Fractionated stereotactic radiotherapy in patients with acromegaly: an interim single-centre audit

Abstract

Aim: To evaluate the effect of fractionated stereotactic radiotherapy (FSRT) in acromegaly in a retrospective analysis.

Patients and methods: Thirty-four patients (17 females, median 43 years (range 30-74)) with acromegaly were treated with FSRT (conformal dynamic arcing, dose 54 Gy, 27-30 fractions) between January 1998 and April 2007. Of the 34 patients, 32 had undergone transsphenoidal adenotomy, and 28 were on medical therapy before FSRT. Patients on medical therapy continued this during and after the irradiation. The treatment was gradually decreased/withdrawn after careful assessment.

Results: Magnetic resonance scanning of the pituitary gland 34 months (median, range 11-95) after irradiation showed stable or reduced volume of the remaining tumour tissue in 31 of 34 patients (91%). Seventeen patients (50%) were biochemically controlled (normalised nadir GH during oral glucose tolerance test and IGF1 <+2 S.D.) 30 months after FSRT (median, range 6-60), and ten of them had true biochemical remission (off medical therapy) 30 months after FSRT (median, range 12-69). Of 28 patients with one or more functioning pituitary axes before irradiation, 8 (29%) developed further deficit of one or two pituitary axes 48 months (median, range 6-102) after FSRT. Of 34 patients, 20 still required medical treatment for acromegaly at the end of this study, mainly those with a short follow-up period after irradiation.

Conclusion: The FSRT seems promising in terms of treatment of acromegaly. Longer follow-up is, however, needed to assess the overall efficacy and safety of FSRT for acromegaly.