South African guidelines for receptor radioligand therapy (RLT) with Lu-177-PSMA in prostate cancer

BACKGROUND

Prostate cancer is an important cause of morbidity and mortality in South Africa, as it is in the rest of the world. In African men, however, prostate cancer tends to follow a more aggressive course when compared to their European counterparts. This is attributed to a plethora of diverse factors of which an underlying genetic component has been shown to be an important aspect. Such differences highlight the need for individualised therapy and for local guidelines. The aim of this guideline is to aid nuclear physicians and other clinicians who manage patients with prostate cancer in the correct identification and treatment of patients who are likely to benefit from receptor radioligand therapy.

RECOMMENDATIONS

There are a multitude of treatment modalities available for the treatment of prostate cancer and these therapies may be required at various time points during the course of the disease in any individual patient. A multidisciplinary approach is crucial in deciding which therapy, or combination of therapies, would be most advantageous at particular time points. The multidisciplinary team should include a urologist, oncologist and nuclear medicine physician as a minimum, and should ideally also involve a palliative/pain specialist, a dietician and a psychologist.

CONCLUSION

Treatment with ¹⁷⁷Lu-PSMA has emerged as a promising systemic modality, which involves the delivery of targeted radiation therapy in the form of β-particles to sites of tumour tissue. Therapy is provided on an outpatient basis, is well tolerated with relatively few side effects and has a positive effect on overall survival and quality of life. At present, it is used mostly in the setting of advanced, castrate-resistant cancer. Patients are selected (amongst other criteria) based on the prior PSMA-based SPECT/PET/CT imaging (⁹⁹mTc-,⁶⁸Ga- or ¹⁸F-PSMA), which should demonstrate sufficient receptor expression in order to consider PSMA-based targeted radionuclide therapy. Such imaging of an intended target prior to its therapeutic targeting is known as a theranostic approach.

The College of Nuclear Physicians of South Africa Practice Guidelines on Peptide Receptor Radionuclide Therapy in Neuroendocrine Tumours

BACKGROUND

Peptide receptor radionuclide therapy (PRRT) for metastatic or inoperable neuroendocrine tumours (NETs) is a systemic therapy which targets somatostatin receptors overexpressed by differentiated NETs for endoradiotherapy. This guideline has been compiled by the College of Nuclear Physicians of the Colleges of Medicine of South Africa, with endorsement by the South African Society of Nuclear Medicine and the Association of Nuclear Physicians to guide Nuclear Medicine Physicians in its application during the management of these patients.

RECOMMENDATIONS

Patients with well- to moderately-differentiated NETs should be comprehensively worked-up to determine their suitability for PRRT. Treatment should be administered by a Nuclear Medicine Physician in a licensed, appropriately equipped and fully staffed facility. Patient monitoring is mandatory during and after each therapy cycle to identify and treat therapy-related adverse events. Patients should also be followed-up after completion of therapy cycles for monitoring of long-term toxicities and response assessment.

CONCLUSION

PRRT is a safe and effective therapy option in patients with differentiated NETs. Its use in appropriate patients is associated with a survival benefit.