Long-term follow-up results of postoperative radiation therapy for Cushing's disease.
OBJECTIVE
Radiotherapy is currently used in patients with residual or recurrent pituitary adenomas after surgery. However, there is little information of long-term outcome of patients with Cushing's disease following radiotherapy. We assessed the long-term efficacy and toxicity of conventional radiotherapy in the control of Cushing's disease after unsuccessful transsphenoidal surgery.


METHODS
Forty patients with Cushing's disease were treated with conventional external beam radiotherapy at our Institution between 1988 and 2002. The median age was 38. All patients received radiotherapy following unsuccessful surgery or at tumour recurrence to a dose of 45-50 Gy in 25-28 fractions. The persistence of active disease after surgery was diagnosed by the increased high plasma cortisol levels, high 24 h urinary cortisol levels and absence of cortisol suppression after administration of dexamethasone.


RESULTS
The 5 and 10 year local tumour control was 93% and the 5 and 10 year survival was 97 and 95%. Normalization of plasma cortisol was seen in 28% of patients at 1 year, 73% at 3 years, 78% at 5 years and 84% at 10 years. The average timing to remission was 24 months. The most common side effect was hypopituitarism that increased progressively during the follow-up, being present in 62% and in 76% of patients at 5 and 10 years after RT. There were no other serious complications as radiation induced optic neuropathy or second tumours.


CONCLUSIONS
Radiotherapy is effective in the long-term tumour- and hormone hypersecretion control of ACTH-secreting pituitary adenomas, however with a high prevalence of hypopituitarism. At the moment, it remains an important treatment option after failure of surgery.
Minniti
Giuseppe
G
Department of Radiotherapy Oncology, Sant'Andrea Hospital, University of Rome La Sapienza, Via di Grottarossa 1035à, 00189, Rome, Italy. Giusepe.Minniti@ospedalesantandrea.it
Osti
Mattia
M
Jaffrain-Rea
Marie Lise
ML
Esposito
Vincenzo
V
Cantore
Giampaolo
G
Maurizi Enrici
Riccardo
R
D049913:ACTH-Secreting Pituitary Adenoma / Q000097:blood / Q000532:radiotherapy* / Q000601:surgery; D000236:Adenoma / Q000097:blood / Q000532:radiotherapy* / Q000601:surgery; D000328:Adult; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000532:radiotherapy*; D018365:Neoplasm, Residual / Q000532:radiotherapy*; D047748:Pituitary ACTH Hypersecretion / Q000097:blood / Q000532:radiotherapy* / Q000601:surgery
D006854:Hydrocortisone