Intra-operative Variation in Size of Brain Tumors after Craniotomy – Observational Comparative Imaging Study

Abstrakt

Background: No previous study to determine the intraoperative changes in the tumor dimensions had been undertaken previously.

Objectives: We planned to evaluate the change in tumor dimensions of intraxial parenchymal tumors after craniotomy by comparing the tumor size on intraoperative ultrasonography (IOUSG) with pre-operative CECT and CEMRI brain.

Study Design: This was a prospective observational study.

Participants: Patients aged 15-65 years undergoing surgery at SKIMS for intraxial parenchymal intracranial tumors were included.

Methods: Standard pre-operative CECT and CEMRI brain were done to measure tumor dimensions and compared with IOUSG.

Results: A total of 51 patients were included.14 patients had a solid tumor with a necrotic component, 12 had a predominantly solid tumor with a cystic component, 10 each in solid tumor and predominantly cystic tumor with the solid component category, and 4 patients had purely cystic tumor. Cystic and solid cystic tumor expanded by >20% after craniotomy on an average on IOUSG as compared to pre-operative CEMRI brain followed by cystic, solid SOL [approximately 15% (p<0.05) ]. Solid tumors and solid tumors with necrotic component had a mean expansion of approximately 10% (p<0.05) . Solid cystic tumors had maximal volume expansion (23.68%) , which was significantly more (p<0.05) as compared to all other tumor categories (solid, solid necrotic, and cystic necrotic solid) except cystic tumors. ‘Ratio of tumor volume on IOUSG to CEMRI, i. e. , intraoperative tumor volume expansion was maximum for grade I gliomas – 1.22, and this achieved significance against grade III gliomas (p=0.005) and grade IV gliomas (p=0.013) .

Conclusion: Tumor volume, as well as surface area, increased after craniotomy, i. e. , tumors, have a tendency to expand.

Implications: This expansion of tumor mass (apart from tumor edema) must also be considered while planning a craniotomy as well as intraoperatively during tumor resection to account for tumor deformation and brain shift.