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TU‐B‐352‐02: Assessing Tumor Response to Therapy Over Time
Author(s) -
Bullitt E
Publication year - 2008
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.2962428
Subject(s) - medicine , gadolinium , radiation therapy , brain tumor , clinical practice , magnetic resonance imaging , biopsy , medical physics , radiology , pathology , materials science , family medicine , metallurgy
Monitoring the efficacy of brain tumor therapy is a clinical dilemma. Results of biopsy provide the most reliable indicator but biopsy is too invasive for frequent use. The clinical standard of practice is to perform serial magnetic resonance scans and to assess changes to tumor “size” as seen on gadolinium enhanced images, with “size” measured in one, two, or three dimensions. This review discusses the advantages and disadvantages of the three measurement methods as well as some of the effects of voxel size on the calculation. Problems inherent to the use of gadolinium enhanced images include the effect of steroids and the confounding appearance of radiation necrosis. New treatment methods, such as administration of anti‐VEGF agents, may even cause disappearance of gadolinium enhancement while the tumor continues to grow. The limitations of the “tumor size” approach have led multiple groups to explore alternative methods of assessing tumor activity. We briefly explore some of these alternative methods to assessing tumor growth and treatment response. Educational Objectives: 1. Understand the clinical standard of practice of monitoring brain tumor therapy from T1 gadolinium enhanced images. 2. Understand the different common approaches to assessing tumor activity and their strengths/limitations. 3. Understand the limitations inherent to various approaches.