ESTRO 2025 - Abstract Book

S751

Clinical - CNS

ESTRO 2025

4307

Digital Poster Beyond the treatment: lasting outcomes of fractionated stereotactic radiotherapy in pituitary adenoma Sara Perez Mata, Jesus Romero Fernandez, Maria Isabel Garcia Berrocal, Maria Hernandez Miguel, Sofia Cordoba Largo, Sofia Santana Jimenez, Mariela Rojas Quesada, Carlota Cascajares Sanz, Beatriz Gil Haro, Raquel Benlloch Rodriguez, Marta Lopez Valcarcel, Cristina de la Fuente Alonso, Irma Zapata Paz, Joaquin Velasco Jimenez, Arancha Gallego Barranco, José Cantilla Barrenas, Susana Sanchez Rico, Peppa Abelairas Ramos, Irene Avila Gomez, Clara Caballero Valls Radiotherapy oncology, Hospital Universitario Puerta de Hierro, Madrid, Spain Purpose/Objective: Pituitary adenomas are benign tumors treated surgically, often complemented with medical therapy. When surgery is not possible or there is a residual growth disease, fractionated stereotactic radiotherapy (FSRT) is an alternative. This study aims to evaluate hormonal, local-control and safety data for patients treated with fractionated stereotactic radiotherapy FSRT at our center. Material/Methods: We analyzed 99 adenoma cases treated between 2010 and 2023. Patients underwent brain MRI, hormonal tests, and ophthalmologic check-ups. Results: The mean age at diagnosis was 53 years (53.5 +/-2.56). Forty-three patients (43.4%) were men and fifty-six (56.6%) were women. Thirty-nine patients present secretory adenoma (twenty-one were GH secreting, eleven ACTH secreting, one TSH secreting, three prolactinomas and three present other type or multiple secretion). Sisty patients (60.6%) non-functioning adenoma. All patients received 50.4 Gy (1.8 Gy/fraction) and were treated with FSRT in Novalis (84.8%), Tomotherapy (3.1%) and TrueBeam (12.1%) equipment. The mean PTV size was 15 cm3 (15.19+/- 2.76). Before radiotherapy, 99% had a prior surgery and 47.5% needed medical treatment. Median follow-up was 83.29 months (1-161). IGF-1 (p<0.001) and cortisol (p<0.009) levels showed a significant decrease in GH and ACTH-producing adenomas respectively. GH, ACTH and prolactin levels decrease was observed, with a trend towards statistical significance in GH, ACTH and prolactin-producing adenoma. Only one case of THS- producing adenoma was reported. 90.5% of GH-producing adenoma, 90% of ACTH-producing adenoma, and all TSH-producing adenoma and prolactinoma did not have hormone hypersecretion post-radiotherapy.