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INTRODUCTION: 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 (< 2 cm) nonfunctioning pNETs. MATERIALS AND METHODS: 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. RESULTS: In a 30-month follow-up of 20 patients (median age 55.5 years), 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 41.5 months, all patients were alive without local or distant progression or need for surgical resection. CONCLUSION: 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.
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OBJECTIVE: This study aimed to assess the efficacy and tolerability of stereotactic body radiation therapy (SBRT) for the treatment of liver metastases. METHODS: Patients with up to 5 liver metastases were enrolled in this prospective multicenter study and underwent SBRT. Efficacy outcomes included in-field local control (LC), progression-free survival (PFS), and overall survival (OS). Acute and late toxicities were evaluated using CTCAE v.4.0. RESULTS: A total of 52 patients with 105 liver metastases were treated between 2015 and 2018. The most common primary tumor was colorectal cancer (72% of cases). Liver metastases were synchronous with the primary tumor diagnosis in 24 patients (46.2%), and 21 patients (40.4%) presented with other extrahepatic oligometastases. All patients underwent intensity-modulated radiation therapy (IMRT)/volumetric-modulated arc therapy (VMAT) with image-guided radiation therapy (IGRT) and respiratory gating, and a minimum biologically effective dose (BED10Gy) of 100 Gy was delivered to all lesions. With a median follow-up of 23.1 months (range: 13.4-30.9 months) since liver SBRT, the median actuarial local progression-free survival (local-PFS) was not reached. The actuarial in-field LC rates were 84.9% and 78.4% at 24 and 48 months, respectively. The median actuarial liver-PFS and distant-PFS were 11 and 10.8 months, respectively. The actuarial median overall survival (OS) was 27.7 months from SBRT and 52.5 months from metastases diagnosis. Patients with lesion diameter ≤ 5 cm had significantly better median liver-PFS (p = 0.006) and OS (p = 0.018). No acute or late toxicities of grade ≥ 3 were observed. CONCLUSIONS: This prospective multicenter study confirms that liver SBRT is an effective alternative for the treatment of liver metastases, demonstrating high rates of local control and survival while maintaining a low toxicity profile.