[Efficacy of external conventional radiotherapy in short and long term control of acromegaly; a comparison with stereotactic irradiation].

AIMS: The aim of this study was to follow up two groups of patients with active acromegaly, who underwent to external irradiation and radio-surgery and to value the efficacy of irradiation in the control of the growth of the adenoma, hypersecretion and incidence of adverse events.

MATERIALS AND

METHODS

In 2 groups of patients, (A) of 47 subjects treated with conventional irradiation at a dose of 45 Gy, (B) of 6 subjects irradiated with stereo taxis radiotherapy at a dose of 15-20 Gy, were evaluated GH, IGF1 levels and pituitary function at 2, 5, 10 and 15 years after treatment. A cerebral MRI scan with detailed study of the sellar region was performed every year.

RESULTS

Group (A): decrease of GH levels in 9% of patients after 2 years from therapy, 29% after 5 years, 52% after 10 years, 77% after 15 years; normalization of IGF1 levels in 8% of cases after 2 years, 23%, 42% and 61% respectively after 5, 10 and 15 years; hypopituitarism in 57, 78, 85% of patients, respectively after 5, 10 and 15 years. Group (B):normalization of IGF1 levels in 4 of 6 patients after 5 years and in all subjects after 10 and 15 years; progressive decrease of GH levels in all patients and GH normalization in 2 of 6 cases after 10 years; hypopituitarism in 1 patient after 2 years.

CONCLUSIONS

We confirm the long term efficacy of external Radiotherapy in active acromegaly. Stereo taxis annuls the risks of neurological and neurovascular complications of conventional RT. Although comparison between the two techniques is not statistical significant in our cases we can affirm a faster normalization of IGF1 levels after stereotactic treatment.