Stereotactic radiosurgery for the management of brain metastases

Risk of radionecrosis in HER2-positive breast cancer with brain metastasis receiving trastuzumab emtansine (T-DM1) and brain stereotactic radiosurgery

OBJECTIVES

To investigate the potential relationship between trastuzumab emtansine (T-DM1) treatment and radionecrosis induced by brain stereotactic radiosurgery (SRS) in patients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer.

MATERIALS AND METHODS

Patients with HER2-positive breast cancer who were diagnosed with brain metastasis and received both SRS and HER2-targeted agents between 2012 and 2022 were retrospectively analyzed. Patients who received T-DM1 within 1 year (either before or after) of SRS were considered as 'T-DM1 exposure (+)'. T-DM1 exposure (-) group had other HER2-targeted agents or received T-DM1 more than 1 year before or after SRS. Symptomatic radionecrosis was defined as Common Terminology Criteria for Adverse Events grade 2 or greater.

RESULTS

A total of 103 patients with 535 treatment sessions were included from seven tertiary medical centers in Korea and Italy. The median follow-up duration was 15.5 months (range 1.1-101.9). By per-patient analysis, T-DM1 exposure (+) group had an increased risk of overall radionecrosis after multivariate analysis (HR 2.71, p = 0.020). Additionally, T-DM1 exposure (+) group was associated with a higher risk of symptomatic radionecrosis compared to T-DM1 exposure (-) patients (HR 4.34, p = 0.030). In per-treatment analysis, T-DM1 exposure (+) was linked to higher incidences of overall (HR 3.13, p = 0.036) and symptomatic radionecrosis (HR 10.4, p = 0.013) after multivariate analysis. A higher prevalence of radionecrosis was observed with T-DM1 exposure (+) and a previous history of whole brain radiotherapy.

CONCLUSION

An increased risk of radionecrosis was observed in patients receiving T-DM1 with brain SRS. Further research is needed to better understand the optimal sequence and interval for administering T-DM1 and SRS.

Severe pneumocranium after gamma knife stereotactic radiosurgery for brain metastasis: A case report and literature review

RATIONALE

Gamma knife stereotactic radiosurgery (GKRS) is a recognized safe and effective treatment for brain metastasis; however, some complications can present significant clinical challenges. This case report highlights a rare occurrence of cerebrospinal fluid (CSF) leakage and pneumocranium following GKRS, emphasizing the need for awareness and prompt management of these complications.

PATIENT CONCERNS

A 35-year-old male with a history of malignant neoplasm of the lip in 2015 and perineural spread of malignancy into the left cavernous sinus was treated with GKRS in 2017. The patient was admitted emergently 39 days after discharge due to persistent headache and dizziness.

DIAGNOSES

Brain computed tomography (CT) revealed diffuse bilateral pneumocranium alongside an observation of CSF leakage.

INTERVENTIONS

A surgical procedure involving a left frontal-temporal craniotomy was performed to excise a residual skull base tumor and repair the dura, guided by a navigator system. The conclusive pathological assessment revealed the presence of squamous cell carcinoma markers.

OUTCOMES

The patient exhibited excellent tolerance to the entire procedure and experienced a prompt and uneventful recovery process. After surgery, the symptoms alleviated and CSF leak stopped. The follow-up image showed the pneumocranium resolved.

LESSONS

Pneumocranium due to early-stage post-GKRS is uncommon. The rapid tumor shrinkage and timing of brain metastasis spreading through the dura can lead to CSF leak and pneumocranium. We reviewed current treatment options and presented a successful craniotomy-based dura repair case.

Radiation therapy for ventricular arrhythmias

Ventricular arrhythmias (VA) can be life-threatening arrhythmias that result in significant morbidity and mortality. Catheter ablation (CA) is an invasive treatment modality that can be effective in the treatment of VA where medications fail. Recurrence occurs commonly following CA due to an inability to deliver lesions of adequate depth to cauterise the electrical circuits that drive VA or reach areas of scar responsible for VA. Stereotactic body radiotherapy is a non-invasive treatment modality that allows volumetric delivery of energy to treat circuits that cannot be reached by CA. It overcomes the weaknesses of CA and has been successfully utilised in small clinical trials to treat refractory VA. This article summarises the current evidence for this novel treatment modality and the steps that will be required to bring it to the forefront of VA treatment.

Adverse radiation effect versus tumor progression following stereotactic radiosurgery for brain metastases: Implications of radiologic uncertainty

BACKGROUND

Adverse radiation effect (ARE) following stereotactic radiosurgery (SRS) for brain metastases is challenging to distinguish from tumor progression. This study characterizes the clinical implications of radiologic uncertainty (RU).

METHODS

Cases reviewed retrospectively at a single-institutional, multi-disciplinary SRS Tumor Board between 2015-2022 for RU following SRS were identified. Treatment history, diagnostic or therapeutic interventions performed upon RU resolution, and development of neurologic deficits surrounding intervention were obtained from the medical record. Differences in lesion volume and maximum diameter at RU onset versus resolution were compared with paired t-tests. Median time from RU onset to resolution was estimated using the Kaplan-Meier method. Univariate and multivariate associations between clinical characteristics and time to RU resolution were assessed with Cox proportional-hazards regression.

RESULTS

Among 128 lesions with RU, 23.5% had undergone ≥ 2 courses of radiation. Median maximum diameter (20 vs. 16 mm, p < 0.001) and volume (2.7 vs. 1.5 cc, p < 0.001) were larger upon RU resolution versus onset. RU resolution took > 6 and > 12 months in 25% and 7% of cases, respectively. Higher total EQD2 prior to RU onset (HR = 0.45, p = 0.03) and use of MR perfusion (HR = 0.56, p = 0.001) correlated with shorter time to resolution; larger volume (HR = 1.05, p = 0.006) portended longer time to resolution. Most lesions (57%) were diagnosed as ARE. Most patients (58%) underwent an intervention upon RU resolution; of these, 38% developed a neurologic deficit surrounding intervention.

CONCLUSIONS

RU resolution took > 6 months in > 25% of cases. RU may lead to suboptimal outcomes and symptom burden. Improved characterization of post-SRS RU is needed.

Umbrella review and network meta-analysis of diagnostic imaging test accuracy studies in Differentiating between brain tumor progression versus pseudoprogression and radionecrosis

PURPOSE

In this study we gathered and analyzed the available evidence regarding 17 different imaging modalities and performed network meta-analysis to find the most effective modality for the differentiation between brain tumor recurrence and post-treatment radiation effects.

METHODS

We conducted a comprehensive systematic search on PubMed and Embase. The quality of eligible studies was assessed using the Assessment of Multiple Systematic Reviews-2 (AMSTAR-2) instrument. For each meta-analysis, we recalculated the effect size, sensitivity, specificity, positive and negative likelihood ratios, and diagnostic odds ratio from the individual study data provided in the original meta-analysis using a random-effects model. Imaging technique comparisons were then assessed using NMA. Ranking was assessed using the multidimensional scaling approach and by visually assessing surface under the cumulative ranking curves.

RESULTS

We identified 32 eligible studies. High confidence in the results was found in only one of them, with a substantial heterogeneity and small study effect in 21% and 9% of included meta-analysis respectively. Comparisons between MRS Cho/NAA, Cho/Cr, DWI, and DSC were most studied. Our analysis showed MRS (Cho/NAA) and 18F-DOPA PET displayed the highest sensitivity and negative likelihood ratios. 18-FET PET was ranked highest among the 17 studied techniques with statistical significance. APT MRI was the only non-nuclear imaging modality to rank higher than DSC, with statistical insignificance, however.

CONCLUSION

The evidence regarding which imaging modality is best for the differentiation between radiation necrosis and post-treatment radiation effects is still inconclusive. Using NMA, our analysis ranked FET PET to be the best for such a task based on the available evidence. APT MRI showed promising results as a non-nuclear alternative.

Robotic-Assisted Navigation for Stereotactic Neurosurgery: A Cadaveric Investigation of Accuracy, Time, and Radiation

BACKGROUND AND OBJECTIVES

Despite frequent use, stereotactic head frames require manual coordinate calculations and manual frame settings that are associated with human error. This study examines freestanding robot-assisted navigation (RAN) as a means to reduce the drawbacks of traditional cranial stereotaxy and improve targeting accuracy.

METHODS

Seven cadaveric human torsos with heads were tested with 8 anatomic coordinates selected for lead placement mirrored in each hemisphere. Right and left hemispheres of the brain were randomly assigned to either the traditional stereotactic arc-based (ARC) group or the RAN group. Both target accuracy and trajectory accuracy were measured. Procedural time and the radiation required for registration were also measured.

RESULTS

The accuracy of the RAN group was significantly greater than that of the ARC group in both target (1.2 ± 0.5 mm vs 1.7 ± 1.2 mm, P = .005) and trajectory (0.9 ± 0.6 mm vs 1.3 ± 0.9 mm, P = .004) measurements. Total procedural time was also significantly faster for the RAN group than for the ARC group (44.6 ± 7.7 minutes vs 86.0 ± 12.5 minutes, P < .001). The RAN group had significantly reduced time per electrode placement (2.9 ± 0.9 minutes vs 5.8 ± 2.0 minutes, P < .001) and significantly reduced radiation during registration (1.9 ± 1.1 mGy vs 76.2 ± 5.0 mGy, P < .001) compared with the ARC group.

CONCLUSION

In this cadaveric study, cranial leads were placed faster and with greater accuracy using RAN than those placed with conventional stereotactic arc-based technique. RAN also required significantly less radiation to register the specimen's coordinate system to the planned trajectories. Clinical testing should be performed to further investigate RAN for stereotactic cranial surgery.

Prognostic value of MRI volumetric parameters in non-small cell lung cancer patients after immune checkpoint inhibitor therapy: comparison with response assessment criteria

BACKGROUND

Accurate response parameters are important for patients with brain metastasis (BM) undergoing clinical trials using immunotherapy, considering poorly defined enhancement and variable responses. This study investigated MRI-based surrogate endpoints for patients with BM receiving immunotherapy.

METHODS

Sixty-three non-small cell lung cancer patients with BM who received immune checkpoint inhibitors and underwent MRI were included. Tumor diameters were measured using a modification of the RECIST 1.1 (mRECIST), RANO-BM, and iRANO adjusted for BM (iRANO-BM). Tumor volumes were segmented on 3D contrast-enhanced T1-weighted imaging. Differences between the sum of the longest diameter (SLD) or total tumor volume at baseline and the corresponding measurement at time of the best overall response were calculated as "changes in SLDs" (for each set of criteria) and "change in volumetry," respectively. Overall response rate (ORR), progressive disease (PD) assignment, and progression-free survival (PFS) were compared among the criteria. The prediction of overall survival (OS) was compared between diameter-based and volumetric change using Cox proportional hazards regression analysis.

RESULTS

The mRECIST showed higher ORR (30.1% vs. both 17.5%) and PD assignment (34.9% vs. 25.4% [RANO-BM] and 19% [iRANO-BM]). The iRANO-BM had a longer median PFS (13.7 months) than RANO-BM (9.53 months) and mRECIST (7.73 months, P = 0.003). The change in volumetry was a significant predictor of OS (HR = 5.87, 95% CI: 1.46-23.64, P = 0.013). None of the changes in SLDs, as determined by RANO-BM or iRANO-BM, were significant predictors of OS, except for the mRECIST, which exhibited a weak association with OS.

CONCLUSION

Quantitative volume measurement may be an accurate surrogate endpoint for OS in patients with BM undergoing immunotherapy, especially considering the challenges of multiplicity and the heterogeneity of sub-centimeter size responses.

Examining the Effect of ALK and EGFR Mutations on Survival Outcomes in Surgical Lung Brain Metastasis Patients

In the context of the post-genomic era, where targeted oncological therapies like monoclonal antibodies (mAbs) and tyrosine-kinase inhibitors (TKIs) are gaining prominence, this study investigates whether these therapies can enhance survival for lung carcinoma patients with specific genetic mutations-EGFR-amplified and ALK-rearranged mutations. Prior to this study, no research series had explored how these mutations influence patient survival in cases of surgical lung brain metastases (BMs). Through a multi-site retrospective analysis, the study examined patients who underwent surgical resection for BM arising from primary lung cancer at Emory University Hospital from January 2012 to May 2022. The mutational statuses were determined from brain tissue biopsies, and survival analyses were conducted. Results from 95 patients (average age: 65.8 ± 10.6) showed that while 6.3% had anaplastic lymphoma kinase (ALK)-rearranged mutations and 20.0% had epidermal growth factor receptor (EGFR)-amplified mutations-with 9.5% receiving second-line therapies-these mutations did not significantly correlate with overall survival. Although the sample size of patients receiving targeted therapies was limited, the study highlighted improved overall survival and progression-free survival rates compared to earlier trials, suggesting advancements in systemic lung metastasis treatment. The study suggests that as more targeted therapies emerge, the prospects for increased overall survival and progression-free survival in lung brain metastasis patients will likely improve.

Cost-effectiveness analysis of 3 radiation treatment strategies for patients with multiple brain metastases

Background

Patients diagnosed with multiple brain metastases often survive for less than 2 years, and clinicians must carefully evaluate the impact of interventions on quality of life. Three types of radiation treatment are widely accepted for patients with multiple brain metastases: Whole brain radiation therapy (WBRT), hippocampal avoidance whole-brain radiation therapy (HA-WBRT), and stereotactic radiosurgery (SRS). WBRT, the standard option, is less costly than its newer alternatives but causes more severe adverse effects such as memory loss. To determine whether the cost-effectiveness ratio of HA-WBRT and SRS are superior to WBRT, we used published data to simulate cases of multiple brain metastases.

Methods

We designed a Markov model using data from previously published studies to simulate the disease course of patients with 5 to 15 brain metastases and determine the cost-effectiveness of HA-WBRT and SRS relative to WBRT. Incremental cost-effectiveness ratios (ICERs) were calculated and compared against a willingness-to-pay threshold of $100 000 per quality-adjusted life year.

Results

SRS met the threshold for cost-effectiveness, with ICERs ranging $41 198-$54 852 for patients with 5 to 15 brain metastases; however, HA-WBRT was not cost-effective, with an ICER of $163 915 for all simulated patients. Model results were robust to sensitivity analyses.

Conclusions

We propose that SRS, but not HA-WBRT, should be offered to patients with multiple brain metastases as a treatment alternative to standard WBRT. Incorporating these findings into clinical practice will help promote patient-centered care and decrease national healthcare expenditures, thereby addressing issues around health equity and access to care.

An exploratory analysis of MR-guided fractionated stereotactic radiotherapy in patients with brain metastases

Purpose

To assess the feasibility and potential benefits of online adaptive MR-guided fractionated stereotatic radiotherapy (FSRT) in patients with brain metastases (BMs).

Methods and materials

Twenty-eight consecutive patients with BMs were treated with FSRT of 30 Gy in 5 fractions on the 1.5 T MR-Linac. The FSRT fractions employed daily MR scans and the contours were utilized to create each adapted plan. The brain lesions and perilesional edema were delineated on MR images of pre-treatment simulation (Fx0) and all fractions (Fx1, Fx2, Fx3, Fx4 and Fx5) to evaluate the inter-fractional changes. These changes were quantified using absolute/relative volume, Dice similarity coefficient (DSC) and Hausdorff distance (HD) metrics. Planning target volume (PTV) coverage and organ at risk (OAR) constraints were used to compare non-adaptive and adaptive plans.

Results

A total of 28 patients with 88 lesions were evaluated, and 23 patients (23/28, 82.1%) had primary lung adenocarcinoma. Significant tumor volume reduction had been found during FSRT compared to Fx0 for all 88 lesions (median -0.75%, -5.33%, -9.32%, -17.96% and -27.73% at Fx1, Fx2, Fx3, Fx4 and Fx5, p < 0.05). There were 47 (47/88, 53.4%) lesions being accompanied by perilesional edema and the inter-fractional changes were significantly different compared to those without perilesional edema (p < 0.001). Patients with multiple lesions (13/28, 46.4%) had more significant inter-fractional tumor changes than those with single lesion (15/28, 53.6%), including tumor volume reduction and anatomical shift (p < 0.001). PTV coverage of non-adaptive plans was below the prescribed coverage in 26/140 fractions (19%), with 12 (9%) failing by more than 10%. All 140 adaptive fractions met prescribed target coverage. The adaptive plans also had lower dose to whole brain than non-adaptive plans (p < 0.001).

Conclusions

Significant inter-fractional tumor changes could be found during FSRT in patients with BMs treated on the 1.5 T MR-Linac. Daily MR-guided re-optimization of treatment plans showed dosimetric benefit in patients with perilesional edema or multiple lesions.

Use of thyroid transcription factor 1 and napsin A to predict local failure and survival after Gamma Knife radiosurgery in patients with brain metastases from lung adenocarcinoma

OBJECTIVE

Stereotactic radiosurgery (SRS), combined with contemporary targeted therapies and immunotherapies, has improved the overall survival of patients with lung adenocarcinoma (ADC). Given that histological subtypes reflect prognosis in patients with primary ADC, it is important to integrate pathological biomarkers to predict clinical outcomes after SRS in patients with brain metastases from lung ADC. Therefore, the authors investigated the prognostic relevance of various biomarkers of primary lung ADC for clinical outcomes after SRS.

METHODS

A total of 95 patients with 136 brain metastases (1-4 oligometastases) who were treated with Gamma Knife radiosurgery between January 2017 and December 2020 were included. The Kaplan-Meier method and univariate and multivariate analyses using Cox proportional hazard regression models were used to identify prognostic factors for local control, survival, and distant brain control.

RESULTS

Multivariate analysis revealed thyroid transcription factor 1 as an independent prognostic factor for local control (HR 0.098, 95% CI 0.014-0.698, p = 0.0203) and napsin A as a significant predictor of overall survival after SRS (HR 0.080, 95% CI 0.017-0.386, p < 0.01). In a subset analysis of epidermal growth factor receptor (EGFR) mutation, patients with EGFR exon 19 mutations showed better distant brain control than those with EGFR exon 21 mutations (p < 0.01).

CONCLUSIONS

Pathological biomarkers of primary cancer should be considered to predict clinical outcomes after SRS in patients with lung ADC. Use of such biomarkers may help to provide personalized treatment to each patient, improving clinical outcomes after SRS.

Melanoma central nervous system metastases: An update to approaches, challenges, and opportunities

Brain metastases are the most common brain malignancy. This review discusses the studies presented at the third annual meeting of the Melanoma Research Foundation in the context of other recent reports on the biology and treatment of melanoma brain metastases (MBM). Although symptomatic MBM patients were historically excluded from immunotherapy trials, efforts from clinicians and patient advocates have resulted in more inclusive and even dedicated clinical trials for MBM patients. The results of checkpoint inhibitor trials were discussed in conversation with current standards of care for MBM patients, including steroids, radiotherapy, and targeted therapy. Advances in the basic scientific understanding of MBM, including the role of astrocytes and metabolic adaptations to the brain microenvironment, are exposing new vulnerabilities which could be exploited for therapeutic purposes. Technical advances including single-cell omics and multiplex imaging are expanding our understanding of the MBM ecosystem and its response to therapy. This unprecedented level of spatial and temporal resolution is expected to dramatically advance the field in the coming years and render novel treatment approaches that might improve MBM patient outcomes.

Prognostic factors to predict the efficacy of surgical interventions against brain metastasis secondary to thyroid cancer

Introduction

Brain metastasis in differentiated thyroid cancer (DTC) is rare (frequency < 1%) and has a poor prognosis. Treatment strategies for brain metastasis are not well established.

Objectives

We conducted a retrospective analysis to identify predictive factors for patient outcomes and verify surgical indications for patients with brain metastasis and DTC.

Methods

The study included 34 patients with pathologically confirmed DTC with brain metastasis from March 2008 to November 2020. The associations between overall survival (OS) and clinical factors were evaluated. Cox regression analysis was used to determine the relationship between clinical factors and OS. To assess the survival benefit of craniotomy, Kaplan-Meier survival analysis was performed for each variable whose statistical significance was determined by Cox regression analysis.

Results

The median OS of the entire patient sample was 11.4 months. Survival was affected by the presence of lung metastasis (P = 0.033) and the number of brain metastases (n > 3) (P = 0.039). Only the subgroup with the number of brain metastases ≤3 showed statistical significance in the subgroup analysis of survival benefit following craniotomy (P = 0.048).

Conclusions

The number of brain metastases and the existence of lung metastasis were regarded more essential than other clinical factors in patients with DTC in this study. Furthermore, craniotomies indicated a survival benefit only when the number of brain metastases was ≤3. This finding could be beneficial in determining surgical indications in thyroid cancer with brain metastasis.

Recent Update on Neurosurgical Management of Brain Metastasis

Brain metastasis (BM), classified as a secondary brain tumor, is the most common malignant central nervous system tumor whose median overall survival is approximately 6 months. However, the survival rate of patients with BMs has increased with recent advancements in immunotherapy and targeted therapy. This means that clinicians should take a more active position in the treatment paradigm that passively treats BMs. Because patients with BM are treated in a variety of clinical settings, treatment planning requires a more sophisticated decision-making process than that for other primary malignancies. Therefore, an accurate prognostic prediction is essential, for which a graded prognostic assessment that reflects next-generation sequencing can be helpful. It is also essential to understand the indications for various treatment modalities, such as surgical resection, stereotactic radiosurgery, and whole-brain radiotherapy and consider their advantages and disadvantages when choosing a treatment plan. Surgical resection serves a limited auxiliary function in BM, but it can be an essential therapeutic approach for increasing the survival rate of specific patients; therefore, this must be thoroughly recognized during the treatment process. The ultimate goal of surgical resection is maximal safe resection; to this end, neuronavigation, intraoperative neuro-electrophysiologic assessment including evoked potential, and the use of fluorescent materials could be helpful. In this review, we summarize the considerations for neurosurgical treatment in a rapidly changing treatment environment.

The Extent of Necrosis in Brain Metastases May Predict Subtypes of Primary Cancer and Overall Survival in Patients Receiving Craniotomy

Although necrosis is common in brain metastasis (BM), its biological and clinical significances remain unknown. We evaluated necrosis extent differences by primary cancer subtype and correlated BM necrosis to overall survival post-craniotomy. We analyzed 145 BMs of patients receiving craniotomy. Necrosis to tumor ratio (NTR) was measured. Patients were divided into two groups by NTR: BMs with sparse necrosis and with abundant necrosis. Clinical features were compared. To investigate factor relevance for BM necrosis, multivariate logistic regression, random forests, and gradient boosting machine analyses were performed. Kaplan−Meier analysis and log-rank tests were performed to evaluate the effect of BM necrosis on overall survival. Lung cancer was a more common origin for BMs with abundant necrosis (42/72, 58.33%) versus sparse necrosis (23/73, 31.51%, p < 0.01). Primary cancer subtype and tumor volume were the most relevant factors for BM necrosis (p < 0.01). BMs harboring moderately abundant necrosis showed longer survival, versus sparse or highly abundant necrosis (p = 0.04). Lung cancer BM may carry larger necrosis than BMs from other cancers. Further, moderately abundant necrosis in BM may predict a good prognosis post-craniotomy.

Histopathology and surgical outcome of symptomatic treatment-related changes after gamma knife radiosurgery in patients with brain metastases

A late-onset treatment-related changes (TRCs), which represent radiographic radiation necrosis (RN), frequently occur after stereotactic radiosurgery (SRS) for brain metastases and often need surgical treatment. This study aimed to validate the true pathology and investigate clinical implication of surgically resected TRCs on advanced magnetic resonance imaging (MRI). Retrospective analyses of 86 patients who underwent surgical resection after radiosurgery of brain metastases were performed. Fifty-four patients displayed TRCs on preoperative MRI, comprising pure RN in 19 patients (TRC-RN group) and mixed viable tumor cells in 35 patients (TRC-PD group). Thirty-two patients revealed the consistent diagnosis of progressive disease in both MRI and histopathology (PD–PD group). The TRC-PD group showed larger prescription isodose volume (9.4 cm³) than the TRC-RN (4.06 cm³, p = 0.014) group and a shorter time interval from SRS to preoperative MRI diagnosis (median 4.07 months) than the PD–PD group (median 8.77 months, p = 0.004). Progression-free survival was significantly different among the three groups (p < 0.001), but not between TRC-RN and TRC-PD (post hoc test, p = 1.00), while no difference was observed in overall survival (p = 0.067). Brain metastases featured as TRCs after SRS frequently contained viable tumor cells. However, this histologic heterogeneity had a minor impact on benign local prognosis of TRCs after surgical resection.

Radiation therapy for brain metastases

We present the update of the recommendations of the French society for radiation oncology on radiation therapy for the management of brain metastases. It has evolved in recent years and has become more complex. As the life expectancy of patients has increased and retreatments have become more frequent, side effects must be absolutely avoided. Cognitive side effects must in particular be prevented, and the most modern radiation therapy techniques must be used systematically. New prognostic classifications specific to the primary tumour of patients, advances in imaging and radiation therapy technology and new systemic therapeutic strategies, are making treatment more relevant. Stereotactic radiation therapy has supplanted whole-brain radiation therapy both for patients with metastases in place and for those who underwent surgery. Hippocampus protection is possible with intensity-modulated radiation therapy. Its relevance in terms of cognitive functioning should be more clearly demonstrated but the requirement for its use is constantly increasing. New targeted cancer treatment therapies based on the nature of the primitive have complicated the notion of the place and timing of radiation therapy and the discussion during multidisciplinary care meeting to indicate the best sequences is becoming a challenging issue as data on the interaction between treatments remain to be documented. In the end, although aimed at patients in the palliative phase, the management of brain metastases is one of the locations for which technical reflection is the most challenging and treatment become increasingly personalized.

Resecting the dominant lesion: Patient outcomes after surgery and radiosurgery vs stand-alone radiosurgery in the setting of multiple brain metastases

BACKGROUND

Brain metastases are the most common central nervous system (CNS) tumors, occurring in 300,000 people per year in the US. While there are immediate local benefits to surgical resection for dominant lesions, including reduction of tumor burden and edema, the survival benefits of surgical resection, over radiosurgery, remains unclear.

METHODS

The University of Pennsylvania Health System database was retrospectively reviewed for patients presenting with multiple brain metastases from 1/1/16-8/31/18 with one dominant lesion > 2 cm in diameter, who underwent initial treatment with either resection of the dominant lesion or Gamma Knife radiosurgery (GKS). Inclusion criteria were age > 18, > 1 brain metastasis, and presence of a dominant lesion (>2 cm). We analyzed factors associated with mortality.

RESULTS

129 patients were identified (surgery=84, GKS=45). The median number of intracranial metastases was 3 (IQR: 2-5). The median diameter of the largest lesion was 31 mm (IQR: 25-38) in the surgery group vs 21 mm (IQR: 20-24) in the GKS group (p < 0.001). Mortality did not differ between surgery and GKS patients (69.1% vs 77.8%, p = 0.292). In a multivariate survival analysis, there was no difference in mortality between the surgery and GKS cohorts (aHR: 1.35, 95% CI: 0.74-2.45 p = 0.32). Pre-operative KPS (aHR: 0.97, 95% CI: 0.95-0.99, p = 0.004), CNS radiotherapy (aHR: 0.33, 95% CI: 0.19-0.56 p < 0.001), chemotherapy (aHR: 0.27, 95% CI: 0.15-0.47, p < 0.001), and immunotherapy (aHR: 0.41, 95% CI: 0.25-0.68, p = 0.001) were associated with decreased mortality.

CONCLUSION

In our institution, patients with multiple brain metastases and one symptomatic dominant lesion demonstrated similar survival after GKS when compared with up-front surgical resection of the dominant lesion.

Dedicated holmium microsphere administration device for MRI-guided interstitial brain microbrachytherapy

Microbrachytherapy with radioactive holmium-166 (¹⁶⁶Ho) microspheres (MS) has the potential to be an effective treatment method for brain malignancies. Direct intratumoural delivery of ¹⁶⁶Ho-MS and dose coverage of the whole tumour are crucial requirements. However, currently no dedicated instruments for controlled intratumoural delivery exist. This study presents an administration device that facilitates this novel magnetic resonance imaging (MRI) -guided intervention. The bioceramic alumina oxide cannula creates a straight channel for a superelastic nitinol precurved stylet to control spatial deposition of Ho-MS. End-point accuracy of the stylet was measured during insertions in phantoms. Imaging tests were performed in a 3 Tesla MRI-scanner to quantify instrument-induced artefacts. Additionally, the feasibility of non-radioactive holmium-165 (¹⁶⁵Ho)-MS delivery with the administration device was evaluated in a brain tumour simulant. Absolute stylet tip error was 0.88 ± 0.61 mm, instrument distortion in MRI depended on needle material and orientation and dose delivery of ¹⁶⁵Ho-MS in a brain tumour phantom was possible. This study shows that the administration device can accurately place the stylet for injection of Ho-MS and that visualization can be performed with MRI.

Stereotactic Radiosurgery (SRS) experience on brain metastases: A 3-year retrospective study at King Abdulaziz University Hospital

Objectives

Stereotactic radiosurgery (SRS), a non-invasive surgical procedure had been utilized for treatment of patients with brain metastases. This study aims to determine the survival, local control of brain metastases and treatment outcome to SRS-treated patients based on radiological imaging.

Methods

The MRI scans of SRS-treated patients with brain metastases (n = 24) from the Radiology Department of King Abdulaziz University from January 2016 to September 2019 were examined. The data was analyzed using descriptive statistics and Chi-square test.

Results

Out of 24 patients, most had brain metastases (95.8%, n = 23) with mean interval development (after primary site) of 21.88 ± 25.2 months. Radiological imaging revealed tumor characteristics of smallest (n = 11) and biggest lesions (n = 24) of patients to be 0.98 ± 0.7 and 2.23 ± 0.9, respectively and number of lesion to be 4-5 lesions (n = 3), 3 lesions (n = 6), 2 lesions (n = 4) and 1 lesion (n = 11). After SRS treatment, findings showed 17.6% (n = 3) no recurrence among the patients. Those with recurrences have decrease in lesion enhancement (11.8%, n = 2), decrease in size (29.4%, n = 5) and decrease in both enhancement and size (29.4%). Overall survival obtained was 16.7% (n = 2) at 313.83 ± 376.0 days (n = 23) survival period. Chi-square test showed that radiological findings were significantly associated with tumor recurrence (p = 0.010), having SRS-treated patients with recurrences (n = 12) to experience significant decrease (p = 0.010) in tumor enhancement, size, and both enhancement and size.

Conclusion

A significant decrease in tumor size and enhancement was observed in SRS-treated patients, suggesting SRS treatment to have associated benefit with prolonged survival duration.

Is Molecular Tailored-Therapy Changing the Paradigm for CNS Metastases in Breast Cancer?

Breast cancer (BC) is the second most common tumour spreading to the central nervous system (CNS). The prognosis of patients with CNS metastases depends on several parameters including the molecular assessment of the disease. Although loco-regional treatment remains the best approach, systemic therapies are acquiring a role leading to remarkable long-lasting responses. The efficacy of these compounds diverges between tumours with different molecular assessments. Promising agents under investigation are drugs targeting the HER2 pathways such as tucatinib, neratinib, pyrotinib, trastuzumab deruxtecan. In addition, there are several promising agents under investigation for patients with triple-negative brain metastases (third-generation taxane, etirinotecan, sacituzumab, immune-checkpoint inhibitors) and hormone receptor-positive brain metastases (CDK 4/5, phosphoinositide-3-kinase-mammalian target of rapamycin [PI3K/mTOR] inhibitors). Also, the systemic treatment of leptomeningeal metastases, which represents a very negative prognostic site of metastases, is likely to change as several compounds are under investigation, some with interesting preliminary results. Here we performed a comprehensive review focusing on the current management of CNS metastases according to molecular subtypes, site of metastases (leptomeningeal vs brain), and systemic treatments under investigation.

A phase I/II trial of 5-fraction stereotactic radiosurgery with 5-mm margins with concurrent temozolomide in newly diagnosed glioblastoma: primary outcomes

BACKGROUND

We sought to determine the maximum tolerated dose (MTD) of 5-fraction stereotactic radiosurgery (SRS) with 5-mm margins delivered with concurrent temozolomide in newly diagnosed glioblastoma (GBM).

METHODS

We enrolled adult patients with newly diagnosed glioblastoma to 5 days of SRS in a 3 + 3 design on 4 escalating dose levels: 25, 30, 35, and 40 Gy. Dose limiting toxicity (DLT) was defined as Common Terminology Criteria for Adverse Events grades 3-5 acute or late CNS toxicity, including adverse radiation effect (ARE), the imaging correlate of radiation necrosis.

RESULTS

From 2010 to 2015, thirty patients were enrolled. The median age was 66 years (range, 51-86 y). The median target volume was 60 cm3 (range, 14.7-137.3 cm3). DLT occurred in 2 patients: one for posttreatment cerebral edema and progressive disease at 3 weeks (grade 4, dose 40 Gy); another patient died 1.5 weeks following SRS from postoperative complications (grade 5, dose 40 Gy). Late grades 1-2 ARE occurred in 8 patients at a median of 7.6 months (range 3.2-12.6 mo). No grades 3-5 ARE occurred. With a median follow-up of 13.8 months (range 1.7-64.4 mo), the median survival times were: progression-free survival, 8.2 months (95% CI: 4.6-10.5); overall survival, 14.8 months (95% CI: 10.9-19.9); O6-methylguanine-DNA methyltransferase hypermethylated, 19.9 months (95% CI: 10.5-33.5) versus 11.3 months (95% CI: 8.9-17.6) for no/unknown hypermethylation (P = 0.03), and 27.2 months (95% CI: 11.2-48.3) if late ARE occurred versus 11.7 months (95% CI: 8.9-17.6) for no ARE (P = 0.08).

CONCLUSIONS

The per-protocol MTD of 5-fraction SRS with 5-mm margins with concurrent temozolomide was 40 Gy in 5 fractions. ARE was limited to grades 1-2 and did not statistically impact survival.

Secondary Parkinsonism in a Patient With a Cerebral Cavernous Hemangioma Treated With Stereotactic Radiosurgery

Secondary parkinsonism is defined with some symptoms similar to idiopathic Parkinson's disease, but with different etiologies. And cerebral cavernous hemangioma is one of the rare cases. A 51-year-old, male patient was consulted with tremor, rigidity and bradykinesia on the right upper extremity. The Hoehn and Yahr Parkinson's scale was Stage І. Radiological evaluations showed a deep-seated cerebral cavernous hemangioma at the left posterior insular region. The patient received stereotactic radiosurgery (CyberKnife®, Accuray Incorporated, Sunnyvale, CA, USA). Clinical and radiological improvements revealed within follow-up, respectively. Stereotactic radiosurgery may be an alternative treatment for secondary parkinsonism by reducing the risk of re-bleeding and reducing its size.

Automated Detection and Segmentation of Brain Metastases in Malignant Melanoma: Evaluation of a Dedicated Deep Learning Model

BACKGROUND AND PURPOSE

Malignant melanoma is an aggressive skin cancer in which brain metastases are common. Our aim was to establish and evaluate a deep learning model for fully automated detection and segmentation of brain metastases in patients with malignant melanoma using clinical routine MR imaging.

MATERIALS AND METHODS

Sixty-nine patients with melanoma with a total of 135 brain metastases at initial diagnosis and available multiparametric MR imaging datasets (T1-/T2-weighted, T1-weighted gadolinium contrast-enhanced, FLAIR) were included. A previously established deep learning model architecture (3D convolutional neural network; DeepMedic) simultaneously operating on the aforementioned MR images was trained on a cohort of 55 patients with 103 metastases using 5-fold cross-validation. The efficacy of the deep learning model was evaluated using an independent test set consisting of 14 patients with 32 metastases. Manual segmentations of metastases in a voxelwise manner (T1-weighted gadolinium contrast-enhanced imaging) performed by 2 radiologists in consensus served as the ground truth.

RESULTS

After training, the deep learning model detected 28 of 32 brain metastases (mean volume, 1.0 [SD, 2.4] cm³) in the test cohort correctly (sensitivity of 88%), while false-positive findings of 0.71 per scan were observed. Compared with the ground truth, automated segmentations achieved a median Dice similarity coefficient of 0.75.

CONCLUSIONS

Deep learning-based automated detection and segmentation of brain metastases in malignant melanoma yields high detection and segmentation accuracy with false-positive findings of <1 per scan.

Central Nervous System Cancers, Version 3.2020, NCCN Clinical Practice Guidelines in Oncology

The NCCN Guidelines for Central Nervous System (CNS) Cancers focus on management of adult CNS cancers ranging from noninvasive and surgically curable pilocytic astrocytomas to metastatic brain disease. The involvement of an interdisciplinary team, including neurosurgeons, radiation therapists, oncologists, neurologists, and neuroradiologists, is a key factor in the appropriate management of CNS cancers. Integrated histopathologic and molecular characterization of brain tumors such as gliomas should be standard practice. This article describes NCCN Guidelines recommendations for WHO grade I, II, III, and IV gliomas. Treatment of brain metastases, the most common intracranial tumors in adults, is also described.

Management of symptomatic radiation necrosis after stereotactic radiosurgery and clinical factors for treatment response

PURPOSE

Approximately 10% of patients who received brain stereotactic radiosurgery (SRS) develop symptomatic radiation necrosis (RN). We sought to determine the effectiveness of treatment options for symptomatic RN, based on patient-reported outcomes.

MATERIALS AND METHODS

We conducted a retrospective review of 217 patients with 414 brain metastases treated with SRS from 2009 to 2018 at our institution. Symptomatic RN was determined by appearance on serial magnetic resonance images (MRIs), MR spectroscopy, requirement of therapy, and development of new neurological complaints without evidence of disease progression. Therapeutic interventions for symptomatic RN included corticosteroids, bevacizumab and/or surgical resection. Patient-reported therapeutic outcomes were graded as complete response (CR), partial response (PR), and no response.

RESULTS

Twenty-six patients experienced symptomatic RN after treatment of 50 separate lesions. The mean prescription dose was 22 Gy (range, 15 to 30 Gy) in 1 to 5 fractions (median, 1 fraction). Of the 12 patients managed with corticosteroids, 6 patients (50%) reported CR and 4 patients (33%) PR. Of the 6 patients managed with bevacizumab, 3 patients (50%) reported CR and 1 patient (18%) PR. Of the 8 patients treated with surgical resection, all reported CR (100%). Other than surgical resection, age ≥54 years (median, 54 years; range, 35 to 81 years) was associated with CR (odds ratio = 8.40; 95% confidence interval, 1.27-15.39; p = 0.027).

CONCLUSION

Corticosteroids and bevacizumab are commonly utilized treatment modalities with excellent response rate. Our results suggest that patient's age is associated with response rate and could help guide treatment decisions for unresectable symptomatic RN.

Role of Nanomedicine in Treatment of Brain Cancer

Background:

Drug delivery to cancerous brain is a challenging task as it is surrounded by an efficient protective barrier. The main hurdles for delivery of bioactive molecules to cancerous brain are blood brain barrier (BBB), the invasive nature of gliomas, drug resistance, and difficult brain interstitium transportation. Therefore, treatment of brain cancer with the available drug regimen is difficult and has shown little improvement in recent years.

Methods:

We searched about recent advancements in the use of nanomedicine for effective treatment of the brain cancer. We focused on the use of liposomes, nanoparticles, polymeric micelles, and dendrimers to improve brain cancer therapy.

Results:

Nanomedicines are well suited for the treatment of brain cancer owing to their highly acceptable biological, chemical, and physical properties. Smaller size of nanomedicines also enhances their anticancer potential and penetration into blood brain barrier (BBB).

Conclusion:

Recently, nanomedicine based approaches have been developed and investigated for effective treatment of brain cancer. Some of these have been translated into clinical practice, in order to attain therapeutic needs of gliomas. Future advancements in nanomedicines will likely produce significant changes in methods and practice of brain cancer therapy.

Common Error Pathways in CyberKnife™ Radiation Therapy

Purpose/Objectives: Stereotactic radiosurgery (SRS) and stereotactic body radiation therapy (SBRT) may be considered “high risk” due to the high doses per fraction. We analyzed CyberKnife™ (CK) SRS and SBRT-related incidents that were prospectively reported to our in-house incident learning system (ILS) in order to identify severity, contributing factors, and common error pathways.

Material and Methods: From 2012 to 2019, 221 reported incidents related to the 4,569 CK fractions delivered (5.8%) were prospectively analyzed by our multi-professional Quality and Safety Committee with regard to severity, contributing factors, as well as the location where the incident occurred (tripped), where it was discovered (caught), and the safety barriers that were traversed (crossed) on the CK process map. Based on the particular step in the process map that incidents tripped, we categorized incidents into general error pathways.

Results: There were 205 severity grade 1–2 (did not reach patient or no clinical impact), 11 grade 3 (clinical impact unlikely), 5 grade 4 (altered the intended treatment), and 0 grade 5–6 (life-threatening or death) incidents, with human performance being the most common contributing factor (79% of incidents). Incidents most commonly tripped near the time when the practitioner requested CK simulation (e.g., pre-CK simulation fiducial marker placement) and most commonly caught during the physics pre-treatment checklist. The four general error pathways included pre-authorization, billing, and scheduling issues (n= 119); plan quality (n= 30); administration of IV contrast during simulation or pre-medications during treatment (n= 22); and image guidance (n= 12).

Conclusion: Most CK incidents led to little or no patient harm and most were related to billing and scheduling issues. Suboptimal human performance appeared to be the most common contributing factor to CK incidents. Additional study is warranted to develop and share best practices to reduce incidents to further improve patient safety.

Combined radiation strategies for novel and enhanced cancer treatment

Numerous studies focus on cancer therapy worldwide, and although many advances have been recorded, the complexity of the disease dictates thinking out of the box to confront it. This study reviews some of the currently available ionizing (IR) and non-ionizing radiation (NIR)-based treatment methods and explores their possible combinations that lead to synergistic, multimodal approaches with promising therapeutic outcomes. Traditional techniques, like radiotherapy (RT) show decent results, although they cannot spare 100% the healthy tissues neighboring with the cancer ones. Targeted therapies, such as proton and photodynamic therapy (PT and PDT, respectively) present adequate outcomes, even though each one has its own drawbacks. To overcome these limitations, the combination of therapeutic modalities has been proposed and has already been showing promising results. At the same time, the recent advances in nanotechnology in the form of nanoparticles enhance cancer therapy, making multimodal treatments worthy of exploring and studying. The combination of RT and PDT has reached the level of clinical trials and is showing promising results. Moreover, in vitro and in vivo studies of nanoparticles with PDT have also provided beneficial results concerning enhanced radiation treatments. In any case, novel and multimodal approaches have to be adopted to achieve personalized, enhanced and effective cancer treatment.

Current approaches to the management of brain metastases

Brain metastases are a very common manifestation of cancer that have historically been approached as a single disease entity given the uniform association with poor clinical outcomes. Fortunately, our understanding of the biology and molecular underpinnings of brain metastases has greatly improved, resulting in more sophisticated prognostic models and multiple patient-related and disease-specific treatment paradigms. In addition, the therapeutic armamentarium has expanded from whole-brain radiotherapy and surgery to include stereotactic radiosurgery, targeted therapies and immunotherapies, which are often used sequentially or in combination. Advances in neuroimaging have provided additional opportunities to accurately screen for intracranial disease at initial cancer diagnosis, target intracranial lesions with precision during treatment and help differentiate the effects of treatment from disease progression by incorporating functional imaging. Given the numerous available treatment options for patients with brain metastases, a multidisciplinary approach is strongly recommended to personalize the treatment of each patient in an effort to improve the therapeutic ratio. Given the ongoing controversies regarding the optimal sequencing of the available and expanding treatment options for patients with brain metastases, enrolment in clinical trials is essential to advance our understanding of this complex and common disease. In this Review, we describe the key features of diagnosis, risk stratification and modern paradigms in the treatment and management of patients with brain metastases and provide speculation on future research directions.

Non-invasive Stereotactic Radioablation: A New Option for the Treatment of Ventricular Arrhythmias

Ventricular tachycardia (VT) is associated with significant morbidity and mortality. Radiofrequency catheter ablation can be effective for the treatment of VT but it carries a high rate of recurrence often attributable to insufficient depth of penetration for reaching critical arrhythmogenic substrates. Stereotactic body radioablation (SBRT) is a commonly used technology developed for the non-invasive treatment of solid tumours. Recent evidence suggests that it can also be effective for the treatment of VT. It is a non-invasive procedure and it has the unique advantage of delivering ablative energy to any desired volume within the body to reach sites that are inaccessible with catheter ablation. This article summarises the pre-clinical studies that have formed the evidence base for SBRT in the heart, describes the clinical approaches for SBRT VT ablation and provides perspective on next steps for this new treatment modality.

Health-related quality of life in adult patients with brain metastases after stereotactic radiosurgery: a systematic, narrative review

PURPOSE

A growing number of patients with brain metastases (BM) are being treated with stereotactic radiosurgery (SRS), and the importance of evaluating the impact of SRS on the health-related quality of life (HRQoL) in these patients has been increasingly acknowledged. This systematic review summarizes the current knowledge about the HRQoL of patients with BM after SRS.

METHODS

We searched EMBASE, Medline Ovid, Web-of-Science, the Cochrane Database, PsycINFO Ovid, and Google Scholar up to November 15, 2018. Studies in patients with BM in which HRQoL was assessed before and after SRS and analyzed over time were included. Studies including populations of several types of brain cancer and/or several types of treatments were included if the results for patients with BM and treatment with SRS alone were described separately.

RESULTS

Out of 3638 published articles, 9 studies met the eligibility criteria and were included. In 4 out of 7 studies on group results, overall HRQoL of patients with BM remained stable after SRS. In small study samples of longer-term survivors, overall HRQoL remained stable up to 12 months post-SRS. Contradictory results were reported for physical and general/global HRQoL, which might be explained by the different questionnaires that were used.

CONCLUSIONS

In general, SRS does not have significant negative effects on patients' overall HRQoL over time. Future research is needed to analyze different aspects of HRQoL, differences in individual changes in HRQoL after SRS, and factors that influence these changes. These studies should take into account several methodological issues as discussed in this review.

Pattern of Recurrence Analysis in Metastatic EGFR-Mutant NSCLC Treated with Osimertinib: Implications for Consolidative Stereotactic Body Radiation Therapy

PURPOSE

Despite the impressive response rate to osimertinib, acquired resistance remains an obstacle to achieving long-term tumor control in metastatic epidermal growth factor receptor-mutant non-small cell lung cancer. Stereotactic body radiation therapy (SBRT) plays a growing role in the management of oligometastatic disease. We investigated the patterns of residual disease and progression on osimertinib, as well as the predictors of candidates for consolidative SBRT.

METHODS AND MATERIALS

The serial scans of patients with metastatic epidermal growth factor receptor-mutant non-small cell lung cancer treated with osimertinib were retrospectively reviewed. Disease progression in residual sites, new sites, and both residual and new sites were classified as residual-site recurrence (RR), new-site recurrence (NR), and combined RR and NR (RNR), respectively. Logistic regression analysis was performed to identify predictors of candidates for consolidative SBRT.

RESULTS

Ninety-seven patients were enrolled. The median time to maximal osimertinib response was 2.6 months. Twenty-six patients (26.8%) with oligoresidual disease were identified as candidates for consolidative SBRT at time of maximal response. Stage T1-2 before initiation of osimertinib (P = .046) was the independent predictor of consolidative SBRT eligibility. During a median follow-up of 10.9 months, disease progression was documented in 50 (51.5%) patients, and 70% of them experienced oligoprogression. Twenty-five (50%) patients developed disease progression in originally involved sites, 11 (22%) had new metastases, and 14 (28%) experienced disease progression in both original and new metastatic sites. Forty-six patients had progressive disease after experiencing initial stable disease or objective response to osimertinib. RR occurred in 20 (43.5%) of these patients, NR in 14 (30.4%), and RNR in 12 (26.1%). Notably, within the subgroup of patients eligible for consolidative SBRT, RR was observed in 6 (54.5%) patients, RNR in 3 (27.3%), and NR in 2 (18.2%).

CONCLUSIONS

The majority of progressive disease on osimertinib was within residual lesions in initially involved sites. Consolidative SBRT may prolong time to progression in a selected subgroup of patients, which merits further investigation.

The Effect of Epidermal Growth Factor Receptor Mutation on Intracranial Progression-Free Survival of Non-Small Cell Lung Cancer Patients with Brain Metastasis Underwent Gamma Knife Radiosurgery

BACKGROUND

The aim of this study was to survey prognostic factors, particularly those focusing on epidermal growth factor receptor (EGFR) mutations, of patients with non-small cell lung cancer (NSCLC) after Gamma Knife Radiosurgery (GKRS) for metastatic brain tumors.

METHODS

We retrospectively reviewed the medical records of 98 patients with NSCLC who underwent GKRS for brain metastases from August 2010 to July 2017. The primary endpoint was progression-free survival (PFS) of the intracranial disease. We analyzed variables such as age, sex, Karnofsky Performance Status, recursive partitioning analysis (RPA) class, smoking status, primary cancer pathology, EGFR mutations, and time to brain metastases as prognostic factors.

RESULTS

The median overall survival (OS) of the patients was 16 months [95% confidence interval (CI), 13-21 months]. Median systemic PFS and intracranial PFS were 9 months (95% CI, 8-11 months) and 11 months (95% CI, 7-14 months), respectively. Kaplan-Meier survival analysis revealed that the patients with EGFR mutations had longer intracranial PFS than those without EGFR mutation (median intracranial PFS: 19 vs. 10 months with p=0.01) while they had no benefits in OS and systemic PFS. Furthermore, the patients harboring adenocarcinoma had longer OS (p<0.01) and intracranial PFS (p<0.01) and the patients with lower RPA class had longer OS (p=0.02) and intracranial PFS (p=0.03).

CONCLUSION

EGFR mutations, primary cancer pathology, and RPA class may be proposed as prognostic factors for intracranial PFS in NSCLC patients after GKRS for brain metastasis in this study.

The Choice of Local Treatment Modalities for Patients with Brain Metastases from Digestive Cancers

Background

Brain metastases (BMs) from digestive cancers are rare; therefore, no optimal treatment modality has been defined.

Methods

We retrospectively reviewed the clinical data of 68257 patients with digestive cancers. Propensity score matching (PSM) was used to balance patient backgrounds between groups. Survival differences between different treatment modalities were compared. Univariate and multivariate Cox proportional hazards models were performed to identify prognostic factors on overall survival (OS).

Results

270 patients with BM entered the study. In the entire group, the median survival time after diagnosis of brain metastases was 10.25 months (95% CI: 8.41–12.09 months); local treatment could significantly prolong OS (respectively, P < 0.01; even after PSM, P < 0.01); combination treatment was more effective than single treatment modality (respectively, P < 0.01; even after PSM, P < 0.01). However, each combination modality was identically effective (P > 0.05). When patients were divided into three groups based on 1, 2-3, or more than 3 metastatic lesion(s), same results were identified between local treatment and without local treatment (1 lesion, P < 0.01; 2-3 lesions, P < 0.01; more than 3 lesions, P < 0.01, respectively) and combination and single treatment (P < 0.01, P=0.02, P=0.03, respectively). However, there was no difference between different combined treatments (P > 0.05). Multivariate analysis revealed that performance status (P < 0.01), presence of extracranial metastasis (P=0.04), number of BM (P < 0.01), and local treatment for BM (P < 0.01) were independent prognostic factors.

Conclusions

Regardless of the number of brain lesions, local treatment achieved higher overall survival times than no local treatment, and combination therapy could offer survival benefit to patients as compared with single therapy.

MRI appearance change during stereotactic radiotherapy for large brain metastases and importance of treatment plan modification during treatment period

Purpose

We aimed to evaluate the magnetic resonance imaging (MRI) appearance changes during stereotactic radiotherapy (SRT) for large sized brain metastases, and analyze the lesions necessitating treatment plan modification.

Materials and methods

A total of 23 patients (27 lesions, >2 cm in tumor diameter) underwent SRT and all lesions were evaluated the appearance changes which had the necessity of the treatment plan modification. The appearance change of tumor during SRT was evaluated using gadolinium-enhanced MRI. The reasons of the modification were classified into tumor reduction, tumor enlargement, displacement, and shape change.

Results

Among the 27 lesions, 55.6% required the treatment plan modification. The reasons were tumor reduction in six lesions, tumor enlargement in three lesions, displacement in three lesions, and shape change in three lesions. The planning target volume (PTV) size changed up to 43.0% and the shift of center of PTV was a maximum of 1.7 mm. The pathological status (adenocarcinoma vs others) and timing of steroid administration (prior vs after SRT start) were the predictive factors of tumor changes required the modification.

Conclusions

As tumor changes might occur even during short period of SRT, the treatment plan evaluation and modification were important in SRT for large brain metastases.

Effect of MRI-based semiautomatic size-assessment in cerebral metastases on the RANO-BM classification

AIM

Evaluation of a semiautomatic software algorithm for magnetic resonance imaging (MRI)-based assessment of cerebral metastases in cancer patients.

MATERIAL AND METHODS

Brain metastases (n = 131) in 38 patients, assessed by contrast-enhanced MRI, were retrospectively evaluated at two timepoints (baseline, follow-up) by two experienced neuroradiologists in a blinded manner. The response assessment in neuro-oncology (RANO) criteria for brain metastases (RANO-BM) were applied by means of a software (autoRANO-BM) as well as manually (manRANO-BM) at an interval of 3 weeks.

RESULTS

The average diameter of metastases was 12.03 mm (SD ± 6.66 mm) for manRANO-BM and 13.97 mm (SD ± 7.76 mm) for autoRANO-BM. Diameter figures were higher when using semiautomatic measurements (median = 11.8 mm) as compared to the manual ones (median = 10.2 mm; p = 0.000). Correlation coefficients for intra-observer variability were 0.993 (autoRANO-BM) and 0.979 (manRANO-BM). The interobserver variability (R1/R2) was 0.936/0.965 for manRANO-BM and 0.989/0.998 for autoRANO-BM. A total of 19 lesions (15%) were classified differently when using semiautomatic measurements. In 14 cases with suspected disease progression by manRANO-BM a stable course was found according to autoRANO-BM.

CONCLUSION

Computerized measuring techniques can aid in the assessment of cerebral metastases by reducing examiner-dependent effects and may consequently result in a different classification according to RANO-BM criteria.

Optimal timing and clinical value of radiotherapy in advanced ALK-rearranged non-small cell lung cancer with or without baseline brain metastases: implications from pattern of failure analyses

Background

Despite development of several next-generation tyrosine kinase inhibitors (TKIs), crizotinib remains one of the first-line treatment options for advanced ALK-positive NSCLC and is widely used in situations where next-generation TKIs aren’t yet approved or economically inaccessible. However, the pattern of failure and clinical value of radiotherapy in metastatic crizotinib-treated ALK-mutant lung cancer, with or without baseline brain metastases (BBM), are largely unknown.

Methods

Consecutive crizotinib-treated NSCLC patients with adequate imaging and measurable disease were retrospectively enrolled. Disease progression in original sites (primary/metastatic), new sites, or both, are classified as original failure (OF), distant failure (DF) and ODF, respectively. Progression free survival, from crizotinib initiation to the first disease progression, and from that to the second disease progression, were calculated as PFS1 and PFS2.

Results

Ninety-three patients were identified. With a median follow up of 22.0 (range, 2.0–72.0) months, 52 patients had crizotinib-treatment failure. The frequencies of OF, ODF, and DF, were 50.0, 26.9, and 23.1%, respectively. Histology, primary tumor size and presence of BBM, were independently associated with OF, using competing risks analyses. The brain was the most common site of initial disease progression. Patients with BBM had a significant higher possibility developing multiple-progressive lesions in the brain (p = 0.002). Importantly, four of the ten patients who had baseline oligo-metastatic cranial disease but didn’t receive upfront brain radiation, developed multiple-progressive disease in the brain. Brain radiation before crizotinib could alter the disease failure patterns and improve PFS1 among patients with BBM (p = 0.006). Extracranial radiation was efficient in controlling symptoms but it was not associated with PFS1 (p = 0.223), and the majority of patients were eligible for salvage radiotherapy upon disease progression to crizotinib. By the time of data cut-off, 28 patients had second disease progression, with a median PFS2 of 7.0 (95% CI 5.4–8.6) months and salvage radiotherapy significantly prolonged PFS2 (p = 0.003). Additionally, patients receiving any radiotherapy during their treatment course had a significant longer overall survival (p = 0.048).

Conclusions

Among patients with baseline oligo-metastatic brain lesions which are suitable for stereotactic radiosurgery, upfront brain radiotherapy provides considerable clinical benefits. While, extracranial radiation may be deferred in asymptomatic patients with multiple-metastatic lesions.

Electronic supplementary material

The online version of this article (10.1186/s13014-019-1240-1) contains supplementary material, which is available to authorized users.

The influence of histology on the response of brain metastases to gamma knife radiosurgery: a propensity score-matched study

BACKGROUND

In terms of response to fractionated radiotherapy, metastatic brain tumors of certain origins are considered radioresistant.

OBJECTIVE

To determine the influence of "radioresistant" histology on outcomes of brain metastases treated with radiosurgery.

METHODS

Between 2001 and 2017, 121 patients with brain metastases from renal cell carcinoma (RCC) and 2151 from non-small cell lung cancer (NSCLC) were reviewed. Eighty-seven pairs were derived using propensity score matching. Local progression-free survival (PFS), progression patterns, distant PFS, and overall survival were investigated.

RESULTS

The median follow-up period was 13.7 months (range, 1.6-78.4 months). A total of 536 lesions were treated using gamma knife radiosurgery (GKS), with a median dose of 20 Gy (range, 12-28 Gy). The actuarial local PFS rates in the RCC group were 91% and 89% at 6 and 12 months, respectively, and did not differ from the NSCLC group (97% and 83% at 6 and 12 months, respectively). Continuous progression, without response to GKS, was noted in seven of the eight progressed RCCs. However, six of the seven progressed NSCLCs showed transient shrinkage before progression. The median distant PFS was 9.3 months (95% CI, 6.3-12.2) in the RCC group and 8.0 months (95% CI, 5.5-10.4) in the NSCLC group. The median overall survival was 16.1 months (95% CI, 11.3-20.8) and 14.9 months (95% CI, 11.9-17.8) in RCC and NSCLC groups, respectively.

CONCLUSION

Histological differences had no effect on local control in the single high-dose range used for radiosurgery. However, changes in tumor volume during progression varied across tumor histology.

Dosimetric comparison between dual-isocentric dynamic conformal arc therapy and mono-isocentric volumetric-modulated arc therapy for two large brain metastases

Mono-isocentric volumetric-modulated arc therapy (VMAT) can be used to treat multiple brain metastases. It remains unknown whether mono-isocentric VMAT can improve the dose distribution compared with dual-isocentric dynamic conformal arc therapy (DCAT), especially for two brain metastases. We compared the dose distribution between dual-isocentric DCAT and mono-isocentric VMAT for two large brain metastases, and analyzed the relationship between the distance between the two targets and the difference in dose distribution. A total of 19 patients, each with two large brain metastases, were enrolled. The dose prescribed for each planning target volume (PTV) was 28 Gy in five fractions (D99.8 = 100%). We created new indices derived from conformity indices suggested by the Radiation Therapy Oncology Group (RTOG; mRTOG-CI) and Paddick et al. (mIP-CI), using the dosimetric parameters of the sum of the two PTVs. The median PTV was 5.05 cm3 (range, 2.10-28.47). VMAT significantly improved mRTOG-CI and mIP-CI compared with DCAT. In all cases, VMAT was able to improve mRTOG-CI and mIP-CI compared with DCAT. Whereas the normal brain volume receiving 5 Gy was similar between the two modalities, the normal brain receiving 10, 12, 15, 20, 25 and 28 Gy (V10-V28) was significantly smaller in VMAT. The mean beam-on times were 213.3 s and 121.9 s in DCAT and VMAT, respectively (P < 0.001). Mono-isocentric VMAT improved the target conformity and reduced the beam-on time and V10-V28 of the normal brain for not only two close metastases but also two distant metastases. Mono-isocentric VMAT seems to be a promising treatment technique for two large brain metastases.

Cognitive effects of stereotactic radiosurgery in adult patients with brain metastases: A systematic review

PURPOSE

Stereotactic radiation surgery (SRS) is increasingly applied in patients with brain metastases (BM) and is expected to have fewer adverse effects on cognitive functioning than whole brain radiation therapy (WBRT). Patients with BM are often confronted with a relatively short life expectancy, and the prevention or delay of cognitive decline to maintain quality of life is a clinically and highly relevant treatment goal. This review systematically and specifically evaluates the current literature on the cognitive effects of SRS in patients with BM.

METHODS AND MATERIALS

Published trials on SRS alone or in combination with WBRT, including objective assessment of cognitive functioning, were identified through a systematic search of the PubMed database up to March 2018.

RESULTS

Of the 241 records screened, 14 studies matched the selection criteria: 2 pilot studies, 7 single-group/observational trials (1 study update), and 5 randomized trials (1 secondary analysis).

CONCLUSIONS

In general, the results show little to no objective cognitive decline up to 4 months after SRS compared with WBRT. However, most trials suffered from methodologic limitations that hindered reliable conclusions. Most importantly, few studies investigated the specific cognitive effects of SRS alone or versus WBRT. Furthermore, disentangling the cognitive effects of SRS from the effects of the disease itself and from the effects of other treatments remains very difficult. By presenting this comprehensive review, we aim to encourage researchers to probe deeper into this area and to do so in a standardized and methodologically optimal manner. The ultimate objective of this line of research is to inform both doctors and patients more precisely about the cognitive effects they can expect from treatment. This study is expected to improve the quality of decision-making and maximize clinical outcomes for each individual patient.

Contemporary Management of 1-4 Brain Metastases

Brain metastases remain the most common neurologic complication of cancer. With improvement in surveillance and systemic therapy, patients with limited CNS disease are living longer after diagnosis, thus influencing the importance of optimal radiation treatment in order to maximize local control and minimize morbidity. In patients with a limited number of brain metastases, stereotactic radiosurgery is more recently seen as an appropriate sole modality for management with excellent local control. As newer systemic therapies emerge and with the advent of immunotherapies and targeted therapies for metastatic CNS disease, further research is needed in the optimal timing and sequencing of these modalities.

Comparison of MRI and PET as Potential Surrogate Endpoints for Treatment Response After Stereotactic Radiosurgery in Patients With Brain Metastasis

OBJECTIVE

The purpose of this study is to compare the diagnostic performance of MRI and PET for differentiating tumor recurrence from radiation necrosis in patients with brain metastasis treated with stereotactic radiosurgery.

MATERIALS AND METHODS

The Ovid-Medline and Embase databases were searched up to November 11, 2017, to find relevant studies. Pooled sensitivity and specificity from entire included studies were obtained using hierarchic logistic regression modeling. Metaregression was performed.

RESULTS

Twenty studies including 728 patients with 872 brain metastases were selected. MRI showed a pooled sensitivity of 84% (95% CI, 72-91%) and specificity of 88% (95% CI, 71-96%). PET showed a pooled sensitivity of 84% (95% CI, 78-88%) and specificity of 86% (95% CI, 81-90%). There were no statistically significant differences in the diagnostic performance of MRI and PET using indirect (p = 0.80) or direct (p = 0.48) comparisons. The diagnostic performance of advanced MRI was significantly higher than that of conventional MRI (p = 0.01). Advanced MRI (sensitivity, 86% [95% CI, 74-93%]; specificity, 95% [95% CI, 82-98%]) showed a significantly higher diagnostic performance than did PET (p < 0.01). All the included studies used perfusion MRI as an advanced MRI technique.

CONCLUSION

MRI and PET showed high diagnostic performance for the detection of tumor recurrence after stereotactic radiosurgery in patients with brain metastasis. There was no significant difference in the diagnostic performance between MRI and PET. Because of heterogeneity and paucity in studies, caution may be needed in applying the results.

Gamma Knife Radiosurgery for Metastatic Brain Tumors with Exophytic Hemorrhage

Objective

Metastatic brain tumors (MBTs) often present with intracerebral hemorrhage. Although Gamma Knife surgery (GKS) is a valid treatment option for hemorrhagic MBTs, its efficacy is unclear. To achieve oncologic control and reduce radiation toxicity, we used a radiosurgical targeting technique that confines the tumor core within the hematoma when performing GKS in patients with such tumors. We reviewed our experience in this endeavor, focusing on local tumor control and treatment-associated morbidities.

Methods

From 2007 to 2014, 13 patients with hemorrhagic MBTs were treated via GKS using our targeting technique. The median marginal dose prescribed was 23 Gy (range, 20–25). GKS was performed approximately 2 weeks after tumor bleeding to allow the patient’s condition to stabilize.

Results

The primary sites of the MBTs included the liver (n=7), lung (n=2), kidney (n=1), and stomach (n=1); in two cases, the primary tumor was a melanoma. The mean tumor volume was 4.00 cm³ (range, 0.74–11.0). The mean overall survival duration after GKS was 12.5 months (range, 3–29), and three patients are still alive at the time of the review. The local tumor control rate was 92% (tumor disappearance 23%, tumor regression 46%, and stable disease 23%). There was one (8%) instance of local recurrence, which occurred 11 months after GKS in the solid portion of the tumor. No GKS-related complications were observed.

Conclusion

Our experience shows that GKS performed in conjunction with our targeting technique safely and effectively treats hemorrhagic MBTs. The success of this technique may reflect the presence of scattered metastatic tumor cells in the hematoma that do not proliferate owing to the inadequate microenvironment of the hematoma. We suggest that GKS can be a useful treatment option for patients with hemorrhagic MBTs that are not amenable to surgery.