A patient with aggressive, treatment-resistant pancreatic neuroendocrine cancer achieved complete regression of bone and lymph node metastases after three cycles of tandem peptide receptor radionuclide therapy using a somatostatin receptor antagonist.
Complete regression of bone & lymph node metastasesAchieved after 3 cycles of TANDEM-PRRT in a patient who had failed all prior standard treatments including conventional PRRT
What the researchers found
A 58-year-old woman with rapidly progressive, therapy-refractory neuroendocrine pancreatic tumor (grade G3) with extensive liver, bone, and lymph node metastases received three cycles of TANDEM peptide receptor radionuclide therapy (PRRT) using concurrently administered [177Lu]Lu-DOTA-LM3 and [225Ac]Ac-DOTA-LM3, a somatostatin receptor antagonist. The treatment produced complete regression of bone and lymph node metastases, significant reduction in liver metastases and hepatomegaly, and improvement in the primary pancreatic tumor. Partial remission was confirmed across multiple imaging modalities (PET/CT, contrast-enhanced CT, and abdominal MRI), with marked clinical improvement in pain, energy levels, and quality of life, enabling the patient to fully resume physical activity.
Why it matters
This case demonstrates the potential of TANDEM-PRRT using a somatostatin receptor antagonist (LM3) in a patient who had already exhausted multiple standard treatments including conventional PRRT with [177Lu]Lu-DOTATATE, chemotherapy, targeted therapy (Everolimus), somatostatin analogs, and liver embolization. The dramatic response suggests that receptor antagonists may bind to more receptor sites than traditional agonists, and that combining lutetium-177 with actinium-225 in a tandem approach could offer a powerful salvage option for patients with no remaining standard therapies.
The numbers in context
3 TANDEM-PRRT cycles · Complete regression of bone and lymph node metastases · Partial remission confirmed on PET/CT, CE-CT, and MRI
How the study worked
Single-patient case report. A 58-year-old woman with therapy-refractory grade G3 neuroendocrine pancreatic tumor underwent [68Ga]Ga-DOTA-LM3 PET/CT for receptor imaging, followed by three cycles of concurrent [177Lu]Lu-DOTA-LM3 and [225Ac]Ac-DOTA-LM3 TANDEM-PRRT. Response was assessed via PET/CT, contrast-enhanced CT of the chest-abdomen-pelvis, and abdominal MRI.
Who was studied
Single patient: 58-year-old woman with therapy-refractory, rapidly progressive neuroendocrine pancreatic tumor (G2→G3) with liver, bone, and lymph node metastases
What this study cannot tell us
As a single case report, these results cannot be generalized to other patients. There is no control comparison, and long-term durability of the response is not described. The specific doses and intervals between TANDEM-PRRT cycles are not detailed in the abstract.
How to read the evidence
This is a single case report, the lowest level of clinical evidence. While the response is striking, results from one patient cannot predict outcomes for others. Controlled trials with larger patient groups are needed to confirm whether this approach is broadly effective.
When this study was published
Published in 2024, this represents cutting-edge research in peptide receptor radionuclide therapy. The TANDEM approach and use of receptor antagonists for PRRT are both active areas of clinical investigation.
The bigger picture
Standard peptide receptor radionuclide therapy (PRRT) with [177Lu]Lu-DOTATATE is already an established treatment for neuroendocrine tumors, but some patients stop responding. This case explores two innovations simultaneously: using a receptor antagonist (LM3) instead of the standard agonist, and combining two radioisotopes in a tandem approach. If these results hold in larger studies, TANDEM-PRRT with receptor antagonists could become an important salvage therapy for patients who have exhausted conventional options.
Questions still open
- How long does the remission last after TANDEM-PRRT with LM3, and will the patient need additional cycles?
- Would this tandem antagonist approach show similar responses in a larger patient cohort or in a controlled trial?
- What is the side effect and toxicity profile of combining lutetium-177 and actinium-225 radionuclides compared to standard single-agent PRRT?
Common questions
What makes TANDEM-PRRT different from standard peptide receptor radionuclide therapy?
Why was a receptor antagonist used instead of the standard agonist for this therapy?
Read the original research
Impressive Response to TANDEM Peptide Receptor Radionuclide Therapy with 177Lu/225AcDOTA-LM3 Somatostatin Receptor Antagonist in a Patient with Therapy-Refractory, Rapidly Progressive Neuroendocrine Neoplasm of the Pancreas.
Diagnostics (Basel, Switzerland), 14(9)
Citation
Perrone, Elisabetta; Ghai, Kriti; Eismant, Aleksandr; Andreassen, Mikkel; Langer, Seppo W; Knigge, Ulrich; Kjaer, Andreas; Baum, Richard P. (2024). Impressive Response to TANDEM Peptide Receptor Radionuclide Therapy with 177Lu/225AcDOTA-LM3 Somatostatin Receptor Antagonist in a Patient with Therapy-Refractory, Rapidly Progressive Neuroendocrine Neoplasm of the Pancreas.. Diagnostics (Basel, Switzerland), 14(9). https://doi.org/10.3390/diagnostics14090907