Linear regression models predict survival and complication rates in patients undergoing gamma knife radiosurgery for recurrent and residual craniopharyngiomas: a meta-analysis of 743 tumors.

PURPOSE: Craniopharyngiomas are clinically aggressive benign tumors that present a special challenge for clinicians due to high recurrence rates and post operative compilations. Surgical intervention alone poses many challenges and therefore, the use of radiotherapeutic adjuvant modalities has become common. This study aims to evaluate the effectiveness of gamma knife radiosurgery (GKRS) in the management of recurrent and residual craniopharyngiomas and identify the factors that could predict survival and complication rates.

METHODS

PubMed and Cochrane library were screened from inception until September 2024. Fixed effect models (I2 < 50%) and Random effects models (I2 > 50%) were created to study the pooled survival rates and complication rates. Linear Regression models were generated to identify the prognostic factors and F-test was used to check the significance of the models.

RESULTS

The meta-analysis included 743 tumors from nine selected studies. Estimated 3, 5 and 10 year OS rates were 96%, 93% and 85% respectively and estimated 3, 5 and 10 year PFS rates were 83%, 68% and 45% respectively. Estimated visual (VD) and endocrinological dysfunction (ED) rates were 5% and 4% respectively. Median marginal dose ≤ 13 Gy was the independent predictor of 3 year OS (β = 1.95, p = 0.02), while female patients (β=-0.52, p = 0.023), age (β=-0.36, p = 0.04) and median marginal dose ≤ 13 Gy (β = 2.55, p = 0.001) were found to be significant predictors of 5 year OS. F-test revealed that the models generated for 3 year and 5 year OS rates were significant with an excellent R2 values of 0.99 (p = 0.03) and 0.98 (p = 0.008) respectively. Age was the single significant predictor of VD (β=-0.80, p = 0.032) while tumor volume (β = 0.61, p = 0.035) and median marginal dose ≤ 13 Gy (β=-1.17, p = 0.039) were significant predictors of ED.

CONCLUSIONS

GKRS is an effective treatment modality for recurrent and residual craniopharyngiomas, providing comparable to improved survival rates to other modalities and significantly lower complication rates with a safe dose of ≤ 13 Gy.