Endocrine Abstracts

Despite advances in neurosurgical techniques, due to their size and their readily invasive nature, surgical resection of functional or non-functional pituitary macroadenomas is often only partial, justifying the use of any additional treatment (resumption of surgery, radiotherapy, treatment drug).

Patients and Methods: 10 patients were included in the study (7 men middle-aged 56 and 3 women middle-aged 48). 4 patients followed for non-functional pituitary adenomas and 6 for somatotropic adenomas. All patients received conventional radiotherapy (average dose 46.2 Grays) combined with drug treatment. The mode of discovery was either a cranial tumor syndrome (for non-secreting adenomas) or a dysmorphic acquired acromegaly syndrome (for somatotropic adenomas) radiotherapy combined with medical treatment has made it possible to normalize hormone secretion (GH and IGF1) in all patients with acromegaly and tumor reduction in 70% of cases and stabilization in 30% of cases. Regarding post radiotherapy complications are marked by the installation of anterior pituitary insufficiency in all cases within a variable period ranging from 1 to 3 years. The other complications (radionecrosis, stroke, radio-induced tumors) were not seen in this series.

Discussion: All studies find stabilization or a decrease in tumor volume in the majority of cases treated by conventional radiotherapy. The issue of routine radiation therapy after incomplete surgery for a non-secreting adenoma has long been debated. Success of radiation therapy in controlling tumor growth is high, 90–100% in most series, regardless of radiation technique and adenoma subtype. Success in achieving hormonal normalization in secretory tumors is more variable because of differences in patient population, radiation technique, and doses employed and variation of the definition of success. Complete biochemical remission is generally achieved in 50% of patients at 10 yr after treatment for most adenomas. Higher rates of normalization can be achieved with additional medical therapy. Hypopituitarism is an expectant result of radiation therapy. Overall rate of other treatment-related adverse effects is low. Radiation therapy should be considered in the management of patients with pituitary adenomas, particularly when medical and surgical options have been exhausted. Because response evolves slowly over many years and because hypopituitarism is likely to occur, patients should be counseled on the importance of continued endocrinological surveillance and medical management.

Conclusion: Radiation therapy retains a place in the therapeutic arsenal of pituitary adenomas, however in case of hypersecretion the period of effectiveness is a problem because it justifies another antisecretory therapy in the meantime.