Stereotactic Radiosurgery in the Management of Patients With Brain Metastases of Non-Small Cell Lung Cancer: Indications, Decision Tools and Future Directions

Abstract

Brain metastases (BM) frequently occur in non-small cell lung cancer (NSCLC) patients. Most patients with BM have a limited life expectancy, measured in months. Selected patients may experience a very long progression-free survival, for example, patients with a targetable driver mutation. Traditionally, whole-brain radiotherapy (WBRT) has been the cornerstone of the treatment, but its indication is a matter of debate. A randomized trial has shown that for patients with a poor prognosis, WBRT does not add quality of life (QoL) nor survival over the best supportive care. In recent decades, stereotactic radiosurgery (SRS) has become an attractive non-invasive treatment for patients with BM. Only the BM is irradiated to an ablative dose, sparing healthy brain tissue. Intracranial recurrence rates decrease when WBRT is administered following SRS or resection but does not improve overall survival and comes at the expense of neurocognitive function and QoL. The downside of SRS compared with WBRT is a risk of radionecrosis (RN) and a higher risk of developing new BM during follow-up. Currently, SRS is an established treatment for patients with a maximum of four BM. Several promising strategies are currently being investigated to further improve the indication and outcome of SRS for patients with BM: the effectivity and safety of SRS in patients with more than four BM, combining SRS with systemic therapy such as targeted agents or immunotherapy, shared decision-making with SRS as a treatment option, and individualized isotoxic dose prescription to mitigate the risk of RN and further enhance local control probability of SRS. This review discusses the current indications of SRS and future directions of treatment for patients with BM of NSCLC with focus on the value of SRS.

Efficacy and safety of immune checkpoint inhibitors in a Danish real life non-small cell lung cancer population: a retrospective cohort study

“…The therapy of choice for BM in NSCLC patients (without EGF-R or ALK-mutations) has been radiotherapy (RT) until implementation of ICI. Stereotactic radiation surgery is preferred over whole brain radiation (WBRT) in cases with small lesions and a maximum of four lesions [36]. In malignant melanoma, the additional effect resulting in improved OSknown as the abs copal effect of adding RT to ICI in patients with BM has been demonstrated in several studies [37,38].…”

Apatinib and fractionated stereotactic radiotherapy for the treatment of limited brain metastases from primary lung mucoepidermoid carcinoma

“…[ 8 ] Combining cranial radiotherapy (SRS/FSRT) with systemic therapy using targeted agents or immunotherapy is a promising strategy to improve the outcomes of SRS/FSRT for BM in NSCLC. [ 9 ]…”

Emerging treatment strategies for breast cancer brain metastasis: from translational therapeutics to real-world experience

“…Individualized isotoxic dose prescription (IDP) has been advocated to mitigate the risk of radionecrosis and further enhance local control probability of SRS. [73][74][75] For large lesions not amenable to single-session treatment, staged SRS has shown promise, 76 whereas preliminary studies of re-treated lesions report promising rates of tumor control and side effects. [77][78][79] Finally, new approaches that use metabolic and functional imaging for treatment planning may provide more precise and safe targeting for recurrent treated tumors and those near functional structures such as the corticospinal tracts.…”