Objective:

To identify predictive factors for progression in postoperative residual findings of non-functioning pituitary macroadenomas (NFPMAs) to support individualized follow-up and adjuvant therapy decisions, particularly in relation to tumor volume.

Key Findings:

• Initial gross total resection (GTR) achieved in 44.3% of patients; 29.2% had durable complete resection without recurrence.
• 35.6% of patients with residual findings showed progression, significantly correlated with larger preoperative tumor volumes (median: 11.6 cm3 vs. 5.81 cm3, p < 0.001).
• Optimal cutoff for distinguishing stable from progressive residual tumor volumes identified at 7.12 cm3 (AUC = 0.748).
• Postoperative cortisol levels were higher in patients with progressive residuals (14.10 μg/dL vs. 10.83 μg/dL; p = 0.022).

Interpretation:

Preoperative and postoperative tumor volumes are significant prognostic markers for progression in NFPMAs, with a critical cutoff of 7.12 cm3 aiding in follow-up strategies and treatment decisions.

Limitations:

• Single-center study may limit generalizability.
• Retrospective design may introduce selection bias.
• Variability in histopathological reporting and follow-up imaging protocols may affect the reliability of findings.

Conclusion:

The study highlights the importance of tumor volume in predicting progression of NFPMAs post-surgery, suggesting a need for tailored follow-up strategies. Further prospective studies are needed to validate these findings.