Focal radiation therapy for patients with persistent/recurrent pituitary adenoma, despite previous radiotherapy.

With the stricter endocrine definitions of cure following conventionally planned and fractionated radiotherapy for functioning pituitary adenomas, together with the move in the profession (since the advent of high quality MRI) to postpone radiation therapy until macroscopic disease appears after surgery, it is now realised that cure rates following conventional radiotherapy approximate three out of four rather than the >90% cited for more than a decade. Patients with persistent active tumours may be successfully further treated by focal radiation therapy by one of the stereotactic focal techniques. We have experience of such re-treatment radiation therapy in 50 patients. With careful case selection, we here demonstrate that in acromegaly, for example, normalisation of both GH and IGF levels may be achieved in 37-58% of these previously irradiated patients with low risk of late morbidity. Unquestionably, growth delay occurs in many cases but the long term tumour control rate has yet to be established.