Glossary

Prothrombin Time – a laboratory blood test for a component of the body’s blood clotting system.

Partial Thromboplastin Time – a laboratory blood test of a component of the body’s blood clotting system.

Planning treatment volume – a term used when discussing radiotherapy that describes the gross tumor volume (the tumor bed at risk for recurrence or progression) plus a margin around it to account for 1) microscopic infiltration by tumor cells plus 2) the daily variation in targeting that is inherent in the equipment being used.

Periventricular leukomalacia. A white-matter brain injury seen in infants that is characterized by the periventricular (lateral ventricles) necrosis (usually coagulative) of white matter. Subsequent coalescence leads to porencephaly. Commonly seen in children with cerebral palsy, it is a marker for a brain injury occurring early in the third trimester.

Perfusion weighted imaging- A variety of MRI techniques used to measure blood flow and volume within the brain and generate maps about this perfusion of blood within the brain.

Pleomorphic Xanthoastrocytoma – a rare glial tumor occurring mostly in the supratentorial brain and having a very indolent behavior.

Quality Of Life

RApid Gradient Echo is a echo gradient MRI sequence used for a wide range of applications including angiography and perfusion techniques.

A clinical assessment tool designed to define the degree of disability present after a stroke or other neurologic injury.  The scale runs from 0-6 with 0=no disability and 6=dead.  1-2 is a mild disability, 3-4 a moderate disability and 5 a severe disability,.

sirolimus (Trade name Rapamune) – a mTOR pathway inhibitor that suppresses the growth of SEGAs.