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

Axial fused (a, c) and sagittal reconstructed 3D (b, d) 68Ga-PSMA PET/CT images in a 63-year-old patient with advanced metastatic castration-resistant prostate cancer before (a, b) and 45 days after (c, d) multifocal, ultrasound-guided injections of a total of 80 units botulinum toxin A into the right parotid gland. The SUVmean of the radioligand in the injected parotid gland shows a highly significant decrease of up to 60% compared with the left side (c, d white arrows), especially in the pars profunda of the gland, and a decrease of up to 64%, but no significant change in the left parotid gland, compared with the baseline PET/CT study (a, b