Stereotactic Radiotherapy for Metastatic Anaplastic Thyroid Cancer: A Single-center Experience and Systematic Review

Anaplastic thyroid cancer (ATC) is a highly aggressive malignancy associated with a limited prognosis. Recent advances in targeted therapies and improved systemic therapy options have led to an increasing number of patients experiencing isolated or limited metastatic progression. Stereotactic radiosurgery (SRS) and stereotactic body radiotherapy (SBRT) have emerged as potential treatment options for metastatic ATC. This prospective observational study aimed to evaluate the role of SBRT and SRS in treating ATC metastases.

Patients with histologically confirmed ATC and an indication for radiotherapy were enrolled at a tertiary care hospital in Munich, Germany from 12/2020 to 01/2025. Treatment-related toxicity was assessed using CTCAE v3, and follow-ups occurred every three months post-radiotherapy. A systematic literature review was conducted using PubMed/Medline, Scopus and Cochrane databases, analyzing studies on SRS and SBRT for ATC metastases.

Our prospective patient cohort enrolled 31 patients, with four (12.9%) receiving SBRT/SRS for metastatic disease. The systematic review identified 11 studies that met the inclusion criteria, of which two were selected for further analysis. Reported overall survival ranged between 2.1 and 3.6 months. Our prospective study demonstrated efficacy of SBRT/SRS in providing symptom relief, accompanied by manageable adverse effects.

SBRT and SRS are viable treatment options for metastatic ATC, providing local tumor control and symptom relief with low toxicity, particularly for bone and brain metastases. However, given the poor prognosis associated with ATC, further research is required to refine patient selection criteria and optimize treatment regimens, particularly in combination with systemic therapy.