Integrated Capecitabine–Temozolomide with Radioembolization for Liver-Dominant G2 NETs: Long-Term Outcomes of a Single-Institution Retrospective Study

Purpose Capecitabine–Temozolomide (CapTem) is an oral chemotherapy regimen for NETs. Both drugs are radiosensitizers. Integrating CapTem and Y90 transarterial radioembolization (TARE) in patients with grade 2 neuroendocrine tumor (NET) liver metastases achieved an encouraging objective response rate (ORR) and progression-free survival (PFS) in a feasibility study. This study expands that report to a larger cohort with longer follow-up. Methods Therapy consisted of monthly cycles of capecitabine 600 mg/m 2 twice daily for 14 days and temozolomide 150–200 mg/m2 on day 10–14. Simulation angiography was performed during the initial cycle. The dominant lobe was treated with 90 Y-resin microspheres using BSA dosimetry on day 7 of the second cycle of CapTem. Patients with bilobar disease had the other lobe treated on day 7 of the third or fourth cycle. CapTem was continued until progression or intolerance. Clinical and laboratory assessment was done monthly and imaging every 3 months. Results 35/37 patients completed the prescribed regimen. Primary sites of disease were pancreas (16), lung (10), gut (7) and unknown (4). Mean duration of CapTem was 12 months (range, 4–32 months). ORR in the liver was 72% with a disease control rate of 100%. Median PFS was 36 months (95% CI, 25–45 months). Median overall survival was 41 months (95% CI, 24–87 months) from initiation of CapTemY90 therapy and 130 months (95% CI, 56–172 months) from initial diagnosis. Conclusion Chemoradiation with CapTem and TARE provided durable control of G2 NET liver metastases for substantially longer than expectations for embolotherapy or chemotherapy alone. Graphical Abstract