RTHP-18. POST-OPERATIVE RADIOTHERAPY FOR PATIENTS WITH FUNCTIONING AND NON-FUNCTIONING PITUITARY ADENOMAS: A SYSTEMATIC REVIEW AND META-ANALYSIS OF 7551 CASES Free

Although surgery is the mainstay of treatment for most pituitary adenomas, post-operative radiotherapy has been shown to be beneficial in improving tumour control and recurrence-free survival. However, due to the potential complications of with radiotherapy, the role of adjuvant radiotherapy in the setting of pituitary adenomas remains unclear. To address this gap, we performed a systematic review and meta-analysis to determine the efficacy and safety of post-operative radiotherapy in the treatment of pituitary adenomas.

A systematic review was performed according to the Meta-analysis Of Observational Studies in Epidemiology (MOOSE) guidelines. We searched PubMed, MEDLINE and Cochrane databases with no language or publication date restrictions, and included studies where patients were treated post-operatively with any form of radiation therapy. Studies reporting on both functioning and non-functioning pituitary adenomas were included. Outcomes were reported as 5- and 10-year progression-free survival, as well as adverse events rates. Forest plots were generated to determine a pooled event rate and 95% confidence interval (CI) for each outcome using a random effect model analysis.

A total of 86 studies from 1986–2017 met the inclusion criteria, with 7551 cumulative patients. Studies included patients with functioning adenomas only (n=12), non-functioning adenomas only (n=12) or both (n=20). The cumulative 5- and 10-year progression-free survival rates were 90.8% (95% CI 86–94%) and 88.6% (95% CI 81–93%), respectively. The overall adverse events rate was 8% (95% CI 5–12%). All outcomes were associated with significant heterogeneity (I2 70%). There were no differences in survival rates or adverse events in relation to study date, tumour pathology, radiosurgery system used or dose of radiation. CONCLUSIONS: Post-operative radiotherapy for pituitary adenomas is effective and safe. Because of the significant heterogeneity and lack of matched controls in the literature, optimum timing and dosage are still unclear. Further prospective studies are needed.