“…This comment points out, as discussed in our reply to letters by Tulchinsky and Flux, the critical importance of lesional dosimetry in patients with large tumor burden to define the optimal administered activity to achieve a therapeutic tumoricidal dose, rather than the maximum activity that can be safely delivered (5). WB/BC studies would be required only if the administered activity exceeded safe empiric activities to optimize the therapeutic efficacy while minimizing treatment-related side effects.…”