Combining Peptide Radiation Therapy with Chemotherapy Dramatically Improves Response in Aggressive Neuroendocrine Tumors | Research

The takeaway

PRRT combined with capecitabine+temozolomide achieved a 71% response rate in FDG-positive neuroendocrine tumors, far exceeding PRRT alone (10%) or PRRT+temozolomide (14%).

71% vs 10% response
Adding CAPTEM chemotherapy to peptide radiation therapy dramatically improved response in aggressive neuroendocrine tumors

What the researchers found

PRRT + CAPTEM achieved 71% ORR and DCR in FDG-positive mNETs, compared to 10% ORR/50% DCR for PRRT alone and 14% ORR/43% DCR for PRRT + temozolomide, without increased toxicity.

Why it matters

FDG-positive neuroendocrine tumors have poor prognosis with standard PRRT. This combination approach could significantly improve outcomes for these aggressive cancers.

How the study worked

Retrospective single-center study of 24 FDG-positive mNET patients receiving PRRT alone (n=10), PRRT+TEM (n=7), or PRRT+CAPTEM (n=7), with response assessment by CT, Ga-68-DOTATOC PET, and FDG PET.

What this study cannot tell us

Small sample size (24 total, 7 per CAPTEM group). Retrospective design. Single center. Cannot control for selection bias between groups. Survival outcomes need longer follow-up.

How to read the evidence

Small retrospective single-center study. Dramatic response rate difference is noteworthy but needs prospective validation.

When this study was published

Published in 2025, addressing an unmet need in aggressive neuroendocrine tumor management.

The bigger picture

This advances peptide-targeted radionuclide therapy by showing that combining it with chemotherapy can overcome the aggressive biology of FDG-positive neuroendocrine tumors.

Questions still open

Would a prospective randomized trial confirm the superiority of PRRT+CAPTEM?
Can the CAPTEM combination extend to other PRRT-treated tumor types?
What is the optimal sequencing of PRRT and chemotherapy cycles?

Common questions

What is PRRT?

Peptide receptor radionuclide therapy uses radioactive peptides that bind to receptors on neuroendocrine tumor cells, delivering targeted radiation directly to the cancer while sparing healthy tissue.

Why combine PRRT with chemotherapy?

Some neuroendocrine tumors are too aggressive for PRRT alone. Adding chemotherapy (capecitabine and temozolomide) appears to dramatically improve response rates, with 71% of patients responding vs only 10% with PRRT alone.

Read the original research

Peptide receptor radionuclide therapy alone or in combination with temozolomide plus/minus capecitabine in [18F]FDG-positive metastatic neuroendocrine tumors.

European journal of nuclear medicine and molecular imaging, 53(3), 1927-1938

View on PubMed ↗Publisher’s paper ↗

Citation

di Santo, Gianpaolo; Santo, Giulia; Wirth, Lukas; Kronthaler, Ariane; Gastl, Günther; Djanani, Angela; Virgolini, Irene J. (2026). Peptide receptor radionuclide therapy alone or in combination with temozolomide plus/minus capecitabine in [18F]FDG-positive metastatic neuroendocrine tumors.. European journal of nuclear medicine and molecular imaging, 53(3), 1927-1938. https://doi.org/10.1007/s00259-025-07606-3