A comparison between cyberknife and neurosurgery in solitary brain metastases from non-small cell lung cancer

Factors associated with the local control of brain metastases: a systematic search and machine learning application

BACKGROUND

Enhancing Local Control (LC) of brain metastases is pivotal for improving overall survival, which makes the prediction of local treatment failure a crucial aspect of treatment planning. Understanding the factors that influence LC of brain metastases is imperative for optimizing treatment strategies and subsequently extending overall survival. Machine learning algorithms may help to identify factors that predict outcomes.

METHODS

This paper systematically reviews these factors associated with LC to select candidate predictor features for a practical application of predictive modeling. A systematic literature search was conducted to identify studies in which the LC of brain metastases is assessed for adult patients. EMBASE, PubMed, Web-of-Science, and the Cochrane Database were searched up to December 24, 2020. All studies investigating the LC of brain metastases as one of the endpoints were included, regardless of primary tumor type or treatment type. We first grouped studies based on primary tumor types resulting in lung, breast, and melanoma groups. Studies that did not focus on a specific primary cancer type were grouped based on treatment types resulting in surgery, SRT, and whole-brain radiotherapy groups. For each group, significant factors associated with LC were identified and discussed. As a second project, we assessed the practical importance of selected features in predicting LC after Stereotactic Radiotherapy (SRT) with a Random Forest machine learning model. Accuracy and Area Under the Curve (AUC) of the Random Forest model, trained with the list of factors that were found to be associated with LC for the SRT treatment group, were reported.

RESULTS

The systematic literature search identified 6270 unique records. After screening titles and abstracts, 410 full texts were considered, and ultimately 159 studies were included for review. Most of the studies focused on the LC of the brain metastases for a specific primary tumor type or after a specific treatment type. Higher SRT radiation dose was found to be associated with better LC in lung cancer, breast cancer, and melanoma groups. Also, a higher dose was associated with better LC in the SRT group, while higher tumor volume was associated with worse LC in this group. The Random Forest model predicted the LC of brain metastases with an accuracy of 80% and an AUC of 0.84.

CONCLUSION

This paper thoroughly examines factors associated with LC in brain metastases and highlights the translational value of our findings for selecting variables to predict LC in a sample of patients who underwent SRT. The prediction model holds great promise for clinicians, offering a valuable tool to predict personalized treatment outcomes and foresee the impact of changes in treatment characteristics such as radiation dose.

Surgical resection versus stereotactic radiosurgery on local recurrence and survival for patients with a single brain metastasis: a systematic review and meta-analysis

BACKGROUND

Brain metastases (BM) are the most frequent intracranial tumours in adults. In patients with solitary BM, surgical resection (SR) or stereotactic radiosurgery (SRS) is performed. There is limited evidence comparing one treatment over the other.

OBJECTIVE

To compare SR versus SRS on patients with solitary BMs, regarding local recurrence (LR) and overall survival (OS) conducting a systematic review and meta-analysis.

METHODS

Systematic review of literature following PRISMA guidelines, using the databases of Medline, Clinicaltrials.gov, Embase, Web of Science, Sciencedirect, CINAHL, Wiley Online Library, Springerlink and LILACS. Following study selection based on inclusion and exclusion criteria, data extraction and a critical analysis of the literature was performed according to the GRADE scale. For quantitative analysis, a random effects model was used. Data were synthetized and evaluated on a forest plot and funnel plot.

RESULTS

Two randomized clinical trials, four cohort studies and one case-control studies met our inclusion criteria for the qualitative analysis. None was excluded subsequently. Overall, 614 patients with single metastasis were included. Studies had high heterogeneity. Multiple significant variables affecting the outcome were signalized. Meta-analysis showed no significant differences for survival (HR, 1.10; 95% CI, 0.75-1.45) or LR (HR, 0.81; 95% CI, 0.42-1.20).

CONCLUSIONS

According to current evidence, in patients with a single small metastasis there is no statistically significant difference in OS or LR among the chosen techniques (SR or SRS). Multiple significant co-variables may affect both outcomes. Different outcomes better than OS should be evaluated in further randomized studies.

[Research Progress in the Treatment of Brain Metastases from Non-small Cell Lung Cancer]

Lung cancer is the leading cause of cancer-related deaths worldwide. The most common pathological type of lung cancer is non-small cell lung cancer (NSCLC). The incidence of brain metastases caused by NSCLC has been on the rise. Brain metastasis seriously affects the patient's cognitive function, survival time and quality of life, and the prognosis is extremely poor. The natural course of the disease is about 1 mon-3 mon. After treatment, the median survival time is only 3 mon-6 mon, the one year survival rate is 14%, and the two years survival rate is only 7.6%. The location, number, and size of brain metastases are related to their symptoms and survival. Patients with central nervous system symptoms have a worse prognosis. The goal of brain metastasis treatment is to optimize overall survival and quality of life, and to prioritize the preservation of neurocognitive functions. At present, the main treatments for brain metastases in NSCLC include radiotherapy, surgery, chemotherapy, molecular targeting, and immunotherapy. Clinically, it is necessary to conduct a multidisciplinary assessment of the best treatment methods for patients according to the heterogeneity of patients (clinical characteristics, pathological types, tissue types, etc). This article aims to review the research progress of current treatment methods.
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Hypofractionated stereotactic radiotherapy for brain metastases from lung cancer : Evaluation of indications and predictors of local control

AIM

To evaluate the efficacy and toxicity of hypofractionated stereotactic radiotherapy (HSRT) for brain metastases (BMs) from lung cancer, and to explore prognostic factors associated with local control (LC) and indication.

PATIENTS AND METHODS

We evaluated patients who were treated with linac-based HSRT for BMs from lung cancer. Lesions treated with stereotactic radiosurgery (SRS) in the same patients during the same periods were analysed and compared with HSRT in terms of LC or toxicity. There were 53 patients with 214 lesions selected for this analysis (HSRT: 76 lesions, SRS: 138 lesions). For HSRT, the median prescribed dose was 35 Gy in 5 fractions.

RESULTS

The 1‑year LC rate was 83.6 % in HSRT; on multivariate analysis, a planning target volume (PTV) of <4 cm(3), biologically effective dose (BED10) of ≥51 Gy, and adenocarcinoma were significantly associated with better LC. Moreover, in PTVs ≥ 4 cm(3), there was a significant difference in LC between BED10 < 51 Gy and ≥ 51 Gy (p = 0.024). On the other hand, in PTVs < 4 cm(3), both HSRT and SRS had good LC with no significant difference (p = 0.195). Radiation necrosis emerged in 5 of 76 lesions (6.6 %) treated with HSRT and 21 of 138 (15.2 %) lesions treated with SRS (p = 0.064).

CONCLUSION

Linac-based HSRT was safe and effective for BMs from lung cancer, and hence might be particularly useful in or near an eloquent area. PTV, BED10, and pathological type were significant prognostic factors. Furthermore, in BMs ≥ 4 cm(3), a dose of BED ≥ 51 Gy should be considered.

Stereotactic body radiation therapy using the CyberKnife(®) system for patients with liver metastases

The aim of this study was to evaluate the efficacy and toxicity of stereotactic body radiation therapy (SBRT) in the treatment of patients with liver metastases. Between August 2006 and July 2011, patients with 1-4 liver metastases were enrolled and treated with SBRT using the CyberKnife(®) system at Tianjin Medical University Cancer Institute and Hospital. The metastases were from different primary tumors, with a maximum tumor diameter of less than 6 cm. The primary endpoint was local control. Secondary endpoints were overall survival, progression-free survival, distant progression-free survival, and adverse events. Fifty-seven patients with 80 lesions were treated with SBRT. The 1-year and 2-year local control rates were 94.4% and 89.7%, respectively. The difference in local control between patients who received adjuvant treatment before SBRT and those who did not reached statistical significance (P=0.049). The median overall survival for the entire cohort was 37.5 months. According to the primary tumor sites, the median overall survival was not reached. The 2-year overall survival rate was 72.2% in the favorable group (primary tumors originating from the colon, breast, or stomach, as well as sarcomas); however, in the unfavorable group (primary tumors originating from the pancreas, lung, ovary, gallbladder, uterus, hepatocellular carcinoma, as well as olfactory neuroblastoma), the median overall survival and 2-year overall survival rates were 37.5 months and 55.9%, respectively (P=0.0001). Grade 1-2 fatigue, nausea, and vomiting were the most common adverse events, and no grade 3 and higher adverse events were observed. With excellent local control in the absence of severe toxicity, SBRT provides an alternative for patients with 1-4 liver metastases who cannot undergo surgery or other treatments.