Fractionated stereotactic radiotherapy with volumetric modulated arc therapy for pituitary adenoma
Ana Castaño Cantos,
Spain
PO-1123
Abstract
Fractionated stereotactic radiotherapy with volumetric modulated arc therapy for pituitary adenoma
Authors: Ana Castaño Cantos1, Marta Rodriguez Roldan2, Elisabet González del Portillo1, Isabel Garrido Botella1, Macarena Teja Ubach3, Mercedes González Cantero1, Rafael Rosel Aller1, Beatriz Debén Méndez1, Raúl Matute Martín4, Rosa Morera López1
1Hospital Universitario La Paz, Radiotherapy Oncology, Madrid, Spain; 2Hospital Universitario La PAz, Radiotherapy Oncology, Madrid, Spain; 3Hospital Universitario la Paz , Radiotherapy Oncology, Madrid, Spain; 4hospital Universitario La Paz, Radiotherapy Oncology, Madrid, Spain
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Purpose or Objective
Pituitary adenoma (PA) is a histologically benign lesion and constitutes approximately 10% to 20% of primary intracranial tumours. Its management is a therapeutic challenge due to their location. Effective treatment should be decided by a multidisciplinary committee consisting of endocrinologists, neurosurgeons, ophthalmologists, radiologists and radiation oncologists.
Our purpose is to analyse our experience of treatment with conventionally fractionated radiotherapy (CFRT) or hypofractionated stereotactic radiotherapy (HSRT) using VMAT technique.
Material and Methods
Seventeen patients evaluated in the Complex Pituitary Pathology Unit of the Hospital Universitario La Paz, from 2015 to 2022. The mean age at diagnosis was 47 years. Sixteen patients were diagnosed with macroadenoma and only one with microadenoma by MRI. Thirteen of them were hormone-secreting PA and underwent medical treatment and subsequent surgery after failing to achieve reduction and/or hormonal normalisation. All of them required radiotherapy treatment due to tumour growth during follow-up. Five patients had non-functioning AP and treatment consisted of surgery and radiotherapy at follow-up due to relapse. All patients received radiotherapy using VMAT technique: 5 patients received CFRT (50.4Gy/28 fractions) and 11 patients received HSRT (25Gy/5 fractions). Hypofractionated stereotactic radiotherapy was administered on the Infinity linac accelerator with Hexapod system, robust immobilization stereotactic frames/masks and daily volumetric image-guidance in order to reduce movements and volume margins without compromising tumour control.
Results
With a median follow-up of 80 months, patients had no tumour progression after radiotherapy treatment. The control rate for HA is around 90% and 95% for non-functioning HA, according to the literature.
No grade 3-4 side effects were observed during radiotherapy treatment. In the long term no severe side effects have been detected.
Conclusion
Radiotherapy is an effective treatment in the management of PA relapse or progression. Hypofractionated stereotactic radiotherapy with VMAT technique and Hexapod system is a safe treatment that allows stereotactic precision, reduced volume margins and limited toxicity.