Needle track recurrence after transrectal prostate biopsy detected by ¹⁸F-Choline PET-CT.

A 72-year-old patient was referred to our department to carry out an 18F-Choline PET–CT due to biochemical PSA failure from prostate cancer. The patient’s prostate cancer history started 5 years ago when he was diagnosed of a Gleason 3 + 4 tumor and treated with external radiotherapy. Three years later he presented biochemical failure and prostate tumor recurrence. Transrectal biopsy confirmed histological diagnosis of local recurrence (Gleason 4 + 5). The patient underwent salvage temporal high-dose-rate brachytherapy (HDR-BT) treatment using an Iridium-192 (192Ir) isotope. The PSA dropped to undetected levels. Fourteen months after salvage HDR-BT, a rising PSA was detected and reached 1.4 mg/dl before the PET–CT study was performed. The PET–CT showed bone metastasis not present in a recent bone scintigraphy (not shown). Also, a focal hypermetabolism near the anterior wall of the rectum was discovered. The activity was difficult to localize due to lack of IV contrast on CT. A rectal MRI was requested for characterization and further localization of the lesion. The MRI showed a submucous lesion in the anterior wall of the rectum adjacent, but without communication with the posterior border of the prostate. This lesion was not present on previous MRI studies. There was good correlation with PET–MRI fusion between the 18F-Choline uptake and the submucous lesion in the rectum (Fig. 1). A fine needle endoscopic biopsy was carried out and the pathological result was compatible with adenocarcinoma of prostate origin.