Ablative magnetic resonance-guided radiation for gastrointestinal neuroendocrine tumors: assessing local control and toxicity.

BACKGROUND

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are an indolent subset of neuroendocrine neoplasms with a propensity to metastasize. In the case of oligoprogression, locoregional therapies are considered but may not be suitable for all patients. Stereotactic body radiotherapy, including magnetic resonance-guided radiotherapy (MRgRT), has emerged as an option to optimize local control and mitigate toxicity.

OBJECTIVE

This study aims to evaluate the efficacy and safety of MRgRT for treating patients with GEP-NETs, focusing on local control and treatment-related toxicity.

METHODS

A retrospective review was conducted on 25 patients diagnosed with abdominal neuroendocrine neoplasms and treated with MRgRT from 2019 to 2023. After excluding patients with neuroendocrine carcinomas and other noneligible conditions, 20 patients with well-differentiated GEP-NETs were included in the final analysis. Primary endpoints were local control and radiation toxicity; secondary endpoints were progression-free survival and overall survival calculated from the date of MRgRT.

RESULTS

The study cohort had a median follow-up of 44.5 months. MRgRT was well-tolerated, with only two (10%) patients experiencing acute grade 3 treatment-related toxicity. Local control was achieved among 95% of patients, with a median progression-free survival of 30 months. No significant variables were associated with progression-free survival or toxicity in the univariate analysis.

CONCLUSION

Magnetic resonance-guided radiotherapy is a well-tolerated treatment that offers high rates of local control for patients with GEP-NETs, including those with metastatic disease. This treatment should be considered a viable alternative for patients who are not candidates for other locoregional therapies.