How would you treat locally advanced melanoma of the scalp with several in transit lesions and a metastatic lesion to the parotid if the patient is progressing on immunotherapy such as pembrolizumab?   

I think it is important to first define whether this is truly primary progression or whether the patient may have a delayed response. The Society for Immunotherapy of Cancer (SITC) has some consensus guidelines for defining this:Kluger et al., PMID 32238470 It is important to recognize that the...