3382 - Stereotactic Body Radiation Therapy for Adrenal Metastases: Evaluation of Efficacy and Toxicity Outcomes.

02:30pm - 03:45pm PT

Hall F

Screen: 26

POSTER

Presenter(s)

Mohammad Alsmairat, MD - King Hussein Cancer Center, Amman, Amman

M. Y. Alsmairat¹, Y. Alswaiti², O. Khader³, A. Alzibdeh¹, M. S. Qamber¹, A. Erjan⁴, J. Khader⁵, A. Almousa¹, and W. A. Asha¹; ¹Department of Radiation Oncology, King Hussein Cancer Center, Amman, Jordan, ²The Hashemite University, Amman, Amman, Jordan, ³KHCC, Amman, Jordan, ⁴King Hussein Cancer Center, Amman, Jordan, ⁵King Hussein Cancer Center, Amman 11941, Jordan

Purpose/Objective(s):

Adrenal metastases represent a common site of disease spread in various malignancies. Stereotactic Body Radiation Therapy (SBRT) has emerged as a promising noninvasive treatment option, particularly in patients with oligometastatic or oligoprogressive disease. This retrospective study assesses the efficacy and toxicity of SBRT for adrenal metastases, focusing on local control (LC), survival outcomes, and treatment-related adverse events.

Materials/Methods:

We retrospectively analyzed the records of patients receiving SBRT for adrenal metastases at a single institution between January 2018 and June 2024. Primary adrenal malignancies were excluded. All time-to-event outcomes were calculated from the date of SBRT delivery.

Results:

A total of 20 patients with 24 adrenal metastases received SBRT, including 4 patients who underwent bilateral adrenal treatments. The median patient age was 67 years. Lung cancer was the most common primary malignancy (60%), and 55% of patients had de novo metastatic disease. The median interval between primary tumor diagnosis and detection of adrenal metastases was 10.5 months (range: 0–86). The median lesion diameter was 2.7 cm (range: 1.2–5.8). Most patients received a median dose of 30 Gy (range: 30–45) in 5 fractions. After a median follow-up of 10.5 months (range: 5-26), LC rates at 6 months, 1 year, and 2 years were 87.5%, 59%, and 59%, respectively. Progression-free survival (PFS) rates at 6 months and 1 year were 55% and 21.9%, respectively. The median overall survival (OS) was 15 months, with 1-year and 2-year OS rates of 57.6% and 20.5%. According to RECIST 1.1 criteria, 91.7% of treated lesions demonstrated complete or partial response. Of the 9 patients who were not receiving systemic therapy at the time of SBRT, 6 (67%) remained off systemic treatment at 12 months.

Grade 1–2 acute toxicity occurred in 54.2% of patients, with nausea being the most frequent adverse event (29.2%). No grade =3 acute toxicity was observed. Among 19 patients with documented estimated glomerular filtration rate (eGFR), 11 (57.9%) experienced a decline (median decrease 12.2 mL/min/1.73 m²; range: 0.5–152). Adrenal insufficiency developed in 7 patients (35%).

Conclusion:

This retrospective analysis suggests that SBRT for adrenal metastases provides favorable LC and a longer systemic therapy–free interval in appropriately selected patients. However, the observed declines in renal function and incidence of adrenal insufficiency underscore the importance of vigilant long-term monitoring, careful patient selection, and the determination of an optimal dose regimen to achieve a high therapeutic ratio.