Volume specific response criteria for brain metastases following salvage stereotactic radiosurgery and associated predictors of response.

BACKGROUND: We aimed to derive three-dimensional volume-based (V(3D)) response criteria that approximate those based on Response Evaluation Criteria in Solid Tumours (RECIST) in patients with brain metastases (BM) treated with salvage stereotactic radiosurgery (SRS). MATERIAL AND METHODS: Seventy patients with 178 BM were treated with SRS. Each BM was characterised at baseline and at each follow-up MRI according to its widest diameter and V(3D) using ITK-SNAP image segmentation software. RESULTS: The median tumour diameter was 1.2 cm (range, 0.2-4.5 cm) and V(3D) was 0.73 cm(3) (range, 0.01-22.7 cm(3)). The V(3D) percent changes that best matched RECIST response criteria were: an increase of ≥71.5% for progressive disease, a ≥58.5% decrease for partial response and a <58.5% decrease or increase of <71.5% for stable disease (k =0.85). A baseline diameter >3.0 cm (p =0.006) and a V(3D) >6.0 cm(3) (p =0.043) predicted for local failure, and a baseline cumulative V(3D) of >3.0 cm(3) (p =0.02) was adversely prognostic for survival. CONCLUSIONS: We define 3D volume specific criteria to base response upon for brain metastases treated with salvage SRS. Tumours with a V(3D) of greater than 6 cm(3) are at a higher risk of local failure.

The Value and Potential of Qualitative Research Methods in Neurosurgery.

OBJECTIVE: To explore the value and potential of qualitative research to neurosurgery and provide insight and understanding to this underused methodology. METHODS: The definition of qualitative research is critically discussed and the heterogeneity within this field of inquiry explored. The value of qualitative research to the field of neurosurgery is articulated through its contribution to understanding complex clinical problems. DISCUSSION: To resolve some of the misunderstanding of qualitative research, this paper discusses research design choices. We explore approaches that use qualitative techniques but are not, necessarily, situated within a qualitative paradigm in addition to how qualitative research philosophy aids researchers to conduct interpretive inquiry that can reveal more than simply what was said by participants. Common research designs associated with qualitative inquiry are introduced, and how complex analysis may contribute more in-depth insights is explained. Approaches to quality are discussed briefly to support improvements in qualitative methods and qualitative manuscripts. Finally, we consider the future of qualitative research in neurosurgery, and suggest how to move forward in the qualitative neurosurgical evidence base. CONCLUSIONS: There is enormous potential for qualitative research to contribute to the advancement of person-centered care within neurosurgery. There are signs that more qualitative research is being conducted and that neurosurgical journals are increasingly open to this methodology. While studies that do not engage fully within the qualitative paradigm can make important contributions to the evidence base, due regard should be given to immersive inquiry within qualitative paradigms to allow complex, in-depth, investigations of the human experience.

Exploratory Analysis into Reasonable Timeframes for the Provision of Neurosurgical Care in Low- and Middle-Income Countries.

BACKGROUND: In low- and middle-income countries (LMICs), 11.8% of the need for neurosurgical care is met. Delays in seeking and receiving care may further exacerbate this situation. Objective analysis of delay and its consequences is contingent on reference to established resource-appropriate acceptable timeframes. This study sought to 1) establish an estimate of the landscape of care provided in LMICs and 2) explore reasonable timeframes for various stages of patient-health care interaction. METHODS: Consensus input from neurosurgeons in select LMICs was collected; 1 high-income country was included for comparison. In phase 1, participants were asked to select neurosurgical procedures performed at their centers. In phase 2, based on procedures shared among all LMICs, representative case scenarios were generated and participants provided input on acceptable timeframes for each stage of patient-health care interaction: 1) presentation to health services, 2) diagnosis by primary care physician, 3) referral to neurosurgical specialist care, and 4) definitive neurosurgical management. RESULTS: Twenty neurosurgeons across 18 centers were identified; 12 participated in phase 1 and 7 in phase 2. The range of procedures offered was broad, similar in scope to high-income countries, and included pediatric and adult neurosurgery, trauma, degenerative spine, and hemorrhagic stroke. Acceptable timeframes had wide ranges in certain cases; however, the overall trend showed agreement between the participants. CONCLUSIONS: This exploratory analysis identified reasonable timeframes for the provision of neurosurgical care in LMICs. If validated, these data can be used to more objectively assess the prevalence of delay in neurosurgical care in individual LMICs, along with its consequences.