OncoTREAT—a software assistant for oncological therapy monitoring L. Bornemann a, T , J.-M. Kuhnigk a , V. Dicken a , S. Zidowitz a , D. Wormanns b , H. Shin c , S. Krass a , H.-O. Peitgen a a MeVis-Center for Medical Diagnostic Systems and Visualization, Bremen, Germany b Institute for Clinical Radiology, University Hospital Muenster, Germany c Diagnostic Radiology, Medical School Hannover, Germany Abstract. A software tool was developed for the volumetric measurement of lung nodules, liver metastasis and lymph nodes to support decision making in treatment planning and monitoring with respect to convenience, accuracy and time consumption. D 2005 CARS & Elsevier B.V. All rights reserved. Keywords: Segmentation; Volumetry; Therapy response; Cancer; Quantification 0531-5131/ D 2005 CARS & Elsevier B.V. All rights reserved. doi:10.1016/j.ics.2005.03.050 T Corresponding author. E-mail address: bornemann@mevis.de (L. Bornemann). 1. Introduction Considering that cancer is one of the leading causes of death worldwide (about 563.700 estimated deaths and 1.368.030 estimated new cases in 2004 in the United States [1]), it becomes apparent that accurate monitoring of therapy response is of particular importance. Although surgery is the treatment of choice for the majority of localized cancers, in many cases the disease has already spread by the time of discovery. In those cases radiation and/or chemotherapy are mostly performed. Since these treatment options are expensive and associated with severe stress for the patient, it is necessary to evaluate the success of the treatment as reliably as possible and to change poorly performing therapies as soon as possible. A key indicator for success or failure of treatment and, thus, for continuation or modification of the current therapy is tumor growth. Given that most CT scans meanwhile provide a large number of slices (about 400–500 or even more for whole body scans), it is prohibitive to measure the volume of each lesion manually. Therefore, according to current International Congress Series 1281 (2005) 429 – 434 www.ics-elsevier.com