Prospective study on stereotactic body radiotherapy for small pancreatic neuroendocrine tumors: tolerance and effectiveness analysis.

Abstract

Surgery is the standard treatment for pancreatic neuroendocrine tumors (pNETs), obtaining favorable results but associating high morbidity and mortality rates. This study assesses stereotactic body radiation therapy (SBRT) as a radical approach for small (< 2cm) nonfunctioning pNETs. From January 2017 to June 2023, 20 patients with small pNETs underwent SBRT in an IRB-approved study. Endpoints included local control, tolerance, progression-free survival, and overall survival (OS). Diagnostic assessments comprised endoscopy, CT scans, OctreScan or PET-Dotatoc, abdominal MRI, and histological confirmatory samples. In a 30-month follow-up of 20 patients (median age 55.5years), SBRT was well-tolerated with no grade > 2 toxicity. 40% showed morphological response, 55% remained stable. Metabolically, 50% achieved significant improvement. With a median OS of 41.5months, all patients were alive without local or distant progression or need for surgical resection. SBRT is a feasible and well-tolerated approach for small neuroendocrine pancreatic tumors, demonstrating effective local control. Further investigations are vital for validation and extension of these findings.