Injection of Botulinum Toxin for Preventing Salivary Gland Toxicity after PSMA Radioligand Therapy: an Empirical Proof of a Promising Concept

The dose-limiting salivary gland toxicity of 225Ac-labelled PSMA for treatment of metastatic, castration-resistant prostate cancer remains unresolved. Suppressing the metabolism of the gland by intraparenchymal injections of botulinum toxin appears to be a promising method to reduce off-target uptake. A 68Ga-PSMA PET/CT scan performed 45 days after injection of 80 units of botulinum toxin A into the right parotid gland in a 63-year-old patient showed a decrease in the SUVmean in the right parotid gland of up to 64% as compared with baseline. This approach could be a significant breakthrough for radioprotection of the salivary glands during PSMA radioligand therapy.

Nuclear medicine and molecular imaging. 2018 Jan 11 [Epub]

Richard P Baum, Thomas Langbein, Aviral Singh, Mostafa Shahinfar, Christiane Schuchardt, Gerd Fabian Volk, Harshad Kulkarni

1Theranostics Center for Molecular Radiotherapy and Molecular Imaging, Zentralklinik Bad Berka, Bad Berka, Germany., 2Department of Otorhinolaryngology, Jena University Hospital, Jena, Germany.