Radiotherapy for non‐functioning pituitary tumours

Abstract

Pituitary radiotherapy (RT) is often used as adjuvant treatment in the post-operative period for patients with clinically non-functioning pituitary tumours (NFTs). There is a distinct lack of objective data, however, describing the efficacy of RT in preventing the regrowth of these tumours. We have therefore determined whether the recurrence rate for NFTs is significantly lower in patients treated with post-operative RT compared with that observed in patients not treated with RT. A retrospective case notes review was performed on 126 patients with NFTs treated at two institutions in the UK. One hospital routinely administered RT within 12 months of initial pituitary surgery whereas the other used post-operative RT only rarely. The main outcome measure was regrowth of pituitary tumours following surgery in patients who did or did not receive post-operative RT. There was no significant difference between patients who received RT versus those who did not in terms of age, sex, initial tumour size or mode of operation. The actuarial progression-free survival was 93% at both 10 years and at 15 years for the RT treated group, and was 68% and 33%, respectively, for the non-RT-treated group. Using Cox's model for proportional hazard analysis, we found the only prognostic factor for NFT regrowth was the administration of pituitary RT (P < 0.00005). Radiotherapy administered within 12 months of initial pituitary surgery for non-functioning pituitary tumours significantly reduces the risk of tumour regrowth. It remains to be determined whether sequential MRI scanning can help delineate those patients who should receive radiotherapy following pituitary surgery for non-functioning pituitary tumours.