As someone trained in an era where every treatment had to be defined as either 'curative' or 'palliative' for the purposes of CT simulation form, here are my thoughts:
Palliative chemotherapy improves survival as well in metastatic patients. Palliative does not mean that it cannot improve survival. It simply means that a treatment is not with curative intent.
SBRT in oligoprogressive disease is also palliative. Just because a treatment is palliative does not mean it has to be low dose. SRS for brain mets the vast majority of the time, also palliative.
Treatment is for either curative or palliative intent. IMO, if it's not curative intent, then it's palliative. Yes, it's not with the text book definition of 'improving symptoms' but until we have a 3rd option for billing/Evicore purposes, I'm not sure what the best system is.
Let me put it this way - the local control with 55/20 is likely sufficient for the vast majority of patients with metastatic disease that local disease is not the reason that they pass away, which should be the goal of these situations.
I do not see any other specialty routinely recommending "palliative" or "non-curative" surgery in patients with diffuse metastatic disease more so than Urologists. Nephrectomy in mRCC, despite CARMENA results (systemic therapy not the same!!111), now prostatectomy in M1 pCa, without clinical trials to defend it (the way RT has STAMPEDE)? And are we seriously talking about cystectomy in metastatic bladder cancer rather than radiation for palliation as first-line?
Care to pontificate on why that is?