Advice on genomic testing and TIL

Good afternoon, thanks in advance for any help. Some of you may remember my sister’s story. Diagnosed 8/2018 , no primary but spread to brain and fibulas. Brain met removed 8/2018, some had to be left due to position. Tested Braf positive, started on Dafrabanib and Trametenib, with some success, Feb2020 some activity at site of brain met, given stereotactic radiotherapy, and then started on immunotherapy, iPi and nivo, however many seizures post radiotherapy and hospitalisations. Fast forward, late April 2021 not sure if scan shows scarring/swelling or tumour but they think it may be tumour, will have surgery to hopefully remove the tumour this Tuesday. No genomic testing was done on the original tumour, I have asked for it to be done now, asking if there are any mutations not typical to melanoma, I also asked about TIL but have been told by her oncologist that it has only been trialed in skin lesions in the UK!

I am asking if anyone can point me in the direction of what we need to preserve from What is removed, I have asked if cells can be harvested, they are not helpful in this regard. If the tumour is preserved can these be harvested after? What genomic testing should I be asking for exactly? I would appreciate greatly any of your advice. Thank you all, ypu have helped me navigate this so much .