Stereotactic radiosurgery for patients with multiple brain metastases (JLGK0901): a multi-institutional prospective observational study

Clinical outcome of patients with isolated central nervous system progression on first-line pertuzumab and trastuzumab treatment for HER2-positive metastatic breast cancer in a real-life cohort

BACKGROUND

More than 10% of HER2-positive metastatic breast cancer (mBC) will develop Central Nervous System (CNS) metastases as first and isolated site of relapse on trastuzumab and pertuzumab first-line therapy. However, few clinical data are available to guide the best strategy in this setting.

METHODS

Patients experiencing isolated CNS progression on trastuzumab and pertuzumab first-line therapy were retrospectively identified from the French Epidemiological Strategy and Medical Economics (ESME) real-life database between 2008 and 2016.

RESULTS

Among 995 patients treated with first-line trastuzumab and pertuzumab for HER2-positive mBC, 132 patients (13%) experienced isolated CNS progression with a median time of 12 months after mBC diagnosis. Twelves patients did not receive any treatment and were excluded from the analysis. Among the 120 patients considered, 76 (63%) received CNS-directed local therapy, 73 (60%) continued trastuzumab and pertuzumab, whereas 47 (39%) started another systemic treatment. After a median follow-up of 21 months, there was no difference in progression-free survival for patient who continued trastuzumab-pertuzumab or switched to another systemic treatment. In multivariate analysis, trastuzumab-pertuzumab continuation was associated with longer OS (HR 0,28 IC 95%: 0,14-0,54 p < 0,001). mOS was not reached (95% 37.6-NE) and was 23.2 months (95% CI 15.5-53.6) in patients who continued trastuzumab and pertuzumab therapy and in patients who switched for another systemic therapy, respectively.

CONCLUSION

In this real-life cohort, trastuzumab-pertuzumab continuation after local treatment for isolated CNS progression did not negatively impact PFS and OS. Prospective trials and assessment of new strategies are warranted in this specific situation.

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

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

Impact of Novel Treatments in Patients with Melanoma Brain Metastasis: Real-World Data

BACKGROUND

Melanoma brain metastasis (MBM) is associated with poor outcome, but targeted therapies (TTs) and immune checkpoint inhibitors (ICIs) have revolutionized treatment over the past decade. We assessed the impact of these treatments in a real-world setting.

METHODS

A single-center cohort study was performed at a large, tertiary referral center for melanoma (Erasmus MC, Rotterdam, the Netherlands). Overall survival (OS) was assessed before and after 2015, after which TTs and ICIs were increasingly prescribed.

RESULTS

There were 430 patients with MBM included; 152 pre-2015 and 278 post-2015. Median OS improved from 4.4 to 6.9 months (HR 0.67, p < 0.001) after 2015. TTs and ICIs prior to MBM diagnosis were associated with poorer median OS as compared to no prior systemic treatment (TTs: 2.0 vs. 10.9 and ICIs: 4.2 vs. 7.9 months, p < 0.001). ICIs directly after MBM diagnosis were associated with improved median OS as compared to no direct ICIs (21.5 vs. 4.2 months, p < 0.001). Stereotactic radiotherapy (SRT; HR 0.49, p = 0.013) and ICIs (HR 0.32, p < 0.001) were independently associated with improved OS.

CONCLUSION

After 2015, OS significantly improved for patients with MBM, especially with SRT and ICIs. Demonstrating a large survival benefit, ICIs should be considered first after MBM diagnosis, if clinically feasible.

Brain Metastasis Growth Kinetics: A Novel Prognosticator for Stereotactic Radiotherapy

AIMS

The rate of size change in brain metastasis may have clinical implications on tumour biology and prognosis for patients who receive stereotactic radiotherapy (SRT). We analysed the prognostic value of brain metastasis size kinetics and propose a model for patients with brain metastases treated with linac-based SRT in predicting overall survival.

MATERIALS AND METHODS

We analysed the patients receiving linac-based SRT between 2010 and 2020. Patient and oncological factors, including the changes in sizes of brain metastasis between the diagnostic and stereotactic magnetic resonance imaging, were collected. The associations between prognostic factors and overall survival were assessed using Cox regression with least absolute selection and shrinkage operator (LASSO) checked by 500 bootstrap replications. Our prognostic score was calculated by evaluating the most statistically significant factors. Patients were grouped and compared according to our proposed score, Score Index for Radiosurgery in Brain Metastases (SIR) and Basic Score for Brain Metastases (BS-BM).

RESULTS

In total, 85 patients were included. We developed the prognostic model based on the most important predictors of overall survival: growth kinetics, i.e. percentage change in brain metastasis size per day between the diagnostic and stereotactic magnetic resonance imaging (hazard ratio per 1% increase, 1.32; 95% confidence interval 1.06-1.65), extracranial oligometastatic diseases (≤5 involvements) (hazard ratio 0.28; 95% confidence interval 0.16-0.52) and the presence of neurological symptoms (hazard ratio 2.99; 95% confidence interval 1.54-5.81). Patients with scores 0, 1, 2 and 3 had a median overall survival of 44.4 (95% confidence interval 9.6-not reached), 20.4 (95% confidence interval 15.6-40.8), 12.0 (95% confidence interval 7.2-22.8) and 2.4 (95% confidence interval 1.2-not reached) years, respectively. The optimism-corrected c-indices for our proposed model, SIR and BS-BM were 0.65, 0.58 and 0.54, respectively.

CONCLUSIONS

Brain metastasis growth kinetics is a valuable metric for survival outcomes of SRT. Our model is useful in identifying patients with brain metastasis treated with SRT with different overall survival.

Intraoperative radiotherapy for brain metastases: first-stage results of a single-arm, open-label, phase 2 trial

OBJECTIVE

Focal stereotactic radiosurgery to the surgical cavity lowers local recurrence after resection of brain metastases (BM). To evaluate local control (LC) and brain disease control (BDC) after intraoperative radiotherapy (IORT) for resected BM.

METHODS

Adult patients with completely resected single supratentorial BM were recruited and underwent IORT to the cavity with a prescribed dose of 18 Gy to 1 mm-depth. Primary endpoints were actuarial LC and BDC. Local failure (LF) and distant brain failure (DBF), with death as a competing risk, were estimated. Secondary endpoints were overall survival (OS) and incidence of radiation necrosis (RN). Simon's two-stage design was used and estimated an accrual of 10 patients for the first-stage analysis and a LC higher than 63% to proceed to second stage. We report the final analysis of the first stage.

RESULTS

Between June 2019 to November 2020, 10 patients were accrued. Median clinical and imaging FU was 11.2 and 9.7 months, respectively. Median LC was not reached and median BDC was 5 months. The 6-month and 12-month LC was 87.5%. The 6-month and 12-month BDC was 39% and 13%, respectively. Incidence of LF at 6 and 12 months was 10% and of DBF at 6 and 12 months was 50% and 70%, respectively. Median OS was not reached. The 6-month and 12-month OS was 80%. One patient had asymptomatic RN.

CONCLUSION

IORT for completely resected BM is associated with a potential high local control and low risk of RN, reaching the pre-specified criteria to proceed to second stage and warranting further studies.

Comparison between the HyperArc™ technique and the CyberKnife® technique for stereotactic treatment of brain metastases

PURPOSE

The purpose of this study was to compare the planimetric capacities between HyperArc™-based stereotactic radiosurgery and robotic radiosurgery system-based planning using CyberKnife® M6 for single and multiple cranial metastases.

MATERIALS AND METHODS

We evaluated 51 treatment plans for cranial metastases, including 30 patients with a single lesion and 21 patients with multiple lesions, treated with the CyberKnife® M6. These treatment plans were optimized using the HyperArc™ (HA) system with the TrueBeam. The comparison of the quality of the treatment plans between the two treatment techniques (CyberKnife and HyperArc) was performed using the Eclipse treatment planning system. Dosimetric parameters were compared for target volumes and organs at risk.

RESULTS

Coverage of the target volumes was equivalent between the two techniques, whereas median Paddick conformity index and median gradient index for all target volumes were 0.9 and 3.4, respectively for HyperArc plans, and 0.8 and 4.5 for CyberKnife plans (P<0.001). The median dose of gross tumor volume (GTV) for HyperArc and CyberKnife plans were 28.4 and 28.8, respectively. Total brain V18Gy and V12Gy-GTVs were 11cm³ and 20.2cm³ for HyperArc plans versus 18cm³ and 34.1cm³ for CyberKnife plans (P<0.001).

CONCLUSION

The HyperArc provided better brain sparing, with a significant reduction in V12Gy and V18Gy, associated with a lower gradient index, whereas the CyberKnife gave a higher median GTV dose. The HyperArc technique seems to be more appropriate for multiple cranial metastases and for large single metastatic lesions.

Treatments for brain metastases from EGFR/ALK-negative/unselected NSCLC: A network meta-analysis

More clinical evidence is needed regarding the relative priority of treatments for brain metastases (BMs) from EGFR/ALK-negative/unselected non-small cell lung cancer (NSCLC). PubMed, EMBASE, Web of Science, Cochrane Library, and ClinicalTrials.gov databases were searched. Overall survival (OS), central nervous system progression-free survival (CNS-PFS), and objective response rate (ORR) were selected for Bayesian network meta-analyses. We included 25 eligible randomized control trials (RCTs) involving 3,054 patients, investigating nine kinds of treatments for newly diagnosed BMs and seven kinds of treatments for previously treated BMs. For newly diagnosed BMs, adding chemotherapy, EGFR-TKIs, and other innovative systemic agents (temozolomide, nitroglycerin, endostar, enzastaurin, and veliparib) to radiotherapy did not significantly prolong OS than radiotherapy alone; whereas radiotherapy + nitroglycerin showed significantly better CNS-PFS and ORR. Surgery could significantly prolong OS (hazard ratios [HR]: 0.52, 95% credible intervals: 0.41-0.67) and CNS-PFS (HR: 0.32, 95% confidence interval: 0.18-0.59) compared with radiotherapy alone. For previously treated BMs, pembrolizumab + chemotherapy, nivolumab + ipilimumab, and cemiplimab significantly prolonged OS than chemotherapy alone. Pembrolizumab + chemotherapy also showed better CNS-PFS and ORR than chemotherapy. In summary, immune checkpoint inhibitor (ICI)-based therapies, especially ICI-combined therapies, showed promising efficacies for previously treated BMs from EGFR/ALK-negative/unselected NSCLC. The value of surgery should also be emphasized. The result should be further confirmed by RCTs.

Application of artificial intelligence to stereotactic radiosurgery for intracranial lesions: detection, segmentation, and outcome prediction

BACKGROUND

Rapid evolution of artificial intelligence (AI) prompted its wide application in healthcare systems. Stereotactic radiosurgery served as a good candidate for AI model development and achieved encouraging result in recent years. This article aimed at demonstrating current AI application in radiosurgery.

METHODS

Literatures published in PubMed during 2010-2022, discussing AI application in stereotactic radiosurgery were reviewed.

RESULTS

AI algorithms, especially machine learning/deep learning models, have been administered to different aspect of stereotactic radiosurgery. Spontaneous tumor detection and automated lesion delineation or segmentation were two of the promising application, which could be further extended to longitudinal treatment follow-up. Outcome prediction utilized machine learning algorithms with radiomic-based analysis was another well-established application.

CONCLUSIONS

Stereotactic radiosurgery has taken a lead role in AI development. Current achievement, limitation, and further investigation was summarized in this article.

Multicenter analysis of stereotactic radiosurgery for multiple brain metastases from EGFR and ALK driven non-small cell lung cancer

INTRODUCTION

Patients with brain metastases (BrMs) arising from EGFR and ALK driven non-small cell lung cancer (NSCLC) have favorable prognoses and evolving treatment options. We evaluated multicenter outcomes for stereotactic radiosurgery (SRS) to multiple (≥4) BrMs, where randomized data remain limited.

METHODS

Data were collected retrospectively from 5 academic centers on EGFR and ALK NSCLC who received SRS to ≥4 BrMs with their first SRS treatment between 2008 and 2018. Analyzed endpoints included overall survival (OS), freedom from CNS progression (FFCNSP), and freedom from whole-brain radiotherapy (FFWBRT).

RESULTS

Eighty-nine patients (50 EGFR, 39 ALK) received a total of 159 SRS treatments to 1,080 BrMs, with a median follow up of 51.3 months. The median number of BrMs treated with SRS treatment-1 was 6 (range 4-26) and median for all treatments was 9 (range 4-47). Sixteen patients (18 %) had received WBRT prior to SRS treatment-1. The median OS was 24.2, 21.2, and 33.2 months for all patients, EGFR, and ALK subsets, respectively. After multivariable adjustment, only receipt of a next-generation tyrosine kinase inhibitor was associated with OS (HR 0.40, p = 0.005). No differences in OS were observed based on number of BrMs treated. The median FFCNSP was 9.4, 11.6, and 7.5 months, for all patients, EGFR, and ALK subsets, respectively. After multivariable adjustment, the number of BrMs (continuous) treated during treatment-1 was the only negative prognostic factor associated with FFCNSP (HR 1.071, p = 0.045). The 5-year FFWBRT was 73.6 %.

CONCLUSIONS

This multicenter analysis over a >10-year period demonstrated favorable OS, FFCNSP, and FFWBRT, in patients with EGFR and ALK driven NSCLC receiving SRS to ≥4 BrMs. These data support SRS as an option in the upfront and salvage setting for higher burden CNS disease in this population.

Association of Brain Metastases With Survival in Patients With Limited or Stable Extracranial Disease: A Systematic Review and Meta-analysis

IMPORTANCE

Intracranial metastatic disease (IMD) is a severe complication of cancer with profound prognostic implications. Patients with IMD in the setting of limited or stable extracranial disease (IMD-SE) may represent a unique and understudied subset of patients with IMD with superior prognosis.

OBJECTIVE

To evaluate overall survival (OS), progression-free survival (PFS), and intracranial PFS (iPFS) in patients with IMD-SE secondary to any primary cancer.

DATA SOURCES

Records were identified from MEDLINE, EMBASE, CENTRAL, and gray literature sources from inception to June 21, 2021.

STUDY SELECTION

Studies in English reporting OS, PFS, or iPFS in patients with IMD-SE (defined as IMD and ≤2 extracranial metastatic sites) and no prior second-line chemotherapy or brain-directed therapy were selected.

DATA EXTRACTION AND SYNTHESIS

Author, year of publication, type of study, type of primary cancer, and outcome measures were extracted. Random-effects meta-analyses were performed to estimate effect sizes, and subgroup meta-analysis and metaregression were conducted to measure between-study differences in February 2022.

MAIN OUTCOMES AND MEASURES

The primary end point was OS described as hazard ratios (HRs) and medians for comparative and single-group studies, respectively. Secondary end points were PFS and iPFS.

RESULTS

Overall, 68 studies (5325 patients) were included. IMD-SE was associated with longer OS (HR, 0.52; 95% CI, 0.39-0.70) and iPFS (HR, 0.63; 95% CI, 0.52-0.76) compared with IMD in the setting of progressive extracranial disease. The weighted median OS estimate for patients with IMD-SE was 17.9 months (95% CI, 16.4-22.0 months), and for patients with IMD-PE it was 8.0 months (95% CI, 7.2-12.8 months). Pooled median OS for all patients with IMD-SE was 20.9 months (95% CI, 16.35-25.98 months); for the subgroup with breast cancer it was 20.2 months (95% CI, 10.43-38.20 months), and for non-small cell lung cancer it was 27.5 months (95% CI, 18.27-49.66 months). Between-study heterogeneity for OS and iPFS were moderate (I2 = 56.5%) and low (I2 = 0%), respectively.

CONCLUSIONS AND RELEVANCE

In this systematic review and meta-analysis of patients with IMD-SE, limited systemic disease was associated with improved OS and iPFS. Future prospective trials should aim to collect granular information on the extent of extracranial disease to identify drivers of mortality and optimal treatment strategies in patients with brain metastases.

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

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

Dosimetric Impact of Lesion Number, Size, and Volume on Mean Brain Dose with Stereotactic Radiosurgery for Multiple Brain Metastases

We evaluated the effect of lesion number and volume for brain metastasis treated with SRS using GammaKnife^® ICON™ (GK) and CyberKnife^® M6™ (CK). Four sets of lesion sizes (<5 mm, 5-10 mm, >10-15 mm, and >15 mm) were contoured and prescribed a dose of 20 Gy/1 fraction. The number of lesions was increased until a threshold mean brain dose of 8 Gy was reached; then individually optimized to achieve maximum conformity. Across GK plans, mean brain dose was linearly proportional to the number of lesions and total GTV for all sizes. The numbers of lesions needed to reach this threshold for GK were 177, 57, 29, and 10 for each size group, respectively; corresponding total GTVs were 3.62 cc, 20.37 cc, 30.25 cc, and 57.96 cc, respectively. For CK, the threshold numbers of lesions were 135, 35, 18, and 8, with corresponding total GTVs of 2.32 cc, 12.09 cc, 18.24 cc, and 41.52 cc respectively. Mean brain dose increased linearly with number of lesions and total GTV while V8 Gy, V10 Gy, and V12 Gy showed quadratic correlations to the number of lesions and total GTV. Modern dedicated intracranial SRS systems allow for treatment of numerous brain metastases especially for ≤10 mm; clinical evidence to support this practice is critical to expansion in the clinic.

Impact of MRI resolution for Linac-based stereotactic radiosurgery

Objective

Magnetic resonance imaging (MRI) is a standard imaging modality in intracranial stereotactic radiosurgery (SRS) for defining target volumes. However, wide disparities in MRI resolution exist, which could directly impact accuracy of target delineation. Here, sequences with various MRI resolution were acquired on phantoms to evaluate the effect on volume definition and dosimetric consequence for cranial SRS.

Materials/Methods

Four T1-weighted MR sequences with increasing 3D resolution were compared, including two Spin Echo (SE) 2D acquisitions with 5mm and 3mm slice thickness (SE5mm, SE3mm) and two gradient echo 3D acquisitions (TFE, BRAVO). The voxel sizes were 0.4×0.4×5.0, 0.5×0.5×3.0, 0.9×0.9×1.25, and 0.4×0.4×0.5 mm³, respectively. Four phantoms with simulated lesions of different shape and volume (range, 0.53-25.0 cm³) were imaged, resulting in 16 total sets of MRIs. Four radiation oncologists provided contours on individual MR image set. All observer contours were compared with ground truth, defined on CT image according to the absolute dimensions of the target structure, using Dice similarity coefficient (DSC), Hausdorff distance (HD), mean distance-to-agreement (MDA), and the ratio between reconstructed and true volume (Ratio_vol ). For dosimetric consequence, SRS plans targeting observer volumes were created. The true Paddick conformity index ( C I p a d d i c k t r u e ), calculated with true target volume, was correlated with quality of observer volume.

Results

All measures of observer contours improved as increasingly higher MRI resolution was provided from SE5mm to BRAVO. The improvement in DSC, HD and MDA was statistically significant (p<0.01). Dosimetrically, C I p a d d i c k t r u e   strongly correlated with DSC of the planning observer volume (Pearson's r=0.94, p<0.00001).

Conclusions

Significant improvement in target definition and reduced inter-observer variation was observed as the MRI resolution improved, which also improved the quality of SRS plans. Results imply that high resolution 3D MR sequences should be used to minimize potential errors in target definition, and multi-slice 2D sequences should be avoided.

Upfront and Repeated Stereotactic Radiosurgery in Patients With Brain Metastases From NSCLC

INTRODUCTION

Approximately 40% of non-small-cell lung cancer (NSCLC) patients develop brain metastases (BM). Stereotactic radiosurgery (SRS) instead of whole-brain radiotherapy (WBRT) is increasingly administered as an upfront treatment to patients with a limited number of BM. We present outcomes and validation of prognostic scores for these patients treated with upfront SRS.

METHODS

We retrospectively analyzed 199 patients with a total of 268 SRS courses for 539 brain metastases. Median patient age was 63 years. For larger BM, dose reduction to 18 Gy or hypofractionated SRS in 6 fractions was applied. We analyzed the BMV-, the RPA-, the GPA- and the lung-mol GPA score. Cox proportional hazards models with univariate and multivariate analyses were fitted for overall survival (OS) and intracranial progression-free survival (icPFS).

RESULTS

Sixty-four patients died, 7 of them of neurological causes. Thirty eight patients (19,3%) required a salvage WBRT. Median OS was 38, 8 months (IQR: 6-NA). In univariate analysis as well as multivariate analysis, the Karnofsky performance scale index (KPI) ≥90% (P = 0, 012 and P = 0, 041) remained as independent prognostic factor for longer OS. All 4 prognostic scoring indices could be validated for OS assessment (BMV P = 0, 007; RPA P = 0, 026; GPA P = 0, 003; lung-mol GPA P = 0, 05).

CONCLUSION

In this large cohort of NSCLC patients with BM treated with upfront and repeated SRS, OS was markedly favourable, in comparison to literature. Upfront SRS is an effective treatment approach in those patients and can decidedly reduce the impact of BM on overall prognosis. Furthermore, the analysed scores are useful prognostic tools for OS prediction.

Five-Fraction Stereotactic Radiotherapy for Brain Metastases-A Retrospective Analysis

PURPOSE

To determine the safety and outcome profile of five-fraction stereotactic radiotherapy (FSRT) for brain metastases (BM), either as a definitive or adjuvant treatment.

METHODS

We assessed clinical data of patients receiving five fractions of 7 Gy each (cumulative physical dose of 35 Gy) to BM or surgical cavities. The primary endpoints were toxicity and radiation necrosis (RN) rates. Secondary endpoints were 1-year cumulative local control rate (LCR) and estimated overall survival (OS).

RESULTS

A total of 36 eligible patients receiving FSRT to a total of 49 targets were identified and included. The median follow up was 9 (1.1-56.2) months. The median age was 64.5 (34-92) years, the median ECOG score was 1, and the median Diagnostic-Specific Graded Prognostic Assessment (DS-GPA) score was 2. Treatment was well tolerated and there were no grade 3 adverse events or higher. The overall RN rate was 14.3% and the median time to RN was 12.9 (1.8-23.8) months. RN occurrence was associated with immunotherapy, young age (≤45 years), and large PTV. The cumulative 1-year local control rate was 83.1% and the estimated median local progression free-survival was 18.8 months. The estimated median overall survival was 11 (1.1-56.2) months and significantly superior in those patients presenting with RN.

CONCLUSIONS

FSRT with 5 × 7 Gy represents a feasible, safe, and efficient fast track approach of intensified FSRT with acceptable LC and comparable RN rates for both the adjuvant and definitive RT settings.

Geometric and dosimetric consequences of intra-fractional movement in single isocenter non-coplanar stereotactic radiosurgery

PURPOSE

To investigate the geometric and dosimetric impacts of intra-fractional movement for patients with single or multiple brain metastasis treated using Varian Hyperarc™ mono-isocentric radiosurgery.

METHODS

A total of 50 single or hypo-fractionated Hyperarc™ treatment courses (118 lesions) were included in the analysis. Intra-fractional translational and rotational movements were quantified according to the post-treatment cone-beam CT (CBCT). Geometric displacements of all targets were calculated individually based on the assessed head movement in each treatment fraction and their relationships with treatment time and target-to-isocenter distances were studied. For dosimetric analysis, only single-fraction treatments (56 lesions) were included. Re-planning was performed with 0, 1, and 2 mm planning target volume (PTV) margins. Doses were then re-calculated on rotated CT images with isocenter shifted which emulate the change in patient treatment position. Target coverage, target and normal brain doses before and after intra-fractional movement were compared.

RESULTS

The mean 3D target displacements was 0.6 ± 0.3 (SD) mm. Target shifts for patients treated within 10 min were significantly smaller than those treated in longer sessions. No correlation was found between target shift and target-to-isocenter distance as the origin of head rotation was not located at the isocenter. Loss of target coverage and minimum Gross Tumor Volume (GTV) dose due to intra-fractional movement were apparent only when no margin was used, leading to an extra 23% of the targets violating the dose acceptance criteria, in contrast, the effects on normal brain V12Gy were negligible regardless of the margin used. The use of 1 mm PTV margin can compensate clinically significant geographical miss caused by intra-fractional movements while limiting V12Gy to within dose criteria for 88% of the cases. The plan acceptance rate (fulfillment of both target and normal brain dose criteria) after intra-fractional movement was also the highest with the 1 mm margin.

CONCLUSION

Although intra-fractional movements during Hyperarc™ treatments were small, there were substantial dosimetric effects due to the sharp dose fall-off near target boundaries. These effects could be mitigated by using a 1 mm PTV margin and maintaining the effective treatment time to within 10 min.

Acute toxicities and cumulative dose to the brain of repeated sessions of stereotactic radiotherapy (SRT) for brain metastases: a retrospective study of 184 patients

BACKGROUND

Stereotactic radiation therapy (SRT) is a focal treatment for brain metastases (BMs); thus, 20 to 40% of patients will require salvage treatment after an initial SRT session, either because of local or distant failure. SRT is not exempt from acute toxicity, and the acute toxicities of repeated SRT are not well known. The objective of this study was to analyze the acute toxicities of repeated courses of SRT and to determine whether repeated SRT could lead to cumulative brain doses equivalent to those of whole-brain radiotherapy (WBRT).

MATERIAL AND METHODS

Between 2010 and 2020, data from 184 patients treated for 915 BMs via two to six SRT sessions for local or distant BM recurrence without previous or intercurrent WBRT were retrospectively reviewed. Patients were seen via consultations during SRT, and the delivered dose, the use of corticosteroid therapy and neurological symptoms were recorded and rated according to the CTCAEv4. The dosimetric characteristics of 79% of BMs were collected, and summation plans of 76.6% of BMs were created.

RESULTS

36% of patients developed acute toxicity during at least one session. No grade three or four toxicity was registered, and grade one or two cephalalgy was the most frequently reported symptom. There was no significant difference in the occurrence of acute toxicity between consecutive SRT sessions. In the multivariate analysis, acute toxicity was associated with the use of corticosteroid therapy before irradiation (OR = 2.6; p = 0.01), BMV grade (high vs. low grade OR = 5.17; p = 0.02), and number of SRT sessions (3 SRT vs. 2 SRT: OR = 2.64; p = 0.01). The median volume equivalent to the WBRT dose (V_WBRT) was 47.9 ml. In the multivariate analysis, the V_WBRT was significantly associated with the total GTV (p < 0.001) and number of BMs (p < 0.001). Even for patients treated for more than ten cumulated BMs, the median BED to the brain was very low compared to the dose delivered during WBRT.

CONCLUSION

Repeated SRT for local or distant recurrent BM is well tolerated, without grade three or four toxicity, and does not cause more acute neurological toxicity with repeated SRT sessions. Moreover, even for patients treated for more than ten BMs, the V_WBRT is low.

Deep Learning for Detecting Brain Metastases on MRI: A Systematic Review and Meta-Analysis

Since manual detection of brain metastases (BMs) is time consuming, studies have been conducted to automate this process using deep learning. The purpose of this study was to conduct a systematic review and meta-analysis of the performance of deep learning models that use magnetic resonance imaging (MRI) to detect BMs in cancer patients. A systematic search of MEDLINE, EMBASE, and Web of Science was conducted until 30 September 2022. Inclusion criteria were: patients with BMs; deep learning using MRI images was applied to detect the BMs; sufficient data were present in terms of detective performance; original research articles. Exclusion criteria were: reviews, letters, guidelines, editorials, or errata; case reports or series with less than 20 patients; studies with overlapping cohorts; insufficient data in terms of detective performance; machine learning was used to detect BMs; articles not written in English. Quality Assessment of Diagnostic Accuracy Studies-2 and Checklist for Artificial Intelligence in Medical Imaging was used to assess the quality. Finally, 24 eligible studies were identified for the quantitative analysis. The pooled proportion of patient-wise and lesion-wise detectability was 89%. Articles should adhere to the checklists more strictly. Deep learning algorithms effectively detect BMs. Pooled analysis of false positive rates could not be estimated due to reporting differences.

Special issue "The advance of solid tumor research in China": 68Ga-PSMA-11 PET/CT for evaluating primary and metastatic lesions in different histological subtypes of renal cell carcinoma

Conventional imaging examinations are not sensitive enough for the early detection of recurrent or metastatic lesions in renal cell carcinoma (RCC) patients. We aimed to explore the role of ⁶⁸ Ga-prostate specific membrane antigen (PSMA)-11 positron emission tomography (PET)/computed tomography (CT) in the detection of primary and metastatic lesions in such patients. We retrospectively analyzed 50 RCC patients who underwent ⁶⁸ Ga-PSMA-11 PET/CT from November 2017 to December 2020. We observed a higher median accuracy and tumor-to-background maximum standard uptake value (SUV_max ) ratio (TBR) of ⁶⁸ Ga-PSMA-11 PET/CT in clear cell RCC (ccRCC; 96.57% and 6.00, respectively) than in non-clear cell RCC (ncRCC; 82.05% and 2.99, respectively). The accuracies in detecting lesions in the renal region, bone, lymph nodes and lungs in ccRCC were 100.00%, 95.00%, 98.08% and 75.00%, respectively, and those in the renal region, bone and lymph nodes in ncRCC were 100.00%, 86.67% and 36.36%, respectively. The median TBRs of the lesions from the above locations were 0.38, 10.96, 6.69 and 13.71, respectively, in ccRCC and 0.13, 4.02 and 0.73, respectively, in ncRCC. The PSMA score evaluated with immunohistochemistry was correlated with the SUV_max (P = .046) in RCC. Higher PSMA scores were observed in ccRCC than in ncRCC (P = .031). ⁶⁸ Ga-PSMA-11 PET/CT resulted in changes in clinical management in 12.9% (4/31) of cases because of the discovery of new metastases not detected with conventional imaging. These results indicate that ⁶⁸ Ga-PSMA-11 PET/CT is a promising method for the detection of metastatic lesions in ccRCC, especially for those in the bone and lymph nodes.

Mind the gap-the use of sodium fluoresceine for resection of brain metastases to improve the resection rate

INTRODUCTION AND PURPOSE

Brain metastases appear to be well resectable due to dissectable tumor margins, but postoperative MRI quite often depicts residual tumor with potential influence on tumor control and overall survival. Therefore, we introduced sodium fluoresceine into the routine workflow for brain metastasis resection. The aim of this study was to evaluate whether the use of fluorescence-guided surgery has an impact on postoperative tumor volume and local recurrence.

MATERIAL AND METHODS

We retrospectively included patients who underwent surgical resection for intracranial metastases of systemic cancer between 11/2017 and 05/2021 at our institution. Tumor volumes were assessed pre- and postoperatively on T1-CE MRI. Clinical and epidemiological data as well as follow-up were gathered from our prospective database.

RESULTS

Seventy-nine patients (33 male, 46 female) were included in this study. Median preoperative tumor volume amounted to 11.7cm3 and fluoresceine was used in 53 patients (67%). Surgeons reported an estimated gross total resection (GTR) in 95% of the cases, while early postoperative MRI could confirm GTR in 72%. Patients resected using fluoresceine demonstrated significantly lower postoperative residual tumor volumes with a difference of 0.7cm3 (p = 0.044) and lower risk of local tumor recurrence (p = 0.033). The use of fluorescence did not influence the overall survival (OS). Postoperative radiotherapy resulted in a significantly longer OS (p = 0.001).

DISCUSSION

While GTR rates may be overrated, the use of intraoperative fluorescence may help neurosurgeons to achieve a more radical resection. Fluoresceine seems to facilitate surgical resection and increase the extent of resection thus reducing the risk for local recurrence.

Stereotactic radiosurgery in brain metastasis: treatment outcomes and patterns of failure

Introduction:

Stereotactic radiosurgery (SRS) has become a preferred treatment in the initial management of brain metastases (BM). This study reported treatment outcomes and identified the patient, tumour, and treatment-related factors that predict failure, survival, and brain necrosis (BN).

Methods:

We retrospectively reviewed the electronic medical records of all BM patients treated with SRS. Patient, tumour characteristics and treatment details data were collected. All recurrences and BN were defined in the neurooncological tumour board.

Results:

From December 2016 to April 2020, 148 patients were analysed. The median follow-up was 14·8 months (range 6–51). At the time of analyses, 72·3% of the patients were alive. Presence of initial neurological deficit (HR; 2·71 (1·07–6·9); p = 0·036) and prior RT (HR; 2·55 (1·28–5·09); p = 0·008) is associated with worse overall survival. The local recurrence rate was 11·5 %. The distant brain metastasis rate was 53·4 %. Leptomeningeal metastasis was seen in 11 patients (7·4%). Symptomatic BN was seen in 19 patients (12·8 %). Bigger lesions (13 versus 23 mm diameter; p = 0·034) and cavity radiosurgery are associated with more BN (63·2 % versus 36·8%; p: 0·004).

Conclusions:

Distant BM is the leading cause of CNS recurrences and, salvage SRS is possible. Due to the increasing risk of developing BN routine metastasectomy should be made with caution.

Efficacy and safety of combined immunotherapy and stereotactic radiosurgery in NSCLCBM patients and a novel prognostic nomogram: A real-world study

Objective

To explore the effectiveness of combined immunotherapy (IT) and stereotactic radiosurgery (SRS) and address the gap between evidence-based clinical practice and academic knowledge of optimal timing of IT relative to SRS. In addition, to meet the unmet need for an up-to-date prognostic assessment model in the era of IT.

Methods

The data of 86 non-small cell lung cancer brain metastasis (NSCLCBM) patients treated with SRS to 268 brain metastases (BMs) were retrospectively extracted from our hospital database. The Kaplan-Meier analysis was employed for overall survival (OS) and a log-rank test for comparison between groups. Cox proportional hazards regression models were used to identify the significant prognostic factors. The prognostic nomogram was established utilizing the rms package of R software.

Results

IT was found to be associated with improved OS (from BM diagnosis: HR 0.363, 95% CI 0.199 - 0.661, P < 0.001; from SRS: HR 0.472, 95% CI 0.260 - 0.857, P = 0.014). Individuals who received IT in combination with SRS had better OS than those who didn't (from the day of BM diagnosis: 16.8 vs. 8.4 months, P = 0.006; from the day of SRS: 12 vs. 7 months, P = 0.037). Peri-SRS timing of IT administration was a significant prognostic factor for OS (from BM diagnosis: HR 0.132, 95% CI 0.034 - 0.517, P = 0.004; from SRS: HR 0.14, 95% CI 0.044 - 0.450, P = 0.001). Initiating IT after SRS led to superior OS than concurrent or before (from BM diagnosis: 26.5 vs. 14.1 vs. 7.1 months; from SRS: 21.4 vs. 9.9 vs. 4.1 months, respectively). Additionally, we build a nomogram incorporating IT, cumulative intracranial tumor volume (CITV), and recursive partitioning analysis (RPA), demonstrating a remarkable prognosis prediction performance for SRS-treated NSCLCBM patients.

Conclusion

Peri-SRS IT is a promising approach in treating NSCLCBM, as improved OS was observed without significantly increasing adverse events. Receipt of IT post-SRS was associated with superior OS than those who received IT concurrently or before. Incorporating IT and CITV into the RPA index could augment its prognosis assessment value for SRS-treated NSCLCBM patients, predominantly in the wild-type.

Breast Cancer Brain Metastases: Achilles' Heel in Breast Cancer Patients' Care

Brain metastases (BM) significantly affect the prognosis as well as the quality of life of breast cancer (BC) patients. Although advancements in neurosurgical and radiotherapy techniques improve local control and symptom management, BM remains associated with a poor prognosis. In addition, the efficacy of currently approved systemic therapies in central nervous system (CNS) compartment is still limited, especially after progression on local therapy. The blood-brain barrier (BBB) has been recognized as a mechanism of primary resistance to many chemotherapeutic agents and targeted therapies due to low drug penetration. Other mechanisms of primary and secondary resistance are still unclear and may vary across the BC subtypes. New small molecules have demonstrated efficacy in BM, in particular for the HER2-positive subtype, with a benefit in survival. A new era has begun in the field of BM, and many trials specifically designed for this population are currently ongoing. The BC research community needs to address this call with the final aim of improving the efficacy of systemic therapy in CNS compartment and ultimately preventing the occurrence of BM.

Leukoencephalopathy in patients with brain metastases who received radiosurgery with or without whole brain radiotherapy

BACKGROUND

Whole brain radiation therapy (WBRT) for brain metastases (BMs) is a common cause of radiation-induced leukoencephalopathy; however the safety of alternative stereotactic radiosurgery (SRS) remains unclear. This study examined the incidence of leukoencephalopathy in patients treated with SRS alone versus WBRT plus SRS for BMs with a focus on the relationship between prognostic factors and leukoencephalopathy.

METHODS

Analysis was performed between 2002 and 2021. The total enrollment was 993 patients with the distribution: WBRT plus SRS (n = 291) and SRS only (n = 702). Leukoencephalopathy was graded from 0 to 3 for changes in white matter indicated by the MRI after WBRT or SRS. Patient characteristics and SRS dosimetric parameters were reviewed to identify factors that contributed to the incidence of leukoencephalopathy or overall survival.

RESULTS

The incidence of leukoencephalopathy was consistently higher in WBRT plus SRS group than in SRS alone group (p < 0.001). Leukoencephalopathy was also associated with a larger total tumor volume (≧28cm³; p = 0.028) and age (> 77 years; p = 0.025). Nonetheless, the SRS integral dose to skull in the subgroup of WBRT plus SRS treatment was not demonstrated significance in development of leukoencephalopathy (p = 0.986 for integral dose 1-2 J, p = 0.776 for integral dose > 2 J).

CONCLUSIONS

This study revealed that SRS is safe for oligo-BMs in terms of leukoencephalopathy development. Patient age and total tumor volume were identified as important factors in assessing the development of leukoencephalopathy. The additional of SRS (even at an integral dose > 2 J) did not increase the incidence of leukoencephalopathy.

Comprehensive review on patulin and Alternaria toxins in fruit and derived products

Mycotoxins are toxic secondary metabolites produced by certain fungi, which can contaminate various food commodities, including fruits and their derived products. Patulin and Alternaria toxins are among the most commonly encountered mycotoxins in fruit and their derived products. In this review, the sources, toxicity, and regulations related to these mycotoxins, as well as their detection and mitigation strategies are widely discussed. Patulin is a mycotoxin produced mainly by the fungal genera Penicillium, Aspergillus, and Byssochlamys. Alternaria toxins, produced by fungi in the Alternaria genus, are another common group of mycotoxins found in fruits and fruit products. The most prevalent Alternaria toxins are alternariol (AOH) and alternariol monomethyl ether (AME). These mycotoxins are of concern due to their potential negative effects on human health. Ingesting fruits contaminated with these mycotoxins can cause acute and chronic health problems. Detection of patulin and Alternaria toxins in fruit and their derived products can be challenging due to their low concentrations and the complexity of the food matrices. Common analytical methods, good agricultural practices, and contamination monitoring of these mycotoxins are important for safe consumption of fruits and derived products. And Future research will continue to explore new methods for detecting and managing these mycotoxins, with the ultimate goal of ensuring the safety and quality of fruits and derived product supply.

Current treatment approaches for brain metastases in ALK/ROS1/NTRK-positive non-small-cell lung cancer

INTRODUCTION

Oncogene-addicted non-small cell lung cancer (NSCLC) patients present a high incidence of CNS metastases either at diagnosis or during the course of the disease. In this case, patients present with worse prognosis and are often excluded from clinical trials unless brain metastases are pre-treated or clinically stable.

AREAS COVERED

As a result of the discovery of several oncogenic drivers in ALK/ROS1/NTRK-positive NSCLC, targeted agents have been tested in several trials. We evaluate and compare the intracranial efficacy of available targeted agents in ALK/ROS1/NTRK-positive NSCLC based on subgroup analysis from pivotal trials.

EXPERT OPINION

Last-generation ALK inhibitors have shown slightly superior intracranial activity but pivotal trials do not consider the same endpoints for intracranial efficacy, therefore data are not comparable. Local treatments for BM including surgical resection, stereotactic radiosurgery (SRS) and WBRT, should be integrated with systemic therapies basing on specific criteria like presence of oligoprogression or symptomatic progression.

Brain metastases from small cell lung cancer and non-small cell lung cancer: comparison of spatial distribution and identification of metastatic risk regions

PURPOSE

This study aims to investigate the spatial distribution difference of brain metastases (BM) between small-cell lung cancer (SCLC) and non-small-cell lung cancer (NSCLC) and to identify the metastatic risk in brain regions.

METHODS

T1-enhanced MR images of 2997 BM from 728 eligible patients with SCLC and NSCLC were retrospectively reviewed by three independent medical institutions in China. All images were spatially normalised according to the Montreal Neurological Institute space, following BM delineation confirmed by three senior radiologists. The brain regions in the normalised images were identified based on the merged Anatomical Automatic Labeling atlas, and all BM locations were mapped onto these brain regions. Two-tailed proportional hypothesis testing was used to compare the BM observed rate with the expected rate based on the region's volume, and metastatic risk regions were finally identified.

RESULTS

In SCLC and NSCLC, BM was mainly present in the deep white matter (22.51% and 17.96%, respectively), cerebellar hemisphere (9.84% and 7.46%, respectively) and middle frontal gyrus (6.72% and 7.97%, respectively). The cerebellar hemisphere was a high-risk brain region in the SCLC. The precentral gyrus, middle frontal gyrus, paracentral lobule and cerebellar hemisphere were high-risk BM in the NSCLC. The inferior frontal gyrus and the temporal pole were a low-risk brain region in the SCLC and NSCLC, respectively.

CONCLUSION

The spatial BM distribution between SCLC and NSCLC is similar. Several critical brain regions had relatively low BM frequency in both SCLC and NSCLC, where a low-dose radiation distribution can be delivered due to adequate preoperative evaluations.

Feasibility of linac-based fractionated stereotactic radiotherapy and stereotactic radiosurgery for patients with up to ten brain metastases

BACKGROUND

Linac-based fractionated stereotactic radiotherapy (fSRT) and stereotactic radiosurgery (SRS) are increasingly being used to manage patients with multiple metastases. This retrospective cohort study aimed to compare the outcomes after linac-based fSRT and SRS between three patient groups classified based on the number of brain metastases (BMs): 1 BM, 2-4 BM, 5-10 BM.

METHODS

The data of consecutive patients with 1-10 BMs treated with fSRT or SRS between July 2016 and June 2018 at a single institution were collected. Patients with previous whole-brain radiotherapy (WBRT), concurrent use of WBRT, or surgical resection were excluded from the analysis. A total of 176 patients were classified into three groups according to the number of BMs: 78, 67, and 31 patients in 1 BM, 2-4 BM, and 5-10 BM, respectively. The Kaplan-Meier method was used to estimate overall survival (OS) curves, and the cumulative incidence with competing risks was used to estimate local control (LC), distant intracranial failure (DIF), and radiation necrosis (RN).

RESULTS

Median OS was 19.8 months (95% confidence interval [CI] 10.2-27.5), 7.3 months (4.9-11.1), and 5.1 months (4.0-9.0) in 1 BM, 2-4 BM, and 5-10 BM, respectively. Compared to 2-4 BM, 1 BM had significantly better OS (hazard ratio [HR] 0.59, 95% CI 0.40-0.87; p = 0.0075); however, 5-10 BM had comparable OS (HR 1.36, 95% CI 0.85-2.19; p = 0.199). There was no significant difference in LC, DIF, and RN between tumor number groups, but DIF was lower in 1 BM. RN of grade 2 or higher occurred in 21 patients (13.5%); grade 4 and 5 RN were not observed.

CONCLUSIONS

The linac-based fSRT and SRS for patients with 5-10 BMs is comparable to that for patients with 2-4 BMs in OS, LC, DIF, and RN. It seems reasonable to use linac-based fSRT and SRS in patients with 5-10 BMs.

A Multi-Disciplinary Approach to Diagnosis and Treatment of Radionecrosis in Malignant Gliomas and Cerebral Metastases

Radiation necrosis represents a potentially devastating complication after radiation therapy in brain tumors. The establishment of the diagnosis and especially the differentiation from progression and pseudoprogression with its therapeutic implications requires interdisciplinary consent and monitoring. Herein, we want to provide an overview of the diagnostic modalities, therapeutic possibilities and an outlook on future developments to tackle this challenging topic. The aim of this report is to provide an overview of the current morphological, functional, metabolic and evolving imaging tools described in the literature in order to (I) identify the best criteria to distinguish radionecrosis from tumor recurrence after the radio-oncological treatment of malignant gliomas and cerebral metastases, (II) analyze the therapeutic possibilities and (III) give an outlook on future developments to tackle this challenging topic. Additionally, we provide the experience of a tertiary tumor center with this important issue in neuro-oncology and provide an institutional pathway dealing with this problem.

Association of Long-term Outcomes With Stereotactic Radiosurgery vs Whole-Brain Radiotherapy for Resected Brain Metastasis: A Secondary Analysis of The N107C/CEC.3 (Alliance for Clinical Trials in Oncology/Canadian Cancer Trials Group) Randomized Clinical Trial

Importance

Long-term outcomes of radiotherapy are important in understanding the risks and benefits of therapies for patients with brain metastases.

Objective

To determine how the use of postoperative whole-brain radiotherapy (WBRT) or stereotactic radiosurgery (SRS) is associated with quality of life (QOL), cognitive function, and intracranial tumor control in long-term survivors with 1 to 4 brain metastases.

Design, Setting, and Participants

This secondary analysis of a randomized phase 3 clinical trial included 48 institutions in the US and Canada. Adult patients with 1 resected brain metastases but limited to those with 1 to 4 brain metastasis were eligible. Unresected metastases were treated with SRS. Long-term survivors were defined as evaluable patients who lived longer than 1 year from randomization. Patients were recruited between July 2011 and December 2015, and data were first analyzed in February 2017. For the present study, intracranial tumor control, cognitive deterioration, QOL, and cognitive outcomes were measured in evaluable patients who were alive at 12 months from randomization and reanalyzed in June 2017.

Interventions

Stereotactic radiosurgery or WBRT.

Main Outcomes and Measures

Intracranial tumor control, toxic effects, cognitive deterioration, and QOL.

Results

Fifty-four patients (27 SRS arm, 27 WBRT arm; female to male ratio, 65% vs 35%) were included for analysis with a median follow-up of 23.8 months. Cognitive deterioration was less frequent with SRS (37%-60%) compared with WBRT (75%-91%) at all time points. More patients declined by 2 or more standard deviations (SDs) in 1 or more cognitive tests for WBRT compared with SRS at 3, 6, and 9 months (70% vs 22%, 46% vs 19%, and 50% vs 20%, respectively). A 2 SD decline in at least 2 cognitive tests was associated with worse 12-month QOL in emotional well-being, functional well-being, general, additional concerns, and total scores. Overall QOL and functional independence favored SRS alone for categorical change at all time points. Total intracranial control for SRS alone vs WBRT at 12 months was 40.7% vs 81.5% (difference, -40.7; 95% CI, -68.1% to -13.4%), respectively. Data were first analyzed in February 2017.

Conclusions and Relevance

The use of SRS alone compared with WBRT resulted in less cognitive deterioration among long-term survivors. The association of late cognitive deterioration with WBRT was clinically meaningful. A significant decline in cognition (2 SD) was associated with overall QOL. However, intracranial tumor control was improved with WBRT. This study provides detailed insight into cognitive function over time in this patient population.

Trial Registration

ClinicalTrials.gov Identifier: NCT01372774; ALLIANCE/CCTG: N107C/CEC.3 (Alliance for Clinical Trials in Oncology/Canadian Cancer Trials Group).

Automated Detection of Brain Metastases on T1-Weighted MRI Using a Convolutional Neural Network: Impact of Volume Aware Loss and Sampling Strategy

BACKGROUND

Detection of brain metastases (BM) and segmentation for treatment planning could be optimized with machine learning methods. Convolutional neural networks (CNNs) are promising, but their trade-offs between sensitivity and precision frequently lead to missing small lesions.

HYPOTHESIS

Combining volume aware (VA) loss function and sampling strategy could improve BM detection sensitivity.

STUDY TYPE

Retrospective.

POPULATION

A total of 530 radiation oncology patients (55% women) were split into a training/validation set (433 patients/1460 BM) and an independent test set (97 patients/296 BM).

FIELD STRENGTH/SEQUENCE

1.5 T and 3 T, contrast-enhanced three-dimensional (3D) T1-weighted fast gradient echo sequences.

ASSESSMENT

Ground truth masks were based on radiotherapy treatment planning contours reviewed by experts. A U-Net inspired model was trained. Three loss functions (Dice, Dice + boundary, and VA) and two sampling methods (label and VA) were compared. Results were reported with Dice scores, volumetric error, lesion detection sensitivity, and precision. A detected voxel within the ground truth constituted a true positive.

STATISTICAL TESTS

McNemar's exact test to compare detected lesions between models. Pearson's correlation coefficient and Bland-Altman analysis to compare volume agreement between predicted and ground truth volumes. Statistical significance was set at P ≤ 0.05.

RESULTS

Combining VA loss and VA sampling performed best with an overall sensitivity of 91% and precision of 81%. For BM in the 2.5-6 mm estimated sphere diameter range, VA loss reduced false negatives by 58% and VA sampling reduced it further by 30%. In the same range, the boundary loss achieved the highest precision at 81%, but a low sensitivity (24%) and a 31% Dice loss.

DATA CONCLUSION

Considering BM size in the loss and sampling function of CNN may increase the detection sensitivity regarding small BM. Our pipeline relying on a single contrast-enhanced T1-weighted MRI sequence could reach a detection sensitivity of 91%, with an average of only 0.66 false positives per scan.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: Stage 2.

ISRS Technical Guidelines for Stereotactic Radiosurgery: Treatment of Small Brain Metastases (≤1 cm in Diameter)

PURPOSE

The objective of this literature review was to develop International Stereotactic Radiosurgery Society (ISRS) consensus technical guidelines for the treatment of small, ≤1 cm in maximal diameter, intracranial metastases with stereotactic radiosurgery. Although different stereotactic radiosurgery technologies are available, most of them have similar treatment workflows and common technical challenges that are described.

METHODS AND MATERIALS

A systematic review of the literature published between 2009 and 2020 was performed in Pubmed using the Preferred Reporting Items for Systematic Review and Meta-analyses (PRISMA) methodology. The search terms were limited to those related to radiosurgery of brain metastases and to publications in the English language.

RESULTS

From 484 collected abstract 37 articles were included into the detailed review and bibliographic analysis. An additional 44 papers were identified as relevant from a search of the references. The 81 papers, including additional 7 international guidelines, were deemed relevant to at least one of five areas that were considered paramount for this report. These areas of technical focus have been employed to structure these guidelines: imaging specifications, target volume delineation and localization practices, use of margins, treatment planning techniques, and patient positioning.

CONCLUSION

This systematic review has demonstrated that Stereotactic Radiosurgery (SRS) for small (1 cm) brain metastases can be safely performed on both Gamma Knife (GK) and CyberKnife (CK) as well as on modern LINACs, specifically tailored for radiosurgical procedures, However, considerable expertise and resources are required for a program based on the latest evidence for best practice.

A Review of the Role of Stereotactic Radiosurgery and Immunotherapy in the Management of Primary Central Nervous System Tumors

Stereotactic radiosurgery (SRS) and immune checkpoint inhibitors (ICIs) are widely used in the management of brain metastases. These therapies are commonly administered concurrently; as SRS may enhance anti-tumor immunity and responsiveness to ICIs. However, the use of ICIs with and without SRS in the management of primary brain tumors remains a controversial topic. Meningiomas are the most common nonmalignant and extra-parenchymal brain tumor, which often respond well to surgery and radiotherapy. However, higher grade meningiomas tend to be resistant to these treatments, and the use of chemotherapy and targeted agents in this setting have yielded disappointing results. Thus, there is heightened interest in the utilization of ICIs. Glioblastoma is the most common malignant primary intraparenchymal brain tumor. It is associated with a grim prognosis with a median overall survival of approximately 20 months, despite optimal therapy. While SRS in the adjuvant setting, and ICI in the recurrent setting, have failed to demonstrate a survival benefit, SRS in the preoperative setting has the potential to enhance anti-tumor immunity and responsiveness to ICIs. Thus, these treatments represent an attractive option to add to the armamentarium of meningioma and glioblastoma management. In this review, we provide a detailed overview of the evidence supporting the use of ICIs and SRS in each of these settings.

Dosimetric potential of knowledge-based planning model trained with HyperArc plans for brain metastases

OBJECTIVE

Dosimetric potential of knowledge-based RapidPlan planning model trained with HyperArc plans (Model-HA) for brain metastases has not been reported. We developed a Model-HA and compared its performance with that of clinical volumetric modulated arc therapy (VMAT) plans.

METHODS

From 67 clinical stereotactic radiosurgery (SRS) HyperArc plans for brain metastases, 47 plans were used to build and train a Model-HA. The other 20 clinical HyperArc plans were recalculated in RapidPlan system with Model-HA. The model performance was validated with the 20 plans by comparing dosimetric parameters for normal brain tissue between clinical plans and model-generated plans. The 20 clinical conventional VMAT-based SRS or stereotactic radiotherapy plans (CL-VMAT) were reoptimized with Model-HA (RP) and HyperArc system (HA), respectively. The dosimetric parameters were compared among three plans (CL-VMAT vs. RP vs. HA) in terms of planning target volume (PTV), normal brain excluding PTVs (Brain - PTV), brainstem, chiasm, and both optic nerves.

RESULTS

In model validation, the optimization performance of Model-HA was comparable to that of HyperArc system. In comparison to CL-VMAT, there were no significant differences among three plans with respect to PTV coverage (p > 0.17) and maximum dose for brainstem, chiasm, and optic nerves (p > 0.40). RP provided significantly lower V_20 Gy , V_12 Gy , and V_4 Gy for Brain - PTV than CL-VMAT (p < 0.01).

CONCLUSION

The Model-HA has the potential to significantly reduce the normal brain dose of the original VMAT plans for brain metastases.

Stereotactic radiosurgery for skull base adenoid cystic carcinoma: A report of two cases

Background:

Adenoid cystic carcinoma (ACC) is an uncommon salivary gland tumor with a relatively favorable prognosis. However, treating ACC is potentially challenging because radical resection is usually difficult once the skull base is involved due to the adjacent critical structures. Stereotactic radiosurgery (SRS) is a less invasive alternative for surgically recalcitrant lesions.

Case Description:

We report two patients with three metastatic skull base ACCs who underwent SRS using the Gamma Knife with a marginal dose of 20 Gy to a 50% isodose line. All tumors were effectively controlled without any adverse events.

Conclusion:

This case report and our review of the literature suggest that SRS can be considered for local control of ACC invading the skull base when surgical resection is unsuitable or a postoperative residual lesion is suspected. Further, investigations on the accumulated subjects are warranted to confirm the role of SRS for the treatment of ACCs.

An Overview of the Role of Radiotherapy in the Treatment of Small Cell Lung Cancer - A Mainstay of Treatment or a Modality in Decline?

AIMS

Small cell lung cancer (SCLC) accounts for about 15% of all lung cancers. Chemotherapy, immunotherapy and radiotherapy all play important roles in the management of SCLC. The aim of this study was to provide a comprehensive overview of the role and evidence of radiotherapy in the cure and palliation of SCLC.

MATERIALS AND METHODS

The search strategy included a search of the PubMed database, hand searches, reference lists of relevant review articles and relevant published abstracts.

CLINICALTRIALS

gov was also queried for relevant trials.

RESULTS

Thoracic radiotherapy improves overall survival in limited stage SCLC, but the timing and dose remain controversial. The role of thoracic radiotherapy in extensive stage SCLC with immunotherapy is the subject of several ongoing trials. Current evidence supports the use of prophylactic cranial irradiation (PCI) for limited stage SCLC but the evidence is equivocal in extensive stage SCLC. Whole brain radiotherapy is well established for the treatment of brain metastases but evidence is rapidly accumulating for the use of stereotactic radiosurgery. Further studies will define the role of PCI, whole brain radiotherapy and hippocampal avoidant PCI in the immunotherapy era.

CONCLUSION

Radiotherapy is an essential component in the multimodality management of SCLC. Technological advances have allowed safer delivery of radiotherapy with reduced toxicities. Discussion at multidisciplinary team meetings is important to ensure radiotherapy is considered and offered in appropriate patients.

Stereotactic radiosurgery and resection for treatment of multiple brain metastases: a systematic review and analysis

OBJECTIVE

Stereotactic radiosurgery (SRS) has recently emerged as a minimally invasive alternative to resection for treating multiple brain metastases. Given the lack of consensus regarding the application of SRS versus resection for multiple brain metastases, the authors aimed to conduct a systematic literature review of all published work on the topic.

METHODS

The PubMed, OVID, Cochrane, Web of Science, and Scopus databases were used to identify studies that examined clinical outcomes after resection or SRS was performed in patients with multiple brain metastases. Radiological studies, case series with fewer than 3 patients, pediatric studies, or national database studies were excluded. Data extracted included patient demographics and mean overall survival (OS). Weighted t-tests and ANOVA were performed.

RESULTS

A total of 1300 abstracts were screened, 450 articles underwent full-text review, and 129 studies met inclusion criteria, encompassing 20,177 patients (18,852 treated with SRS and 1325 who underwent resection). The OS for the SRS group was 10.2 ± 6 months, and for the resection group it was 6.5 ± 3.8 months. A weighted ANOVA test comparing OS with covariates of age, sex, and publication year revealed that the treatment group (p = 0.045), age (p = 0.034), and publication year (0.0078) were all independently associated with OS (with SRS, younger age, and later publication year being associated with longer survival), whereas sex (p = 0.95) was not.

CONCLUSIONS

For patients with multiple brain metastases, SRS and resection are effective treatments to prolong OS, with published data suggesting that SRS may have a trend toward lengthened survival outcomes. The authors encourage additional work examining outcomes of treatments for multiple brain metastases.

Management of Brain Metastases from Human Epidermal Growth Factor Receptor 2 Positive (HER2+) Breast Cancer

Simple Summary

Treatment options for patients with Human Epidermal growth factor Receptor 2 positive (HER2+) metastatic breast cancer are rapidly changing, especially for patients with brain metastasis. Historically, treatment options for brain metastasis were focused on local therapies, radiation and surgery. There are now multiple targeted therapies that are able to treat brain metastasis and prolong the lives of patients with HER2+ breast cancer. With the growing number of treatment options, making medical decisions for patients and clinicians is more complicated. This paper reviews the treatment options for patients with HER2+ breast cancer brain metastasis and provides a simplified algorithm for when to consider delaying local treatments.

Abstract

In the past 5 years, the treatment options available to patients with HER2+ breast cancer brain metastasis (BCBM) have expanded. The longer survival of patients with HER2+ BCBM renders understanding the toxicities of local therapies even more important to consider. After reviewing the available literature for HER2 targeted systemic therapies as well as local therapies, we present a simplified algorithm for when to prioritize systemic therapies over local therapies in patients with HER2+ BCBM.

Clinical determinants impacting overall survival of patients with operable brain metastases from non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is currently the leading cause of cancer-related death worldwide, and the incidence of brain metastases (BM) in NSCLC patients is continuously increasing. The recent improvements of systemic treatment in NSCLC necessitate continuous updates on prognostic subgroups and factors determining overall survival (OS). In order to improve clinical decision-making in tumor boards, we investigated the clinical determinants affecting survival in patients with resectable NSCLC BM. A retrospective analysis was conducted of NSCLC patients with surgically resectable BM treated in our institution between 01/2015 and 12/2020. The relevant clinical factors affecting survival identified by univariate analysis were included in a multivariate logistic regression model. Overall, 264 patients were identified, with a mean age of 62.39 ± 9.98 years at the initial diagnosis of NSCLC BM and OS of 23.22 ± 1.71 months. The factors that significantly affected OS from the time of primary tumor diagnosis included the systemic metastatic load (median: 28.40 ± 4.82 vs. 40.93 ± 11.18 months, p = 0.021) as well as a number of BM &lt;2 (median: 17.20 ± 2.52 vs. 32.53 ± 3.35 months, p = 0.014). When adjusted for survival time after neurosurgical intervention, a significant survival benefit was found in patients &lt;60 years (median 16.13 ± 3.85 vs. 9.20 ± 1.39 months, p = 0.011) and, among others, patients without any concurrent systemic metastases at time of NSCLC BM diagnosis. Our data shows that the number of BM (singular/solitary), the Karnofsky Performance Status, gender, and age but not localization (infra-/supratentorial), mass-edema index or time to BM occurrence impact OS, and postsurgical survival in NSCLC BM patients. Additionally, our study shows that patients in prognostically favorable clinical subgroups an OS, which differs significantly from current statements in literature. The described clinically relevant factors may improve the understanding of the risks and the course of this disease and Faid future clinical decision making in tumor boards.

Historical Review of Stereotactic Radiosurgery in Juntendo University

Juntendo University Hospital is the second hospital in Japan to start stereotactic brain irradiation using linear accelerator (LINAC) system. This report details the historical transition of stereotactic irradiation, progress of treatment technology, and change of treatment method from the beginning to the Juntendo University Hospital and Juntendo Nerima Hospital. The hospital changed the use of cobalt to the LINAC system when it was rebuilt in 1993. Total body irradiation treatment for leukemia had started around the same time. A year later, in 1994, the hospital used their LINAC systems to perform stereotactic head irradiation, otherwise known as pinpoint irradiation. In 2005, Juntendo University Nerima Hospital was opened and in September of the same year, radiation therapy using the latest model of LINAC system at that time was initiated. This was the first among all Juntendo hospitals to start intensity-modulated radiation therapy (IMRT) and image-guided radiotherapy (IGRT). In 2014, a second LINAC system for IMRT and IGRT was equipped at the Juntendo Hongo Hospital. In 2021, the LINAC systems of the Juntendo University Nerima Hospital were replaced after 15 years of usage. The new method of SRS was started using a latest LINAC systems. In this paper, I introduce the technique and progress of SRS that I have experienced mainly in Juntendo University.

The Present and Future of Clinical Management in Metastatic Breast Cancer

Regardless of the advances in our ability to detect early and treat breast cancer, it is still one of the common types of malignancy worldwide, with the majority of patients decease upon metastatic disease. Nevertheless, due to these advances, we have extensively characterized the drivers and molecular profiling of breast cancer and further dividing it into subtypes. These subgroups are based on immunohistological markers (Estrogen Receptor-ER; Progesterone Receptor-PR and Human Epidermal Growth Factor Receptor 2-HER-2) and transcriptomic signatures with distinct therapeutic approaches and regiments. These therapeutic approaches include targeted therapy (HER-2+), endocrine therapy (HR+) or chemotherapy (TNBC) with optional combination radiotherapy, depending on clinical stage. Technological and scientific advances in the identification of molecular pathways that contribute to therapy-resistance and establishment of metastatic disease, have provided the rationale for revolutionary targeted approaches against Cyclin-Dependent Kinases 4/6 (CDK4/6), PI3 Kinase (PI3K), Poly ADP Ribose Polymerase (PARP) and Programmed Death-Ligand 1 (PD-L1), among others. In this review, we focus on the comprehensive overview of epidemiology and current standard of care treatment of metastatic breast cancer, along with ongoing clinical trials. Towards this goal, we utilized available literature from PubMed and ongoing clinical trial information from clinicaltrials.gov to reflect the up to date and future treatment options for metastatic breast cancer.

Brain metastases: A Society for Neuro-Oncology (SNO) consensus review on current management and future directions

Brain metastases occur commonly in patients with advanced solid malignancies. Yet, less is known about brain metastases than cancer-related entities of similar incidence. Advances in oncologic care have heightened the importance of intracranial management. Here, in this consensus review supported by the Society for Neuro-Oncology (SNO), we review the landscape of brain metastases with particular attention to management approaches and ongoing efforts with potential to shape future paradigms of care. Each coauthor carried an area of expertise within the field of brain metastases and initially composed, edited, or reviewed their specific subsection of interest. After each subsection was accordingly written, multiple drafts of the manuscript were circulated to the entire list of authors for group discussion and feedback. The hope is that the these consensus guidelines will accelerate progress in the understanding and management of patients with brain metastases, and highlight key areas in need of further exploration that will lead to dedicated trials and other research investigations designed to advance the field.

Gamma Knife radiosurgery for metastatic brain tumors from ovarian cancer: histopathological analysis of survival and local control. A Japanese multi-institutional cooperative and retrospective cohort study

OBJECTIVE

Brain metastasis is rare in ovarian cancer patients. The results of Gamma Knife radiosurgery (GKRS) for the treatment of patients with brain metastases from ovarian cancer were retrospectively analyzed to derive the efficacy and prognostic factors for survival and local tumor control. Further histopathological analysis was also performed.

METHODS

The authors retrospectively reviewed the medical records of 118 patients with 566 tumors who had undergone GKRS at the 10 GKRS institutions in Japan.

RESULTS

After the initial GKRS, the median overall survival time was 18.1 months. Multivariate analysis showed that uncontrolled primary cancer (p = 0.003) and multiple intracranial metastases (p = 0.034) were significant unfavorable factors. Ten patients died of uncontrolled brain metastases at a median of 17.1 months. The 6-, 12-, and 24-month neurological death rates were 3.2%, 4.6%, and 11.9%, respectively. The 6-, 12-, and 24-month neurological deterioration rates were 7.2%, 13.5%, and 31.4%, respectively. The 6-, 12-, and 24-month distant brain control failure rates were 20.6%, 40.2%, and 42.3%, respectively. Median tumor volume was 1.6 cm3 and marginal dose was 20 Gy. The 6-, 12-, and 24-month local tumor control rates were 97.6%, 95.2%, and 88.0%, respectively. Peritumoral edema (p = 0.043), more than 7-cm3 volume (p = 0.021), and prescription dose less than 18 Gy (p = 0.014) were factors that were significantly correlated in local tumor control failure. Eight patients had symptomatic radiation injury. The 6-, 12-, and 24-month GKRS-related complication rates were 3.3%, 7.8%, and 12.2%, respectively. Primary ovarian cancer was histopathologically diagnosed for 313 tumors in 69 patients. Serous adenocarcinoma was found in 37 patients and other types in 32 patients. Median survival times were 32.3 months for the serous type and 17.4 months for other types after initial GKRS. Patients with serous-type tumors survived significantly longer than patients with other types (p = 0.039). The 6-, 12-, and 24-month local tumor control rates were 100%, 98.8%, and 98.8%, respectively. Serous-type tumors were a significantly good prognosis factor for local tumor control after GKRS (p = 0.005).

CONCLUSIONS

This study established a relationship between the efficacy of GKRS treatment for brain metastases and the histological type of primary ovarian cancer. GKRS for ovarian cancer brain metastasis can provide satisfactory survival and local control, especially in cases of serous adenocarcinoma.

Single isocenter stereotactic irradiation for multiple brain metastases: current situation and prospects

The prognosis of patients with brain metastases has dramatically improved, and long-term tumor control and reduction of the risk of late toxicities, including neurocognitive dysfunction, are important for patient quality of life. Stereotactic irradiation for multiple brain metastases, rather than whole-brain radiotherapy, can result in high local control rate with low incidence of neurocognitive deterioration and leukoencephalopathy. Recent advances in radiotherapy devices, treatment-planning systems, and image-guided radiotherapy can realize single isocenter stereotactic irradiation for multiple brain metastases (SI-STI-MBM), in which only one isocenter is sufficient to treat multiple brain metastases simultaneously. SI-STI-MBM has expanded the indications for linear accelerator-based stereotactic irradiation and considerably reduced patient burden. This review summarizes the background, methods, clinical outcomes, and specific consideration points of SI-STI-MBM. In addition, the prospects of SI-STI-MBM are addressed.

Stereotactic radiosurgery combined with immune checkpoint inhibitors for brain metastasis: A systematic review and meta-analysis

Many studies have reported the combination of radiosurgery and immune checkpoint inhibitors (ICI) in the treatment of brain metastasis, but these studies have not reached a consistent conclusion. Therefore, we conducted this systematic review and meta-analysis to evaluate the effect of combination therapy compared with radiosurgery alone on the prognosis of patients with brain metastasis. The Pubmed-MEDLINE and Ovid-EMBASE databases were comprehensively searched to identify relevant articles until May 5, 2022. The search results were filtered by the inclusion and exclusion criteria described in this paper. The pooled hazard ratios (HR) with 95% confidence intervals (CI) were presented as estimates effect to reflect the effect of combined therapy on each outcome. A total of 17 eligible studies covering 2079 patients were included in this meta-analysis. The pooled results showed that the use of targeted drugs could significantly improve the overall survival (HR = 0.62, 95%CI: 0.51-0.76; P<0.01), reduce the risk of local recurrence (HR = 0.48, 95%CI: 0.38-0.62; P<0.01) and distant brain recurrence (HR = 0.70, 95%CI: 0.50-0.97; P<0.05). Overall, SRS combined with ICIs could significantly improve overall survival, local control, and distant brain control of patients with brain metastasis compared to SRS alone, but the effect varies for different pathological types. Our results verified the rationality of the current treatment strategy for brain metastasis which emphasizes the combination of local and systematic therapy.

Efficacy and Safety of Combined Brain Stereotactic Radiotherapy and Immune Checkpoint Inhibitors in Non-Small-Cell Lung Cancer with Brain Metastases

Background: To analyze the outcomes of patients with brain metastases (BM) from non-small cell lung cancer (NSCLC) treated with immunotherapy (IT) and stereotactic radiotherapy (SRT) and to study the impact of the sequence between the two modalities. Methods: The authors reviewed the records of 51 patients with 84 BM from NSCLC treated at Institut Curie with IT and SRT. BM were categorized into three groups: ‘SRT before IT’, ‘concurrent SRT and IT’, and ‘SRT after IT.’ Regional progression-free interval (R-PFI) and overall survival (OS) were estimated using the Kaplan–Meier method. Results: After a median follow-up from SRT of 22.5 months (2.7–47.3), the 1-year and 2-year OS were 69.7% (95%CI [58.0–83.8]) and 44.0% [30.6–63.2], respectively. Concerning distant intracranial control, the 1-year and 2-year R-PFI were 40.1% [30.1–53.3] and 35.2% [25.1–49.4], respectively. Moreover, one-year R-PFI in ‘SRT before IT’, ‘concurrent SRT and IT’, and ‘SRT after IT’ groups were 24.1%, 49.6%, and 34.2%, respectively (p = 0.094). The type of therapeutic sequence did not appear to impact the risk of brain necrosis. Conclusions: The concurrent administration of SRT and IT appeared to offer the best locoregional control, without increasing the risk of toxicity, compared to patients treated with SRT before or after IT.

Treatment of Brain Metastases: The Synergy of Radiotherapy and Immune Checkpoint Inhibitors

Brain metastases are a devastating sequela of common primary cancers (e.g., lung, breast, and skin) and have limited effective therapeutic options. Previously, systemic chemotherapy failed to demonstrate significant benefit in patients with brain metastases, but in recent decades, targeted therapies and more recently immune checkpoint inhibitors (ICIs) have yielded promising results in preclinical and clinical studies. Furthermore, there is significant interest in harnessing the immunomodulatory effects of radiotherapy (RT) to synergize with ICIs. Herein, we discuss studies evaluating the impact of RT dose and fractionation on the immune response, early studies supporting the synergistic interaction between RT and ICIs, and ongoing clinical trials assessing the benefit of combination therapy in patients with brain metastases.