Response assessment criteria for brain metastases: proposal from the RANO group

Semi-Supervised Learning Allows for Improved Segmentation With Reduced Annotations of Brain Metastases Using Multicenter MRI Data

BACKGROUND

Deep learning-based segmentation of brain metastases relies on large amounts of fully annotated data by domain experts. Semi-supervised learning offers potential efficient methods to improve model performance without excessive annotation burden.

PURPOSE

This work tests the viability of semi-supervision for brain metastases segmentation.

STUDY TYPE

Retrospective.

SUBJECTS

There were 156, 65, 324, and 200 labeled scans from four institutions and 519 unlabeled scans from a single institution. All subjects included in the study had diagnosed with brain metastases.

FIELD STRENGTH/SEQUENCES

1.5 T and 3 T, 2D and 3D T1-weighted pre- and post-contrast, and fluid-attenuated inversion recovery (FLAIR).

ASSESSMENT

Three semi-supervision methods (mean teacher, cross-pseudo supervision, and interpolation consistency training) were adapted with the U-Net architecture. The three semi-supervised methods were compared to their respective supervised baseline on the full and half-sized training.

STATISTICAL TESTS

Evaluation was performed on a multinational test set from four different institutions using 5-fold cross-validation. Method performance was evaluated by the following: the number of false-positive predictions, the number of true positive predictions, the 95th Hausdorff distance, and the Dice similarity coefficient (DSC). Significance was tested using a paired samples t test for a single fold, and across all folds within a given cohort.

RESULTS

Semi-supervision outperformed the supervised baseline for all sites with the best-performing semi-supervised method achieved an on average DSC improvement of 6.3% ± 1.6%, 8.2% ± 3.8%, 8.6% ± 2.6%, and 15.4% ± 1.4%, when trained on half the dataset and 3.6% ± 0.7%, 2.0% ± 1.5%, 1.8% ± 5.7%, and 4.7% ± 1.7%, compared to the supervised baseline on four test cohorts. In addition, in three of four datasets, the semi-supervised training produced equal or better results than the supervised models trained on twice the labeled data.

DATA CONCLUSION

Semi-supervised learning allows for improved segmentation performance over the supervised baseline, and the improvement was particularly notable for independent external test sets when trained on small amounts of labeled data.

PLAIN LANGUAGE SUMMARY

Artificial intelligence requires extensive datasets with large amounts of annotated data from medical experts which can be difficult to acquire due to the large workload. To compensate for this, it is possible to utilize large amounts of un-annotated clinical data in addition to annotated data. However, this method has not been widely tested for the most common intracranial brain tumor, brain metastases. This study shows that this approach allows for data efficient deep learning models across multiple institutions with different clinical protocols and scanners.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY: Stage 2.

PEARL: A Multicenter Phase 2 Study of Lorlatinib in Patients with ALK-Rearranged NSCLC and Central Nervous System Disease

BACKGROUND

Patients with ALK-rearranged non-small cell lung cancer (ALK+ NSCLC) with symptomatic brain (BM) and leptomeningeal (LM) metastases are underrepresented in clinical trials due to poor performance status. Additionally, the need for improved and validated assessment criteria for evaluating central nervous system (CNS) response remains critical. Lorlatinib has demonstrated systemic activity in patients with ALK+ NSCLC. This ongoing phase II study aims to evaluate the efficacy and safety of lorlatinib in ALK+ NSCLC patients with progressive CNS metastases.

PATIENTS AND METHODS

This study is a multicenter, open-label, single-arm, prospective trial. Fifty eligible subjects will be divided into 2 cohorts: BM (progressive or new brain parenchymal; n = 30) and LM (positive cerebrospinal fluid cytology and/or MRI ± brain parenchymal metastasis; n = 20). Key inclusion criteria include ALK status confirmed using FDA-approved tests, at least 1 CNS lesion, with or without CNS-related symptoms, and an ECOG performance status of 0-2 for the BM cohort and 0-3 for the LM cohort. Primary endpoint is intracranial objective response rate based on the modified version of response evaluation criteria in solid tumors v1.1 for BM and modified RANO-LM criteria for LM. Key secondary endpoints include intracranial progression-free survival, overall progression-free survival, objective response rate, overall survival, safety and quality of life. Biomarker analysis of paired pretreatment tumor, blood and optional cerebrospinal fluid will be performed as preplanned exploratory analyses.

CONCLUSIONS

The PEARL study (CTONG2303) will evaluate efficacy of lorlatinib in CNS metastases in ALK+ NSCLC using refined CNS response evaluation criteria, with biomarker analyses providing insights into response and resistance mechanisms.

Intracranial Disease Control and Survival among Patients with KRAS-mutant Lung Adenocarcinoma and Brain Metastases Treated with Stereotactic Radiosurgery

PURPOSE

Precision medicine according to molecularly defined subgroups offers great potential to improve outcomes for patients with metastatic lung adenocarcinoma. This study describes clinical outcomes and the impact of co-occurring genetic alterations on outcomes following stereotactic radiosurgery (SRS) among patients with Kirsten rat sarcoma viral oncogene homolog (KRAS)-mutant lung adenocarcinoma.

METHODS AND MATERIALS

A total of 195 patients with KRAS-mutant lung adenocarcinoma were treated with SRS for brain metastases (BMs) between 2014 and 2018 with follow-up until 2022 or death. Coprimary outcomes were median overall survival (OS) and intracranial progression-free survival (iPFS); univariable and multivariable Cox regression models and Kaplan-Meier survival analysis were used.

RESULTS

Median follow-up from the date of BM diagnosis was 11 months. Median OS and iPFS for the cohort were 27.7 months (95% CI, 19.7-36.8) and 22.1 months (95% CI, 16.8-48.9), respectively. Lesion-level local control at 12 and 24 months was 89.9% and 87.5%, respectively. In a multivariable Cox regression model, inferior OS was associated with coalterations in KEAP1 and STK11 (hazard ratio [HR], 1.94; 95% CI, 1.04-3.62; q = 0.087), progressive (HR, 3.41; 95% CI, 1.38-8.39; q = 0.087), and mixed response (HR, 3.52; 95% CI, 1.2-10.3; q = 0.092) extracranial disease, and 6 or more BMs at time of diagnosis (HR, 2.58; 95% CI, 1.22-6.63; q = 0.087). Positive programmed death ligand 1 status was associated with improved OS (HR, 0.57; 95% CI, 0.37-0.87; P = .01). Inferior iPFS was associated with chemotherapy before SRS (HR, 2.69; 95% CI, 1.42-5.09; q = 0.04) and age >65 years (HR, 2.21; 95% CI, 1.25-3.93; q = 0.055). KRAS G12C was not associated with differences in iPFS, OS, or type of intracranial progression event following SRS.

CONCLUSIONS

Coalteration of KRAS and KEAP1/STK11 was associated with inferior OS, but not iPFS. Similar outcomes were found in patients harboring KRAS G12C and non-G12C mutant non-small cell lung cancer BMs. Further understanding of molecularly characterized subgroups will be critical in driving personalized radiation therapy for patients with lung cancer BMs.

Stereotactic Radiosurgery Dose Reduction for Melanoma Brain Metastases Patients on Immunotherapy or Target Therapy: A Single-Center Experience

BACKGROUND AND OBJECTIVES

Better local control but higher rates of adverse radiation events (ARE) have been reported when combining American Society for Radiation Oncology (ASTRO)-guideline-suggested dose (SD) stereotactic radiosurgery (SRS) with immunotherapy or targeted therapy for melanoma brain metastases. The objective of this study is to explore the efficacy and safety of lower prescription doses compared with ASTRO guidelines for single-fraction SRS for patients with melanoma metastases who are concurrently receiving immunotherapy or targeted therapy.

METHODS

We conducted a retrospective, single-center study on 194 patients who underwent SRS between 2009 and 2022. After propensity score matching, 71 patients with 292 metastases were included in the ASTRO-SD (20-24 Gy for <2 cm, 18 Gy for ≥2 to <3 cm) group and 33 patients with 292 metastases in the reduced dose (RD, <20 Gy for <2 cm, <18 Gy for ≥2 to <3 cm) group.

RESULTS

The median diameter (5.4 vs 5.2 mm, P = .6), prescription volume (0.2 vs 0.2 cm 3 , P = .2), and radiographic follow-up (11 vs 12 months, P = .2) were similar in the 2 groups. The cumulative incidence of progressing metastases was significantly higher in the SD compared with the RD group ( P = .018). Higher prescription volumes and ASTRO-suggested radiation doses were associated with local progression in multivariable analysis. Radiographic AREs were significantly more common in the SD compared with the RD group (8.6% vs 3.1%, P = .005). BRAF and other tyrosine kinase inhibitors' concurrent use, higher prescription volumes, and ASTRO-suggested radiation doses were associated with an increased risk of radiographic ARE.

CONCLUSION

This study provides evidence that RD SRS could offer reduced toxicity rates, while maintaining high local control as compared with the current guideline-SDs for the treatment of melanoma brain metastases.

Upfront frameless hypofractionated gamma knife radiosurgery for large posterior Fossa metastases

The management of large metastatic brain tumors (METs), particularly those in the posterior fossa (pf-METs), is challenging. While surgery can alleviate symptoms, it carries the risk of complications such as leptomeningeal disease (LMD). Upfront hypofractionated Gamma Knife radiosurgery (hf-GKRS) has shown promise as an alternative approach for managing large METs. This study assesses the efficacy and safety of upfront hf-GKRS for treatment-naïve large pf-METs. In this retrospective, single-center study, 40 patients with 42 pf-METs received hf-GKRS from October 2017 to June 2024. Patients eligible for the study were 18 years or older, had histologically confirmed malignancy, large pf-METs (> 4 cm3), and a minimum of two follow-up MRI scans. The primary outcome was local control (LC), with secondary assessments of distant intracranial failure (DICF), intracranial progression-free survival (PFS), overall survival (OS), and toxicity. LC was achieved in 88.1% of pf-METs over a median follow-up of 6 months (mean: 13.7 months). LC rates at 6, 12, and 24 months were 95.8%, 95.8%, and 74.5%, respectively. Local failure (LF) occurred in 11.9% of cases, with a median recurrence time of 12 months. DICF was noted in 35% of patients, while no cases of LMD were reported. Intracranial PFS rates at 6, 12, and 24 months were 54.1%, 39.0%, and 16.7%, respectively, with a median PFS of 8 months. Symptomatic hydrocephalus developed in one patient (2.5%). Controlled primary tumor status (HR: 0.17, p = 0.036) was significantly associated with lower risk of death, while no other parameters were predictive of LC, DICF, or intracranial PFS. hf-GKRS demonstrates strong efficacy and safety as a primary treatment for selected, treatment-naïve large pf-METs over a relatively short follow-up duration. Further studies are warranted to refine patient selection, fractionation, and dosing strategies for this challenging population.

Temporal evolution of MRI findings and survival outcomes in patients with brain metastases after stereotactic radiosurgery

OBJECTIVE

This study aims to investigate the temporal evolution of magnetic resonance imaging (MRI) findings in brain metastases following stereotactic radiosurgery (SRS) and their correlation with treatment response and survival outcomes. By analyzing volumetric changes in tumor size, perilesional edema, and necrotic components, we seek to identify imaging biomarkers that predict prognosis and treatment efficacy.

METHODS

A retrospective analysis was conducted on 97 patients (200 metastatic lesions) who underwent SRS for brain metastases between 2010 and 2022. Multiparametric MRI (MPMRI) scans were analyzed at four distinct follow-up periods: 1 to 3 months, 3 to 8 months, 8 to 16 months, and 16 to 24 months post-SRS. Volumetric measurements of tumor size, perilesional edema, and necrosis were obtained using semi-automated segmentation. Apparent diffusion coefficient (ADC) values and relative cerebral blood volume (rCBV) ratios were also assessed. Statistical analyses, including Kaplan-Meier survival curves and ROC analysis, were performed to determine prognostic imaging biomarkers.

RESULTS

The most significant reduction in tumor and perilesional edema volume occurred within the first 1 to 3 months post-SRS and continued until the 8th month. A transient increase in lesion size (pseudoprogression) was observed in 31.5% of cases, predominantly between 3 and 8 months post-SRS. Pretreatment tumor volume was found to be significantly associated with treatment response. ROC analysis identified 1.22 cm³ as the optimal cutoff value for differentiating between Group A (good response) and Group B (poor response) lesions (AUC = 0.754, sensitivity = 87.0%, specificity = 57.1%). Survival analysis revealed that higher pretreatment tumor volume, larger necrotic volume, and extensive perilesional edema were associated with shorter survival times (p < 0.05). No significant association was found between survival and ADC or rCBV.

CONCLUSION

Following SRS, early reductions in tumor and edema volume were observed, while 31.5% of cases showed transient enlargement. Smaller tumors responded better to SRS, whereas larger volume, extensive edema, and necrosis were linked to shorter survival. Given the high rate of pseudoprogression, not every post-treatment size increase indicates true progression. A wait-and-see approach may help avoid unnecessary interventions in selected cases.

CLINICAL TRIAL NUMBER

Not applicable.

Efficacy and safety of dacomitinib in treatment-naïve patients with advanced NSCLC and brain metastasis: a multicenter cohort study

BACKGROUND

The data for dacomitinib, a second-generation EGFR-TKI, treating patients with advanced non-small cell lung cancer (NSCLC) and brain metastasis was lacking. This study aimed to explore the efficacy and safety of dacomitinib in treating EGFR-mutated advanced NSCLC with brain metastasis in first-line settings.

METHODS

Eligible patients were treatment-naïve advanced NSCLC patients with ≥1 brain metastasis no less than 5 mm treated with dacomitinib. The primary endpoint was intracranial objective response rate (ORR). Secondary endpoints included intracranial and extracranial progression-free survival (PFS), overall survival (OS), intracranial and extracranial ORR, disease control rate (DCR), and safety. The response was evaluated per modified Response Evaluation Criteria in Solid Tumors (mRECIST) and RANO-BM (Response Assessment in Neuro-Oncology Brain Metastases) criteria.

RESULT

Between July 2nd, 2019, and September 30th, 2022, a total of 87 treatment-naïve patients with advanced NSCLC and brain metastasis treated with dacomitinib from four hospitals were included. The data cutoff date was March 24th, 2023, and the median duration of follow-up time was 17.5 months (range 1.6-34.7 months). Based on mRECIST criteria, for all the 87 patients with evaluable brain metastasis, the iORR was 89.7% (95%CI, 81.3%-95.2%) and iDCR was 97.7% (95%CI, 91.9-99.7%), with 42 patients achieving CR, 36 patients achieving PR, and 7 patients maintaining SD. Based on RANO-BM criteria, the iORR was 71.3% (62/87, 95%CI 60.6%-80.5%) and iDCR was 97.7% (85/87, 95%CI, 91.9%-99.7%), with 42 patients achieving CR, 20 patients achieving PR, and 23 patients maintaining SD (Table). Median iPFS was 26.0 (95%CI, 20.7-31.4) months, and the 1-year and 2-year iPFS rate were 68.9% and 51.5%, respectively. Of 75 patients with evaluable extracranial lesions, 2 patients achieved CR (2.7%), the systemic ORR was 73.8% (95%CI 63.1%-82.8%) and DCR was 96.4% (89.9%-99.3%) (Table). Systemic median PFS was 14.0 (95%CI 11.1-16.9) months and median OS was 34.0 (95%CI 28.0-39.9) months. Overall, 86 of 87 (98.9%) patients experienced adverse events (AEs) of any grade. The most common (≥20%) AEs including rash (89.7%), oral ulcer (74.2%), diarrhea (67.8%), and paronychia (59.8%). Most of the AEs were grade 1 or grade 2 and no patients died due to severe AEs.

CONCLUSIONS

Dacomitinib showed promising efficacy and a manageable safety profile for advanced NSCLC with brain metastasis harboring EGFR mutation in the first-line treatment.

Local recurrence and radionecrosis after single-isocenter multiple targets stereotactic radiotherapy for brain metastases

Stereotactic radiotherapy (SRT) is frequently used to treat brain metastases (BMs). The single-isocenter for multiple targets (SIMT) technique allows for faster treatment of large numbers of BMs, but may adversely affect planning target volume (PTV) coverage due to possible increased positioning uncertainties with an increased isocenter to tumor distance (ITD). This study aims to investigate the association of ITD with local recurrence (LR) and radionecrosis (RN). Patients treated with SRT using a single isocenter for multiple BMs were retrospectively analyzed. Previous cranial radiotherapy and inability to undergo MR imaging were exclusion criteria. Patients were irradiated using a Versa HD LINAC with 6 MV flattening filter-free (FFF) energy and a 6D robotic couch. A non-coplanar volumetric modulated arc technique was used and plans were delivered using 6MV FFF energy. Associations between potential risk factors and LR/RN were investigated with Cox regression analyses. Seventy-five patients with a total of 357 BMs were included. Median survival after SRT was nine months. LR occurred in 7 (9%) patients and 10 (13%) had RN. After 18 months, LR-free survival was 89% and RN-free survival was 85%, respectively. ITD was not significantly associated with LR and RN. GTV was significantly associated with both LR (HR 1.10, 95% CI 1.02-1.17, P 0.0079) and RN (HR 1.09, 95% CI 1.01-1.17, P 0.020). LINAC-based SIMT SRT is a safe and effective treatment modality for patients with multiple BMs. We found no increased risk of LR or RN for BMs located further away from the isocenter.

RANO criteria for response assessment of brain metastases based on amino acid PET imaging

Novel diagnostic and therapeutic opportunities are needed to improve medical care and outcome of patients with brain metastases, a frequent and severe complication of several cancer types. Currently, magnetic resonance imaging (MRI) is the primary method used for detection, treatment planning and disease monitoring in patients with brain metastases, but this method has limitations. These limitations mean that MRI can inform on lesion size but cannot directly measure the activity or viability of tumor tissue. Positron emission tomography (PET) imaging, however, can visualize metabolically active tumor cells and is therefore increasingly incorporated into cancer care to assess tumor burden and response to treatment. Here, we define the PET Response Assessment in Neuro-Oncology (RANO) for brain metastasis (BM) 1.0 criteria for metabolic response assessment of brain metastases using amino acid PET. By introducing an innovative endpoint for next-generation clinical trials, the PET RANO BM 1.0 criteria aim to facilitate development of novel therapies for patients with brain metastases.

The role of upfront radiation therapy for brain metastases in the era of CNS-active systemic therapies: a narrative review of clinical trial design and lessons learned

PURPOSE

Systemic therapies are increasingly being considered as primary treatments for brain metastases (BM), deferring the upfront use of local treatment modalities. However, evidence to support this paradigm shift is difficult to interpret given the volume of data published and the intricacies of the outcomes reported. The objective of this narrative review is to evaluate the current evidence guiding treatment selection for BM patients by assembling and analyzing a detailed dataset of clinical trials, completed and published during the last two decades.

METHODS

Obstacles in interpreting the results of prospective systemic therapy clinical trials are detailed, including non-standardized study cohorts, inconsistent use of response assessment criteria, insufficient endpoint definition for central nervous system (CNS) efficacy, and under-reporting of previous radiotherapy. The paucity of prospective data to guide radiation therapy options is also addressed, and caveats of the available published evidence are detailed.

RESULTS

Proposed treatment and follow-up recommendations for patient with newly diagnosed BM are provided based on currently available evidence.

CONCLUSION

Prospective trials evaluating contemporary treatment paradigms and defining the respective roles of systemic and local therapies are eagerly awaited.

Anti‑HER2‑targeted therapies for the treatment of advanced HER2‑positive breast cancer with brain metastases (Review)

Compared with other metastatic sites, breast cancer brain metastases (BCBMs) are associated with the shortest survival time. In addition, human epidermal growth factor receptor 2 (HER2) is observed to be amplified in 20-25% of breast cancer cases where it is a poor prognostic factor for brain metastases. Various anti-HER2 targeted therapies have brought both new opportunities and challenges to patients with HER2-positive BCBM over the past decade. However, prolonging survival time and improving quality of life of patients have become controversial issues in the field of clinical research on BCBMs. On the basis of the latest literature, the present review documents the anti-HER2 targeted drugs applied in patients with HER2-positive BCBM. Further studies on the efficacy and safety of novel HER2-targeted drugs and combined or sequential therapy in clinical treatment are expected to provide more effective strategies for the treatment of patients with HER2-positive BCBM.

Nivolumab and stereotactic radiosurgery for patients with breast cancer brain metastases: long-term results and biomarker analysis from a non-randomized, open-label, phase Ib study

BACKGROUND

We hypothesized treatment with nivolumab and stereotactic radiosurgery (SRS) would be feasible, well tolerated, and may improve intracranial tumor control over SRS alone for breast cancer brain metastases (BCBM).

METHODS

The study is a phase Ib trial of nivolumab and SRS for BCBM.

CLINICAL TRIAL INFORMATION

NCT03807765. Key eligibility criteria include BCBM of all subtypes, age ≥18, Eastern Cooperative Oncology Group Performace Status (ECOG-PS)≤2 with ≤10 brain metastases. Treatment was initiated with a dose of nivolumab (480 mg intravenously) that was repeated every 4 weeks. The initial dose of nivolumab was followed 1 week later by SRS. Blood was collected at baseline and every 4 weeks for flow cytometry and cell-free DNA (cfDNA) assessment.

RESULTS

A total of 12 patients received SRS to 17 brain metastases. Breast cancer subtypes included triple negative (50%), hormone receptor (HR)+/HER2- (33%), and HR-/HER2+ (17%). Median follow-up from start of protocol therapy is 56 months. No cases of radionecrosis were noted. Two lesions were noted to undergo local failure, both pathologically confirmed, for a 12-month local control of 94%. Median distant intracranial control was 7.4 months with a 12-month control rate of 33%. Median systemic progression-free survival was 7.7 months with a 12-month rate of 42%. Median overall survival (OS) was 24.7 months with a 12-month OS of 75%. Most patients were noted to have an increase in cfDNA throughout study treatment, at week 5 compared with baseline (83%), week 25 compared with baseline (89%), and 100% at first follow-up. Intracranial control was associated with lower levels of CD4 regulatory T cells (Treg) (p=0.03) and higher levels of CD4 T effector memory (p=0.04).

CONCLUSIONS

Nivolumab and SRS is a safe and feasible treatment option in BCBM. Long-term follow-up revealed no cases of radiation necrosis.

TRIAL REGISTRATION NUMBER

NCT03807765.

Liquid biopsies for the monitoring of gliomas and brain metastases in adults

Clinical evaluation and MR imaging are currently the cornerstone of brain tumor progression monitoring. However, this is complicated by the occurrence of treatment effects such as pseudoprogression and radionecrosis. While essential for patient management, the distinction from true progression remains a significant challenge. Moreover, MR imaging provides limited real-time insights into tumor heterogeneity, genetic divergence, and treatment resistance. Although surgical histopathological biopsies can yield additional valuable information, they are not always conclusive, invasive, and therefore, not suitable for longitudinal measurements. In the era of precision medicine, there is a critical need for minimally invasive, accurate, and cost-effective monitoring methods for both primary brain tumors and brain metastases. Liquid biopsies have emerged as a potential candidate. Various analytes, including circulating nucleic acids, extracellular vesicles, platelet RNAs, and circulating tumor cells, can be obtained from whole blood and its derivatives, as well as other body fluids such as cerebrospinal fluid. In this narrative review, we outline the potential of liquid biopsies for the management of gliomas and brain metastases in adults and emphasize their utility in monitoring disease progression and treatment response. We discuss the most studied biofluids and analytes, along with their respective advantages and downsides. Furthermore, we address key considerations for future research and biobanking to pave the way for clinical implementation.

Excellent efficacy of trastuzumab deruxtecan in a patient with HER2-positive advanced breast cancer complicated by pulmonary lymphangitic carcinomatosis: a case report and literature review

Trastuzumab deruxtecan (T-DXd or DS-8201), as a novel antibody-drug conjugate, has demonstrated good efficacy in HER2-positive advanced breast cancer. However, its effectiveness in treating pulmonary lymphangitic carcinomatosis (PLC) has not been previously reported. This paper presents a case of a HER2-positive advanced breast cancer patient who experienced disease progression after treatment with trastuzumab and pertuzumab. The patient developed multiple metastases along with PLC and subsequently received T-DXd treatment, achieving 14.2 months of progression-free survival (PFS). This case is the first to reveal the therapeutic potential of T-DXd in breast cancer patients with PLC.

International multicenter study of stereotactic radiosurgery for bladder cancer brain metastases

PURPOSE

Bladder cancer rarely metastasizes to the brain. This study was performed to evaluate stereotactic radiosurgery (SRS) for the management of bladder cancer brain metastases.

METHODS

Cases of bladder cancer brain metastases treated with SRS were collected by members of the International Radiosurgery Research Foundation (IRRF) and outcome data was analyzed for patients with at least one clinical or imaging follow-up.

RESULTS

103 patients received SRS for 301 brain metastases. Median age at SRS was 68 and 73.8% of patients were male. Median KPS was 80%. Median time from primary to brain metastases diagnosis was 18 months. At the time of SRS, 50% of patients had other systemic metastases. The median number of metastases treated was 1, and median cumulative SRS volume was 1.16 cc. Most patients had single fraction SRS using a median margin dose of 18 Gy. At the time of analysis, 9.7% of patients were alive. Median survival after SRS was 7 months. Local control was achieved for 89.3% of metastases, 42% of patients developed new remote brain metastases, and 4.9% had leptomeningeal dissemination. Subsequent management included repeat SRS in 21.7%, surgical resection in 8.8% and WBRT in 7.6% of patients. At last follow-up, 32.1% of patients had improvement of their symptoms, whereas 38.5% remained stable. Adverse radiation effects occurred in 4.3% of treated metastases. On multivariate analyses, KPS ≥ 80% and non-urothelial histology predicted improved survival, while absence of corticosteroid intake predicted longer tumor control.

CONCLUSION

Bladder cancer brain metastases can be safely managed with SRS.

Impact of brain metastasis size at the time of radiotherapy on local control and radiation necrosis

PURPOSE

No consensus has been reached regarding whether upfront versus deferred radiation to small, asymptomatic brain metastases is most optimal. We sought to assess the relationship between tumor size at radiation and subsequent development of local recurrence and radiation necrosis to make data-driven recommendations regarding timing of radiation utilization.

METHODS

We identified 2268 patients with 6308 newly diagnosed brain metastases between 2010 and 2022 managed with brain-directed radiotherapy at Brigham and Women's Hospital/Dana-Farber Cancer Institute (Boston, MA). Tumors were grouped by maximal unidimensional size: <0.5 cm, 0.5 to < 1 cm, 1 cm to < 2 cm, and ≥ 2 cm; local recurrence and radiation necrosis by tumor size were assessed using competing risks regression.

RESULTS

Among metastases initially treated with stereotactic radiation or whole brain radiotherapy, lesions 1 to < 2 cm (HR 2.30 [95% CI, 1.38-3.81], p = 0.001 and HR 2.61 [95% CI 1.76-3.89], p < 0.001, respectively) and ≥ 2 cm (HR 3.10 [95% CI, 1.62-5.94], p < 0.001 and HR 3.03 [95% CI 1.92-4.79], p < 0.001, respectively) displayed greater local recurrence compared to tumors < 0.5 cm. In addition, among patients treated with stereotactic radiation, significantly higher risk of radiographic and symptomatic necrosis was observed in tumors ≥ 0.5 cm versus < 0.5 cm at radiotherapy, with hazard ratios ranging from 3.27 to 18.90.

CONCLUSION

Larger metastasis size is associated with markedly poorer local control and increased necrosis following brain-directed radiation, suggesting a role for earlier utilization of radiation therapy in patients with small, asymptomatic metastases and a favorable prognosis.

Repeat stereotactic radiosurgery for recurrent brain metastases: a retrospective comparison of local progression and distant brain metastases after prior radiosurgery

AIM

This study evaluated the efficacy and safety of repeat stereotactic radiosurgery (SRS) for recurrent brain metastases (BMs), focusing on failure patterns of local progression (LP) and distant brain metastases (DBM).

METHODS

Patients who underwent first-time SRS for newly diagnosed BMs (2011-2022) and repeat SRS (until June 2024) were included. Treatment courses were first-time or repeat SRS, with repeat SRS classified as LP and DBM. The primary endpoint was the 1-year local control rate (LCR). Secondary endpoints included survival and radiation necrosis (RN) incidence.

RESULTS

Among 723 courses (427 patients, 4,524 BMs), 404 (141 patients, 2,924 BMs) met criteria. First-time SRS was performed in 141 courses (775 BMs), and repeat SRS in 263 (2,149 BMs), including 45 LP (38 patients, 224 BMs) and 218 DBM (126 patients, 1,925 BMs). The median age was 65 years, and 75.9% had lung cancer. LP had a longer interval from prior SRS (12.6 vs. 6.3 months, P < 0.001) but similar follow-up (12.4 vs. 13.7 months). The 1-year LCR was lower in LP (72.4% vs. 88.3%, P = 0.0022), though survival was similar (17.9 vs. 16.3 months). LP had higher RN incidence (20.6% vs. 5.7%, P < 0.001) and symptomatic RN (13.3% vs. 2.8%, P < 0.001). Multivariate analysis identified LP failure as a significant factor for increased local failure (subdistribution hazard ratio [SHR] 2.35, P = 0.039) and RN (SHR 3.41, P < 0.001).

CONCLUSIONS

Despite similar survival, LP failure was associated with lower LCR and higher RN incidence, highlighting the need for optimized repeat SRS strategies.

Rezivertinib versus gefitinib as first-line therapy for patients with EGFR-mutated locally advanced or metastatic non-small-cell lung cancer (REZOR): a multicentre, double-blind, randomised, phase 3 study

BACKGROUND

This study aimed to compare the efficacy and safety of rezivertinib (BPI-7711) and gefitinib as first-line therapies in patients with EGFR-mutated locally advanced or metastatic non-small-cell lung cancer (NSCLC).

METHODS

This multicentre, double-blind, randomised, phase 3 study (REZOR) included eligible patients from 50 hospitals across China. Those who had been histologically or cytologically confirmed as having NSCLC with EGFR exon 19 deletion or exon 21 Leu858Arg mutation by central laboratory were randomly assigned (1:1) to receive once daily either rezivertinib 180 mg or gefitinib 250 mg, until unacceptable toxicity occurred, disease progression, or other treatment discontinuation criteria were met. Each cycle lasted for 21 days. The primary endpoint was progression-free survival evaluated by masked independent central review (MICR) in the intention-to-treat set. This trial is registered with ClinicalTrials.gov, NCT03866499 and follow-up is ongoing.

FINDINGS

Between July 15, 2019, and Feb 14, 2022, 695 patients were screened. Among them, 369 eligible patients were randomly assigned to receive either rezivertinib 180 mg/day plus placebo (n=184) or gefitinib 250 mg/day plus placebo (n=185) in a 1:1 ratio; all of eligible participants were included in the intention-to-treat set. Median MICR-assessed progression-free survival was 19·3 months (95% CI 13·8-22·1) in the rezivertinib group and 9·6 months (8·4-11·3) in the gefitinib group (hazard ratio [HR] 0·48, 95% CI 0·36-0·63; p<0·0001) and the prespecified subgroup efficacy analysis showed consistent results. Median duration of exposure was 16·0 months (95% CI 0·0-29·7) in the rezivertinib group and 11·0 months (0·0-28·9) in the gefitinib group. Grade 3 or higher treatment-emergent adverse events (82 [45%] of 184 in the rezivertinib group; 80 [43%] of 185 in the gefitinib group) and treatment-related adverse events (TRAEs; 43 [23%] of 184 in the rezivertinib group; 43 [23%] of 185 in the gefitinib group) were similar in both groups. One patient died from a TRAE in the rezivertinib group, due to pneumonia and interstitial lung disease.

INTERPRETATION

Our findings suggested that rezivertinib is a potential choice for patients with EGFR-mutated locally advanced or metastatic NSCLC as first-line therapy, owing to the superior overall efficacy and subgroup progression-free survival compared with gefitinib in targeted patients. No new safety signals were identified.

FUNDING

Beta Pharma (Shanghai) and the China National Science and Technology Major Project for Key New Drug Development.

Clinical Outcomes and Targeted Genomic Analysis of Renal Cell Carcinoma Brain Metastases Treated with Stereotactic Radiosurgery

BACKGROUND

Molecular profiles of renal cell carcinoma (RCC) brain metastases (BMs) are not well characterized. Effective management with locoregional therapies, including stereotactic radiosurgery (SRS), is critical as systemic therapy advancements have improved overall survival (OS).

OBJECTIVE

To identify clinicogenomic features of RCC BMs treated with SRS in a large patient cohort.

DESIGN, SETTING, AND PARTICIPANTS

A single-institution retrospective analysis was conducted of all RCC BM patients treated with SRS from January 1, 2010 to March 31, 2021.

INTERVENTION

SRS for RCC BMs.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Next-generation sequencing was performed to identify gene alterations more prevalent in BM patients. Clinical factors and genes altered in ≥10% of samples were assessed per patient using Cox proportional hazards models and per individual BM using clustered competing risks regression with competing risk of death.

RESULTS AND LIMITATIONS

Ninety-one RCC BM patients underwent SRS to 212 BMs, with a median follow-up of 38.8 mo for patients who survived. The median intracranial progression-free survival and OS were 7.8 (interquartile range [IQR] 5.7-11) and 21 (IQR 16-32) mo, respectively. Durable local control of 83% was achieved at 12 mo after SRS, and 59% of lesions initially meeting the radiographic criteria for progression at 3-mo evaluation would be considered to represent pseudoprogression at 6-mo evaluation. A comparison of genomic alterations at both the gene and the pathway level for BM+ patients compared with BM- patients revealed phosphoinositide 3-kinase (PI3K) pathway alterations to be more prevalent in BM+ patients (43% vs 16%, p = 0.001, q = 0.01), with the majority being PTEN alterations (17% vs 2.7%, p = 0.003, q = 0.041).

CONCLUSIONS

To our knowledge, this is the largest study investigating genomic profiles of RCC BMs and the only such study with annotated intracranial outcomes. SRS provides durable in-field local control of BMs. Recognizing post-SRS pseudoprogression is crucial to ensure appropriate management. The incidence of PI3K pathway alterations is more prevalent in BM+ patients than in BM- patients and warrants further investigation in a prospective setting.

PATIENT SUMMARY

We examined the outcomes of radiotherapy for the treatment of brain metastases in kidney cancer patients at a single large referral center. We found that radiation provides good control of brain tumors, and certain genetic mutations may be found more commonly in patients with brain metastasis.

Comparative Analysis of Intracranial Response Assessment Criteria in Patients With Melanoma Brain Metastases Treated With Combination Nivolumab + Ipilimumab in CheckMate 204

PURPOSE

In CheckMate 204, nivolumab + ipilimumab showed high intracranial (IC) objective response rates (icORRs) in patients with melanoma brain metastases (MBMs). Using icORR as a surrogate for overall survival (OS) has prompted use of alternate response criteria. To set the stage for harmonized MBM trials, the aim of this exploratory analysis was to determine icORR using several response criteria and examine correlations of response with survival.

METHODS

Patients (N = 119) with ≥one unirradiated MBMs received nivolumab + ipilimumab every 3 weeks (four doses), followed by nivolumab every 2 weeks for ≤24 months. Blinded review icORR was assessed with modified RECIST (mRECIST), Response Assessment in Neuro-Oncology Brain Metastases (RANO-BM; 5 mm and 10 mm cutoffs), and volumetric criteria (5 mm and 10 mm). Using a 6-week response landmark, IC progression-free survival (icPFS) and OS were compared for responders versus nonresponders.

RESULTS

icORR was higher with mRECIST and volumetric criteria than with RANO-BM or RECIST. mRECIST and volumetric response also showed stronger correlations with icPFS and OS. mRECIST responders who were RANO-BM 5 mm nonresponders (n = 14) had similar OS to RANO-BM 5 mm responders (n = 41). Clinical deterioration affected RANO-BM icORR; however, when assessed only radiographically without deterioration, RANO-BM 5 mm performed similarly to mRECIST. Among 41 patients with target lesions all <10 mm, responder icPFS and OS were similar to those of responders in the total population, indicating that response could be accurately determined in these patients.

CONCLUSION

This analysis supports mRECIST or radiographic-only RANO-BM 5 mm as reliable assessment scales in MBM trials. Volumetric response correlated with survival, supporting its application in future trials. Response could be accurately determined in patients with MBMs all <10 mm, supporting the inclusion of patients with MBMs ≥5 mm in future trials.

Efficacy and safety of combined anti-vascular and two-staged stereotactic radiosurgery therapy for brain metastases with brainstem compression: a retrospective multicenter study

Stereotactic radiosurgery poses a significant risk when treating brain metastases in close proximity to the brainstem. To address this issue, a novel approach known as "combined anti-vascular therapy" has been devised for these metastases. This treatment regimen involves a one-week course of two-staged stereotactic radiosurgery (2-SSRS), supplemented with the administration of the anti-vascular agent bevacizumab during the radiosurgery interval. We tried to find out the effectiveness and safety of 2-SSRS plus bevacizumab therapy for brain metastases that compress the brainstem, and prognostic factors that related to the tumor local control. A retrospective analysis was conducted on patients treated at five gamma knife treatment centers to assess changes in tumor size and peritumoral edema volume. Cox regression model was used to find out prognostic factors for tumor local control. Clinical symptom changes were evaluated using the Headache Scale (VAS), Dizziness Disorder Inventory (DHI), Vomiting Scale (VS), and Glasgow Coma Scale (GCS). The Karnofsky Task Scale (KPS) and Barthel Index (BI) were used to assess overall physical fitness and physical activity rehabilitation. Tumor local control (TLC) and overall survival (OS) rate were also calculated for the patients. Among the 36 patients with brain metastases with brainstem compression, 36 received combined anti-vascular therapy. Both edema volume and tumor volume significantly decreased during the treatment period and post-treatment 3 months (p < 0.01). Clinical symptoms, as indicated by median scores of VAS, DHI, VS, and GCS, showed significant improvement during treatment and at the 3-month follow-up (p < 0.01). Median changes in KPS and BI, reflecting overall physical fitness and physical activity rehabilitation, were also similar and statistically significant (p < 0.01). The patient cohort exhibited a median overall survival of 14.2 months, with corresponding 6-month and 12-month survival rates of 91.7% and 80.0%, respectively. Tumor local control rates at 6 and 12 months were 94.7% and 78.9%, Patient with KPS score > = 60 and single intracranial brain metastasis before treatment enjoy longer local tumor control. The combination of anti-vascular therapy with 2-SSRS demonstrates safety and efficacy in treating patients with brain metastases with brainstem compression. This approach rapidly alleviates patient symptoms, effectively manages tumor progression, extends overall survival, and exhibits manageable adverse effects.

MRI distortion correction is associated with improved local control in stereotactic radiotherapy for brain metastases

Distortions in brain MRI caused by gradient nonlinearities may reach several millimeters, thus distortion correction is strongly recommended for radiotherapy treatment planning. However, the significance of MRI distortion correction on actual clinical outcomes has not been described yet. Therefore, we investigated the impact of planning MRI distortion correction on subsequent local control in a historic series of 419 brain metastases in 189 patients treated with stereotactic radiotherapy between 01/2003 and 04/2015. Local control was evaluated using a volumetric extension of the RANO-BM criteria. The predictive significance of distortion correction was assessed using competing risk analysis. In this cohort, 2D distortion-corrected MRIs had been used for treatment planning in 52.5% (220/419) of lesions, while uncorrected MRIs had been employed in 47.5% (199/419) of metastases. 2D distortion correction was associated with improved local control (Cumulative incidence of local progression at 12 months: 14.3% vs. 21.2% and at 24 months: 18.7% vs. 28.6%, p = 0.038). In multivariate analysis, adjusting for histology, baseline tumor volume, interval between MRI and treatment delivery, year of planning MRI, biologically effective dose and adjuvant Whole-brain radiotherapy, use of distortion correction remained significantly associated with improved local control (HR 0.55, p = 0.020). This is the first study to clinically evaluate the impact of MRI gradient nonlinearity distortion correction on local control in stereotactic radiotherapy for brain metastases. In this historic series, we found significantly higher local control when using 2D corrected vs. uncorrected MRI studies for treatment planning. These results stress the importance of assuring that MR images used for radiotherapy treatment planning are properly distortion-corrected.

Long-term impact of bevacizumab for the treatment of brain radiation necrosis

PURPOSE

To evaluate short and long-term efficacy of bevacizumab (Bev), for the treatment of radiation necrosis (RN) in patients with brain metastasis after stereotactic radiosurgery (SRS).

METHODS

The database of a tertiary medical center was reviewed for all adult patients treated by Bev (from January 2018 to January 2023) for RN after having received SRS for BM. Clinical and MRI data were systematically collected at baseline, immediately after the completion of Bev treatment, and at 6, 12, and, when available, 24 months post-treatment.

RESULTS

The cohort included 23 patients with a total of 31 RN lesions (defined as target lesion) which have been previously treated by SRS, either as single-session SRS (27/31) or as fractionated stereotactic radiotherapy (4/31). Median follow-up time was 15 months (range: 8-28.5). Immediately after completion of Bev, 15 patients (65.2%) exhibited a complete/partial response, 6 (26.1%) had stable disease, and 2 had progressive disease (8.7%). thirteen patients (56%) improved clinically. Greater than 50% reduction in volume was observed in 84% of target lesions. At 12 months, among the 13 patients still evaluable (9 other being deceased, 1 loss to follow up), three continued to improve, and four remained stable. Median volume of target lesion was then 1.4 cm3 (range 0.7-2.9) demonstrating a reduction of 67.4% compared to the initial target volume, which was 4.35 cm3 (range 2.14-10.37). During the entire follow-up period, 11 patients experienced regrowth of the target lesion; median time to progression was 7 months. Five underwent Bev re-challenge, but only 2 responded.

CONCLUSION

Bev for the treatment of SRS-induced RN was associated with a high initial response rate, significant lesion reduction, and prolonged clinical improvement. However, the high rate of lesion regrowth (50%) and poor response to Bev re-challenge highlight the complexity of diagnosis and treatment of RN.

Gut microbiome is associated with radiotherapy response in lung cancer patients with brain metastases

Purpose

To investigate the gut microbiome of lung cancer patients with brain metastases undergoing radiotherapy, identify key microorganisms associated with radiotherapy response, and evaluate their potential as biomarkers.

Methods and materials

This study enrolled 55 newly diagnosed lung cancer patients with brain metastases. Fecal samples were collected before radiotherapy and analyzed by 16S rRNA sequencing to assess the gut microbiome's composition and function. Patients were categorized into response (n=28) and non-response (n=27) groups based on treatment efficacy, and α-diversity, β-diversity, and functional pathways were compared between them. Linear Discriminant Analysis Effect Size was used to identify microbial features associated with treatment efficacy. Logistic regression analyses were performed to evaluate the predictive capacity of clinical and microbial factors for treatment outcomes.

Results

No significant difference in α-diversity was observed between the groups (P > 0.05), but β-diversity differed significantly (P = 0.036). Twelve characteristic microorganisms were identified in the response group, including g_ Oscillibacter and g_ Blautia, and nine in the non-response group, such as f_ Desulfovibrionaceae and g_ Megamonas. Metabolic pathways associated with treatment response included ketone body metabolism and pathways related to amyotrophic lateral sclerosis. Multivariate analysis identified g_Flavonifractor (odds ratio [OR] = 6.680, P = 0.004), g_Negativibacillus (OR = 3.862, P = 0.014), C-reactive protein (OR = 1.054, P = 0.017), and systemic inflammation response index (OR = 1.367, P = 0.043) as independent predictors of radiotherapy response. The nomogram and microbiome models achieved area under the curve (AUC) values of 0.935 and 0.866, respectively, demonstrating excellent predictive performance. Decision curve analysis further confirmed these models provided significant net benefits across risk thresholds.

Conclusions

The composition and functional characteristics of the gut microbiome in lung cancer patients with brain metastases prior to radiotherapy are associated with therapeutic response and possess potential as predictive biomarkers. Further studies are warranted to validate these findings.

Real-World outcomes with sacituzumab govitecan among breast cancer patients with central nervous system metastases

Central nervous system (CNS) metastases are associated with poor prognosis in patients with metastatic breast cancer (MBC). In this retrospective study, we investigated the activity of sacituzumab govitecan (SG) in 33 patients with HER2-negative MBC and CNS metastases, including active, stable/treated, and leptomeningeal disease (LMD). SG demonstrated a modest CNS objective response rate of 4/30 (13%) and median CNS-progression-free survival of 2.9 months (95%CI:2.0-4.3) in a heavily pretreated population.

Prediction of brain metastasis progression after stereotactic radiosurgery: sensitivity to changing the definition of progression

Purpose

Machine learning (ML) has been used to predict tumor progression post-stereotactic radiosurgery (SRS) based on pre-treatment MRI for brain metastasis (BM) patients, but there is variability in the definition of what constitutes progression. We aim to measure the magnitude of the change of performance of an ML model predicting post-SRS progression when various definitions of progression were used.

Approach

We collected pre- and post-SRS contrast-enhanced T1-weighted MRI scans from 62 BM patients ( n = 115 BMs). We trained a random decision forest model using radiomic features extracted from pre-SRS scans to predict progression versus non-progression for each BM. We varied the definition of progression by changing (1) the follow-up period ( < 9 , < 12 , < 15 , < 18 , or < 24 months); (2) the size change metric denoting progression ( ≥ 10 % , ≥ 15 % , ≥ 20 % , or ≥ 25 % in volume) or response assessment in neuro-oncology BM diameter ( ≥ 20 % ); and (3) whether BMs with treatment-related size changes (TRSCs) (pseudo-progression and/or radiation-necrosis) were labeled as progression. We measured performance using the area under the receiver operating characteristic curve (AUC).

Results

When we varied the follow-up period, size change metric, and TRSC labeling, the AUCs had ranges of 0.06 (0.69 to 0.75), 0.06 (0.69 to 0.75), and 0.08 (0.69 to 0.77), respectively. Radiomic feature importance remained similar.

Conclusions

Variability in the definition of BM progression has a measurable impact on the performance of an MRI radiomic-based ML model predicting post-SRS progression. A consistent, clinically relevant definition of post-SRS progression across studies would enable robust comparison of proposed ML systems, thereby accelerating progress in this field.

Patterns of failure after stereotactic radiosurgery for brain metastases from small cell lung cancer: outcomes in the immunotherapy era

PURPOSE/OBJECTIVE(S)

Small cell lung cancer (SCLC) is known to have high rates of development of brain metastases. Standard treatment has been whole brain radiation therapy (WBRT) but the role for more focused treatment and hippocampal avoidance has arisen in the past decade. In addition, with possible penetration of the central nervous system by more modern immunotherapies, the risk of distant failure may be lower. As such, we reviewed patients at our institution treated with stereotactic radiosurgery (SRS) to look at patterns, locations, and predictors of failure in the brain.

MATERIALS/METHODS

A retrospective review and analysis of charts was done on 46 patients treated with SRS (no history of prior WBRT) for their brain metastases from SCLC. Multivariate analysis was used to determine significant prognostic factors influencing survival and local/distant failure. We tracked timing and type of immunotherapy, if any, as well as if patients failed in the hippocampus or required WBRT.

RESULTS

There were 46 patients with 97 total brain metastases treated with SRS in this study. Median number of metastases was 2 (1-5). The median dose of radiation was 20 Gy (20-30) in 3 fractions (1-5) for all 97 tumors. 11 patients did not receive immunotherapy, whereas 35 patients had immunotherapy of some sort. Median overall survival (OS) for the entire cohort was 13 months, with a 12 month OS of 59% and 2 year OS of 30%. Cox regression did not reveal any significant predictors of OS, including age, sex, total volume, extracranial disease, KPS, immunotherapy, or number of metastases. 12 month and 24 month local control of disease was 95% and 80%, respectively. There were no significant predictors of local failure including volume, dose, or immunotherapy. 25 of the patients had distant brain failure, with a rate of distant failure of 38% and 64% for 6 and 12 months, respectively. Immunotherapy, number of metastases, total target volume, nor presence of extracranial disease was predictive of distant brain failure. WBRT free survival was also measured and found to be 73% at 1 year. There were no significant predictors for this measure. Lastly, five patients in this cohort showed failure in the hippocampus, where the rate of failure at 6 and 12 months was 16%.

CONCLUSION

Rates of distant brain failure in SCLC patients after SRS remain similar to those of NSCLC patients in the immunotherapy era. We did not show a decrease in distant failure rate based on immunotherapy use. The rate of hippocampal failure was quite low and should provide reassurance that SRS and techniques such as HA-IMRT can be reasonably used in these patients. Ongoing clinical trials will help provide more definitive answers in this arena.

The LITT Fit in neuro-oncology: indications, imaging, and adjunctive therapies

PURPOSE

There is an unmet need for new treatments for many central nervous system tumors. An expanding body of research supports the use of laser interstitial thermal therapy (LITT) in the treatment of gliomas, recurrent brain metastases, and radiation necrosis.

METHODS

In this review, we highlight emerging indications for LITT, including its use adjacent to eloquent structures, in the posterior fossa, and for meningioma and tumors of the vertebral column. We conclude by providing an overview of current research into post-LITT response assessment and adjunctive therapies.

RESULTS

Evidence has continued to accumulate regarding the safety of LITT in locations as varied as the motor cortex, posterior fossa, and vertebral column, as well as for novel pathologies such as meningioma. Regardless of disease histology, most patients leave the hospital within 12-48 h of LITT and can rapidly return to systemic and radiation therapies. Emerging data has allowed for a characterization of post-LITT imaging findings, and receipt of LITT should not preclude subsequent clinical trial enrollment, especially as hyperthermia modulates blood-brain barrier permeability and may synergize with immunotherapies.

CONCLUSION

As LITT is incorporated into neurosurgical oncology practice, novel use cases will continue to emerge. Given that laser ablation is associated with shortened length of stay and decreased debility relative to open resection, development of radiographic response assessment criteria for LITT-treated lesions is urgently needed so that patients may more rapidly receive definitive management or proceed to clinical trial enrollment. Prospective evaluation of LITT and adjunctive combination therapies is ongoing.

Perfusion-MRI for differentiating cerebral metastatic lesions and gliomas: An evidence-based review

BACKGROUND

Lesions affecting the brain are variable and have multiple pathologies. Brain metastasis is a common entity of lesions that can be misleading in diagnosis. Brain metastasis affects the patient's life and survival in about 40% of cases; all patients with metastatic brain lesions are indicated for surgery, so proper diagnosis is crucial for each patient. Non-invasive diagnosis is a promising way to confirm the diagnosis of cerebral metastatic lesions for patients who are not indicated for surgery for medical reasons. To our knowledge, this is the first evidence-based review article regarding utilizing perfusion-MRI for approaching cerebral metastatic lesions.

METHODS

A comprehensive database search on PubMed/Medline, Scopus and Google Scholar was done by the relevant keywords. Eligibility of articles was done by following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Cochrane risk of bias assessment tool was used to determine the risk of bias among the included studies.

RESULTS

From 2989 articles, only 31 studies were eligible for the qualitative synthesis. A comprehensive summary of the included study was made according to population, intervention, comparator and outcomes (PICO) method.

CONCLUSIONS

Diagnosing cerebral metastases, categorizing subtypes, and monitoring their response to treatment is a challenging endeavor for neurosurgeons, neuroradiologists, and oncologists. Technological advances in MRI software as perfusion-based MRIs are designated to facilitate diagnosis and follow-up for patients with cerebral metastases.

MR perfusion characteristics of pseudoprogression in brain tumors treated with immunotherapy - a comparative study with chemo-radiation induced pseudoprogression and radiation necrosis

PURPOSE

Pseudoprogression is an atypical imaging pattern of response to immunotherapy in patients with brain tumors. MR perfusion studies in this field are limited. The purpose of our study is to compare the perfusion features between pseudoprogression lesions in malignant gliomas and brain metastases treated with immunotherapy (iPsP) and the pseudoprogression after chemo-radiation therapy and radiation necrosis after radiation treatment (ChR-PsP & RN).

METHODS

We retrospectively reviewed 25 iPsP lesions in 16 brain tumor patients and 48 ChR-PsP & RN lesions in 35 patients. The cerebral blood volume (CBV) of MR dynamic susceptibility contrast (DSC) perfusion weighted imaging (PWI) was analyzed, and the mean and maximal values of the ratio of CBV (rCBVmean and rCBVmax) of iPsPs and ChR-PsP & RNs were calculated and compared between these two groups using the Mann-Whitney U test. A receiver operating characteristic curve analysis was conducted, and the optimal cutoff of perfusion parameters were determined using the area under the curve, sensitivity, and specificity.

RESULTS

The medians of rCBVmean and rCBVmax in iPsP group were significantly higher (0.94 and 1.39 respectively) than ChR-PsP & RN group (0.67, p < 0.01 and 1.1, p = 0.01 respectively). The rCBVmean value of 0.69 can differentiate the iPsP from ChR-PsP & RN with the area under the curve of 0.71, sensitivity of 0.72, and specificity of 0.56.

CONCLUSION

These findings may suggest immunotherapy-induced higher perfusion in the iPsP lesions compared to ChR-PsP & RN lesions in primary and metastatic brain tumors.

Gradient-Based Radiomics for Outcome Prediction and Decision-Making in PULSAR: A Preliminary Study

Purpose

Personalized ultrafractionated stereotactic adaptive radiation therapy (PULSAR) has emerged as an innovative method for delivering high-dose radiation over extended intervals, adapting treatment based on the patient's response. However, current adaptation largely relies on physicians' experience and tumor size assessment, underscoring the need for a data-driven approach to improve outcome prediction and support decision-making.

Materials and Methods

We analyzed 69 lesions from 39 patients undergoing PULSAR treatment. Gradient-based features, including gradient magnitude, radial gradient, and radial deviation, were extracted from both intratumoral and peritumoral regions, with the latter further divided into octant subregions. Support vector machine models were developed using features from first magnetic resonance imaging (MRI), second MRI, and delta mode (change between the 2). An ensemble feature selection (EFS) model was then created by combining the features of the top-performing individual models. The approach was validated on a non-PULSAR cohort (37 lesions from 23 patients) treated with standard fractionated stereotactic radiation therapy.

Results

The EFS model shows strong predictive performance in determining whether tumor volume reduction exceeds 20% at the 3-month postradiation time point. Features derived from octant subregions exhibit significantly better prediction than those from the core or entire margin. Pretreatment features (from first MRI) generally outperform second MRI and delta-mode features, while the inclusion of 1 delta feature in the EFS model enhances performance. In the non-PULSAR cohort, the gradient-based approach outperforms conventional radiomics, demonstrating its strong generalizability.

Conclusion

Our gradient-based radiomics approach, combining spatial segmentation and temporal features, significantly enhances treatment response prediction in PULSAR therapy. Its superior performance compared to conventional radiomics, coupled with its effectiveness in both PULSAR and non-PULSAR cohorts, highlights its potential as a robust tool for personalized treatment planning in neuro-oncology, applicable to both photon and particle therapies.

Stereotactic radiosurgery for 1-10 brain metastases to avoid whole-brain radiotherapy: Results of the CYBER-SPACE randomized phase 2 trial

BACKGROUND

Stereotactic radiosurgery (SRS) is an emerging alternative to whole-brain radiotherapy (WBRT) for treating multiple brain metastases (BM), reducing toxicity, and improving tumor control. The CYBER-SPACE trial compared SRS based on either SPACE or MPRAGE MRI sequence for avoiding or delaying WBRT in patients with 1-10 BM.

METHODS

Patients with 1-10 untreated BM were randomized 1:1 to receive SRS of all lesions based on either SPACE or MPRAGE MRI sequences. If subsequently new BM occurred, SRS was repeated. WBRT was indicated upon occurrence of >10 new BM, leptomeningeal disease, or exhausted SRS-radiotolerance. The primary outcome was freedom from WBRT indication (WBRTi). Secondary outcomes included overall survival (OS), safety, and quality of life.

RESULTS

A total of 202 patients were randomized; SPACE n = 99, MPRAGE n = 103. Twelve-month WBRTi-free survival was 77.1% (95% CI: 69.5%-83.1%) overall, 78.5% (95% CI: 66.7%-86.5%) for SPACE, and 76.0% (95% CI: 65.2%-83.9%) for MPRAGE (hazard ratio [HR] = 0.84, 95% CI: 0.43-1.63, P = .590). Patients with 5-10 BM had shorter WBRTi-free survival (HR = 3.13, 95% CI: 1.53-6.40, P = .002). Median OS was 13.1 months overall, 10.5 months for SPACE, and 15.2 months for MPRAGE (HR = 1.10, 95% CI: 0.78-1.56, P = .585). Neurologic death rate was 10.1%. Predictors for longer OS included Karnofsky Performance Status >80% (HR = 0.51, 95% CI: 0.33-0.77, P = .002) and concurrent immunotherapy (HR = 0.34, 95% CI: 0.23-0.52, P < .001).

CONCLUSIONS

The more sensitive SPACE sequence did not improve outcomes over MPRAGE. SRS with thorough monitoring and immediate re-treatment for new lesions decreases the need for WBRT and achieves low neurologic death rates. SRS should be considered a favorable alternative to WBRT for patients with 1-10 BM.

Utilizing Vision Transformers for Predicting Early Response of Brain Metastasis to Magnetic Resonance Imaging-Guided Stage Gamma Knife Radiosurgery Treatment

BACKGROUND/OBJECTIVES

This study explores the application of vision transformers to predict early responses to stereotactic radiosurgery in patients with brain metastases using minimally pre-processed magnetic resonance imaging scans. The objective is to assess the potential of vision transformers as a predictive tool for clinical decision-making, particularly in the context of imbalanced datasets.

METHODS

We analyzed magnetic resonance imaging scans from 19 brain metastases patients, focusing on axial fluid-attenuated inversion recovery and high-resolution contrast-enhanced T1-weighted sequences. Patients were categorized into responders (complete or partial response) and non-responders (stable or progressive disease).

RESULTS

Despite the imbalanced nature of the dataset, our results demonstrate that vision transformers can predict early treatment responses with an overall accuracy of 99%. The model exhibited high precision (99% for progression and 100% for regression) and recall (99% for progression and 100% for regression). The use of the attention mechanism in the vision transformers allowed the model to focus on relevant features in the magnetic resonance imaging images, ensuring an unbiased performance even with the imbalanced data. Confusion matrix analysis further confirmed the model's reliability, with minimal misclassifications. Additionally, the model achieved a perfect area under the receiver operator characteristic curve (AUC = 1.00), effectively distinguishing between responders and non-responders.

CONCLUSIONS

These findings highlight the potential of vision transformers, aided by the attention mechanism, as a non-invasive, predictive tool for early response assessment in clinical oncology. The vision transformer (ViT) model employed in this study processes MRIs as sequences of patches, enabling the capture of localized tumor features critical for early response prediction. By leveraging patch-based feature learning, this approach enhances robustness, interpretability, and clinical applicability, addressing key challenges in tumor progression prediction following stereotactic radiosurgery (SRS). The model's robust performance, despite the dataset imbalance, underscores its ability to provide unbiased predictions. This approach could significantly enhance clinical decision-making and support personalized treatment strategies for brain metastases. Future research should validate these findings in larger, more diverse cohorts and explore the integration of additional data types to further optimize the model's clinical utility.

Competing Risks and Their Impact on Treatment Efficacy Assessment in Fractionated Stereotactic Radiotherapy for Brain Metastases: A Retrospective Study

Background and Aims

The Kaplan-Meier (KM) method and competing risk analysis are two statistical approaches for analyzing time-to-event data. These methods differ in their treatment of competing events, such as deaths occurring before the event of interest, which can impact the interpretation of treatment efficacy in oncology.

Methods

This retrospective study included 73 patients who underwent fractionated stereotactic radiotherapy (six fractions of 5 Gy) for brain metastases at the University Hospital Regensburg between January 2017 and December 2021. The events of interest were the cumulative incidences of local failure within the planning target volume and the development of new brain metastases. Premature deaths occurring before the events of interest were treated as competing events. The complement of the KM method (1-KM), which censors patients who die prematurely, was compared to the cumulative incidence function (CIF), which accounts for the fact that patients who die without experiencing the event of interest are no longer at risk for that event.

Results

The median follow-up was 56 months. The most common cancer types were non-small cell lung cancer (n = 26, 35.6%) and malignant melanoma (n = 25, 34.2%). Using CIF, the cumulative incidences of local failure and new brain metastases were 27% and 55% at 24 months, respectively. The 1-KM method overestimated the cumulative incidence of local failure by 9% at 24 months and 14% at 36 months, and new brain metastases by 13% at both 24 and 36 months. Survival curves for 1-KM and CIF showed simultaneous increases for each event, with 1-KM consistently higher, reflecting differing approaches to competing risks.

Conclusion

This study highlights the impact of statistical method selection on clinical data interpretation and underscores the bias inherent in studies that fail to account for competing risks. Recognizing these differences is crucial for accurately assessing treatment outcomes.

Outcomes of Patients With Five or More Brain Metastases Treated With Stereotactic Radiosurgery From 2014 to 2019: A UK Series

AIMS

Treatment with stereotactic radiosurgery/radiotherapy (SRS/SRT) is standard practice in selected patients with small numbers of brain metastases (BMs). It is less accepted in those with ≥5 BMs, due to the lack of a prospective evidence base. While randomised trials are ongoing, we present the experience of a single UK cancer centre in using SRS/SRT for patients with 5 or more BMs without whole brain radiotherapy (WBRT).

MATERIALS AND METHODS

Patients undergoing treatment at a single centre between 2014 and 2019 were prospectively identified. All follow-up imaging was reviewed to identify any evidence of local failure or distant brain progression, which was analysed using a death-censored approach.

RESULTS

A total of N = 88 patients were included, with a median of seven BMs (range: 5-37). Post-SRS/SRT toxicity events occurred in 42%, most commonly reliance on steroids for ≥4 weeks (36% of the cohort). Median survival was 10 months, with median freedom from local failure and distant brain progression of 12 and 8 months, respectively; none of these outcomes differed significantly by the number of BMs. Brain-directed salvage treatment was required after a median of 21 months, and was not significantly associated with the number of BMs.

CONCLUSION

SRS/SRT alone may have a role in the management of selected patients with multiple BMs. Since the number of BMs were not significantly associated with overall survival or disease control, the National Health Service (NHS) commissioning criteria should continue to be based on tumour volume.

Measurement variability of radiologists when measuring brain tumors

BACKGROUND

In oncology trials, response evaluation criteria are pivotal in developing new treatments. This study examines the influence of measurement variability in brain lesions on response classification, considering long-standing cut-offs for progression and response were determined before the era of submillimeter resolutions of medical imaging.

METHODS

We replicate a key study using modern radiological tools. Sixteen radiologists were tasked with measuring twelve near-spherical brain tumors using visual estimation (eyeballing), diameter measurements and artificial intelligence (AI) assisted segmentations. Analyses for inter- and intraobserver variability from the original were replicated. Additionally, we researched the effect of measurement error on the misclassification of progressive disease using a computer simulation model.

RESULTS

The combined effect of intra- and interobserver error varied between 13.6 and 22.2% for eyeballing and 6.8-7.2% for diameter measurement, using AI-assisted segmentation as reference. We observed erroneously declared progression (cut-off at 20% increase) in repeat measurements of the same tumor in 25.5% of instances for eyeballing and in 1.1% for diameter measurements. Response (cut-off at 30% decrease) was erroneously declared in 12.3% for eyeballing and in 0% for diameter measurements. The simulation model demonstrated a more pronounced impact of measurement error on cases with fewer total number of lesions.

CONCLUSIONS

This study provides a minimum expected measurement error using real-world data. The impact of measurement error on response evaluation criteria misclassification in brain lesions was most pronounced for eyeballing. Future research should focus on measurement error for different tumor types and assess its impact on response classification during patient follow-up.

The 5-factor modified frailty index as a prognostic factor following stereotactic radiosurgery for metastatic disease to the brain from non-small cell lung cancer: A multi-center cohort analysis

BACKGROUND

Non-small cell lung cancer (NSCLC) patients often develop brain metastases (BMs), complicating management. We have shown that increasing frailty is associated with decreased overall survival (OS) and central nervous system progression free survival (PFS) for patients undergoing stereotactic radiosurgery (SRS) to BMs. Leveraging the International Radiosurgery Research Foundation, we sought to expand upon these findings, in NSCLC specifically.

METHODS

Across four institutions, 193 patients with (≥1) NSCLC derived BMs with minimum 3 months of clinical/radiographic follow-up were analyzed. Primary outcomes included OS and PFS. Patients were stratified utilizing the mFI-5 into pre-frail (0-1), frail (2), and severely frail (3 + ).

RESULTS

Increased frailty was associated with diminished OS (frail hazard ratio (HR) = 2.49, 95 % CI [1.61-3.85]; severely frail HR = 2.65, 95 % CI [1.57-4.45]). The 6-month post-SRS survival rate was 86.1 %, 69.5 % and 54.5 % for pre-frail, frail and severely frail patients, respectively (p < 0.001). Frailty was not significantly predictive of time to PFS on multivariate Cox Proportional Hazards analysis although there was a trend towards diminished PFS with increasing frailty (median PFS was 18.4, 8.0, and 7.4 months for pre-frail, frail, and severely frail, respectively (p = 0.11). As age > 65 was also predictive of shorter OS (HR = 1.78, 95 % CI [1.23-2.56]). We generated a novel scoring system incorporating age and frailty status. The median survival of patients that scored 0, 1, 2, and 3 points were 21.1, 18.3, 8.9, and 5.6 months, respectively (p < 0.001). The area under the curve of the validation cohort using a logistic regression model was 0.77.

CONCLUSIONS

Our results indicate that the MFI-5 is a promising metric with application at the point of care to provide decision support for patients with NSCLC derived BMs.

Development and routine implementation of deep learning algorithm for automatic brain metastases segmentation on MRI for RANO-BM criteria follow-up

RATIONALE AND OBJECTIVES

The RANO-BM criteria, which employ a one-dimensional measurement of the largest diameter, are imperfect due to the fact that the lesion volume is neither isotropic nor homogeneous. Furthermore, this approach is inherently time-consuming. Consequently, in clinical practice, monitoring patients in clinical trials in compliance with the RANO-BM criteria is rarely achieved. The objective of this study was to develop and validate an AI solution capable of delineating brain metastases (BM) on MRI to easily obtain, using an in-house solution, RANO-BM criteria as well as BM volume in a routine clinical setting.

MATERIALS (PATIENTS) AND METHODS

A total of 27,456 post-Gadolinium-T1 MRI from 132 patients with BM were employed in this study. A deep learning (DL) model was constructed using the PyTorch and PyTorch Lightning frameworks, and the UNETR transfer learning method was employed to segment BM from MRI.

RESULTS

A visual analysis of the AI model results demonstrates confident delineation of the BM lesions. The model shows 100 % accuracy in predicting RANO-BM criteria in comparison to that of an expert medical doctor. There was a high degree of overlap between the AI and the doctor's segmentation, with a mean DICE score of 0.77. The diameter and volume of the BM lesions were found to be concordant between the AI and the reference segmentation. The user interface developed in this study can readily provide RANO-BM criteria following AI BM segmentation.

CONCLUSION

The in-house deep learning solution is accessible to everyone without expertise in AI and offers effective BM segmentation and substantial time savings.

Early characterization and prediction of glioblastoma and brain metastasis treatment efficacy using medical imaging-based radiomics and artificial intelligence algorithms

Among brain tumors, glioblastoma (GBM) is the most common and the most aggressive type, and brain metastases (BMs) occur in 20%-40% of cancer patients. Even with intensive treatment involving radiotherapy and surgery, which frequently leads to cognitive decline due to doses on healthy brain tissue, the median survival is 15 months for GBM and about 6 to 9 months for BM. Despite these treatments, GBM patients respond heterogeneously as do patients with BM. Following standard of care, some patients will respond and have an overall survival of more than 30 months and others will not respond and will die within a few months. Differentiating non-responders from responders as early as possible in order to tailor treatment in a personalized medicine fashion to optimize tumor control and preserve healthy brain tissue is the most pressing unmet therapeutic challenge. Innovative computer solutions recently emerged and could provide help to this challenge. This review will focus on 52 published research studies between 2013 and 2024 on (1) the early characterization of treatment efficacy with biomarker imaging and radiomic-based solutions, (2) predictive solutions with radiomic and artificial intelligence-based solutions, (3) interest in other biomarkers, and (4) the importance of the prediction of new treatment modalities' efficacy.

Real life outcome analysis of breast cancer brain metastases treated with Trastuzumab Deruxtecan

Tumor dissemination to the central nervous system (CNS) is almost a rule in the treatment journey of advanced HER2+ breast cancer (BC). Recent results demonstrated high intracranial efficacy with Trastuzumab Deruxtecan (T-DXd). However, a real-world evidence is lacking in literature. We conducted a multicenter, observational, retrospective real-world analysis on 39 cases collected at 12 Italian Oncological Units. Patients with brain metastases (BMs) from HER2 + BC treated with T-DXd in various treatment lines were enrolled. Primary endpoint was the intracranial overall response rate (iORR). Secondary endpoints were intra- and global progression free survival (iPFS - gPFS); other secondary objectives were the intracranial disease control rate (iDCR), duration of response (iDoR), clinical benefit rate at 6 and 12 months (iCBr), overall survival, and safety. iORR was 59%, iPFS was 15.6 months, gPFS was 11.8 months. iDCR was 94.9%, iDoR was 11.9 months, and iCBr at 6 and 12 months were 69.2% and 59%, respectively. OS was not reached, with an overall rate of 77.9% of patients alive at 12 months. This study confirmed the high intracranial efficacy and manageable safety profile of T-DXd in this first-ever real world analysis.

High incidence of radiation-induced brain necrosis in the periventricular deep white matter: stereotactic radiotherapy for brain metastases using volumetric modulated arc therapy

PURPOSE

In this retrospective study, we aimed to evaluate the efficacy and incidence of radiation-induced brain necrosis (RBN) after volumetric modulated arc therapy-based stereotactic irradiation (VMAT-STI) for brain metastases.

METHODS

In the 220 brain metastatic lesions included between January 2020 and June 2022, there were 1-9 concurrently treated lesions (median 1). A biologically effective dose (BED)10 of 80 Gy and a reduced BED10 of 50 Gy were prescribed to the gross tumor volume (GTV) and planning target volume (PTV) (PTV = GTV + 3 mm) margins, respectively. The number of fractions was adjusted from 3 to 15 to accommodate different GTV sizes; for larger tumor volumes, this was increased while maintaining the BED10 values comparable to those for GTV and PTV margins.

RESULTS

Of the total patients, 16 (7%) exhibited locally progressive lesions; local tumor recurrence was observed in 2 (1%) patients, while RBN was noted in 14 (6%) patients. RBN was significantly more prevalent in the deep white matter around the lateral ventricles (DWM-LV) than in other sites, occurring in 9/22 (41%) lesions of metastases in the DWM-LV. The 2-year actuarial incidence risk of developing RBN was significantly higher in the DWM-LV (69%) than at other sites (5%).

CONCLUSION

The recurrence rate of brain metastases was low, and the incidence of RBN was lower in tumor sites other than the DWM-LV. However, the frequency of RBN was significantly higher in the DWM-LV region. Additional VMAT-STI-prescribed dose protocols are necessary to reduce RBN incidence in DWM-LVs.

Gadolinium-Enhanced T2 FLAIR Is an Imaging Biomarker of Radiation Necrosis and Tumor Progression in Patients with Brain Metastases

BACKGROUND AND PURPOSE

Differentiating radiation necrosis (RN) from tumor progression (TP) after radiation therapy for brain metastases is an important clinical problem requiring advanced imaging techniques that may not be widely available and are challenging to perform at multiple time points. The ability to leverage conventional MRI for this problem could have a meaningful clinical impact. The purpose of this study was to explore contrast-enhanced T2 FLAIR (T2FLAIRc) as a new imaging biomarker of RN and TP.

MATERIALS AND METHODS

This single-institution retrospective study included patients with treated brain metastases undergoing DSC-MRI between January 2021 and June 2023. Reference standard assessment was based on histopathology or serial follow-up, including the results of DSC-MRI for a minimum of 6 months from the first DSC-MRI. The index test was implemented as part of the institutional brain tumor MRI protocol and preceded the first DSC-MRI. T2FLAIRc and gadolinium-enhanced T1 (T1c) MPRAGE signal were normalized against normal brain parenchyma and expressed as a z score. The mean signal intensity of enhancing disease for the RN and TP groups was compared using an unpaired t test. Receiver operating characteristic curves and area under the receiver operating characteristic curve (AUC) were derived by bootstrapping. The DeLong test was used to compare AUCs.

RESULTS

Fifty-six participants (mean age, 62 [SD, 12.7] years; 39 women; 28 with RN, 28 with TP) were evaluated. The index MRI was performed, on average, 73 [SD, 34] days before the first DSC-MRI. Significantly higher z scores were found for RN using T2FLAIRc (8.3 versus 5.8, P < .001) and T1c (4.1 versus 3.5, P = .02). The AUC for T2FLAIRc (0.83; 95% CI, 0.72-0.92) was greater than that for T1c (0.70; 95% CI, 0.56-0.83) (P = .04). The AUC of DSC-derived relative CBV (0.82; 95% CI, 0.70-0.93) was not significantly different from that of T2FLAIRc (P = .9).

CONCLUSIONS

A higher normalized T1c and T2FLAIRc signal intensity was found for RN. In a univariable test, the mean T2FLAIRc signal intensity of enhancing voxels showed good discrimination performance for distinguishing RN from TP. The results of this work demonstrate the potential of T2FLAIRc as an imaging biomarker in the work-up of RN in patients with brain metastases.

Intracranial outcomes following neurosurgical resection in patients with brain metastases secondary to HER2-positive breast cancer versus other subtypes

PURPOSE

Neurosurgical resection serves an important role in select patients with breast cancer and brain metastases but can delay systemic therapy and yield complications. Consequently, identification of patients most likely to benefit from surgery is important. Given the poorer long-term intracranial responses to radiotherapy sometimes observed in HER2-positive (HER2 +) patients, we investigated whether neurosurgical resection is differentially beneficial in this population.

METHODS

We identified 633 patients with newly diagnosed brain metastases arising from breast cancer managed at Brigham and Women's Hospital/Dana-Farber Cancer Institute between 2010 and 2022. Patients were stratified by breast cancer subtype: HER2 + (N = 189), hormone receptor positive (HR +)/HER2- (N = 267), and triple negative (N = 177). Per-patient and per-metastasis outcomes were evaluated; interaction models assessing the impact of neurosurgical resection by subtype were constructed.

RESULTS

Relative to HR + /HER2- subtype, omission of upfront neurosurgical resection in patients with HER2 + disease was associated with increased subsequent utilization of salvage stereotactic radiation, whole brain radiotherapy, and craniotomy (interaction HR 2.02 [95% CI, 1.04-3.93], p = 0.04; HR 3.92 [95% CI, 1.24-12.40], p = 0.02; HR 4.98 [95% CI, 1.34-18.58], p = 0.02, respectively). Tumors stemming from HER2 + versus HR + /HER2- primaries displayed increased local recurrence when upfront neurosurgical resection was omitted (interaction HR 3.62 [95% CI, 1.06-12.38], p = 0.04). No such associations were noted when comparing triple negative to HR + /HER2- subtype (p-interaction > 0.05 in all cases).

CONCLUSION

Patients with HER2 + disease and brain metastases may disproportionately benefit from upfront neurosurgical resection relative to other subtypes. If validated, our results may suggest a lower threshold to consider surgery in brain metastases secondary to HER2 + breast cancer.

Central Nervous System Metastases in Breast Cancer

OPINION STATEMENT

Breast cancer metastasizing to the central nervous system (CNS) encompasses two distinct entities: brain metastases involving the cerebral parenchyma and infiltration of the leptomeningeal space, i.e., leptomeningeal disease. CNS metastases affect 10-15% of patients with hormone receptor-positive-status and nearly one-half of those with HER2-positive and triple-negative breast cancer with distant metastatic disease. Significant clinical morbidity and heterogeneous penetration of the blood-brain barrier by systemic therapies contribute to the poor prognosis associated with brain metastases. Recent advances in radiotherapy, including stereotactic approaches and morbidity-reducing strategies such as the use of memantine and hippocampal avoidance in whole brain radiation, coupled with the development of more effective CNS-penetrant systemic therapies, including small molecules and antibody-drug conjugates, have significantly improved patient outcomes. Consequently, patients with breast cancer CNS metastases have improved survival compared to prior decades, and longitudinal care has become increasingly complex, necessitating a multidisciplinary approach to achieve optimal outcomes for patients.

The value of AI for assessing longitudinal brain metastases treatment response

Background

Effective follow-up of brain metastasis (BM) patients post-treatment is crucial for adapting therapies and detecting new lesions. Current guidelines (Response Assessment in Neuro-Oncology-BM) have limitations, such as patient-level assessments and arbitrary lesion selection, which may not reflect outcomes in high tumor burden cases. Accurate, reproducible, and automated response assessments can improve follow-up decisions, including (1) optimizing re-treatment timing to avoid treating responding lesions or delaying treatment of progressive ones, and (2) enhancing precision in evaluating responses during clinical trials.

Methods

We compared manual and automatic (deep learning-based) lesion contouring using unidimensional and volumetric criteria. Analysis focused on (1) agreement in size and RANO-BM categories, (2) stability of measurements under scanner rotations and over time, and (3) predictability of 1-year outcomes. The study included 49 BM patients, with 184 MRI studies and 448 lesions, retrospectively assessed by radiologists.

Results

Automatic contouring and volumetric criteria demonstrated superior stability (P < .001 for rotation; P < .05 over time) and better outcome predictability compared to manual methods. These approaches reduced observer variability, offering reliable and efficient response assessments. The best outcome predictability, defined as 1-year response, was achieved using automatic contours and volumetric measurements. These findings highlight the potential of automated tools to streamline clinical workflows and provide consistency across evaluators, regardless of expertise.

Conclusion

Automatic BM contouring and volumetric measurements provide promising tools to improve follow-up and treatment decisions in BM management. By enhancing precision and reproducibility, these methods can streamline clinical workflows and improve the evaluation of response in trials and practice.

Quality of life after stereotactic radiosurgery for brain metastasis: an assessment from a prospective national registry

PURPOSE

Stereotactic radiosurgery (SRS) is frequently used in the management of brain metastasis patients. However, there is an urgent need to evaluate post-treatment outcomes and quality of life metrics for patients undergoing SRS for brain metastases.

METHODS

The NeuroPoint Alliance (NPA) SRS Quality Registry conducted prospective enrollment of patients undergoing SRS from 2017 to 2024. Patients with brain metastases from lung cancer, breast cancer, and melanoma were included in the analysis. Outcomes of interest included quality of life metrics, as captured by the five-dimension Euro-QOL (EQ-5D) at 6-12 months and last record follow-up, overall survival, local progression, out-of-field progression, and overall intracranial progression.

RESULTS

522 patients comprised our analytic cohort, and 315 patients had available EQ-5D data at the time of SRS and final follow-up. 264 (47.8%), 197 (35.7%), and 91 (16.5%) patients had 1, 2-4, and 5-14 lesions pre-SRS, respectively. The median overall survival time from diagnosis was 27.3 months. The median time-to-local progression was not reached. At final follow-up, 107 (34.0%) patients had improvement, 51 (16.2%) patients had stable, and 113 patients (35.9%) had worsening EQ-5D scores when compared to baseline. For 44 (13.9%) patients mixed responses across the EQ-5D indices were reported. Linear regression analysis showed that male sex, smoking status, primary tumor type, time-to-overall progression, cumulative intracranial tumor volume (CITV), and baseline EQ-5D were statistically significantly associated with EQ-5D single index at the final follow-up.

CONCLUSION

Real-world data from the SRS NPA Registry demonstrated that most patients with brain metastasis had no change or improvement in quality of life after SRS. Baseline EQ-5D was predictive of EQ-5D single index at final follow-up, and, as such, EQ-5D at baseline would be a valuable assessment measure for brain metastasis patients undergoing SRS.

Fractionated stereotactic radiotherapy of brainstem metastases - Clinical outcome and prognostic factors

Introduction

Brain metastases (BM) are the most common malignancy in the central nervous system (CNS) and observed in approximately 30% of cancer patients. Brainstem metastases (BSM) are challenging because of their location and the associated neurological risks. There are still no general therapeutic recommendations in this setting. Stereotactic radiosurgery (SRS) is one of few possible local therapy options but limited due to the tolerance dose of the brainstem. There is still no standard regarding the optimal dose und fractionation.

Methods

We retrospectively analyzed 65 patients with fractionated stereotactic radiotherapy (fSRT) for 69 BSM. FSRT was delivered at a dose of 30 Gy in six fractions prescribed to the 70 % isodose performed with Cyberknife. Overall survival (OS), local control (LC) and total intracranial brain control (TIBC) were analyzed via Kaplan-Meier method. Cox proportional hazards models were used to identify prognostic factors.

Results

Median follow-up was 27.3 months. One-year TIBC was 35.0 % and one-year LC was 84.1 %. Median OS was 8.9 months. In total, local progression occurred in 7.7 % and in 8.2 % symptomatic radiation-induced contrast enhancements (RICE) were diagnosed. In univariate analysis the Karnofsky performance scale index (KPI) (p = 0,001) was an independent prognostic factor for longer OS. Acute CTCAE grade 3 toxicities occurred in 18.4 %.

Conclusion

FSRT for BSM is as an effective and safe treatment approach with high LC rates and reasonable neurological toxicity despite the poor prognosis in this patient cohort is still very poor. Clinical and imaging follow-up is necessary to identify cerebral progression and adverse toxicity including RICE.