Outcomes of Gamma Knife Radiosurgery for Brain Metastases From Anaplastic Lymphoma Kinase Rearrangement-Positive and EGFR Mutation-Positive Non-Small Cell Lung Cancer

Management strategies for intracranial progression in ALK-positive non-small cell lung cancer: a real-world cohort study

PURPOSE

ALK-positive NSCLC patients exhibit a particularly high propensity for the development of brain metastases. Current guidelines suggest transit to next-line therapy (SysTx) or local radiotherapy (RadTx) including whole-brain radiotherapy and radiosurgery. However, the clinical impact of these two strategies remains unclear.

METHODS

We conducted a retrospective analysis focusing on patients with stage IV ALK-positive NSCLC who underwent first-line ALK TKI treatment. Patients with intracranial progression may receive two different treatment strategies: SysTx and RadTx. Our objective was to investigate the outcomes associated with these two distinct treatment pathways.

RESULTS

A total 20 patients of ALK-positive NSCLC who received first-line ALK TKI therapy and subsequently developed intracranial progression were enrolled. About 55% of patients had brain metastasis initially. Nine patients (45%) were treated with crizotinib at first. Patients treated with crizotinib demonstrated a significantly shorter intracranial PFS1 (crizotinib: 8.27 months vs. others: 27.0 months, p = 0.006). Following intracranial progression, approximately 60% of patients transitioned to the next line of systemic treatment (SysTx), while the remaining 40% opted for local cranial radiotherapy (RadTx). Intriguingly, our analysis revealed no statistically significant difference in intracranial progression-free survival (PFS2) between these two distinct treatment strategies. (SysTx: 20.87 months vs. RadTx: 28.23 months, p = 0.461).

CONCLUSION

The intracranial progression-free survival showed no difference between the two strategies suggesting that both local radiotherapy and systemic therapy may be valid options. Individualized strategy, molecular analysis, and multidisciplinary conferences may all play a pivotal role in decision-making.

Comparing Fractionated and Single-Fraction Gamma Knife Radiosurgery for Brain Metastases From Non-Small-Cell Lung Cancer With a Focus on Driver Alterations

Background As the overall survival in non-small-cell lung cancer has increased, safer, long-term treatments for brain metastases are increasingly needed. This study aimed to analyze the outcomes of fractionated and single-fraction gamma knife radiosurgery for brain metastases from non-small-cell lung cancer, focusing on driver alteration status. Methodology Patients who underwent gamma knife radiosurgery as their first local treatment for brain metastases from non-small-cell lung cancer between May 2018 and December 2021 at our institution were retrospectively enrolled. Results Among the 98 patients (287 lesions), 45 (130 lesions) harbored driver alterations, including epidermal growth factor receptor mutations in 35 patients and anaplastic lymphoma kinase or ROS1 rearrangement in 10 patients. Overall, 64 and 34 patients underwent single-fraction and fractionated radiosurgery (3-15 fractions), respectively. Large tumor size was a risk factor for recurrence, while fractionated radiosurgery (subdistribution hazard ratio (sHR) = 16.47; confidence interval (CI) = 3.58-75.77; p < 0.001) and small tumor size (sHR = 1.15; CI = 1.04-1.28; p = 0.008) independently protected against radiation necrosis. In the case-matched analyses, the cumulative radiation necrosis rates were significantly lower in the fractionated group than in the single-fraction group among all lesions (p = 0.017) and among those with driver alterations (p = 0.046), whereas no significant difference was confirmed among wild-type lesions (p = 0.382). Conclusions Fractionated gamma knife radiosurgery may be an alternative therapeutic approach for reducing the risk of radiation necrosis, particularly for patients with driver alterations, even when the tumors are small. Further research is necessary to determine the optimal indications for fractionated gamma knife radiosurgery and fractionation methods.

5-Fraction Re-radiosurgery for Progression Following 8-Fraction Radiosurgery of Brain Metastases From Lung Adenocarcinoma: Importance of Gross Tumor Coverage With Biologically Effective Dose ≥80 Gy and Internal Dose Increase

The criteria for indication of salvage stereotactic radiosurgery (SRS) for local progression following multi-fraction (mf) SRS of brain metastases (BMs) remain controversial, along with the optimal planning scheme. Herein, we described a case of BMs from pan-negative lung adenocarcinoma (LAC), in which the two lesions of local progression following initial eight-fraction (8-fr) SRS were re-treated with 5-fr SRS with the biologically effective dose (BED10) of ≥80 Gy, based on the linear-quadratic (LQ) formula with an alpha/beta ratio of 10. The re-SRS resulted in the alleviation of symptoms and favorable tumor responses with minimal adverse effects during the 7.3-month follow-up. In the lesions of local progression, the gross tumor volume (GTV) coverage with 49.6 Gy (BED10 80 Gy) was generally insufficient, and the GTV dose wes relatively homogeneous with ≥87% isodose covering. In contrast, the 5-fr re-SRS was performed with sufficient GTV coverage with ≤68% isodose of 43 Gy (BED10 80 Gy). Taken together, sufficient GTV coverage with a BED10 of ≥80 Gy and steep dose increase inside the GTV boundary, that is, extremely inhomogeneous GTV dose, are important in 8-fr SRS for ensuring excellent local control of BMs from pan-negative LAC. For local progression following mfSRS that does not fulfill both criteria, re-SRS with the above planning scheme can be an efficacious and safe treatment option for at least six months, especially in cases in which the prior SRS was performed with a dose/fractionation under adequate consideration of brain tolerance. The BED10 seems to be the most suitable for estimating the anti-tumor efficacies of SRS doses in 3-8 fr, similar to that of a single fraction of 24 Gy.

Real-world analysis of different intracranial radiation therapies in non-small cell lung cancer patients with 1–4 brain metastases

Purpose

Stereotactic radiosurgery (SRS) has become a standard approach for the treatment of patients with few metastatic brain lesions. However, the optimal treatment approach for the use radiotherapy in the treatment of non-small cell lung cancer (NSCLC) patients with brain metastases (BMs) remain unclear. This study aimed to compare the survival outcomes and intracranial local control in NSCLC patients with 1–4 BMs who are treated with SRS using linear accelerators (LINAC-SRS), whole-brain radiotherapy (WBRT), or WBRT plus radiotherapy boost (WBRT + RTB).

Materials and methods

We retrospectively analyzed 156 NSCLC patients with 1–4 BMs who received LINAC-SRS, WBRT, and WBRT + RTB. The median overall survival (OS), intracranial progression-free survival (iPFS), and distant brain failure-free survival (DBF-FS) and related prognostic factors were analyzed.

Results

The median follow-up period was 31.6 months. The median OS times in the LINAC-SRS, WBRT, and WBRT + RTB groups were not reached, 33.3 months and 27.9 months, respectively. The difference in survival rate was non-significant (P = 0.909). The 2-year iPFS and DBF-FS rates in the LINAC-SRS, WBRT and WBRT + RTB groups were 51.6% and 37.5%; 42.0% and 50.4%; and 51.1% and 56.1%, respectively. There was no significant difference in 2-year iPFS or DBF-FS among the three groups (P = 0.572 for iPFS, P = 0.628 for DBF-FS). Multivariate analysis showed that the independent adverse prognostic factors for OS, iPFS, and DBF-FS were neurological symptoms, recursive partitioning analysis (RPA) class, and targeted therapy.

Conclusion

LINAC-SRS did not result in significantly superior survival times or intracranial local control compared to WBRT or WBRT + RTB in the treatment of NSCLC patients with 1–4 BMs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-10083-8.