177Lu-PSMA therapy – 100 mCi

177Lu-PSMA Therapy, or Lutetium-177 Prostate-Specific Membrane Antigen Therapy, is an advanced molecular-targeted therapy used in prostate cancer patients who have progressed after conventional treatments such as surgery, hormone therapy, chemotherapy, or external beam radiation. This therapy is most commonly administered to patients with metastatic castration-resistant prostate cancer (mCRPC) who have PSMA-expressing lesions visible on a PSMA PET-CT scan. This highly precise form of radioligand therapy works by targeting PSMA (Prostate-Specific Membrane Antigen), a protein that is overexpressed in prostate cancer cells, and delivering a therapeutic dose of beta radiation directly to the tumor sites using the Lutetium-177 isotope. The treatment is given in multiple cycles—usually 2 to 6 sessions, spaced 6–8 weeks apart, depending on clinical response and tolerability.

What is PSMA and Why It Matters in Therapy

PSMA, or Prostate-Specific Membrane Antigen, is a protein highly overexpressed in over 90% of prostate cancer cells, particularly in advanced and treatment-resistant stages. It is not found in significant amounts in most healthy tissues, making it an ideal target for both imaging and treatment.177Lu-PSMA combines this targeting capability with Lutetium-177, a beta-emitting radionuclide, which delivers cytotoxic radiation to cancer cells expressing PSMA while sparing most healthy tissues. This approach improves precision and reduces the adverse effects typically associated with systemic cancer treatments.

Indications for 177Lu-PSMA Therapy

177Lu-PSMA Therapy is indicated in:

• Metastatic castration-resistant prostate cancer (mCRPC)
• Patients who have failed conventional treatment options
• Those with PSMA-avid lesions confirmed on a PSMA PET-CT scan
• Patients experiencing symptoms such as bone pain, rising PSA, or disease progression

It is especially beneficial in patients with limited treatment alternatives, providing them with a potentially life-prolonging and quality-of-life-improving option.

How 177Lu-PSMA Therapy Works

The therapy process involves:

• Pre-treatment Evaluation:
  • PSMA PET-CT to confirm targetable disease
  • Blood work (kidney, liver, bone marrow function)
  • Clinical assessment for therapy suitability
• Therapy Administration:
  • The 177Lu-PSMA radiotracer is administered through intravenous injection
  • The infusion usually takes 10–15 minutes
  • Patient is observed post-infusion for any immediate reactions
  • Radiation safety instructions are provided before discharge
• Treatment Regimen:
  • Administered in multiple cycles (2–6 on average)
  • Each cycle is spaced 6 to 8 weeks apart, allowing time for therapeutic action and recovery
  • Interim assessment is done via PSA levels and repeat imaging
• Post-Therapy Monitoring:
  • Periodic clinical follow-up
  • PSA monitoring
  • Repeat imaging to track disease response
  • Monitoring for side effects and adjusting treatment accordingly

Benefits of 177Lu-PSMA Therapy

• Highly targeted – Directs radiation to cancer cells, sparing normal tissue
• Minimally invasive – Administered via IV in an outpatient setting
• Improved quality of life – Especially in patients with pain due to bone metastases
• Symptom control – Reduces tumor load and associated discomfort
• Effective even in advanced stages – Shown to lower PSA and delay disease progression
• Potential survival benefit – Clinical trials show improvement in overall outcomes

Common Side Effects

While generally well-tolerated, some patients may experience:

• Mild fatigue or weakness
• Dry mouth (xerostomia) due to salivary gland involvement
• Nausea or vomiting (typically self-limiting)
• Temporary decrease in blood counts (anemia, leukopenia, thrombocytopenia)
• Rarely, kidney or liver function abnormalities

These side effects are usually mild to moderate and are monitored throughout the therapy course. Supportive treatments can be given when required.

Who Should Not Receive This Therapy?

177Lu-PSMA Therapy may not be suitable for patients with:

• Severe bone marrow suppression
• Renal insufficiency or compromised kidney function
• PSMA-negative disease on imaging
• Uncontrolled medical illnesses or infections

Patient suitability is always confirmed after thorough clinical and imaging evaluation.

Response Monitoring

Response to therapy is monitored through:

• PSA trends (decline is a positive indicator)
• Repeat PSMA PET-CT scans
• Clinical symptom relief, especially pain and fatigue
• Performance status improvement

Patients who show significant PSA decline and disease stabilization are often considered for additional cycles if well-tolerated.

Conclusion

177Lu-PSMA Therapy is a revolutionary treatment for prostate cancer patients who have exhausted traditional options. By combining targeted therapy with internal radiation, it addresses the need for precision treatment in advanced stages with minimal systemic side effects. Given in multiple outpatient cycles, it not only helps control disease progression, but also improves pain relief, functional ability, and overall quality of life in many cases. With growing evidence supporting its effectiveness and safety, 177Lu-PSMA is quickly becoming a standard of care for appropriately selected prostate cancer patients. If you or your loved one is dealing with advanced prostate cancer, consult a nuclear medicine specialist to evaluate if 177Lu-PSMA therapy is the right choice.