SPECT-based tumor dosimetry was performed for the whole tumor burden and correlated with PSA response at 12 weeks with a significantly higher mean dose for “whole-body” tumor lesions in patients with PSA decline ≥50% compared to patients with a decline <50% (14.1 Gy vs. 9.6 Gy; p < 0.01). Here, KLK3 is linked to neoplasm.