The Relationship Between Total Lesion Activity on 18F Choline Positron Emission Tomography-Computed Tomography and Clinical Outcome in Patients with Castration-Resistant Prostate Cancer Bone Metastases Treated with 223Radium

Abstract

The aim of the study was to assess the correlation between metabolic response measured through positron emission tomography-computed tomography (PET-CT) with ¹⁸F choline (¹⁸F FCH) and overall survival (OS) in patients affected by bone lesions from metastatic castration-resistant prostate cancer treated with ²²³Ra dichloride. Eleven subjects were subjected to PET-CT with ¹⁸F FCH before and 1 month after ²²³Ra treatment. Reduction in total lesion activity (ΔTLA) between pretreatment and post-treatment scan was determined and patients were divided into responders (ΔTLA >50%) and nonresponders (ΔTLA <50%). The OS of the entire cohort was 12.7 ± 3.8 months. Kaplan-Meier analysis showed that responders presented a significantly longer survival than nonresponders (16.5 ± 1.9 months vs. 10.5 ± 0.9 months, p < 0.05). Reduction in TLA after ²²³Ra treatment seems to be correlated with a trend toward a longer survival.

Keywords: 18F choline; 223Radium dichloride; PET-CT; metastatic castration-resistant prostate cancer; targeted α therapy; total lesion activity.