Intensity Modulated Radiation Therapy With Simultaneous Integrated Boost in Patients With Brain Oligometastases: A Phase 1 Study (ISIDE-BM-1)

Efficacy and safety evaluation of combined therapies incorporating whole-brain radiotherapy in patients with brain metastases: a systematic review and meta-analysis

BACKGROUND

Whole-brain radiotherapy (WBRT) is a standard and effective approach for brain metastases, but it is linked to neurocognitive complications, specifically issues related to the hippocampus. Innovative strategies are being explored to enhance outcomes. However, a consensus is yet to be reached in this field. Our aim is to investigate the efficacy and safety of WBRT combined with simultaneous integrated boost (SIB), memantine, and hippocampal avoidance (HA) techniques in treatment of brain metastases.

METHODS

In this systematic review and meta-analysis, we comprehensively searched PubMed, MEDLINE, Embase, and Cochrane for studies reporting the efficacy and toxicity of WBRT-based combination therapies from inception to September 19, 2023. Data were pooled using random-effects models. Results were reported as risk ratios (RRs) and risk differences (RDs) for dichotomous outcomes, along with their 95% confidence intervals (CIs). Heterogeneity was evaluated using the I2 statistic.

RESULTS

Among 2175 articles, 29 studies involving 3460 patients were included. The meta-analysis revealed that compared to WBRT alone, combination therapies significantly mitigated neurocognitive function decline (RD = -0.09, 95% CI [-0.18-0.01]; P = 0.03) and intracranial control failure (RR = 0.86, 95% CI [0.52-1.44]; P = 0.02), without increasing the risk of hippocampal recurrence or high-grade toxicities. Notably, HA-WBRT + SIB/memantine demonstrated improved neurocognitive outcomes and survival benefits.

CONCLUSION

WBRT-based combination therapies demonstrate improved efficacy and comparable safety to WBRT alone, with specific emphasis on the effectiveness of HA-WBRT + Memantine and HA-WBRT + SIB in optimizing therapeutic outcomes for brain metastases.

Immunotherapy combined with cranial radiotherapy for driver-negative non-small-cell lung cancer brain metastases: a retrospective study

Background: This study assesses immune checkpoint inhibitors' efficacy for non-small-cell lung cancer (NSCLC) with brain metastases (BM) and explores the role of cranial radiation therapy (CRT) in the immunotherapy era. Methods: The retrospective analysis screened NSCLC patients with BMs from July 2018 to December 2021. Treatment involved chemotherapy combined with immune checkpoint inhibitors as the first-line, with patients divided into CRT and non-CRT groups. Overall survival (OS), progression-free survival and intracranial progression-free survival were calculated and compared. Results: Among 113 patients, 74 who received CRT had significantly better median OS (not reached vs 15.31 months), particularly among those with one to three BMs. Factors correlating with better OS included CRT, PD-L1 expression and diagnosis-specific graded prognostic assessment scores. Conclusion: Integrating CRT with anti-PD-1 therapy notably enhanced long-term survival in NSCLC patients with BMs.

The First Survival Score for Patients Treated with Whole-Brain Radiotherapy Plus Simultaneous Integrated Boost for Brain Metastases

A modern approach for brain metastases includes whole-brain radiotherapy plus simultaneous boost (WBRT+SIB). We developed a survival score in 128 patients treated with WBRT+SIB. Three models, each including three prognostic groups, were created. Positive predictive values (PPVs) for death ≤6 and survival ≥6 months were calculated. On multivariate analyses, performance score (KPS) and the number of brain metastases were significantly associated with survival. On univariate analyses, age showed a strong trend, and extra-cerebral cranial metastases a trend. In Model 1 (KPS, number of lesions), compared groups had 6-month survival rates of 15%, 38% and 57%. In Model 2 (KPS, lesions, age), rates were 17%, 33% and 75%, and in Model 3 (KPS, lesions, age, extra-cerebral metastases), 14%, 34% and 78%. PPVs for death ≤6 and survival ≥6 months were 85% and 57% (Model 1), 83% and 75% (Model 2), and 86% and 78% (Model 3). Thus, all models were accurate in predicting death ≤ 6 months; poor-prognosis patients may not benefit from SIB. Models 2 and 3 were superior in predicting survival ≥ 6 months. Given that Model 3 requires more data (including extensive staging), Model 2 is considered favorable for many patients. If extra-cerebral metastases are already known or extensive staging has been performed, Model 3 can also be used.

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

IMPORTANCE

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

OBJECTIVE

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

DATA SOURCES

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

STUDY SELECTION

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

DATA EXTRACTION AND SYNTHESIS

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

MAIN OUTCOMES AND MEASURES

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

RESULTS

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

CONCLUSIONS AND RELEVANCE

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

Optimizing Whole Brain Radiotherapy Treatment and Dose for Patients With Brain Metastases From Small Cell Lung Cancer

Purpose

This study aimed to evaluate the survival outcomes of whole brain radiotherapy (WBRT) compared to whole brain radiotherapy plus local radiation boost (WBRT + boost), and further identify whether higher biologically effective dose (BED) of WBRT + boost translates into a survival benefit in small cell lung cancer (SCLC) patients with brain metastasis (BM).

Methods

SCLC patients with BM from January 1, 2012, to December 31, 2019, were retrospectively analyzed. Overall survival (OS) and intracranial progression-free survival (iPFS) were evaluated by the Kaplan–Meier method and compared by the log-rank test. Univariate and multivariate regression analyses of prognostic factors for OS were performed using Cox proportional hazards regression models. The cutoff value of BED was determined by the receiver operating characteristic (ROC) curve analysis.

Results

Among the 180 eligible patients, 82 received WBRT + boost and 98 received WBRT. Both OS and iPFS in the WBRT + boost group were significantly superior to those in the WBRT group (median OS: 20 vs. 14 months, p = 0.011; median iPFS: 16 vs. 10 months, p = 0.003). At a cutoff value of 58.35 Gy in the WBRT + boost group, 52 for the high-BED (>58.35 Gy) group, 30 for the low-BED (≤58.35 Gy) group. High BED was significantly associated with improved OS and iPFS compared with low BED in the WBRT + boost group (median OS: 23 vs. 17 months, p = 0.002; median iPFS: 17 vs. 10 months, p = 0.002).

Conclusions

Compared with WBRT alone, WBRT + boost improved OS and iPFS in SCLC patients with BM. High BED (>58.35 Gy) for WBRT + boost may be a reasonable consideration for SCLC patients with BM.

Re-irradiation of recurrent glioblastoma using helical TomoTherapy with simultaneous integrated boost: preliminary considerations of treatment efficacy

Although there is still no standard treatment for recurrent glioblastoma multiforme (rGBM), re-irradiation could be a therapeutic option. We retrospectively evaluated the efficacy and safety of re-irradiation using helical TomoTherapy (HT) with a simultaneous integrated boost (SIB) technique in patients with rGBM. 24 patients with rGBM underwent HT-SIB. A total dose of 20 Gy was prescribed to the Flair (fluid-attenuated inversion recovery) planning tumor volume (PTV) and 25 Gy to the PTV-boost (T1 MRI contrast enhanced area) in 5 daily fractions to the isodose of 67% (maximum dose within the PTV-boost was 37.5 Gy). Toxicity was evaluated by converting the 3D-dose distribution to the equivalent dose in 2 Gy fractions on a voxel-by-voxel basis. Median follow-up after re-irradiation was 27.8 months (range 1.6-88.5 months). Median progression-free survival (PFS) was 4 months (95% CI 2.0-7.9 months), while 6-month PFS was 41.7% (95% CI 22.2-60.1 months). Median overall survival following re-irradiation was 10.7 months (95% CI 7.4-16.1 months). There were no cases of re-operation due to early or late toxicity. Our preliminary results suggest that helical TomoTherapy with the proposed SIB technique is a safe and feasible treatment option for patients with rGBM, including those large disease volumes, reducing toxicity.

Brain metastases of lung cancer: comparison of survival outcomes among whole brain radiotherapy, whole brain radiotherapy with consecutive boost, and simultaneous integrated boost

PURPOSE

Radiotherapy is the mainstay for treating brain metastasis (BM). The objective of this study is to evaluate the overall survival (OS) of patients with BM of lung cancer treated with different radiotherapy modalities.

METHODS

Patients with BM of lung cancer who underwent radiotherapy between July 2007 and November 2017 were collected, and their baseline demographics, clinicopathological characteristics and treatments were recorded. Survival was estimated by the Kaplan-Meier method and compared by using the log-rank test. Univariate and multivariate analysis of the prognostic factors were performed using the Cox proportional hazard regression model.

RESULTS

A total of 144 patients were enrolled, of whom 77 underwent whole-brain radiotherapy (WBRT), 39 underwent whole brain radiotherapy with consecutive boost (WBRT + boost), and 28 underwent integrated simultaneous integrated boost intensity-modulated radiotherapy (SIB-IMRT). The OS in SIB-IMRT group was significantly longer than that in WBRT group (median OS 14 (95% confidence interval [CI] 8.8-19.1) vs.7 (95% CI 5.5-8.5) months, log-rank p < 0.001) and WBRT + boost group (median OS: 14 (95% CI 8.8-19.1) vs.11 (95% CI 8.3-13.7) months, log-rank p = 0.037). Multivariable analysis showed that mortality risk of patients treated with SIB-IMRT decrease by 56, 59, 64 and 64% in unadjusted model (hazard ratio [HR] = 0.44; 95% CI 0.28-0.70, p < 0.001), model 1 (HR = 0.41; 95% CI 0.26-0.65, p < 0.001), model 2 (HR = 0.36; 95% CI 0.21-0.61, p < 0.001), and model 3 (HR = 0.36; 95% CI 0.21-0.61, p < 0.001).

CONCLUSIONS

For patients with BM of lung cancer, SIB-IMRT seems to be associated with a more favorable prognosis.