Long-Term Results Of Stereotactic Radiosurgery In Secretory Pituitary Adenomas

Frederic Castinetti, Mariko Nagai, Isabelle Morange, Henry Dufour, Philippe Caron, Philippe Chanson, Christine Cortet-Rudelli, Jean-Marc Kuhn, Bernard Conte-Devolx, Jean Regis,  and Thierry Brue*

Service d'Endocrinologie, diabète et maladies métaboliques, et Centre de reference des maladies rares d'origine hypophysaires DEFHY, Hôpital de la Timone, Marseille, France; Service de neurochirurgie fonctionnelle stereotaxique, Hôpital de la Timone, Marseille, France; Service de Neurochirurgie, Hôpital de la Timone, Marseille, France; Service d'Endocrinologie - Maladies métaboliques – Nutrition - CHU de Toulouse - Hôpital Larrey - Pôle Cardio-Vasculaire et Métabolique - 24 Chemin de Pouvourville TSA 30030 FR-31059 TOULOUSE CEDEX 9 France; Assistance Publique-Hôpitaux de Paris, Service d'Endocrinologie et des Maladies de la Reproduction, Hôpital de Bicêtre, Université Paris Sud 11, INSERM U693. F-94275 Le Kremlin-Bicêtre, France; Centre Hospitalier Universitaire de Lille, 58 Avenue de l'Amiral Courbet FR-59130 LAMBERSART France; Institut Fédératif de Recherches Multidisciplinaires sur les Peptides - INSERM U 413 - UA CNRS IFRMP 23- CHU de Rouen - 147 Avenue du Maréchal Juin - FR-76230 BOIS-GUILLAUME France

* To whom correspondence should be addressed. E-mail: thierry.brue@mail.ap-hm.fr.

Context: To date, no study reported long-term follow-up results of Gamma Knife stereotactic radiosurgery (SR).

Objective: To determine long-term efficacy and adverse effects of SR in secreting pituitary adenomas.

Design: Retrospective study of patients treated by SR in the center of Marseille, France, with a follow-up at least equal to 60 months.

Patients: 76 patients were treated by SR for acromegaly (n=43), Cushing's disease (CD, n=18) or prolactinoma (n=15), as a primary (n=27) or adjunctive post-surgical treatment (n=49).

Main Outcome Measures: After withdrawal of antisecretory drugs, patients were considered in remission if they had mean GH levels < 2 ng/ml and normal IGF1 (acromegaly), normal 24h urinary free cortisol and cortisol < 50 nmol/l after low dose dexamethasone test (CD), or 2 consecutive normal samplings of prolactin levels (prolactinoma).

Results: After a mean follow-up of 96 months, 44.7% of the patients were in remission. Mean time to remission was 42.6 months. Twelve patients presented late remission at least 48 months after SR. Two patients with CD presented late recurrence 72 and 96 months after SR. Forty percent of patients treated primarily with SR were in remission. Target volume and initial hormone levels were significant predictive factors of remission in univariate analysis. Radiation-induced hypopituitarism was observed in 23% patients; in half of them, hypopituitarism was observed after a mean time of 48 to 96 months. Twenty-four patients were followed more than 120 months: rates of remission and hypopituitarism were similar to the whole cohort.

Conclusions: SR is an effective and safe primary or adjunctive treatment in selected patients with secreting pituitary adenomas.

Key words: gamma knife • radiosurgery • stereotactic radiosurgery • radiotherapy • acromegaly • Cushing's disease • prolactinoma

From http://jcem.endojournals.org/cgi/content/abstract/jc.2008-2772v1