Diagnosis of Recurrent Prostate Cancer at MRI Following Radiation Therapy |Biomedgrid

Prostate cancer (PCa)recurrence following radiation therapy (RT) is a significant issue. Despite advances in diagnosis and management of PCa, the disease still recurs after definitive treatment in up to 30% of patients [1]. Early diagnosis of local recurrence is strongly associated with improved patient prognosis because of prompt treatment decisions based on the diagnosis. It is approximately 3 years from development of local recurrence to distant metastasis on average if without salvage therapy [2]. According to the Phoenix criterion, after RT, biochemical recurrence (BCR) is defined as an absolute increase in PSA level of 2 ng/ml above nadir (i.e., the lowest post-treatment PSA value) [3,4]. The recurrence may be local, nodal and/or metastatic. A rising serum prostate-specific antigen (PSA) level is typically the first sign of relapse, unfortunately it does not differentiate local recurrence from systemic disease. If PSA doubles in less than 8 months, especially in the first year after treatment, this can be a predictor for metastatic disease [5]. Since there is no reliable way to diagnose local recurrence clinically, imaging is needed to determine if there is a local recurrence. Fortunately, recent advances in multiparametric MRI (mp-MRI) techniques have markedly improved detection of local recurrence following RT [6].