MSK treatment may not be an option. It depends on the type of neuroblastoma a person has, as to what their treatment options worldwide are. Also, some treatments are only offered, worldwide, to those who have exhausted worldwide protocol.
I'm sure the consultant will know, but without knowing the particular case it's hard to say.
This was true in our daughter's case, different cancer, obviously, but there was a trial (now suspended as it failed) for those who had already undergone stem cell transplant and had relapsed. It was not open to others. We had others posting about treatments that would not apply to her. It's nice, to give that hope, but it wasn't really a hope for her because it wasn't available to her due to her form of cancer.
Similarly, some treatments you read about, and I'm thinking of a personal friend of mine, the treatment is not known to be a cure. It is to hopefully prolong life, and so some decide the risk and quality of life following treatment may outweigh benefits.
Again, a decision for the parents to make with their medical team and I wish you all the strength in the world, Trazzle.