Linear accelerator radiosurgery for pituitary macroadenomas: a 7-year follow-up study

Area of Science:

• Neurosurgery
• Radiation Oncology
• Endocrinology

Background:

• Pituitary macroadenomas often require treatment for hormone hypersecretion or mass effect.
• Surgical options may be limited for certain pituitary macroadenomas.
• Radiosurgery offers a non-invasive treatment modality for these tumors.

Purpose of the Study:

• To evaluate the efficacy and side effects of linear accelerator-based radiosurgery (LINAC-RS) using a reduced radiation dose for surgically inaccessible pituitary macroadenomas.
• To assess tumor control rates, hormone secretion normalization, and endocrine cure.
• To identify potential risks and complications associated with this treatment approach.

Main Methods:

• A prospective study included 175 patients with pituitary macroadenomas treated with LINAC-RS.
• A reduced therapeutic radiation dose of 20 grays was administered to minimize pituitary function damage.
• 142 patients with a minimum 12-month follow-up were analyzed for outcomes.

Main Results:

• High local tumor control rate (96.5%) and a tumor response rate of 32.4% were observed.
• Normalization of pathologic hormone secretion occurred in 34.3% at 3 years and 51.1% at 5 years.
• Anterior pituitary function deterioration (12.3%) and other radiation-induced side effects were reported.

Conclusions:

• LINAC-RS with a lower dose achieves comparable local tumor control and hormone normalization to gamma-knife radiosurgery.
• The reduced dose may delay the time to normalization or endocrine cure.
• While effective, the lower dose does not completely eliminate the risk of radiation-induced pituitary damage.