RADIOLIGAND THERAPY:
TARGETED RADIONUCLIDE TREATMENT
A complete guide to radioligand therapy โ how targeted molecules carrying radioactive payloads home in on cancer cells to deliver localised radiation. Covers Lu-177 PSMA for prostate cancer, Lu-177 DOTATATE for neuroendocrine tumours, radium-223 for bone metastases, eligibility, and international access.
analyticsAt a Glance
- check_circleRadioligand therapy combines a cancer-targeting molecule with a radioactive isotope โ the targeting vector homes in on tumour cells and the radiation kills them at close range.
- check_circleLu-177 PSMA (Pluvicto): VISION Phase III trial improved median overall survival from 11.3 to 15.3 months in mCRPC โ FDA approved 2022.
- check_circleLu-177 DOTATATE (Lutathera): NETTER-1 Phase III trial showed 79% reduction in disease progression risk for midgut neuroendocrine tumours โ FDA approved 2018.
- check_circleAvailable in China (select centres) and India (Apollo, HCG, AIIMS) at significantly lower cost than in the US โ CancerFax coordinates access and eligibility screening.
What Is Radioligand Therapy?
Radioligand therapy (also called radiopharmaceutical therapy or targeted radionuclide therapy) combines two components: a targeting molecule that recognises and binds to specific proteins on cancer cells, and a radioactive isotope that delivers localised radiation once the molecule has attached to the tumour.
โRadioligand therapy is sometimes described as a guided missile โ the targeting vector homes in on cancer cells that express the target protein, carries the radioactive payload to them, and releases localised radiation at close range.โ
The Ligand: Targeting Vector
The targeting component may be a small molecule, peptide, antibody, or antibody fragment designed to bind selectively to a specific receptor or antigen expressed on cancer cells. PSMA-617 binds to PSMA on prostate cancer cells; DOTATATE binds to somatostatin receptors on neuroendocrine tumour cells.
The Radionuclide: Radioactive Payload
The radioactive isotope attached to the targeting vector emits radiation at short range โ killing the cancer cells to which it binds and their immediate neighbours. Beta emitters (Lu-177) travel a few millimetres; alpha emitters (Ra-223) travel only cell diameters โ delivering highly localised, highly potent radiation.
Theranostics: Diagnosis and Treatment Together
Radioligand therapy is part of theranostics โ the combination of targeted imaging and targeted therapy using the same molecular vehicle. The same PSMA molecule used in Lu-177 PSMA therapy is first used diagnostically in PSMA PET-CT to confirm the tumour expresses PSMA at sufficient levels. Treatment and imaging use the same targeting principle.
Systemic but Targeted
Unlike external beam radiation (localised) or conventional chemotherapy (systemic without targeting), radioligand therapy is systemic in administration (given IV) but targeted in effect. The radioligand distributes throughout the body but preferentially accumulates at tumour sites expressing the target โ reducing off-target radiation to normal tissue.
Approved Radioligand Therapies and Key Indications
Four radioligand therapies have robust Phase III evidence and major regulatory approvals. Each targets a specific protein expressed by a specific cancer type.
Lu-177 PSMA-617 (Pluvicto) โ Prostate Cancer
VISION Phase III trial (NEJM 2021, n=831): Lu-177 PSMA-617 vs standard care in mCRPC with positive PSMA PET-CT and prior ARPI and taxane chemotherapy. Primary endpoints both met: radiographic PFS (8.7 vs 3.4 months) and overall survival (15.3 vs 11.3 months). FDA approved March 2022 โ the first PSMA-targeted radioligand therapy approved globally.
Lu-177 DOTATATE (Lutathera) โ Neuroendocrine Tumours
NETTER-1 Phase III trial (NEJM 2017): Lu-177 DOTATATE vs octreotide in progressive somatostatin receptor-positive midgut NETs. 79% reduction in risk of disease progression or death (HR 0.21). 65% vs 11% response rates. FDA approved January 2018 for somatostatin receptor-positive gastroenteropancreatic NETs. The most mature radioligand therapy evidence base.
Radium-223 Dichloride (Xofigo) โ Prostate Cancer Bone Metastases
ALSYMPCA Phase III trial: Ra-223 improved OS (14.9 vs 11.3 months) in patients with symptomatic bone metastases from mCRPC. Ra-223 is an alpha emitter โ high-energy, very short-range radiation selectively targeting bone metastases. FDA approved May 2013. Used when symptomatic bone-dominant metastatic prostate cancer is the clinical priority.
Iodine-131 (Radioactive Iodine) โ Thyroid Cancer
The oldest approved radioligand therapy. Thyroid cells and differentiated thyroid cancers uniquely express the sodium-iodide symporter, which actively accumulates iodine. I-131 is given orally; it localises in thyroid remnants and metastases and destroys them with beta radiation. Standard adjuvant treatment after thyroidectomy for intermediate and high-risk differentiated thyroid cancer.
Key Radioligand Therapies: Comparison Table
A quick reference for the principal approved radioligand therapies and their regulatory status.
| Therapy | Target / Cancer | Key Trial | FDA Approval | Administration |
|---|---|---|---|---|
| Lu-177 PSMA-617 (Pluvicto) | PSMA / mCRPC prostate cancer | VISION Phase III: OS 15.3 vs 11.3 months | March 2022 | IV infusion every 6 weeks ร 6 cycles |
| Lu-177 DOTATATE (Lutathera) | Somatostatin receptors / GEP-NETs | NETTER-1 Phase III: HR 0.21 progression risk | January 2018 | IV infusion every 8 weeks ร 4 cycles |
| Radium-223 (Xofigo) | Bone / mCRPC bone metastases | ALSYMPCA Phase III: OS 14.9 vs 11.3 months | May 2013 | IV injection every 4 weeks ร 6 cycles |
| Iodine-131 (RAI) | Sodium-iodide symporter / thyroid cancer | Standard of care since 1940s | 1951 (original approval) | Oral capsule โ single dose or repeat |
| Ac-225 PSMA (investigational) | PSMA / mCRPC โ alpha emitter | Phase II data โ VISION-2 ongoing | Not yet approved | IV infusion โ trial access only |
The Radioligand Therapy Treatment Process
Using Lu-177 PSMA therapy for prostate cancer as the primary example โ the process is similar for other radioligand therapies.
- 1
PSMA PET-CT Imaging โ Eligibility Confirmation
PSMA PET-CT scan confirms that tumour deposits express PSMA at sufficient levels and that there are no significant PSMA-negative metastases (which would not respond to PSMA-targeted therapy). This selection step is mandatory before treatment initiation.
- 2
Eligibility Review and Treatment Planning
Oncologist confirms prior ARPI therapy and taxane chemotherapy (VISION criteria), adequate kidney function, bone marrow reserve, and liver function. Performance status assessment.
- 3
Lu-177 PSMA Administration
IV infusion of Lu-177 PSMA-617 in a nuclear medicine department equipped for radionuclide therapy. Takes approximately 30-60 minutes. Radiation safety precautions during and for several days after each cycle.
- 4
Post-Treatment Imaging and Radiation Safety Period
Post-treatment SPECT/CT imaging confirms radioligand distribution and tumour uptake. Radiation safety precautions: reduced close contact for 2-3 days after each treatment. Outpatient in most cases.
- 5
Cycle Repetition and Response Assessment
Treatment repeats every 6 weeks for up to 6 cycles depending on response, tolerance, and eligibility. PSA and imaging response assessed at intervals. Dose modifications or discontinuation based on toxicity.
Key Evidence Numbers
- 4 monthsOS Improvement โ Lu-177 PSMA (VISION Trial)Median OS: 15.3 vs 11.3 months. rPFS: 8.7 vs 3.4 months. Both primary endpoints met.
- 79%Reduction in Progression Risk โ Lu-177 DOTATATE (NETTER-1)HR 0.21 for progression or death vs octreotide alone in midgut GEP-NETs.
- 3.6 monthsOS Improvement โ Radium-223 (ALSYMPCA)Median OS: 14.9 vs 11.3 months in symptomatic bone-dominant mCRPC.
- 6 cyclesMaximum Cycles โ Lu-177 PSMA Standard ProtocolOne cycle every 6 weeks โ total treatment period approximately 8 months.
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Frequently Asked Questions
About Radioligand Therapy
Is Lu-177 PSMA therapy the same as chemotherapy?
No. Lu-177 PSMA therapy is a radioligand therapy โ a form of targeted radionuclide treatment, not chemotherapy. It works by delivering radiation specifically to cancer cells that express PSMA, rather than through the cytotoxic mechanisms of chemotherapy drugs. It has a different side effect profile (less nausea, hair loss less common, different haematological effects) and is given at much less frequent intervals (every 6 weeks) than typical chemotherapy cycles.
Who is eligible for Lu-177 PSMA therapy?
Eligibility requires: confirmed metastatic castration-resistant prostate cancer (mCRPC); positive PSMA PET-CT demonstrating adequate PSMA expression on tumours without significant PSMA-negative disease; prior treatment with at least one ARPI (enzalutamide, abiraterone) and at least one taxane chemotherapy (in most protocols); adequate kidney function (GFR), bone marrow reserve, and liver function; and performance status that supports systemic treatment.
Is radioligand therapy available in China and India?
Lu-177 PSMA therapy is available at select specialist nuclear medicine and oncology centres in both China and India. In India, centres including Apollo Cancer Centres, HCG, and AIIMS have established programmes. In China, selected major cancer centres offer Lu-177 PSMA as part of expanded access or clinical trial frameworks. Availability is more limited than in the US or Europe and access coordination is important โ CancerFax helps identify eligible centres and coordinates the PSMA PET-CT and eligibility assessment remotely.
How CancerFax Helps
CancerFax is a specialist cancer access and patient-navigation platform. We help patients and families understand their options, organise medical records, coordinate hospital communication, and support cross-border treatment planning where appropriate.
We help collect and organise reports, scans, pathology, biomarker results, and treatment history for structured case review.
We communicate with hospitals or trial teams to assess whether a case may be suitable for further screening.
We support appointment coordination, document submission, translation, and direct communication with international departments.
For international patients, we help with practical coordination โ travel planning, hospital admission guidance, and local support.
If this option is not suitable, we help explore other relevant treatments, clinical trials, or advanced care pathways.
From inquiry through to follow-up, our coordinators provide a single point of contact for the family.
CancerFax does not guarantee treatment access, eligibility, or clinical outcome. Our role is to help patients access accurate information, structured review, and appropriate specialist pathways.
Is Radioligand Therapy an Option for Your Cancer?
Upload your medical reports and prior treatment history โ our oncology team will review your eligibility for Lu-177 PSMA, Lu-177 DOTATATE, or other radioligand therapies and identify appropriate access routes in China, India, or internationally.
This content is for informational purposes only and does not constitute medical advice. All treatment decisions must be made in consultation with a qualified oncologist and nuclear medicine specialist.