schematic illustration of the IDRF evaluation in neuroblastoma

A schematic illustration of the IDRF evaluation. Regarding the arteries, in cases where a vessel is completely surrounded by the tumor (total encasement), or more than half of the circumference of the vessel is surrounded by the tumor (contact ≧ 50 %), the vessel is considered to be “encased,” and the patient is considered to be IDRF positive. Vessel “contact” is defined by the surrounding of less than half of the artery circumference by the tumor; such cases are considered to be IDRF negative. In the case of veins, “encased” means the complete compression of the vessel with no visible lumen. “Contact” means that the lumen is visible and that case is IDRF negative