2023 American Academy of Neurology Abstract Website

Objective:

To assess the distribution of RCC BrM in clinical context.

Background:

RCC frequently presents with hemorrhagic BrMs. BrM distribution patterns and their associations with lab/clinical parameters are poorly understood.

Design/Methods:

We performed a retrospective analysis including RCC patients who underwent BrM resection at our institution. We reviewed gadolinium-enhanced MRI brain and CT head at the time of BrM diagnosis and assessed the presence of hemosiderin (MRI) or hemorrhage (CT) in the BrM. BrMs were marked in their corresponding anatomic location in a brain template. Public brain atlases (Faria and Liu 10.25790/bml0cm.109; Vachet, SCR_002606) were used for distribution analysis. Serum markers were correlated with imaging.

Results:

A total of 67 BM were analyzed from 46 patients (age 63±10years/35M), 23 synchronous BM, 9 patients had two, 6 had 3 concurrent BrMs. 97% of the lesions were spheric in shape. Mean 1D and 2D (RANO) tumor dimensions were 2.0±1.1cm and 4.7±4.9cm², respectively and correlated with neutrophil count at BrM diagnosis (r=0.3, p=0.01). Multilobar edema was seen in 36% of BrM. 82% of BrMs contained hemosiderin and 80% were hemorrhagic. Most BrMs were in the frontal (45%), parietal (21%) and occipital (18%) lobes. Posterior cerebral artery distribution contained 34% of BrM despite it supplying only 16% of brain volume. Higher platelet counts were associated with BrMs in the posterior circulation territories (p=0.05).

BrM hemosiderin was associated with larger tumors (p=0.04), lower platelet counts (p=0.01) and higher hemoglobin (p=0.08). Renal vein thrombosis (RVT) at primary diagnosis was associated both BrM hemosiderin (p=0.05) and hemorrhage (p=0.03). CNS progression-free survival was shorter in those who had RVT (p=0.04), or had BrM hemosiderin (p=0.04).

Conclusions:

The presented mapping method offers an objective and efficient way to assess lesion distribution that reveals clinically relevant patterns. BrM hemosiderin deposits are linked to lower platelet counts and may provide prognostic information. Further analyses are underway.