b. Partial Response (PR) : Radiographic PR applies only to patients with at least one measurable lesion. Greater than or equal to 30% decrease under baseline of the sum of longest diameters of all target measurable lesions. No unequivocal progression of non-measurable disease. No new lesions. All target measurable lesions must be assessed using the same techniques as baseline. PSA PR refers to PSA decline by >50% from baseline and confirmed at least 3 weeks later. c.