Marieke van Son

168 CHAPTER 9 During the first six months of follow-up, tamsulosin 0.4 mg once daily was prescribed due to minor urinary retention and frequency symptoms. His erectile function decreased in the same period but restored without medication. There were no rectal complaints. Three months posttreatment, the nadir PSA was 0.9 ng/ml. Anmp-MRI for response eval- uation six months after treatment showed no signs of loco-regional malignant disease and post-radiation fibrosis was visible in the right seminal vesicle. Nevertheless, PSA levels started to rise again, up to 3.4 ng/ml one year after treatment (PSADT, six months). Once again, disease status evaluation was performed with 68Ga-PSMA PET-CT and 3T mp-MRI. As compared to the first diagnostic PET-CT scan, less PSMA uptake was visible in the right peripheral zone. A new suspect lesion of approximately 10 millimeters was suggested in the left dorsal peripheral zone, in close relation to the seminal vesicle (Figure 4). Diminutive diffusion restriction and contrast enhancement on the mp-MRI could not verify this lesion (also due to an overall heterogeneous aspect of the prostate). Figure 4 – Second recurrence lesion on 68Ga-PSMA PET-CT Transversal plane (upper image), coronal plane (lower-left image), and sagittal plane (lower- right image), showing the second recurrence lesion in the left dorsal peripheral zone on the 68Ga-PSMA PET-CT, 11 years after initial prostate cancer treatment.