative incidences of systemic death (SD), neurologic death (ND), and tumor progression were estimated by competing risk analysis.

RESULTS

OS differed among subtypes. The median OS time (months) after GKS was 10.4 in triple-negative (TN), 13.7 in Luminal, 31.4 in HER2, and 35.8 in Luminal-HER2 subtype BC (p < 0.0001). On multivariate analysis, poor control of the primary disease (hazard ratio [HR] = 1.84, p < 0.0001), active extracranial disease (HR = 2.76, p < 0.0001), neurological symptoms (HR 1.44, p = 0.01), and HER2 negativity (HR = 2.66, p < 0.0001) were significantly associated with worse OS. HER2 positivity was an independent risk factor for local recurrence (p = 0.03) but associated with lower rates of ND (p = 0.03). TN histology was associated with higher rates of distant brain failure (p = 0.03).

CONCLUSIONS

HER2 positivity is related to the longer OS after SRS; however, we should pay attention to preventing recurrence in Luminal-HER2 patients. Also, TN patients require meticulous follow-up observation to detect distant metastases and/or LMD.

Whole-brain radiotherapy plus sequential or simultaneous integrated boost for the treatment of a limited number of brain metastases in non-small cell lung cancer: A single-institution study

Background

To compare the survival outcomes and neurocognitive dysfunction in non‐small cell lung cancer (NSCLC) patients with brain metastases (BM ≤10) treated by whole‐brain radiotherapy (WBRT) with sequential integrated boost (SEB) or simultaneous integrated boost (SIB).

Materials

Fifty‐two NSCLC patients with a limited number of BMs were retrospectively analyzed. Twenty cases received WBRT+SEB (WBRT: 3 Gy*10 fractions and BMs: 4 Gy*3 fractions; SEB group), and 32 cases received WBRT+SIB (WBRT: 3 Gy*10 fractions and BMs: 4 Gy*10 fractions; SIB group). The survival and mini‐mental state examination (MMSE) scores were compared between the groups.

Results

The cumulative 1‐, 2‐, and 3‐year survival rates in the SEB vs SIB groups were 60.0% vs 47.8%, 41.1% vs 19.1%, and 27.4% vs 0%, respectively. The median survival times in the SEB and SIB groups were 15 and 10 months, respectively. The difference in survival rate was significant (P = .046). Subgroup analysis revealed that 1‐, 2‐, and 3‐year survival rates and median survival time in the SEB group were significantly superior to those of the SIB group, especially for male patients (age <60 years) with 1‐2 BMs (P < .05). The MMSE score of the SEB group at 3 months after radiation was higher than that of the SIB group (P < .05). Nevertheless, WBRT+SEB required a longer treatment time and greater cost (P < .005).

Conclusions

WBRT + SEB results in better survival outcomes than WBRT+SIB, especially for male patients (age <60 years) with 1‐2 BMs. WBRT+SEB also appeared to induce less neurocognitive impairment than WBRT+SIB.

Brain tumour post-treatment imaging and treatment-related complications

Purpose

The imaging of primary and metastatic brain tumours is very complex and relies heavily on advanced magnetic resonance imaging (MRI). Utilisation of these advanced imaging techniques is essential in helping clinicians determine tumour response after initiation of treatment. Many options are currently available to treat brain tumours, and each can significantly alter the brain tumour appearance on post-treatment imaging. In addition, there are several common and uncommon treatment-related complications that are important to identify on standard post-treatment imaging.

Methods

This article provides a review of the various post-treatment-related imaging appearances of brain neoplasms, including a discussion of advanced MR imaging techniques available and treatment response criteria most commonly used in clinical practice. This article also provides a review of the multitude of treatment-related complications that can be identified on routine post-treatment imaging, with an emphasis on radiation-induced, chemotherapy-induced, and post-surgical entities.

Summary/Conclusion

Although radiological evaluation of brain tumours after treatment can be quite challenging, knowledge of the various imaging techniques available can help the radiologist distinguish treatment response from tumour progression and has the potential to save patients from inappropriate alterations in treatment. In addition, knowledge of common post-treatment-related complications that can be identified on imaging can help the radiologist play a key role in preventing significant patient morbidity/mortality.

Teaching points

• Contrast enhancement does not reliably define tumour extent in many low-grade or infiltrative gliomas.

• Focal regions of elevated cerebral blood volume (rCBV) on dynamic susceptibility contrast (DSC) perfusion-weighted imaging are suggestive of tumour growth/recurrence.

• Brain tumour treatment response criteria rely on both imaging and clinical parameters.

• Chemotherapeutic agents can potentiate many forms of radiation-induced injury.

• Ipilimumab-induced hypophysitis results in transient diffuse enlargement of the pituitary gland.

Imaging findings in radiation therapy complications of the central nervous system

Radiation therapy is a useful treatment for tumors and vascular malformations of the central nervous system. Radiation therapy is associated with complications, including leukoencephalopathy, radiation necrosis, vasculopathy, and optic neuropathy. Secondary tumors are also often seen long after radiation therapy. Secondary tumors are often benign tumors, such as hemangiomas and meningiomas, but sometimes malignant gliomas and soft tissue sarcomas emerge. We review the imaging findings of complications that may occur after brain radiation therapy.

Prolonged survival of patients with EGFR-mutated non-small cell lung cancer with solitary brain metastases treated with surgical resection of brain and lung lesions followed by EGFR TKIs

BACKGROUND

The standard combination of initial and subsequent treatments of epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC) patients with solitary brain metastases (BM) remain unclear. Thus, the management options and the progression-free survival (PFS) and the overall survival (OS) of EGFR-mutated NSCLC patients with solitary BM were investigated in the study.

METHODS

We retrospectively reviewed the clinical data from NSCLC patients who harbored EGFR mutations and who presented solitary BM at diagnosis in our institute between 2012 and 2014. PFS and OS were evaluated using Kaplan-Meier methods and compared using log-rank tests.

RESULTS

In total, 36 NSCLC patients with solitary BM who harbored EGFR mutations were enrolled in this study. The PFS and OS of these patients was 12.4 and 19.3 months, respectively. Sixteen patients underwent surgical resection of brain and lung lesions followed by EGFR-TKIs treatment, and the median OS was 28.0 months, which was significantly longer than 16.4 months of 14 patients received radiotherapy combined with or followed by EGFR-tyrosine kinase inhibitors (TKIs) and 15.8 months of 6 patients received radiotherapy followed by chemotherapy. The median PFS also showed the same trend in each group (16.1, 10.4, and 9.8 months, respectively).

CONCLUSIONS

The survival was extended in the patients receiving surgical resection of brain and lung lesions followed by EGFR-TKIs treatment, and surgery combined with EGFR-TKIs could be a recommended treatment for EGFR mutated NSCLC patients with solitary BM.

Delayed leukoencephalopathy of non-small cell lung cancer patients with brain metastases underwent whole brain radiation therapy

To explore the incidence, MR imaging findings, dynamic developing process of delayed leukoencephalopathy (DLE) in non-small cell lung cancer (NSCLC) patients with brain metastases patients who undergone whole brain radiation (WBRT) therapy, we retrospectively reviewed 48 NSCLC patients who underwent WBRT for brain metastases from January 2010 through June 2015 and had evaluable magnetic resonance imaging after treatment. The DLE were graded using a scale to evaluate T2-FLAIR (fluid attenuated image recovery) images: grade 1 = little or no white matter hyperintensity, grade 2 = limited periventricular hyperintensity and grade 3 = diffuse white matter hyperintensity. 48 NSCLC patients with brain metastases were enrolled. The median age of these patients was 55.7 years (range 33-75 years). The median follow-up was 12 months. The characteristic MR imaging of DLE in those patients was bilaterally diffuse white matter T2 hyperintensity around the periventricular areas without enhancement, sparing from U-fiber, callosum and gray matter structure. The incidence of DLE developed 6.25% (3/48), 30.00% (12/40), 48.39% (15/31), 61.90% (13/21), 85.71% (6/7), 100% (3/3) in those patients who were followed up for 3, 6, 9, 12, 24, 36 months, respectively. Through increased understanding of it, it may be possible to help clinicians develop further therapeutic strategies to maximize benefit while limiting potential long term toxicities. These data supplement existing reports regarding the late effects of WBRT in NSCLC patients with brain metastasis.

White matter changes in breast cancer brain metastases patients who undergo radiosurgery alone compared to whole brain radiation therapy plus radiosurgery

Delayed toxicity after whole brain radiation therapy (WBRT) is of increasing concern in patients who survive more than one year with brain metastases from breast cancer. Radiation-related white matter toxicity is detected by magnetic resonance imaging (MRI) and has been correlated with neurocognitive dysfunction. This study assessed the risk of developing white matter changes (WMC) in breast cancer patients who underwent either WBRT plus stereotactic radiosurgery (SRS) or SRS alone. We retrospectively compared 35 patients with breast cancer brain metastases who received WBRT and SRS to 30 patients who only received SRS. All patients had evaluable imaging at a median of one year after their initial management. The development of white matter T2 prolongation as detected by T2 or FLAIR imaging was graded: grade 1 = little or no white matter T2 hyperintensity; grade 2 = limited periventricular hyperintensity; and grade 3 = diffuse white matter hyperintensity. After WBRT plus SRS, patients demonstrated a significantly higher incidence of WMC (p < 0.0001). After one year, 71.5 % of patients whose treatment included WBRT demonstrated WMC (42.9 % grade 2; 28.6 % grade 3). Only one patient receiving only SRS developed WMC. In long-term survivors of breast cancer, the risk of WMC was significantly reduced when SRS alone was used for management. Further prospective studies are necessary to determine how these findings correlate with neurocognitive toxicity. WBRT usage as initial management of limited brain disease should be replaced by SRS alone to reduce the risk of delayed white matter toxicity.

[Differential diagnosis of local tumor recurrence or radionecrosis after stereotactic radiosurgery for treatment of brain metastasis]

Magnetic resonance imaging (MRI) is a method of choice for follow-up of irradiated brain metastasis. It is difficult to differentiate local tumour recurrences from radiation induced-changes in case of suspicious contrast enhancement. New advanced MRI techniques (perfusion and spectrometry) and amino acid positron-emission tomography (PET) allow to be more accurate and could avoid a stereotactic biopsy for histological assessment, the only reliable but invasive method. We report the case of a patient who underwent surgery for a single, left frontal brain metastasis of a breast carcinoma, followed by adjuvant stereotactic radiotherapy in the operative bed. Seven months after, she presented a local change in the irradiated area on the perfusion-weighted MRI, for which the differentiation between a local tumour recurrence and radionecrosis was not possible. PET with 2-deoxy-((18)F)-fluoro-D-glucose (FDG) revealed a hypermetabolic lesion. After surgical resection, the histological assessment has mainly recovered radionecrosis with few carcinoma cells. The multimodal MRI has greatly contributed to refine the differential diagnosis between tumour recurrence and radionecrosis, which remains difficult. The FDG PET is helpful, in favour of the diagnosis of local tumour recurrence when a hypermetabolic lesion is found. Others tracers (such as carbon 11 or a fluoride isotope) deserve interest but are not available in all centres. Stereotactic biopsy should be discussed if any doubt remains.

Stereotactic radiotherapy for large solitary brain metastases

PURPOSE

To assess effectiveness and toxicity levels of stereotactic radiation therapy without whole brain radiation therapy in patients with solitary brain metastases larger than 3cm.

PATIENTS AND METHODS

Between June 2007 and March 2009, 12 patients received fractionated stereotactic radiation therapy and 24 patients underwent stereotactic radiosurgery. For the fractionated stereotactic radiation therapy group, 3×7.7Gy were delivered to the planning target volume (PTV); median volume and diameter were 29.4 cm(3) and 4.4cm, respectively. For the stereotactic radiosurgery group, 14Gy were delivered to the PTV; median volume and diameter were 15.6 cm(3) and 3.7cm, respectively.

RESULTS

Median follow-up was 218 days. For the fractionated stereotactic radiation therapy group, local control rates were 100% at 360 days and 64% at 720 days; for the stereotactic radiosurgery group, rates were 58% at 360 days and 48% at 720 days (P=0.06). Median survival time was 504 days for the fractionated stereotactic radiation therapy group and 164 days for the stereotactic radiosurgery group (P=0.049). Two cases of grade 2 toxicity were observed in the fractionated stereotactic radiation therapy group, and 6 cases of grade 1-2 toxicity, in the stereotactic radiosurgery group.

CONCLUSIONS

This study provides data to support that fractionated stereotactic radiation therapy without whole brain radiation therapy with a margin dose of 3 fractions of 7.7Gy for treatment of solitary large brain metastases is efficient and well-tolerated. Because of the significant improvement in overall survival, this schedule should be assessed in a randomized trial.