Faint = tracer uptake at or below liver level at baseline scintigraphy; heterogeneous = uptake between liver and salivary gland level at baseline scintigraphy; intense = uptake above salivary gland level at baseline scintigraphy; PR = partial remission (PSA < 50% of baseline level, tumor uptake < baseline level); SD = stable disease (change in PSA within −50% to +30% of baseline level, stable semiquantitative uptake and no new lesions in posttherapeutic imaging); MR = mixed response (change in PSA within −50% to +30% of baseline level, heterogeneous semiquantitative uptake in known lesions. No new lesions in posttherapeutic scintigraphy); PD = progression of disease (PSA > 30% of baseline level, occurrence of new lesions or increase in all known lesions).