Lutetium-177 Dotatate: Radioligand Therapy for Neuroendocrine Tumours


Lutetium-177 dotatate is a radioactive medicine given into a vein. It joins a small protein-like molecule that sticks to somatostatin receptors, which sit on the surface of most well-differentiated neuroendocrine tumour cells, to a radioactive metal, lutetium-177. The molecule carries the radiation to the tumour, and the radiation damages the cells from inside and close by. This kind of treatment is called peptide receptor radionuclide therapy (PRRT) or radioligand therapy.

The U.S. Food and Drug Administration (FDA) approved it on January 26, 2018 for adults with somatostatin-receptor-positive gastroenteropancreatic neuroendocrine tumours (GEP-NETs), the neuroendocrine tumours of the stomach, intestines and pancreas. On April 23, 2024 the approval was widened to children aged 12 years and older. The main evidence is the NETTER-1 trial in tumours that had grown during standard octreotide treatment, and the NETTER-2 trial, which tested it as the first treatment for faster-growing tumours.

The tumours themselves, their grades, hormone syndromes and other treatments, are described on the Neuroendocrine Tumors page. This page goes further into the drug: how it works, how it is given, what each trial found, what the label says about safety and radiation at home, and what is still unknown.


Table of Contents

  1. Lutetium-177 Dotatate at a Glance
  2. How the Radiation Reaches the Tumour
  3. Finding the Receptor With a Dotatate Scan
  4. How the Label Says It Is Given
  5. NETTER-1: Tumours That Grew on Octreotide
  6. NETTER-2: The First Treatment for Grade 2 and 3 Tumours
  7. Quality of Life and Daily Symptoms
  8. The Label Warnings
  9. Long-Term Blood-Cancer and Kidney Risk in Cohort Studies
  10. Radiation Safety in the Label's Words
  11. Adolescents Aged 12 to 17
  12. What Is Not Known
  13. Regulatory Documents
  14. Key Research Papers
  15. Connections
  16. Featured Videos

Lutetium-177 Dotatate at a Glance

How the Radiation Reaches the Tumour

Somatostatin is a natural hormone that switches off the release of other hormones. Its receptors come in five subtypes. The label states that lutetium-177 dotatate binds somatostatin receptors with the highest affinity for subtype 2, and that once it binds to a receptor-bearing cell the compound is taken inside the cell. The lutetium-177 then gives off beta-minus particles (fast electrons). The label says this radiation causes cell damage by forming free radicals, in the receptor-positive cells and in neighbouring cells.

The particles travel only a short way. The label gives a maximum reach in tissue of 2.2 mm and an average of 0.67 mm, so most of the dose stays near the cells that took up the drug. Lutetium-177 decays to stable hafnium-177 with a half-life of 6.647 days. The label states that it also gives off some gamma rays (photons).

Most of the drug that does not stick to tumour cells leaves through the kidneys. The label reports that 44% of the radioactivity is passed in the urine within 5 hours, 58% within 24 hours and 65% within 48 hours, and that more than 99% of the given radioactivity is gone within 14 days. Within 4 hours of the infusion the drug is found in the kidneys, the tumours, the liver and the spleen, and in some people in the pituitary and thyroid glands. In the NETTER-1 measurements, the average radiation dose over four treatments was 19.4 gray to the kidneys, 25.1 gray to the spleen and 1.0 gray to the red bone marrow.

Because ordinary somatostatin analogs such as octreotide occupy the same receptors, the label states that they may interfere with the treatment. Long-acting forms are stopped at least 4 weeks before each dose, and short-acting octreotide at least 24 hours before. The label also states that glucocorticoid (steroid) medicines can reduce the number of subtype 2 receptors on cells, and it warns against repeated high doses during treatment.

Finding the Receptor With a Dotatate Scan

The treatment only reaches tumours that carry somatostatin receptors, so the receptors are shown on a scan first. The same dotatate molecule can carry a different radioactive metal that is made for imaging rather than treatment. Paired with gallium-68 or copper-64, it lights up receptor-bearing tumours on a positron emission tomography (PET) scan. Using one molecule to find a target and a sister molecule to treat it is often called "theranostics".

The scan gives information about receptors, not a promise of response. Grade, tumour size, earlier treatments and blood counts also shape who receives the drug, as a 2022 clinical guide describes (Becx 2022).

How the Label Says It Is Given

The label sets 7.4 GBq every 8 weeks (plus or minus 1 week) for a total of 4 doses, for adults and for children aged 12 and older. Each dose drips into a vein over about 30 to 40 minutes; the label states it is not given as a fast push (bolus). The full course delivers 29.6 GBq.

The label states that the medicine is handled only by staff trained and licensed in radiopharmaceuticals, with waterproof gloves, radiation shielding and tongs for the vial.

NETTER-1: Tumours That Grew on Octreotide

NETTER-1 enrolled people with advanced, well-differentiated, somatostatin-receptor-positive neuroendocrine tumours of the midgut (mostly the small intestine) whose disease had grown while they were on a standard dose of long-acting octreotide. In the first report, 229 people were randomly assigned to four doses of 7.4 GBq every 8 weeks plus octreotide 30 mg (116 people) or to a doubled octreotide dose of 60 mg every 4 weeks (113 people). The trial was open-label: patients and doctors knew which treatment was given.

Final overall survival

An early analysis had shown fewer deaths with lutetium-177 dotatate (14 versus 26), and the authors wrote that confirmation would need the final analysis. That final analysis came 5 years after the last person joined, when 142 of 231 people had died, with a median follow-up of about 76 months. Median overall survival was 48.0 months with lutetium-177 dotatate and 36.3 months with high-dose octreotide. The hazard ratio was 0.84 and the two-sided p value 0.30, so the difference was not statistically significant and the overall-survival goal was not met (Strosberg 2021). The authors wrote that the 11.7-month difference "might be considered clinically relevant". The label likewise states there was no statistically significant difference in overall survival.

One reason offered for the result is crossover. Reviews that read the full report state that 41 of the 114 people in the octreotide group (36%) later received radioligand treatment during follow-up, 26 of them within 24 months of joining (Chauhan 2022; Becx 2022). People who switch blur the comparison of survival between the two groups.

In long-term follow-up, 2 of 111 people (2%) given lutetium-177 dotatate developed myelodysplastic syndrome (MDS), a bone-marrow disorder that can turn into leukaemia. One of them died 33 months after joining; this was the only death reported as caused by the treatment. No new cases of myelodysplastic syndrome or acute myeloid leukaemia (AML) appeared during long-term follow-up (Strosberg 2021).

NETTER-2: The First Treatment for Grade 2 and 3 Tumours

NETTER-2 asked a different question: whether lutetium-177 dotatate helps as the first treatment, straight after diagnosis, in faster-growing tumours. It enrolled people aged 15 and older with newly diagnosed, advanced, well-differentiated gastroenteropancreatic neuroendocrine tumours of higher grade 2 (Ki-67 10% to 20%) or grade 3 (Ki-67 above 20% and up to 55%), with somatostatin receptors in all target lesions. Ki-67 is a stain that shows how many tumour cells are dividing.

Across 45 centres in nine countries, 226 people were randomly assigned in a 2-to-1 ratio to four cycles of lutetium-177 dotatate plus octreotide 30 mg (151 people) or to high-dose octreotide 60 mg every 4 weeks (75 people). The trial was open-label, but tumour growth was judged by blinded central radiologists.

The trial authors wrote that the combination should be considered a new standard first treatment for this group. A 2026 commentary on trial design took a more cautious view. Its authors pointed to higher toxicity, the absence of a demonstrated overall-survival or quality-of-life benefit, the open-label design and a possibly suboptimal comparison treatment, and wrote that these complicate the reading of the result (de Jong 2026). The FDA label's clinical-studies section, as read for this page, describes NETTER-1 and the Dutch ERASMUS cohort and does not describe NETTER-2.

Quality of Life and Daily Symptoms

NETTER-1 asked patients to fill in standard cancer questionnaires every 12 weeks until the tumour grew. The analysis measured the time until a score worsened by 10 points or more. This time was longer with lutetium-177 dotatate for global health status (hazard ratio 0.406), physical functioning (0.518), role functioning (0.580), fatigue (0.621), pain (0.566), diarrhoea (0.473), disease-related worries (0.572) and body image (0.425). The median time to a worsening of global health status was 28.8 months versus 6.1 months, and of physical functioning 25.2 versus 11.5 months (Strosberg 2018). Because patients knew their treatment, these self-reports were not blinded.

NETTER-1 patients also kept daily diaries. Compared with their starting point, those on lutetium-177 dotatate reported 4.10 fewer days with abdominal pain, 4.55 fewer with diarrhoea and 4.52 fewer with flushing per 4 weeks, against 0.99, 1.44 and 2.54 fewer days on high-dose octreotide. The differences between groups were 3.11, 3.11 and 1.98 days per 4 weeks, all statistically significant (Strosberg 2021, symptom diaries).

Outside a trial, a Swedish study of 204 people who rated their quality of life before the first and the fourth cycle found improvements in global quality of life, in role, social and emotional functioning, and in several symptoms. The study flagged overweight people who completed four cycles and people over 65 as groups at risk of a worse quality of life during treatment (Edfeldt 2023). This study had no comparison group given another treatment.

For NETTER-2, the primary paper does not report a quality-of-life benefit, and the 2026 commentary describes a quality-of-life benefit as not demonstrated (de Jong 2026).

The Label Warnings

The figures below are as the FDA label states them. "ERASMUS" is a long-running Dutch single-hospital cohort of 1,214 treated people, a subset of whom (811) supplied safety data for the label.

The most common severe side effects that were more frequent on the drug in NETTER-1 were low lymphocytes, raised liver enzymes (GGT, AST and ALT), vomiting, nausea, high blood sugar and low potassium, according to the label.

Long-Term Blood-Cancer and Kidney Risk in Cohort Studies

Trials follow people for a limited time and are small, so most of the long-term picture comes from hospital cohorts. These are observational: they describe what happened to treated people but cannot fully separate the drug's effect from earlier treatments, age and the cancer itself.

Radiation Safety in the Label's Words

The label does not set fixed home rules of its own. It points to hospital radiation-safety practice, federal patient-release guidance and the instructions each patient receives. Its statements are:

The label also states that more than 99% of the given radioactivity is eliminated within 14 days.

Adolescents Aged 12 to 17

The 2024 approval for children aged 12 and older rests on the adult trial evidence plus safety, blood-level and radiation-dose data from the NETTER-P study, according to the label. NETTER-P enrolled 11 people aged 13 to 17: 4 with gastroenteropancreatic tumours and 7 with pheochromocytoma or paraganglioma. They received the adult schedule of 7.4 GBq every 8 weeks for four cycles.

The most common side effect during treatment was a fall in lymphocytes, in 7 of 11 (64%), severe in 5 of 11 (45%). No treatment-related kidney damage was seen. The projected median radiation dose over four treatments was 21 gray to the kidneys and 0.76 gray to the bone marrow, and blood levels were similar to adults' (Gaze 2025). The label adds that radiation risks are greater in children because of their longer life expectancy and that long-term follow-up is continuing. Safety and effectiveness below age 12 have not been established.

What Is Not Known

Regulatory Documents

  1. U.S. National Library of Medicine, DailyMed. Lutetium Lu 177 dotatate injection: prescribing information (read through the openFDA label record effective January 15, 2026, in November 2026). DailyMed label
  2. U.S. Food and Drug Administration, Drugs@FDA. New Drug Application 208700: original approval January 26, 2018, priority review, new molecular entity; efficacy supplement approved April 23, 2024, priority review. Drugs@FDA record
  3. ClinicalTrials.gov. NETTER-1, NCT01578239. NCT01578239
  4. ClinicalTrials.gov. NETTER-2, NCT03972488. NCT03972488
  5. ClinicalTrials.gov. NETTER-P, NCT04711135. NCT04711135

Key Research Papers

  1. Strosberg J, El-Haddad G, Wolin E, Hendifar A, Yao J, Chasen B, et al. Phase 3 Trial of (177)Lu-Dotatate for Midgut Neuroendocrine Tumors. N Engl J Med. 2017;376(2):125-135. PubMed PMID: 28076709
  2. Strosberg JR, Caplin ME, Kunz PL, Ruszniewski PB, Bodei L, Hendifar A, et al. (177)Lu-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 Oncol. 2021;22(12):1752-1763. PubMed PMID: 34793718
  3. Singh S, Halperin D, Myrehaug S, Herrmann K, Pavel M, Kunz PL, et al. [(177)Lu]Lu-DOTA-TATE plus long-acting octreotide versus high-dose long-acting octreotide for the treatment of newly diagnosed, advanced grade 2-3, well-differentiated, gastroenteropancreatic neuroendocrine tumours (NETTER-2): an open-label, randomised, phase 3 study. Lancet. 2024;403(10446):2807-2817. PubMed PMID: 38851203
  4. Strosberg J, Wolin E, Chasen B, Kulke M, Bushnell D, Caplin M, et al. Health-Related Quality of Life in Patients With Progressive Midgut Neuroendocrine Tumors Treated With (177)Lu-Dotatate in the Phase III NETTER-1 Trial. J Clin Oncol. 2018;36(25):2578-2584. PubMed PMID: 29878866
  5. Strosberg JR, Srirajaskanthan R, El-Haddad G, Wolin EM, Chasen BA, Kulke MH, et al. Symptom Diaries of Patients with Midgut Neuroendocrine Tumors Treated with (177)Lu-DOTATATE. J Nucl Med. 2021;62(12):1712-1718. PubMed PMID: 33771903
  6. Gaze MN, Handkiewicz-Junak D, Hladun R, Laetsch TW, Sorge C, Sparks R, et al. Safety and dosimetry of [(177)Lu]Lu-DOTA-TATE in adolescent patients with somatostatin receptor-positive gastroenteropancreatic neuroendocrine tumours, or pheochromocytomas and paragangliomas: Primary analysis of the Phase II NETTER-P study. Eur J Nucl Med Mol Imaging. 2025;52(11):4001-4015. PubMed PMID: 40198358
  7. Kwekkeboom DJ, de Herder WW, Kam BL, van Eijck CH, van Essen M, Kooij PP, et al. Treatment with the radiolabeled somatostatin analog [177 Lu-DOTA 0,Tyr3]octreotate: toxicity, efficacy, and survival. J Clin Oncol. 2008;26(13):2124-30. PubMed PMID: 18445841
  8. Brabander T, van der Zwan WA, Teunissen JJM, Kam BLR, Feelders RA, de Herder WW, et al. Long-Term Efficacy, Survival, and Safety of [(177)Lu-DOTA(0),Tyr(3)]octreotate in Patients with Gastroenteropancreatic and Bronchial Neuroendocrine Tumors. Clin Cancer Res. 2017;23(16):4617-4624. PubMed PMID: 28428192
  9. Bergsma H, van Lom K, Raaijmakers MHGP, Konijnenberg M, Kam BLBLR, Teunissen JJM, et al. Persistent Hematologic Dysfunction after Peptide Receptor Radionuclide Therapy with (177)Lu-DOTATATE: Incidence, Course, and Predicting Factors in Patients with Gastroenteropancreatic Neuroendocrine Tumors. J Nucl Med. 2018;59(3):452-458. PubMed PMID: 28775205
  10. Bergsma H, Konijnenberg MW, van der Zwan WA, Kam BL, Teunissen JJ, Kooij PP, et al. Nephrotoxicity after PRRT with (177)Lu-DOTA-octreotate. Eur J Nucl Med Mol Imaging. 2016;43(10):1802-11. PubMed PMID: 27160225
  11. Sonbol MB, Halfdanarson TR, Hilal T. Assessment of Therapy-Related Myeloid Neoplasms in Patients With Neuroendocrine Tumors After Peptide Receptor Radionuclide Therapy: A Systematic Review. JAMA Oncol. 2020;6(7):1086-1092. PubMed PMID: 32297906
  12. Kusne Y, Lasho T, Finke C, Elsabbagh Z, McCue S, Hobday T, et al. Clonal Hematopoiesis in Patients With Neuroendocrine Tumor Treated With Lutetium-177 and the Risk of Thrombocytopenia: A Prospective Study. JCO Precis Oncol. 2024;8:e2400143. PubMed PMID: 38976813
  13. de Keizer B, van Aken MO, Feelders RA, de Herder WW, Kam BL, van Essen M, et al. Hormonal crises following receptor radionuclide therapy with the radiolabeled somatostatin analogue [177Lu-DOTA0,Tyr3]octreotate. Eur J Nucl Med Mol Imaging. 2008;35(4):749-55. PubMed PMID: 18210106
  14. Edfeldt K, Hellman P, Granberg D, Lagergren P, Thiis-Evensen E, Sundin A, et al. Improved health-related quality of life during peptide receptor radionuclide therapy in patients with neuroendocrine tumours. J Neuroendocrinol. 2023;35(10):e13342. PubMed PMID: 37807573
  15. Deppen SA, Liu E, Blume JD, Clanton J, Shi C, Jones-Jackson LB, et al. Safety and Efficacy of 68Ga-DOTATATE PET/CT for Diagnosis, Staging, and Treatment Management of Neuroendocrine Tumors. J Nucl Med. 2016;57(5):708-14. PubMed PMID: 26769865
  16. Delpassand ES, Ranganathan D, Wagh N, Shafie A, Gaber A, Abbasi A, et al. (64)Cu-DOTATATE PET/CT for Imaging Patients with Known or Suspected Somatostatin Receptor-Positive Neuroendocrine Tumors: Results of the First U.S. Prospective, Reader-Masked Clinical Trial. J Nucl Med. 2020;61(6):890-896. PubMed PMID: 31924723
  17. Becx MN, Minczeles NS, Brabander T, de Herder WW, Nonnekens J, Hofland J. A Clinical Guide to Peptide Receptor Radionuclide Therapy with (177)Lu-DOTATATE in Neuroendocrine Tumor Patients. Cancers (Basel). 2022;14(23):5792. PubMed PMID: 36497273
  18. Chauhan A, Del Rivero J, Ramirez RA, Soares HP, Li D. Treatment Sequencing Strategies in Advanced Neuroendocrine Tumors: A Review. Cancers (Basel). 2022;14(21):5248. PubMed PMID: 36358667
  19. de Jong F, Douma LH, Baas P, de Gooijer CJ, Gelderblom H, Burgers JA, et al. Critical appraisal of combination therapies: the impact of trial design on Benefit-Risk outcomes. J Natl Cancer Inst. 2026 (online ahead of print):djag343. PubMed PMID: 42786595

PubMed Topic Searches

  1. PubMed: lutetium-177 dotatate in neuroendocrine tumours
  2. PubMed: receptor-targeted radiation therapy and myelodysplastic syndrome
  3. PubMed: lutetium-177 dotatate and kidney toxicity
  4. PubMed: NETTER-2

Connections