For that occasional "single lymph node metastasis" referral in patients with no other sites of disease, is there a therapeutic dose below which you're not really helping the patient? Perhaps the BED equivalent of 30Gy in 10 fractions? I haven't been able to achieve the doses reported in the (very limited) literature, while staying within the normal tissue constraints (that are minimally validated). I wonder if there is any benefit to a low dose like 6Gy x 3 when treating a para-aortic/pelvic lymph node met.