Peptide Receptor Radionuclide Therapy (PRRT): How It Works

Written and medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: November 2026 · How we review

Quick Answer

Peptide receptor radionuclide therapy (PRRT) is a targeted cancer treatment that delivers radiation directly to neuroendocrine tumor cells. It treats gastroenteropancreatic tumors that can't be removed by surgery and have somatostatin receptors. A course is usually four infusions, two months apart. It's not a cure, but it can shrink tumors or stop their growth and help people live longer.

What the research says

• PRRT greatly slowed tumor growth: in the NETTER-1 trial of 229 people with advanced midgut NETs, 65.2% were free of tumor progression at 20 months with Lu-177 dotatate versus 10.8% with high-dose octreotide, and 18% versus 3% had tumors shrink (Strosberg J et al., New England Journal of Medicine, 2017) [2]

• Survival wasn't significantly longer, and blood complications were rare: in the final NETTER-1 analysis of 231 people, median survival was 48.0 months with Lu-177 dotatate versus 36.3 months, a difference that wasn't statistically significant; 2% developed myelodysplastic syndrome (Strosberg JR et al., Lancet Oncology, 2021) [3]

Key takeaways

• PRRT delivers radiation directly to neuroendocrine tumor cells.

• The approved drug is lutetium Lu 177 dotatate.

• It's for NETs that can't be removed by surgery.

• A course is usually four infusions over eight months.

• It slows or shrinks tumors but isn't a cure.

What is PRRT?

Neuroendocrine tumors often have somatostatin receptors on their surface. PRRT's carrier molecule binds to these receptors, bringing radiation right to the tumor. It's given by nuclear medicine teams. The first PRRT drug was approved in 2018. Sources: [1]

Who it's for

A special scan confirms the receptors.

• Gastrointestinal NETs in the pancreas, stomach, rectum or intestines.

• Tumors that can't be removed by surgery, often because they've spread.

• Tumors that haven't responded to hormone therapy.

• Tumors with somatostatin receptors confirmed by a scan. Sources: [1]

How it works

The radiation leaves the body over several days.

1. The carrier peptide travels through your blood.

2. It binds to receptors on tumor cells.

3. Its radioactive part damages tumor DNA.

4. Healthy cells are mostly spared. Sources: [1]

How to prepare

• Stop long-acting somatostatin analogs at least four weeks before.

• Stop short-acting ones 24 hours before.

• Avoid repeated high doses of steroids during treatment.

• Get blood tests a week before each session. Sources: [1]

What happens during treatment

Each visit takes about five to six hours.

1. An IV is placed.

2. You get anti-nausea medicine about an hour before.

3. Amino acids flow in over about four hours to protect your kidneys.

4. PRRT is infused over 30 to 45 minutes.

5. Scans the next day show where the treatment went. Sources: [1]

A usual course is four treatments, two months apart, over eight months, usually as an outpatient. Sources: [1]

Side effects

• Nausea and vomiting, the most common right away.

• Kidney or liver problems.

• Low blood counts, causing tiredness, infections or easy bruising.

• Rarely, blood cancers such as myelodysplastic syndrome or leukemia.

• Rarely, a carcinoid crisis with flushing, diarrhea and trouble breathing. Sources: [1, 3]

After treatment

• Most people tolerate it well and recover quickly.

• The radiation leaves through urine and stool over several days.

• You may need to limit close contact and wash your hands often.

• Carry your treatment card for up to three months when traveling. If you could become pregnant, use effective birth control during treatment and for 7 months after the last dose; men with partners who could become pregnant should do so for 4 months. PRRT may also cause infertility. Sources: [1]

Outlook

For many people, tumors shrink or stop growing, which can extend life and improve quality of life. For most, tumors eventually return. Sources: [1, 2, 3]

When to get help

A carcinoid crisis usually happens within 48 hours. Call 911 or go to the ER for flushing, diarrhea, shortness of breath or a racing heartbeat. Discuss any other side effects with your care team. Sources: [1]

Conclusion

PRRT brings radiation straight to neuroendocrine tumors and can control them for years. Regular blood tests help your team keep treatment safe.

Keep learning: read about neuroendocrine tumors and carcinoid syndrome.

Frequently asked questions

What is PRRT?

A targeted treatment that delivers radiation to neuroendocrine tumors.

What drug is used?

Lutetium Lu 177 dotatate (Lutathera).

Who can get PRRT?

People with NETs that can't be removed and have somatostatin receptors.

How is it given?

By IV infusion.

How many treatments are needed?

Usually four, two months apart.

How long is each visit?

About five to six hours.

What are common side effects?

Nausea, vomiting and low blood counts.

Is it a cure?

No, but it can shrink or control tumors.

Am I radioactive afterward?

For a few days; limit close contact as advised.

What is a carcinoid crisis?

A rare reaction with flushing, diarrhea and trouble breathing.

Related Reading

Neuroendocrine Tumors: Symptoms, Causes, Diagnosis and Treatment — What You Need to Know neuroendocrine tumors.

Carcinoid Tumors: Symptoms, Diagnosis, Treatment and Support carcinoid tumors.

Carcinoid Syndrome: Symptoms, Causes, Diagnosis, and Treatment of This Rare NET Complication carcinoid syndrome.

Gastrointestinal Neuroendocrine Tumors (GI NETs): Symptoms, Causes, Diagnosis, Treatment, and Outlook — What You Need to Know digestive NETs.

Nuclear Medicine Imaging: How Tracer Scans Work, Safety and Results nuclear medicine.

References

1. Cleveland Clinic. Peptide Receptor Radionuclide Therapy (PRRT): What it Is. Cleveland Clinic. Last updated August 29, 2022. https://my.clevelandclinic.org/health/treatments/24073-peptide-receptor-radionuclide-therapy-prrt

2. Strosberg J, El-Haddad G, Wolin E, et al. Phase 3 trial of 177Lu-Dotatate for midgut neuroendocrine tumors. New England Journal of Medicine. 2017;376(2):125-135. PMID 28076709. https://doi.org/10.1056/NEJMoa1607427

3. Strosberg JR, Caplin ME, Kunz PL, et al. 177Lu-Dotatate plus long-acting octreotide versus high-dose long-acting octreotide in patients with midgut neuroendocrine tumours (NETTER-1): final overall survival and long-term safety results from an open-label, randomised, controlled, phase 3 trial. Lancet Oncology. 2021;22(12):1752-1763. PMID 34793718. https://doi.org/10.1016/S1470-2045(21)00572-6

Medical disclaimer

This article is for general education only and does not replace advice from a qualified healthcare professional. Talk to your doctor about your own diagnosis and treatment, and seek emergency care right away for severe or sudden symptoms.