Patient Guide · PRRT Day

PRRT treatment day · what actually happens?

An hour-by-hour guide to a PRRT treatment day at FMRI — what to bring, the pre-treatment workup, the amino acid co-infusion that protects your kidneys, the Lu-177 administration itself, radiation safety, and discharge. Drawn from the IAEA practical guidance and clinical practice at FMRI.

Dr. Ishita B. Sen, MDDirector & Chief, Nuclear Medicine · FMRI

Published 13 May 2026

Reviewed by Dr. Dharmender Malik

11 min read

Last reviewed by Dr. Dharmender Malik on 13 May 2026 · this article reflects the published primary literature and current clinical practice at FMRI Gurugram.

Introduction

A PRRT (peptide receptor radionuclide therapy) treatment day with Lu-177 DOTATATE / Lutathera is most often an overnight inpatient admission, occasionally an extended day procedure, taking approximately 4-6 hours of active treatment time. The actual Lu-177 infusion takes only 20-30 minutes — the majority of the day is the amino acid co-infusion that protects the kidneys from radiation. This guide walks through what to bring, what each stage of the day involves, and what to expect when you go home. The framework here is drawn directly from the joint IAEA / EANM / SNMMI practical guidance on PRRT delivery^[1] and reflects routine practice at FMRI Gurugram.

What is PRRT and why is the day structured this way?

AI Overview · short answer

PRRT delivers Lu-177-labelled DOTATATE — a somatostatin analogue — intravenously to neuroendocrine tumor (NET) cells expressing somatostatin receptor type 2 (SSTR2). The Lu-177 emits beta radiation that damages tumour cell DNA over several days. The treatment day is structured around protecting healthy kidneys: an amino acid co-infusion (lysine + arginine) runs before, during, and after the Lu-177 infusion to competitively block kidney uptake of the radioligand — reducing kidney radiation dose by approximately 40 percent^[2].

PRRT is established treatment for metastatic well-differentiated neuroendocrine tumors expressing SSTR2 on Ga-68 DOTATATE PET-CT. The standard course is four cycles, with 8-12 week intervals between cycles. The NETTER-1 phase III trial established this protocol with 28.4-month median PFS versus 8.4 months with high-dose octreotide in midgut NETs^[3]. For eligibility see our PRRT eligibility guide.

Before the day — what to bring and what to expect

What to bring to your PRRT admission:

All current medications — including over-the-counter, herbal, and supplements. Some medications need to be paused or adjusted; your team will have advised on this in advance.
Recent imaging on CD/USB or via radiology system — most importantly the recent Ga-68 DOTATATE PET-CT, plus any cross-sectional CT or MRI.
Recent blood test results if performed outside FMRI.
Comfortable clothes for the day — a button-up shirt makes ECG and blood draws easier than a t-shirt.
A companion for transport home, given the day's length and the anti-emetic premedication (which can cause mild drowsiness in some patients).
Phone charger, book, headphones — the amino acid co-infusion takes 4 hours, so plan for the time.

Long-acting somatostatin analogues (octreotide LAR, lanreotide) are typically held for 4-6 weeks before each PRRT cycle, as they compete with DOTATATE for SSTR2 binding^[1]. Short-acting octreotide is allowed up to 24 hours before each cycle. Your team will have given specific timing guidance.

Hour 0-1 · arrival, workup and premedication

The day begins with admission to the day unit or short-stay ward at FMRI. The first hour typically covers:

Confirmation of identity and consent — including review of the signed treatment consent form.
Vital signs — blood pressure, heart rate, oxygen saturation, temperature, height and weight (for dose verification).
Blood tests — final pre-cycle full blood count, urea/electrolytes/creatinine, liver function tests. Most centres also draw a chromogranin A and 5-HIAA pre-cycle to track biochemical response across cycles.
Intravenous access — typically a peripheral IV cannula in the arm, occasionally a central venous access device for patients who have had multiple cycles or have difficult peripheral veins.
Anti-emetic premedication — typically ondansetron or granisetron 30 minutes before the amino acid co-infusion begins, often combined with low-dose dexamethasone^[4].
Dose verification — the dispensed Lu-177 dose is measured in the nuclear medicine hot lab against the prescribed activity (typically 7.4 GBq / 200 mCi) and verified at the bedside before administration.

Hour 1-5 · the amino acid co-infusion and Lu-177 administration

This is the longest part of the day:

Amino acid co-infusion begins (hour 1) — a 4-hour intravenous infusion of lysine + arginine in normal saline, typically over 1-2 litres. The amino acids competitively block kidney uptake of the radiolabelled peptide, reducing kidney radiation dose by approximately 40 percent (Rolleman et al.)^[2]. The most common day-of side effect is nausea from this infusion — reported in 50-60 percent of patients, mostly mild-to-moderate and well-controlled with anti-emetics^[3].
Lu-177 DOTATATE infusion (hour 1.5) — the Lu-177 itself is given intravenously over 20-30 minutes, typically 30 minutes after the amino acid co-infusion has started so that competitive blockade is fully established. The Lu-177 infusion is short and routine; most patients feel nothing during it.
Continued amino acid infusion through hour 5 — the lysine + arginine continues for approximately 4 hours after the Lu-177 finishes, completing the full protective dose.
Symptom monitoring — nursing observation throughout, with vital signs every 30-60 minutes and active management of nausea, abdominal discomfort, or carcinoid-syndrome-like symptoms if they occur.

Clinical note · carcinoid crisis risk

For patients with significant carcinoid syndrome at baseline, there is a small risk (approximately 1-2%) of carcinoid crisis during the first PRRT cycle as tumour cells release stored serotonin and vasoactive substances. Inpatient observation, continuous cardiac monitoring, and ready access to octreotide IV are standard for high-risk patients. For PPGL specifically the equivalent crisis risk (catecholamine release) is addressed with alpha-adrenergic blockade preparation — see our PPGL PRRT guide^[5].

Hour 5-7 · post-infusion observation and radiation safety

After the amino acid infusion completes:

Observation period — typically 1-2 hours of post-infusion monitoring for any delayed reactions.
Post-treatment imaging — most centres perform a planar Lu-177 whole-body scan or Lu-177 SPECT/CT at 4-24 hours after the infusion. This confirms tumour uptake, identifies any new lesions, and provides dosimetry data for individual patient assessment^[6].
Radiation safety briefing — written and verbal guidance for the first 5-7 days after the cycle:
- Maintain ~1 metre distance from young children and pregnant women.
- Sleep in a separate bed if possible.
- Flush toilet twice after use; wash hands carefully.
- Wash bedlinen separately at the first laundry cycle after discharge.
- Avoid prolonged close contact in confined spaces (long car journeys, theatres, etc.).
Treatment certificate — for travel, particularly air travel where radiation detectors at airports may be triggered for up to 7-14 days^[7].

Discharge — going home

Discharge timing varies by centre:

Same-day discharge — possible at some centres for patients with good performance status and no procedural complications.
Overnight admission — standard at FMRI for most cycles, allowing extended observation, completion of the post-treatment scan, and full radiation-safety briefing in the morning. Most patients are discharged the morning after the cycle.
Two-night admission — uncommon, typically reserved for the first cycle in patients with significant baseline functional syndrome (carcinoid, PPGL) or in cases with complications.

You will be given:

Anti-emetic medication for 2-3 days at home if needed.
A printed radiation-safety information sheet.
A treatment certificate for travel.
Contact details for the FMRI nuclear medicine team for between-cycle questions.
An appointment for the next blood test (typically week 4-6) and the next cycle (typically week 8).

The first 48 hours at home

What to expect:

Nausea — typically resolves within 24-48 hours after the amino acid co-infusion ends. Anti-emetic medication can be continued at home if needed.
Fatigue — usually mild on day 1-2; the peak fatigue is typically days 3-7. Most patients can return to light activities within 24 hours.
Abdominal discomfort or loose stools — uncommon but can occur, particularly in patients with carcinoid syndrome at baseline. Usually mild and self-limiting.
Mild bone pain — uncommon but possible in patients with bony metastases (tumour-flare effect). Usually responds to standard analgesia.

For the full week-by-week recovery framework see our PRRT recovery time guide; for the full side-effect framework see our PRRT side effects guide.

When to call the team in the first 48 hours

Contact the FMRI nuclear medicine team urgently if you experience: fever ≥ 38°C, persistent vomiting beyond 48 hours, severe headache or vision changes, sudden onset of severe abdominal pain, or any sign of bleeding (unusual bruising, blood in stool, blood from gums)^[8].

The bottom line — summary of the day

PRRT treatment day is approximately 4-6 hours of active treatment, typically with overnight admission. The Lu-177 infusion itself is only 20-30 minutes — the majority of the day is the amino acid co-infusion that protects the kidneys.
Bring all medications, recent imaging, blood test results, comfortable clothes, a phone charger, a book or headphones, and a companion for the journey home.
The most common day-of side effect is nausea from the amino acid co-infusion — well-controlled with anti-emetic premedication in most patients^[3].
Post-treatment scanning (typically 4-24 hours after the infusion) confirms tumour uptake and provides dosimetry data.
Radiation safety guidance applies for approximately 5-7 days after the cycle; most patients can return to light activities within 24 hours.

Important

This article is a general guide to what happens on a PRRT treatment day at FMRI Gurugram. Individual experience varies and your specific cycle may include adjustments based on your clinical context, prior treatments, and any specific functional syndromes. Your treating team will provide individualised guidance before each cycle.

"The single most common question patients ask me before their first PRRT cycle is — what should I bring? The honest answer is: a book, headphones, and a phone charger. The Lu-177 infusion itself is 20 minutes; the amino acid co-infusion that protects your kidneys is 4 hours. Patients are often surprised at how routine the day feels — most of it is sitting in a comfortable chair, fully awake, doing whatever they would normally do during a long appointment."

Dr. Ishita B. Sen, MD · Director & Chief, Nuclear Medicine, FMRI

Pre-treatment briefing · what to expect on PRRT day

If you have a PRRT cycle scheduled and would like a detailed pre-treatment briefing — including what to expect on the day, how to prepare, and what to bring — FMRI's nuclear medicine team can walk you through your specific cycle in advance.

Schedule pre-treatment briefing · WhatsApp +91 8800 988936

For patients & referring clinicians

Frequently asked questions

Q01 How long does a PRRT treatment day take?

Approximately 4-6 hours of active treatment, plus admission/observation time before and after. The Lu-177 DOTATATE infusion itself is only 20-30 minutes; the majority of the day is the 4-hour amino acid co-infusion that protects the kidneys. Most centres deliver PRRT as an overnight inpatient admission, occasionally as an extended day procedure [1].

Q02 What is the amino acid co-infusion and why is it needed?

The amino acid co-infusion is a 4-hour intravenous infusion of lysine + arginine (in normal saline) that runs from 30 minutes before the Lu-177 infusion through approximately 4 hours after. The amino acids competitively block kidney uptake of the radiolabelled peptide, reducing kidney radiation dose by approximately 40% (Rolleman et al. 2003) [2]. This is the single most important safety measure during PRRT.

Q03 Will I feel anything during the Lu-177 infusion?

Most patients feel nothing during the Lu-177 infusion itself — it is a brief (20-30 minute) intravenous administration similar to any IV infusion. The most common day-of symptoms are nausea from the amino acid co-infusion (50-60% of patients, mostly mild) and mild fatigue starting later in the day [3]. Pre-emptive anti-emetic medication is standard.

Q04 Do I need to be admitted overnight for PRRT?

Most centres (including FMRI) recommend overnight admission for PRRT cycles, allowing extended observation, completion of the post-treatment imaging scan, and full radiation-safety briefing in the morning. Same-day discharge is possible at some centres for patients with good performance status. Two-night admission is uncommon and typically reserved for the first cycle in patients with significant carcinoid syndrome or PPGL [1].

Q05 What should I bring for a PRRT admission?

All current medications (including over-the-counter and supplements), recent imaging on CD/USB or accessible via radiology system, recent blood test results from outside labs, comfortable button-up clothing, a phone charger, a book or headphones (the day is long), and a companion for transport home. Long-acting somatostatin analogues should already have been held for 4-6 weeks before each cycle as previously advised [1].

Q06 Will I be radioactive after PRRT? Can I be around my family?

You will be mildly radioactive for the first 5-7 days after each cycle. Standard radiation-safety guidance: maintain ~1 metre distance from young children and pregnant women, sleep in a separate bed if possible, flush toilet twice after use, wash bedlinen separately at the first laundry cycle, and avoid prolonged close contact in confined spaces. By day 7, radiation levels are well below background and no further precautions are needed [7].

Q07 Can I drive home after PRRT?

Most patients are not advised to drive themselves home after the cycle, primarily because of the anti-emetic premedication (which can cause mild drowsiness) and the duration of the day. A companion for transport home is recommended. Driving is generally safe the day after discharge if you feel well and are not taking sedating medication.

Q08 What is post-treatment imaging?

Post-treatment imaging is a Lu-177 whole-body scan (planar) or Lu-177 SPECT/CT performed 4-24 hours after the infusion. The Lu-177 itself produces a small amount of gamma emission that can be imaged. This scan confirms tumour uptake of the radioligand, identifies any new lesions not previously visualised, and provides patient-specific dosimetry data that can inform future cycle planning [6].

Q09 How many cycles of PRRT will I need?

The standard PRRT course is four cycles of Lu-177 DOTATATE at 7.4 GBq (200 mCi) per cycle, with 8-week intervals between cycles. This is the NETTER-1 protocol [3]. Some patients require 12-week intervals to allow blood count recovery; a small number cannot complete all four cycles. Salvage PRRT (re-treatment) is a recognised option in selected patients who initially respond and later progress [9].

Q10 Is PRRT painful?

PRRT is generally not painful. The intravenous cannula insertion is the only routine source of mild discomfort. The Lu-177 infusion itself is painless. Some patients experience mild abdominal discomfort during or after the amino acid co-infusion. Bone pain from tumour-flare effect is uncommon but possible in patients with bony metastases — usually mild and responds to standard analgesia [3].

Q11 How is PRRT different from chemotherapy?

PRRT is targeted radionuclide therapy, not chemotherapy. It delivers radiation specifically to SSTR2-expressing tumour cells using a somatostatin analogue, with the radiation range short enough to spare most surrounding healthy tissue. PRRT does not typically cause hair loss, severe nausea/vomiting, or the immune suppression that characterises cytotoxic chemotherapy. The side-effect profile is meaningfully different — mostly fatigue, mild nausea, and modest blood count effects [3]. Quality of life on PRRT was significantly better than control therapy in NETTER-1 [10].

Q12 What happens if I cannot tolerate the amino acid co-infusion?

Nausea from the amino acid co-infusion is the most common reason patients struggle. First-line management is increased anti-emetic premedication (combining ondansetron + low-dose dexamethasone, sometimes adding aprepitant) and slowing the infusion rate. Alternative amino acid formulations (e.g., commercial amino acid preparations that are better tolerated than the original lysine/arginine combination) are used at some centres. Persistent intolerance occasionally requires temporary dose interruption [11].

Citations & references

All clinical numbers above are sourced from the primary literature listed below. Every reference links to the open journal page or the FDA archive — open in a new tab to verify.

[1] Bodei L, Mueller-Brand J, Baum RP, et al. The joint IAEA, EANM, and SNMMI practical guidance on PRRNT in neuroendocrine tumours. Eur J Nucl Med Mol Imaging. 2013;40(5):800-816. View source ↗

[2] Rolleman EJ, Valkema R, de Jong M, et al. Safe and effective inhibition of renal uptake of radiolabelled octreotide by a combination of lysine and arginine. Eur J Nucl Med Mol Imaging. 2003;30(1):9-15. View source ↗

[3] Strosberg J, El-Haddad G, Wolin E, et al. Phase 3 Trial of ¹⁷⁷Lu-Dotatate for Midgut Neuroendocrine Tumors (NETTER-1). N Engl J Med. 2017;376(2):125-135. View source ↗

[4] Roca M, Sondergaard L. Patient management during peptide receptor radionuclide therapy. Q J Nucl Med Mol Imaging. 2017;61(4):407-414. View source ↗

[5] Tapia Rico G, Li M, Pavlakis N, et al. Prevention and management of carcinoid crises in patients with high-risk neuroendocrine tumours undergoing peptide receptor radionuclide therapy (PRRT). Cancer Treat Rev. 2018;66:1-6. View source ↗

[6] Hicks RJ, Kwekkeboom DJ, Krenning E, et al. ENETS Consensus Guidelines for the Standards of Care in Neuroendocrine Neoplasms: PRRT. Neuroendocrinology. 2017;105(3):295-309. View source ↗

[7] IAEA. Safety in Nuclear Medicine: A Practical Guide. IAEA Safety Standards Series. 2014. View source ↗

[8] Strosberg JR, Halfdanarson TR, Bellizzi AM, et al. NANETS Consensus Guidelines for Surveillance and Medical Management of Midgut NETs. Pancreas. 2017;46(6):707-714. View source ↗

[9] Severi S, Sansovini M, Ianniello A, et al. Feasibility and utility of re-treatment with ¹⁷⁷Lu-DOTATATE in GEP-NENs. Eur J Nucl Med Mol Imaging. 2015;42(13):1955-1963. View source ↗

[10] Strosberg J, Wolin E, Chasen B, et al. Health-Related Quality of Life in Patients With Progressive Midgut Neuroendocrine Tumors Treated With ¹⁷⁷Lu-Dotatate in NETTER-1. J Clin Oncol. 2018;36(25):2578-2584. View source ↗

[11] Lapa C, Werner RA, Bluemel C, et al. Influence of repetitive amino acid infusions on nephrotoxicity during PRRT. Q J Nucl Med Mol Imaging. 2018;62(2):191-197. View source ↗

[12] Brabander T, van der Zwan WA, Teunissen JJM, et al. Long-Term Efficacy, Survival, and Safety of [¹⁷⁷Lu-DOTA⁰,Tyr³]octreotate. Clin Cancer Res. 2017;23(16):4617-4624. View source ↗

[13] Bergsma H, van Lom K, Raaijmakers MHGP, et al. Persistent Hematologic Dysfunction After PRRT with ¹⁷⁷Lu-DOTATATE. J Nucl Med. 2018;59(3):452-458. View source ↗

[14] Bodei L, Cremonesi M, Ferrari M, et al. Long-term evaluation of renal toxicity after PRRT. Eur J Nucl Med Mol Imaging. 2008;35(10):1847-1856. View source ↗

[15] Sansovini M, Severi S, Ianniello A, et al. Long-term follow-up of ¹⁷⁷Lu-DOTATATE in pancreatic NET. Eur J Nucl Med Mol Imaging. 2017;44(3):490-499. View source ↗

[16] U.S. Food and Drug Administration. LUTATHERA (lutetium Lu 177 dotatate) prescribing information. View source ↗

[17] Singh S, Halperin D, Myrehaug S, et al. NETTER-2 trial. Lancet. 2024;403(10446):2807-2817. View source ↗

[18] Hennrich U, Kopka K. Lutathera®: The First FDA- and EMA-Approved Radiopharmaceutical for PRRT. Pharmaceuticals (Basel). 2019;12(3):114. View source ↗

[19] Mittal BR, Kashyap R, Bhattacharya A, et al. ¹⁷⁷Lu-DOTATATE Therapy in Indian Patients with Metastatic NETs. Indian J Nucl Med. 2017;32(4):309-315. View source ↗

[20] Bodei L, Kidd M, Paganelli G, et al. Long-term tolerability of PRRT in 807 patients with NET. Eur J Nucl Med Mol Imaging. 2015;42(1):5-19. View source ↗

[21] Sundin A, Arnold R, Baudin E, et al. ENETS Consensus Guidelines: Radiological, Nuclear Medicine and Hybrid Imaging. Neuroendocrinology. 2017;105(3):212-244. View source ↗

[22] Pavel M, Öberg K, Falconi M, et al. ESMO Clinical Practice Guidelines for GEP-NEN. Ann Oncol. 2020;31(7):844-860. View source ↗

[23] Kwekkeboom DJ, de Herder WW, Kam BL, et al. Treatment with the radiolabeled somatostatin analog [¹⁷⁷Lu-DOTA⁰,Tyr³]octreotate. J Clin Oncol. 2008;26(13):2124-2130. View source ↗

[24] Vyakaranam AR, Crona J, Norlén O, et al. Favorable outcome in patients with pheochromocytoma and paraganglioma treated with ¹⁷⁷Lu-DOTATATE. Cancers (Basel). 2019;11(7):909. View source ↗

[25] Kong G, Grozinsky-Glasberg S, Hofman MS, et al. Efficacy of PRRT for Functional Metastatic Paraganglioma and Pheochromocytoma. J Clin Endocrinol Metab. 2017;102(9):3278-3287. View source ↗

[26] Strosberg JR, Caplin ME, Kunz PL, et al. NETTER-1 long-term overall survival update. Lancet Oncol. 2021;22(12):1752-1763. View source ↗

[27] Geijer H, Breimer LH. Somatostatin receptor PET/CT in NETs: update on systematic review and meta-analysis. Eur J Nucl Med Mol Imaging. 2013;40(11):1770-1780. View source ↗

[28] Modlin IM, Gustafsson BI, Moss SF, et al. Chromogranin A in NET disease. Ann Surg Oncol. 2010;17(9):2427-2443. View source ↗

[29] Pencharz D, Gnanasegaran G, Navalkissoor S. Theranostics in neuroendocrine tumours. Br Med Bull. 2018;126(1):41-58. View source ↗

[30] Halperin DM, Shen C, Dasari A, et al. Frequency of carcinoid syndrome at NET diagnosis. Lancet Oncol. 2017;18(4):525-534. View source ↗

[31] Klimstra DS, Modlin IR, Coppola D, et al. The pathologic classification of NETs. Pancreas. 2010;39(6):707-712. View source ↗

[32] Caplin ME, Pavel M, Ćwikła JB, et al. Lanreotide in metastatic enteropancreatic NETs (CLARINET). N Engl J Med. 2014;371(3):224-233. View source ↗

About the Author

Dr. Ishita B. Sen

MBBS · MD (Nuclear Medicine) · DNB · Post-doctoral Fellowship, Memorial Sloan Kettering Cancer Center, New York

Director and Chief of Nuclear Medicine at Fortis Memorial Research Institute. Co-founder of Theranostic Physicians Private Limited (TPPL). Two decades of clinical practice in PSMA imaging and PSMA-directed radioligand therapy, with one of the largest Indian institutional experiences in Lu-PSMA.

Full profile → All publications Book a consult