Performance of Ga-68 PSMA PET/CT for diagnosis and grading of local prostate cancer.

BACKGROUND: We aimed to evaluate the utility of prostate-specific membrane antigen (PSMA) PET/CT for the detection of local disease within the prostate. METHODS: This is a retrospective review of a single-center experience evaluating intraprostatic detection rates compared with final histopathology in a radical prostatectomy (RP) population. Seventy-two patients had PSMA PET/CT scan performed as part of their primary staging. Intraprostatic PSMA PET/CT avidity was assessed. PSMA PET/CT uptake was retrospectively correlated with patient characteristics including final histopathology, MRI Prostate Imaging Reporting and Data System (PI-RADS) score, clinical tumor stage, prostate-specific antigen (PSA) level, and patient age. RESULTS: The sensitivity of PSMA PET/CT for the detection of RP-confirmed prostate cancer was 81.2%. Much higher sensitivity was found within certain subpopulations. The patient characteristics that most strongly correlated with focal intraprostatic PSMA PET/CT uptake were patient age (Kendall's tau coefficient τb = 0.24, p < 0.05) and clinical T stage (τb = 0.21, p < 0.05).The International Society of Urological Pathology (ISUP) grade group from final RP was predicted by standardized uptake value (SUVmax) and to a lesser extent PSA and the maximal dimension of PET-avid lesions. SUVmax monotonically increased with ISUP grade group. If SUVmax was above 10 g/mL, the final RP histopathology had a relative risk of 2.3 (95% CI 1.3-4.1) of being ISUP grade group 5. CONCLUSION: This trial provides early evidence that PSMA PET/CT assists in the grading of prostate cancer and suggests that the imaging modality is particularly accurate in subpopulations including the elderly and those with palpable disease.

Rectal ulcer associated with SpaceOAR hydrogel insertion during prostate brachytherapy.

We present a case of rectal ulceration associated with SpaceOAR hydrogel insertion during low-dose-rate (LDR) brachytherapy in a patient with prostate cancer.

Migration of a strand of four seeds in low-dose-rate brachytherapy.

We report a case of stranded-seed migration (one strand of four seeds), via the prostatic venous plexus to the internal pudendal vein, in low-dose-rate (LDR) prostate brachytherapy. A 70-year-old man with low-risk prostate adenocarcinoma underwent transperineal permanent seed implantation. A total of 93 iodine-125 seeds were implanted (91 stranded seeds and 2 loose seeds). Immediate postimplantation fluoroscopic image and day 1 postimplantation CT scan indicated all implanted seeds to be within the vicinity of the prostate as planned. Day 30 pelvic X-ray and CT scan revealed migration of a strand of four seeds to the right pelvis (adjacent to ischial spine). At 2 years postimplantation, the patient continues to have good disease control with prostate specific antigen level of 0.69 µg/L, and asymptomatic. To the best of our knowledge, this is the first report of migration of an entire strand of seeds following LDR prostate brachytherapy.