Endocrine Abstracts

Introduction: CyberKnife (CK), an innovative LINAC-based robotic device for frameless stereotactic surgery, is an emerging approach in the management of tumours of the sellar region.

Patients and methods: In total, 14 patients (six men, mean age 52.7 years) with sellar tumours (three craniopharyngiomas and 11 pituitary adenomas) were evaluated. Pituitary adenomas (PA) were non-functioning (7), GH-secreting (2), one GH/TSH-secreting (1) or PRL-secreting (1). Before CK, hypopituitarism had been diagnosed in six patients. CK was performed as first line treatment in one patient with non-functioning adenoma, in one with GH/TSH-secreting adenoma and in one with craniopharyngioma. Tumours were treated with a median coverage of 96.11±2.2% (range, 93.7–98.6%), a median conformity index of 1.37 (range, 1.2–1.63), and a median treatment isodose line of 70% (range, 60–84%). Patients were treated with multiple (2–5) fractions with a BED of 85–105 Gy for alfa/beta 2. The mean follow-up period was 17.7 months (range 4–48 months).

Results: CK induced tumour disappearance in three cases with non-functioning PA (CK was first line treatment in one) and decrease in one with non-functioning PA and in two with craniopharyngioma (CK was first line treatment in one). Five out of eight patients with previously normal pituitary function developed hypopituitarism (one GH deficit and four multiple impairments). Among six patients with previous hypopituitarism, two developed panhypopituitarism while no worsening of pituitary function was seen in the other cases. One acromegalic patient, resistant to medical therapies, reached IGF1 normalization.

Conclusions: This mid-long term evaluation shows that CK induced tumor shrinkage in 43% of cases and in 2/3 of those treated as first line approach. However, hypopituitarism occurred in 62% of patients with normal pituitary function and adjunctive pituitary deficiencies were demonstrated in 33% of the others. Acromegaly control was reached in the patient resistant to other therapies.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.