Evaluating the heterogeneity of hippocampal avoidant whole brain radiotherapy treatment effect: A secondary analysis of NRG CC001

Evaluating the efficacy and safety of Anlotinib in conjunction with stereotactic radiosurgery for small cell lung cancer patients with brain metastases

Background

Small cell lung cancer (SCLC) is characterized by its aggressive nature and high propensity for brain metastases. This study investigates the clinical efficacy and safety profile of Anlotinib in combination with Stereotactic Radiotherapy (SRT) for treating brain metastases in patients with small cell lung cancer (SCLC).

Methods

This research included 98 SCLC brain metastasis patients treated at Chengde Central Hospital from October 2020 to January 2024. The patients were categorized into a combined treatment group (CTG) (n = 45) and a Simple SRT group (SSG)(n = 53). The CTG (58 lesions) received Anlotinib with brain SRS, while the SSG (67 lesions) underwent only brain SRS. We compared the rates of intracranial hypertension relief, intracranial lesion treatment efficacy, radiation-induced brain necrosis, intracranial progression-free survival, and overall survival between the groups. Additionally, Anlotinib usage and adverse reactions in the CTG were documented.

Results

Intracranial hypertension relief was significantly higher in the CTG at 80.0% (36/45) compared to 11.3% (6/53) in the SSG (p < 0.001). Radiation-induced brain necrosis occurred in 3.4% (2/58) of the CTG, markedly less than the 20.9% (14/67) in the SSG, indicating a significant difference (χ2 = 8.479, p = 0.004). Effective intracranial lesion treatment rates were 86.7% (39/45) in the CTG and 62.3% (33/53) in the SSG, with a notable difference (χ2 = 7.951, p = 0.047). The median intracranial progression-free survival was 7.8 months in the CTG vs. 4.8 months in the SSG (p < 0.0001). Median overall survival times were 11.3 months for the CTG and 7.8 months for the SSG (p = 0.3506). The duration of Anlotinib treatment in the CTG was 6 (6, 18) weeks. Adverse reactions included Grade I hypertension in three patients and Grade I hand-foot skin reactions in two patients, with a drug-related adverse reaction rate of 11.1% (5/45).

Conclusion

Anlotinib combined with SRT significantly alleviates brain edema, reduces the incidence of radiation-induced brain necrosis, enhances intracranial progression-free survival, and demonstrates a low adverse reaction rate.

Metastatic brain tumors: from development to cutting-edge treatment

Metastatic brain tumors, also called brain metastasis (BM), represent a challenging complication of advanced tumors. Tumors that commonly metastasize to the brain include lung cancer and breast cancer. In recent years, the prognosis for BM patients has improved, and significant advancements have been made in both clinical and preclinical research. This review focuses on BM originating from lung cancer and breast cancer. We briefly overview the history and epidemiology of BM, as well as the current diagnostic and treatment paradigms. Additionally, we summarize multiomics evidence on the mechanisms of tumor occurrence and development in the era of artificial intelligence and discuss the role of the tumor microenvironment. Preclinically, we introduce the establishment of BM models, detailed molecular mechanisms, and cutting-edge treatment methods. BM is primarily treated with a comprehensive approach, including local treatments such as surgery and radiotherapy. For lung cancer, targeted therapy and immunotherapy have shown efficacy, while in breast cancer, monoclonal antibodies, tyrosine kinase inhibitors, and antibody-drug conjugates are effective in BM. Multiomics approaches assist in clinical diagnosis and treatment, revealing the complex mechanisms of BM. Moreover, preclinical agents often need to cross the blood-brain barrier to achieve high intracranial concentrations, including small-molecule inhibitors, nanoparticles, and peptide drugs. Addressing BM is imperative.

Mitigating radiation-induced cognitive toxicity in brain metastases: More questions than answers

The emergence of advanced systemic therapies added to the use of cranial radiation techniques has significantly improved outcomes for cancer patients with multiple brain metastases (BM), leading to a considerable increase in long-term survivors. In this context, the rise of radiation-induced cognitive toxicity (RICT) has become increasingly relevant. In this critical narrative review, we address the controversies arising from clinical trials aimed at mitigating RICT. We thoroughly examine interventions such as memantine, hippocampal avoidance irradiation during BM treatment or in a prophylactic setting, and the assessment of cognitive safety in stereotactic radiosurgery (SRS). Our focus extends to recent neuroscience research findings, emphasizing the importance of preserving not only the hippocampal cortex but also other cortical regions involved in neural dynamic networks and their intricate role in encoding new memories. Despite treatment advancements, effectively managing patients with multiple BM and determining the optimal timing and integration of radiation and systemic treatments remain areas requiring further elucidation. Future trials are required to delineate optimal indications and ensure SRS safety. Additionally, the impact of new systemic therapies and the potential effects of delaying irradiation on cognitive functioning also need to be addressed. Inclusive trial designs, encompassing patients with multiple BM and accounting for diverse treatment scenarios, are essential for advancing effective strategies in managing RICT and the treatment of BM patients.

Hippocampal subfield volumetric changes after radiotherapy for brain metastases

Background

Changes in the hippocampus after brain metastases radiotherapy can significantly impact neurocognitive functions. Numerous studies document hippocampal atrophy correlating with the radiation dose. This study aims to elucidate volumetric changes in patients undergoing whole-brain radiotherapy (WBRT) or targeted stereotactic radiotherapy (SRT) and to explore volumetric changes in the individual subregions of the hippocampus.

Method

Ten patients indicated to WBRT and 18 to SRT underwent brain magnetic resonance before radiotherapy and after 4 months. A structural T1-weighted sequence was used for volumetric analysis, and the software FreeSurfer was employed as the tool for the volumetry evaluation of 19 individual hippocampal subregions.

Results

The volume of the whole hippocampus, segmented by the software, was larger than the volume outlined by the radiation oncologist. No significant differences in volume changes were observed in the right hippocampus. In the left hippocampus, the only subregion with a smaller volume after WBRT was the granular cells and molecular layers of the dentate gyrus (GC-ML-DG) region (median change -5 mm3, median volume 137 vs. 135 mm3; P = .027), the region of the presumed location of neuronal progenitors.

Conclusions

Our study enriches the theory that the loss of neural stem cells is involved in cognitive decline after radiotherapy, contributes to the understanding of cognitive impairment, and advocates for the need for SRT whenever possible to preserve cognitive functions in patients undergoing brain radiotherapy.