Yttrium-90 TARE efficacy in neuroendocrine liver metastases predicted by high baseline vascularity

Patients with neuroendocrine liver metastases (NELM) often face limited treatment options, especially when surgical resection is not feasible. Conventional systemic therapies can have significant side effects and varying efficacy. Yttrium-90 (Y-90) transarterial radioembolization (TARE) offers a liver-directed therapy, delivering targeted radiation to tumors. However, patient selection for TARE to maximize therapeutic benefit and minimize futility remains a critical challenge, with a need for better predictive biomarkers of response.

This retrospective study analyzed 30 patients with neuroendocrine liver metastases who underwent lobar Yttrium-90 TARE between 2015 and 2022. Researchers assessed pre- and post-treatment target lesion volumes using total tumor volume (TTV) and enhancing tumor volume (ETV) on MRI. They used Cox-regression and Kaplan-Meier statistics to evaluate baseline volumetric imaging parameters and clinical variables as predictors of overall survival (OS) and tumor debulking.

The median overall survival (mOS) for the cohort was 33.0 months (95%CI [21.2; 44.7]). Eligibility for peptide receptor radionuclide therapy (PRRT) was the strongest predictor of survival, with a hazard ratio of 0.22 (p=0.024), leading to a mOS of 60.8 months for receptor-positive patients compared to 7.0 months for receptor-negative patients (p=0.019). A key finding regarding TARE efficacy was:

A baseline ETV/TTV ratio greater than 50% was associated with a significant decrease in median ETV by 41% after lobar TARE, whereas patients with poor baseline vascularity experienced an 18% increase in ETV (p=0.018). Prior PRRT did not significantly impact the change in ETV after TARE. For the 17/30 patients who received systemic therapies exclusively before TARE, mOS was 15 months versus 6.8 months (p=0.082).