Endocrine Abstracts

Introduction: Radiation therapy is an effective treatment for relapsing or recurrent pituitary functioning adenomas, providing tumor volume control and hormone secretion normalization. However, there are several secondary effects to consider.

Aims: To assess the efficacy of radiotherapy in the management of patients with acromegaly and Cushing’s disease (CD) treated in our Department, and the prevalence of radiation secondary effects.

Methods: Retrospective analysis of clinical data, hormonal and radiological parameters of all the patients with acromegaly and CD submitted to radiotherapy from 1989 until present time.

Results: Total of 28 patients, 7♂ (25%) and 21♀ (75%); 75% with acromegaly and 25% with CD. Fractionated external beam radiotherapy was performed in 78.6%, GammaKnife radiosurgery in 14.3% and fractionated stereotactic conformal radiotherapy in 7.1%.

In the acromegaly group, all the patients had previous pituitary surgery. Thirteen patients (61.9%) had also therapy with somatostatin analogs that were discontinued after radiotherapy in 28.6% of the cases. Remission was achieved in 42.9% of the patients after 109.5±68.9 months. Tumor volume reduction was visible in 61.9% of the cases after 85.2±62.4 months.

In the CD group, six patients (85.7%) were previously submitted to surgery. All of them were under steroid synthesis inhibitors for 48.3±66.6 months, which were stopped after radiotherapy in every patient. Remission was achieved in four patients (57.1%), after 70±61.1 months. There was tumor shrinkage in six cases (85.8%), after 67±61.8 months.

The reported secondary effects were: stroke in one patient, meningioma in one, epilepsy in two and dementia in one. Of the 11 (39.3%) patients with previous hypopituitarism, 4 (36.4%) worsened the number of deficits. There was de novo hypopituitarism in nine patients (32.1%).

Conclusion: In this sample, radiotherapy was effective in the normalization of hormonal hypersecretion (remission) in 46.4% of the patients, and tumor volume control (decrease of the tumor residue) in 67.9%. The most prevalent secondary effect was hypopituitarism (68.5%).