Under certain conditions the IND may grant a residence permit to allow someone to undergo vital medical treatment.
One of the main conditions to qualify for this permit is to demonstrate plausibly that a particular vital treatment cannot be provided in the country of origin for technical reasons.
If you are already in the Netherlands, you can apply for this type of residence permit. However, this permit is granted only if on health grounds it is unsafe to travel to the country of origin in order to apply for a visa from the local Dutch embassy. If travel is possible, in most cases the IND will reject the application.
In addition to granting residence permits for medically vital treatments, the IND may also grant aliens an ‘extension of departure’ based on Article 64 of the Aliens’ Act, if travel to the country of origin would result in a medical emergency and the need for vital medical treatment is expected to last less than one year.