11C-Choline Pet/Ct in the Detection of Prostate Cancer Relapse in Patients After Radical Treatment With Psa Level < 10 Ng/Ml

Abstract

Purpose: To evaluate the usefulness of 11C-Choline PET/CT in the detection of recurrent prostate cancer (PCa) in patients with biochemical relapse after radical treatment. Materials and methods:This retrospective study included 217 PCa patients who underwent 11C-Choline PET/CT in the Department of Nuclear Medicine of Bakoulev Scientific Centre. All patients had biochemical relapse 3±2 years after radical treatment for locally advanced PCa (T1-3 N0-1 M0): radical prostatectomy (n = 159) and radiation therapy (n = 58). The mean PSA value in the group was 2.1±2.5 (0.2-9.7) ng/ml, median -1.9 ng/ml. Imaging was performed on PET/CT scanner (Biograph-64, Siemens) 10 min after injection of 11 C-Choline (400-550 Mbq). Results:Overall, according to 11C-Choline PET/CT results PCa relapse was detected in 56% (121/217) of cases: in 50% (80/159) after radical prostatectomy and in 71% (41/58) after radiation therapy.The mean PSA value in PET-positive cases was 3.1±2.2 (0.2-9.7) ng/ml, while in PETnegative cases -1.8±1.7 (0.2-4.6) ng/ml. The majority -68% (65/96) patients with PET-negative scan had low PSA levels (< 2 ng/ml).PET/CT results were positive in 43% (50/115) patients with PSA of < 2 ng/ml, in 63%(45/72) with PSA of 2 to 5 ng/ml, and in 87% (26/30) with PSA of > 5 ng/ml.Local relapse was detected in 51% (62/121) patients, distant metastases -in 28%(34/121) of cases, both local and distant metastases -in 21% (25/121) of cases.Lymph node metastases were detected in 38% (86/217) of all patients included in the analysis, of which 28% (24/86) had lesions in lymph node of normal size (median 7 mm). KnE Energy & Physics PhysBioSymp17Of all PET-positive patients bone metastases were detected in 33% (40/121), of which 60% (24/40) had isolated skeletal involvement. Importantly, that 27% (11/40) of PETpositive patients with bone metastases had no structural abnormalities on CT images (CT-negative cases), corresponding to isolated involvement of bone marrow. And half of these CT-negative patients (5/11) had single lesions. The mean PSA value in patients with bone metastases was 5.0±3.7 (0.4-9.1) ng/ml, median -3.8 ng/ml.According to 11C-Choline PET/CT results oligometastatic PCa recurrence was revealed in 38% (82/217) of all patients, of which 62% (51/82) had local relapse only. Distant oligometastatic lesions were detected in 38% (31/82), of which 13% (4/31) were presented by normal-size lymph nodes and 19% (6/31) -by early bone marrow metastases.48% (58/121) of PET-positive results were confirmed by data of repeated PET/CT examinations.Conclusion: 11C-Choline PET/CT has been shown to be a single noninvasive accurate technique for detection of recurrent PCa in patients with rising PSA after radical treatment, which allows to differentiate patients with local and distant metastases in one study, as well as identify oligometastatic process, and therefore was useful in determining the further personalized therapeutic approach.