PSMA theranostics

Last revised by Khalid Alhusseiny on 14 Jul 2023

Citation, DOI, disclosures and article data

Citation:

Liao A, Alhusseiny K, DeSai C, et al. PSMA theranostics. Reference article, Radiopaedia.org (Accessed on 29 Apr 2024) https://doi.org/10.53347/rID-168760

DOI:

https://doi.org/10.53347/rID-168760

Permalink:

https://radiopaedia.org/articles/168760

rID:

168760

Article created:

21 May 2023, Angela Liao

Disclosures:

At the time the article was created Angela Liao had no financial relationships to ineligible companies to disclose.

View Angela Liao's current disclosures

Last revised:

14 Jul 2023, Khalid Alhusseiny ◉

Disclosures:

At the time the article was last revised Khalid Alhusseiny had no financial relationships to ineligible companies to disclose.

View Khalid Alhusseiny's current disclosures

Revisions:

5 times, by 4 contributors - see full revision history and disclosures

Systems:

Urogenital, Oncology

Tags:

theranostics, prostate cancer, prostate malignancy

Synonyms:

177Lu-PSMA therapy
177Lu-PSMA
225Ac-PSMA therapy
225Ac-PSMA

PSMA theranostics is an emerging nuclear medicine approach in the management of prostate cancer that combines the use of prostate-specific membrane antigen (PSMA)-targeted imaging and therapy ¹. PSMA-targeted imaging can be used to identify and locate prostate cancer cells, while PSMA radioligand (or radionuclide) therapy delivers radiation to these targets.

The prostate-specific membrane antigen (PSMA) is a transmembrane protein that has upregulated expression on the surface of approximately 95% of prostate cancer cells ². This makes it an attractive target for the development of new diagnostic and therapeutic agents.

PSMA imaging facilitates patient selection for PSMA-targeted radioligand therapy and provides information on the localization and extent of PSMA-expressing lesions. Currently, PSMA theranostics is primarily indicated for the treatment of patients with metastatic castration-resistant prostate cancer ^1,3. PSMA theranostics can also be used to treat patients with locally advanced prostate cancer who are not eligible for surgery or local radiotherapy.

Procedure

PSMA theranostics involves two main steps ^4,6:

PSMA imaging: fluorodeoxyglucose (FDG) PET/CT or SPECT imaging with intravenous administration of radiolabeled PSMA ligand (commonly ⁶⁸Ga-PSMA-aa or ¹⁸F-DCFPyL)
PSMA-targeted radioligand therapy: therapeutic radioligands (¹⁷⁷Lu or ²²⁵Ac) bound to PSMA ligands administered; these radioligands emit beta particles (¹⁷⁷Lu) or alpha particles (²²⁵Ac), delivering localized radiation to PSMA-expressing tumor cells while sparing other tissue; response my be monitored through follow-up PSMA imaging

Complications

Although generally well tolerated, patients may experience radioligand-induced toxicity including myelosuppression and xerostomia ⁵. Patients may also experience allergic reactions to radiotracers.