A prospective study on the early evaluation of response to androgen receptor-targeted agents with 11C-Choline, 68Ga-PSMA, and 18F-FACBC PET in metastatic castration-resistant prostate cancer: a single-center experience.

BACKGROUND: The early identification of responsive and resistant patients to androgen receptor-targeting agents (ARTA) in metastatic castration-resistant prostate cancer (mCRPC) is not completely possible with prostate-specific antigen (PSA) assessment and conventional imaging. Considering its ability to determine metabolic activity of lesions, positron emission tomography (PET) assessment might be a promising tool. PATIENTS AND METHODS: We carried out a monocentric prospective study in patients with mCRPC treated with ARTA to evaluate the role of different PET radiotracers: 49 patients were randomized to receive 11C-Choline, Fluorine 18 fluciclovine (anti-1-amino-3-18F-fluorocyclobutane-1-carboxylic acid - FACBC) (18F-FACBC), or Gallium-68-prostate-specific-membrane-antigen (68Ga-PSMA) PET, one scan before therapy and one 2 months later. The primary aim was to investigate the performance of three novel PET radiotracers for the early evaluation of response to ARTA in metastatic CRPC patients; the outcome evaluated was biochemical response (PSA reduction ≥50%). The secondary aim was to investigate the prognostic role of several semiquantitative PET parameters and their variations with the different radiotracers in terms of biochemical progression-free survival (bPFS) and overall survival (OS). The study was promoted by the Italian Department of Health (code RF-2016-02364809). RESULTS: Regarding the primary endpoint, at log-rank test a statistically significant correlation was found between metabolic tumor volume (MTV) (P = 0.018) and total lesion activity (TLA) (P = 0.025) percentage variation among the two scans with 68Ga-PSMA PET and biochemical response. As for the secondary endpoints, significant correlations with bPFS were found for 68Ga-PSMA total MTV and TLA at the first scan (P = 0.001 and P = 0.025, respectively), and MTV percentage variation (P = 0.031). For OS, statistically significant correlations were found for different 68Ga-PSMA and 18F-FACBC parameters and for major maximum standardized uptake value at the first 11C-Choline PET scan. CONCLUSIONS: Our study highlighted that 11C-Choline, 68Ga-PSMA, and 18F-FACBC semiquantitative PET parameters and their variations present a prognostic value in terms of OS and bPFS, and MTV and TLA variations with 68Ga-PSMA PET a correlation with biochemical response, which could help to assess the response to ARTA.

Wunderlich syndrome during antiplatelet drug therapy.

AIMS: Spontaneous hemorrhage in the kidney, also known as Wunderlich Syndrome, is a rare clinical problem. The most common cause of spontaneous renal hemorrhage is tumor. Other causes are rupture of a renal cyst, vasculitis, hydronephrosis, preeclampsia, and kidney infections. CASE HISTORY: A 67-year-old man was admitted complaining left flank colic pain. A contrast CT scan showed the presence of a subcapsular hematoma of the left kidney extending from the upper to the lower pole. He had no history of trauma and immunological screening tests for vasculitis were normal. His current therapy included acetylsalicylic acid (100 mg/daily) and lisinopril (20 mg/ daily). The patient was hospitalized for 4 days and his circulatory state remained stable. Nine months later an ultrasound examination showed complete resolution of the hematoma. One year later the patient was admitted again because of a spontaneous right calf hematoma and a thoroughly investigation of his coagulation pattern was carried out. Laboratory finding revealed a platelet defect, as the number of adenine nucleotides and other marker related to platelet activation were increased: ADP 1 mcM lack 2 masculine wave, ADP 2 mcM lack 2 masculine wave, Adrenalina 5 mcM lack 2 masculine wave, Adrenalina 10 mcM lack 2 masculine wave. Platelet activation markers: Gp53 in lysosomal membrane 0.48 Dpar (0 - 0.26). CONCLUSION: Our case describes the recurrence of spontaneous hemorrhages (perirenal and intramuscular hematoma) as a result of an underlying platelet aggregation defect worsened by administration of acetylsalicylic acid. In patients on antiplatelet treatment with a history of excessive bleeding a thorough investigation of coagulation status appears beneficial.