OBJECTIVE

To investigate the impact of resection quality on subsequent survival of patients with glioblastoma.

MATERIAL AND METHODS

There were 141 patients with morphologically confirmed glioblastoma (grade 4). Fractionation with the prescribed dose of 2 and 3 Gy was alternately used (pairwise modeling strategy). Total resection was performed in 29.8% of patients (EOR: 100%; n=42), subtotal — 56.7% (EOR: 70-99%; n=80). Extent of resection 1—69% was registered in 19 patients (13.5%).

RESULTS

As of December 2022, 124 out of 141 patients (87.9%) were diagnosed with primary progression, 101 (71.6%) ones died. We analyzed the threshold role of EOR. The most informative level was 70% (p=0.002). EOR 100% was followed by median overall survival about 32.2 months (95% Cl: 15.3—49.1), EOR 70—99% — 21.3 months (95% Cl: 15.1—27.5), EOR 1-69% — 10.3 months (95% Cl: 3.8—16.9; p=0.003). Fractionation mode with the prescribed dose of 3 Gy partially eliminated significance of EOR (p=0.148) in contrast to standard fractionation (p=0.015). Tumor growth in the interval between surgery and radiotherapy (REP) reduces significance of EOR (p=0.042). Inclusion of second-line therapy with bevacizumab in multivariate analysis model (OR=0.488; p=0.002) makes EOR less significant (OR=0.749; p=0.085) in contrast to REP (OR=2.482; p<0.0001).

CONCLUSION

To date, the principle of maximum safe resection remains fundamental in neurosurgery. EOR about 70% is sufficient regarding overall survival, but total resection should be sought if possible.