Abstract
Purpose A semantic feature-based reporting proforma for intraoperative
ultrasound findings in brain tumors was devised to standardize reporting. It was
applied as a pilot study on a cohort of histologically confirmed high-grade
supratentorial gliomas (Grade 3 and 4) for internal validation.
Materials and Methods This intraoperative semantic ultrasound proforma was
used to evaluate 3D ultrasound volumes using Radiant DICOM software by 3
surgeons. The ultrasound semantic features were correlated with histological
features like tumor grade, IDH status, and MIB index.
Results 68 patients were analyzed using the semantic proforma. Irregular
crenated was the most common margin (63.2%) and lesions were
heterogeneously hyperechoic (95.6%). Necrosis was commonly seen and
noted as single (67.6%) or multiple (13.2%) in over 80%
cases. A separate perilesional zone, which was predominantly hyperechoic in
41.8% and both hypo and hyperechoic in 12.7%, could be
identified in 54.5% of cases. Grade 4 tumors were more likely to have an
irregular crenated margin (71.2%) with a single large area of necrosis,
while Grade 3 tumors were likely to have smooth (31.3%) or
non-characterizable margins (31.2%) with no or multiple areas of
necrosis. IDH-negative tumors were more likely to have a single large focus of
necrosis. Among the GBMs (52 cases), MIB labelling index of>15%
was associated with poorly delineated, uncharacterizable margins, when compared
with MIB labelling index<15% (23.5 vs. 0%),
(p=0.046).
Conclusion A detailed semantic proforma was developed for brain tumors and
was internally validated. A few ultrasound sematic features were identified
correlating with histological features in high-grade gliomas. It will require
further external validation for refinement and acceptability.
Key words intraoperative - brain - gliomas, semantic features, ultrasound
