Radiosurgery alone versus radiosurgery plus whole-brain irradiation for very few cerebral metastases from lung cancer

An integrated disease-specific graded prognostic assessment scale for melanoma: contributions of KPS, CITV, number of metastases, and BRAF mutation status

Background

Stereotactic radiosurgery (SRS) remains a mainstay therapy in the treatment of melanoma brain metastases (BM). While prognostic scales have been developed for melanoma patients who underwent SRS treatment for BM, the pertinence of these scales in the context of molecularly targeted therapies remains unclear.

Methods

Through a multi-institutional collaboration, we collated the survival patterns of 331 melanoma BM patients with known BRAF mutation status treated with SRS. We established a prognostic scale that was validated in an independent cohort of 174 patients. All patients with BRAF mutations in this series were treated with BRAF inhibitors. Prognostic utility was assessed using Net Reclassification Index (NRI > 0) and integrated discrimination improvement (IDI) metrics.

Results

In a multivariate Cox proportional hazards model, BRAF mutation status, KPS, number of metastases, and cumulative intracranial tumor volume (CITV) independently contributed to survival prognostication for melanoma patients with SRS-treated BM (P < .05 for all variables). These variables were incorporated into a prognostic scale using the disease-specific graded prognostic assessment (ds-GPA) framework. This integrated melanoma ds-GPA scale was validated in 2 independent cohorts collated through a multi-institutional collaboration. In terms of order of prognostic importance, BRAF mutation status exerted the greatest influence on survival, while KPS, the number of metastases, and CITV exhibited comparable, lesser impacts.

Conclusions

Optimal survival prognostication for SRS-treated patients with melanoma BM requires an integrated assessment of patient characteristics (KPS), tumor characteristics (CITV and number of metastases), and the mutational profile of the melanoma (BRAF mutation status).

The effect of brain metastasis location on clinical outcomes: A review of the literature

It is common clinical practice to consider the location of a brain metastasis when making decisions regarding local therapies and, in some scenarios, estimating clinical outcomes, such as local disease control and patient survival. However, the location of a brain metastasis is not included in any validated prognostic nomogram and it is unclear if this is due to a lack of a relationship or a lack of support from published data. We performed a comprehensive review of the literature focusing on studies that have investigated a relationship between brain metastasis location and clinical outcomes, including patient survival. The vast majority of reports anatomically categorized brain metastases as supratentorial or infratentorial whereas some reports also considered other subdivisions of the brain, including different lobes or with particular areas defined as eloquent cortex. Results were variable across studies, with some finding a relationship between metastasis location and survival, but the majority finding either no relationship or a weak correlation that was not significant in the context of multivariable analysis. Here, we highlight the key findings and limitations of many studies, including how neurosurgical resection might influence the relative importance of metastasis location and in what ways future analyses may improve anatomical categorization and resection status.

Validation of a Survival Score for Patients Receiving Radiosurgery or Fractionated Stereotactic Radiotherapy for 1 to 3 Brain Metastases

BACKGROUND/AIM

We developed a scoring system to predict 1-year survival after radiosurgery for 1-3 brain metastases. This study aimed to validate this system.

PATIENTS AND METHODS

Seventy-six new patients were included in this validation study. Like in the original scoring-system, three factors (age, performance status, extra-cranial metastases) were used. For each factor, 1-year survival rates in % were divided by 10, and the three scoring-points were added for each patient.

RESULTS

Patient's scores were 10, 11, 13, 14, 16 or 17 points with 1-year survival rates ranging between 31% and 80%. Two groups, 10-14 and 16-17 points were formed. In the 14-16 points group, 1-year survival was 47% (versus 33% in the preceding study, p=0.060). In the 16-17 points group, 1-year survival rates were 75% versus 77% (p=0.79).

CONCLUSION

In the more favorable group, the scoring-system was very reproducible. In the less favorable group, the difference was larger, but also not signficant.

Local control and overall survival after frameless radiosurgery: A single center experience

Introduction

Stereotactic radiosurgery (SRS) has been increasingly advocated for 1-3 small brain metastases. The goal of this study was to evaluate the clinical results in patients with brain metastases treated with LINAC-based SRS using a thermoplastic mask (non-invasive fixation system) and Image-Guided Radiotherapy (IGRT).

Material and Methods

In this single-institution study 48 patients with 77 brain metastases were treated between February 2012 and January 2014. The prescribed dose was 20 Gy or 18 Gy as a single fraction. SRS was performed with a True Beam STX Novalis Radiosurgery LINAC (Varian Medical Systems). The verification of positioning was done using the BrainLAB ExacTrac ® X-ray 6D system and cone-beam CT.

Results

In 69 of 77 treated brain metastases (90%) the follow-up was documented on MR imaging performed every 3 months. Mean follow-up time was 10.86 months. Estimated 1-year local control was 83%, using the Kaplan-Meier method. In 7/69 brain metastases (10%) local failure (LF) was diagnosed. Median progression free survival (PFS) was 3.73 months, largely due to distant brain relapse. A GTV of ≤2.0 cm³ was significantly associated with a better PFS than a GTV >2.0 cm³. Extracranial stable disease and GTV ≤2.5 cm³ were significant predictors of OS.We observed 2 cases of radiation necrosis diagnosed by histology after surgical resection. No other cases of severe side effects (CTACE ≥ 3) were observed.

Conclusion

LINAC-based frameless SRS with the BrainLAB Mask using the BrainLAB ExacTrac ® X-ray 6D system for patient positioning is well tolerated, safe and leads to favorable crude local control of 90%. In our experience, local control after frameless (ringless) SRS is as good as ring-based SRS reported in literature. Without invasive head fixation, radiotherapy is more comfortable for patients.

A Neuro-oncologist's Perspective on Management of Brain Metastases in Patients with EGFR Mutant Non-small Cell Lung Cancer

Management of non-small cell lung cancer (NSCLC) with brain metastasis (BrM) has been revolutionized by identification of molecular subsets that have targetable oncogenes. Historically, survival for NSCLC with symptomatic BrM was weeks to months. Now, many patients are surviving years with limited data to guide treatment decisions. Tumors with activating mutations in epidermal growth factor receptor (EGFRact+) have a higher incidence of BrM, but a longer overall survival. The high response rate of both systemic and BrM EGFRact+ NSCLC to tyrosine kinase inhibitors (TKIs) has led to the rapid incorporation of new therapies but is outpacing evidence-based decisions for BrM in NSCLC. While whole brain radiation therapy (WBRT) was the foundation of management of BrM, extended survival raises concerns for the subacute and late effects radiotherapy. We favor the use of TKIs and delaying the use of WBRT when able. At inevitable disease progression, we consider alternative dosing schedules to increase CNS penetration (such as pulse dosing of erlotinib) or advance to next generation TKI if available. We utilize local control options of surgery or stereotactic radiosurgery (SRS) for symptomatic accessible lesions based on size and edema. At progression despite available TKIs, we use pemetrexed-based platinum doublet chemotherapy or immunotherapy if the tumor has high expression of PDL-1. We reserve the use of WBRT for patients with more than 10 BrM and progression despite TKI and conventional chemotherapy, if performance status is appropriate.

The role of stereotactic radiosurgery and whole brain radiation therapy as primary treatment in the treatment of patients with brain oligometastases - A systematic review

The management of patients presenting with a limited number of brain metastases (BM) (oligo-metastases, defined as less than 3 BM) has evolved from Whole-Brain Radiotherapy (WBRT) alone to more aggressive strategies adding surgical resection and Stereotactic Radiosurgery (SRS) to the armamentarium. In choosing treatment modalities, the relative importance of the patient's age and clinical parameters, the number or volume of BM and the potential treatment related adverse-effects has been a matter of much debate. For patients with oligometastatic BM, local therapy using SRS in addition to WBRT was shown to improve time to neurologic deterioration, relapse rate and Overall Survival (OS). In patients who receive local therapy (SRS or surgery), adjuvant WBRT was shown to improve regional (brain) relapse rate. In the contemporary era, the beneficial effect of WBRT on lengthening the time of neurologic independence or OS when compared to no further treatment is unclear. One Meta-analysis pooling of information from several reports concluded that for younger patients (<50 years), SRS alone favored survival and that the initial omission of WBRT did not impact distant brain relapse rates. Other recent reports demonstrated on the contrary an OS benefit, more pronounced in good prognosis patients (diagnosis-specific Graded Prognostic Assessment 2.4-4.0) treated with SRS+WBRT compared to those who received SRS alone. As of today, there remains a role for both SRS and WBRT in the management of patients with oligo-metastatic BM but consensus about when to employ one or both is lacking. The exact patient selection criteria to benefit from either or both are still a matter of active research and heated debate.