For a recurrent medulloblastoma in the posterior fossa several years after initial standard risk therapy (23.4 Gy CSI), and in which the patient is still less than 18, how would you approach re-irradiation?

If the recurrences are localized to the resection bed, I would re-irradiate only the recurrences (and possibly the entire resection bed depending on number of recurrences). If there is evidence of CSF dissemination (recurrences not associated with primary--whether in posterior fossa or not) then CSI...

This is my approach.

Short version: it depends on a lot and no answer on a website can do this situation justice. This is not a good situation and will likely not end well.

Long version: In reality is very case by case (will repeat this on purpose) - patient and family inputs are invaluable. If the...