Recent studies suggest that tumour assessment methods accounting for both tumour density and volume (SACT, MASS, Choi) add value beyond assessing axial dimensions (RECIST) or selective regions of interest (ROI). See figure 1 for diagram demonstrating the limiation of ROI, especially in rim-enhancing metastatic lesions that would not be fully exploited. We have developed a comprehensive tumour response method termed Total Volume of Viable Tumour (TVVT) that assesses rate of change in Hounsfield unit (HU) density over treatment course (tumour trajectory), thereby quantifying viable tumour...

We co-developedan experimental volumetric densityapproach (TVVT)within our Picture Archiving and Communication System (Carestream Health, Rochester, NY) to circumscribe, segment and characterise volumetric density distribution throughout all parts of measurable lesions on CT. Using the FDA anthropomorphic thoracic phantom (figure 3)with simulated lesions of known volume and density, we plotted density histogram ranges (containing all HU values)with various thresholds to eliminate noise (anything not viable tumor) such as lung tissue and pulmonary vasculature. We also applied various threshold ranges to the enhancing lesions (figure 4), cross...

Preliminary investigation shows feasibility of semi-automatic segmentation to outline and quantify density distribution in whole tumour volumes. We selected a reasonable threshold of the histogram from both phantom data (figure 5) and assessment in our sarcoma patients (figure 6) of 0 to 180 HU. Initial assessment of our set of metastatic lesions suggests that hypervascular sarcomas are a worthwhile study cohort. Seetable 1of sarcomas we considered (current protocols at National Institutes of Health, NIH). See figure7 for an example mediastinal lesion with enhancing rim (left...

Aveolar Soft Part Sarcomas are theideal study cohort to evaluate ourapproach using segmentation and resultant voluemtric size and density of all lesions. The hypervascular lesions necrose with anti-angiogenic targeted therapy; resulting in histogram shifts to the left and steeper tumor trajectories over time. Although ASPS is a rare sarcoma, VEGFR inhibition is being used much more commonly in the broader group of sarcomas; for example, pazopanib (related tocediranib used in ASPS) was recently approved for soft tissue sarcomas. TVVT may be an ideal way to...

Gavrielides, MA. A resource for the assessment of lung nodule size estimation methods: database of thoracic CT scans of an anthropomorphic phantom. Optics Express 2010. Also:FDA Phantom Data sets: http://hdl.handle.net/10376/1538 Folio LR. et al. Consistency and Efficiency of Computed Tomography Analysis in Metastatic Disease Using a Semi-automated Lesion Management Application within PACS. AJR. In press. Folio L, Choi M, Solomon J, Schaub NP. Automated Registration, Segmentation and Measurement of Metastatic Melanoma Tumors in Serial CT Scans. Aca Rad. In press. Huang J, Sandouk A, Folio...

Vana Derderian is a research assistant at the National Institutes of Health (NIH)and works under Dr.Folio (lead radiologist for Computed Tomography at NIH Clinical Center) researching tumor trajectory. Melinda Merchant, MD, PhD is with thepediatric oncology branch at the National Cancer Institute (NCI) and provided expertise in treatment of pediatric sarcomas and helped with study design. Dr Jones and Dr. Venkatesan are fellowship trained in body imaging and provided oversight of study design, lesion segmentation and registration. Dr. Lotan is a radiology resident at Sheba...