Rebuttal from Dr. Bezjak and Dr. Giuliani

In response to Nguyen and Palma’s submission arguing that radiological suspicion of a local recurrence can be sufficient indication to proceed to salvage therapy, it is clear that despite efforts from several international groups, distinguishing recurrent tumor from radiation induced lung injury (RILI) using radiological evidence, such as CT or FDG-PET scans, is far from an exact science. The authors correctly point out that clinical practice in presumed medically inoperable stage I lung cancer allows for SBRT treatment without biopsy confirmation, for lesions with radiological features strongly suggesting malignancy. However, they are proposing that this approach could be reasonably extended to salvage therapy following SBRT. We contend that the therapeutic ratio, i.e., risk versus benefit, is substantially different for initial SBRT treatment versus post-SBRT salvage treatment, and thus we maintain that pathological proof of recurrence be obtained wherever reasonable.