Identification of Recurrence Sites Following Post-Prostatectomy Treatment for Prostate Cancer Using ¹¹ C-Choline Positron Emission Tomography and Multiparametric Pelvic Magnetic Resonance Imaging

Purpose: We describe anatomical sites of recurrence in patients with prostate cancer who had biochemical recurrence following radical prostatectomy and who received radiotherapy and/or androgen deprivation therapy postoperatively. We performed ¹¹ C-choline positron emission tomography/computerized tomography and multiparametric magnetic resonance imaging. Materials and Methods: After radiotherapy and/or androgen deprivation therapy patients who underwent radical prostatectomy were evaluated by ¹¹ C-choline positron emission tomography/computerized tomography and multiparametric magnetic resonance imaging to determine recurrence patterns and clinicopathological features. Recurrent sites were described as local only (seminal vesicle bed/prostate fossa, vesicourethral anastomosis and bladder neck) or distant metastatic disease. Features associated with the identification of any distant metastatic disease were evaluated by multivariable logistic regression. Results: A total of 550 patients were identified. Treatment included androgen deprivation therapy in 108, radiotherapy in 201, and androgen deprivation therapy and radiotherapy in 241. Median prostate specific antigen at evaluation was 3.9, 3.6 and 2.8 ng/ml in patients treated with androgen deprivation therapy, radiotherapy and a combination, respectively. Recurrence developed locally in 77 patients (14%), as distant metastasis only in 411 (75%), and as local and distant metastatic disease in 62 (11%). On multivariable analysis treatment with radiotherapy (OR 7.18, 95% CI 2.92–17.65), and radiotherapy and hormonal therapy (OR 9.23, 95% CI 3.90–21.87, all p <0.01) was associated with increased odds of distant failure at evaluation. Conclusions: The combination of ¹¹ C-choline positron emission tomography/computerized tomography and multiparametric magnetic resonance imaging successfully identified patterns of recurrence after postoperative radiotherapy and/or androgen deprivation therapy at a median prostate specific antigen of less than 4 ng/ml. Half of this cohort had local only recurrence and/or a low disease burden limited to pelvic lymph nodes. These patients may benefit from additional local therapy. These data and this analysis may facilitate the evaluation of such patients with biochemically recurrent prostate cancer.