Endocrine Abstracts

Background: Stereotactic radiotherapy techniques have been recently employed in the control of skull base tumours, such as pituitary edenomas, craniopharyngiomas and meningiomas.

Purpose: To assess the long-term endocrinological effect of fractionated stereotactic conformal radiotherapy (SCRT) in patients with residual and recurrent sellar and parasellar tumours treated at Royal Marsden Hospital.

Patients and methods: 245 patients (median age 50 years) with residual or recurrent pituitary adenomas (n=98), meningiomas (n=108) and craniopharyngiomas (n=39) were treated between 1995 and 2004 at The Royal marsden Hospital. 102 patients had partial or complete hypopituitarism before SCRT (69, 29 and 5 patients with pituitary adenomas, craniopharyngiomas and meningiomas), including 44 with a complete and 58 with a partial hypopituitarism. Patients were treated supine and immobilized in a Gill-Thomas-Cosman relocatable frame. High-resolution planning CT scan was fused with magnetic resonance imaging (MRI) scan. The treatment was delivered by 4–6 noncoplanar conformal fixed fields using a 6-MV linear accelerator to a dose of 45–55 Gy in 25–33 fractions.

Results: At a median follow-up of 38 months (range 3–120) the 5 year actuarial progression free is 98.9%, 93%, 92% and overall survival is 98%, 97% and 100% for adenomas, meningiomas and craniopharyngiomas. The treatment was well tolerated with minimal acute and long-term toxicity. Hypopituitarism was the most common long-term effect and 26%, 42% and 6% of patients with a pituitary adenoma, a craniopharyngioma and a meningioma worsened pituitary function. Hypopituitarism was more common in patients with pre-SCRT pituitary hormone abnormalities.

Conclusion: SCRT is an effective treatment for patients with benign skull base tumours and is associated with low toxicity. Tumour control was equivalent to that seen following conventional radiotherapy and radiosurgery. Longer follow-up is needed to assess a potential reduction in long-term morbidity. Hypopituitarism develops in a significant number of patients requiring a regular follow-up in these patients.