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Objective. Manual analysis of individual cancer lesions to assess disease response is clinically impractical and requires automated lesion tracking methodologies. However, no methodology has been developed for whole-body individual lesion tracking, across an arbitrary number of scans, and acquired with various imaging modalities. Approach. This study introduces a lesion tracking methodology and benchmarked it using 23 68Ga-DOTATATE PET/CT and PET/MR images of eight neuroendocrine tumor patients. The methodology consists of six steps: (1) alignment of multiple scans via image registration, (2) body-part labeling, (3) automatic lesion-wise dilation, (4) clustering of lesions based on local lesion shape metrics, (5) assignment of lesion tracks, and (6) output of a lesion graph. Registration performance was evaluated via landmark distance, lesion matching accuracy was evaluated between each image pair, and lesion tracking accuracy was evaluated via identical track ratio. Sensitivity studies were performed to evaluate the impact of lesion dilation (fixed versus automatic dilation), anatomic location, image modalities (inter- versus intra-modality), registration mode (direct versus indirect registration), and track size (number of time-points and lesions) on lesion matching and tracking performance. Main results. Manual contouring yielded 956 lesions, 1570 lesion-matching decisions, and 493 lesion tracks. The median residual registration error was 2.5 mm. The automatic lesion dilation led to 0.90 overall lesion matching accuracy, and an 88% identical track ratio. The methodology is robust regarding anatomic locations, image modalities, and registration modes. The number of scans had a moderate negative impact on the identical track ratio (94% for 2 scans, 91% for 3 scans, and 81% for 4 scans). The number of lesions substantially impacted the identical track ratio (93% for 2 nodes versus 54% for ≥5 nodes). Significance. The developed methodology resulted in high lesion-matching accuracy and enables automated lesion tracking in PET/CT and PET/MR. [ABSTRACT FROM AUTHOR]

Purpose: The clinical utility of positron emission tomography/computed tomography (PET/CT) in comparison to standard workup in patients with known or suspected inflammatory bowel disease (IBD) is unknown.Procedures: Clinical data were collected on seven patients with known or suspected IBD undergoing PET/CT. Standard workup included history, physical exam, laboratory tests, colonoscopy and/or cross-sectional imaging. We divided the intestine into five regions [small bowel and four colon (ascending, transverse, descending and rectosigmoid)] and graded relative standard uptake values 0, 1, 2 or 3 by comparison to the liver, using a region-of-interest analysis (0 = no activity, 1 = liver, 2 and 3 = significant inflammation).Results: In patients 1 and 2, PET/CT demonstrated more activity than we thought clinically present. The other patients avoided unnecessary escalation or initiation of IBD therapy based on PET/CT results. Compared with standard workup, all seven patients had superior results when therapeutic decisions were based on PET/CT.Conclusions: We found PET/CT to be very useful in diagnosis and management in patients with known or suspected IBD. [ABSTRACT FROM AUTHOR]

Purpose: Accurate staging of esophageal cancer (ECA) is critical in determining appropriate therapy. Endoscopic ultrasound (EUS), computed tomography (CT) and positron emission tomography (PET) scanning can be used, but limited data exists regarding the use of combined PET/CT fusion imaging and EUS in ECA staging. The objective of this study is to evaluate the role of integrated PET/CT imaging and EUS in the staging of ECA.Procedures: Identification of patients diagnosed with ECA from 2004 to 2007 that underwent staging PET/CT and EUS. Data regarding tumor detection, lymph node identification, presence of metastatic disease, and affect on patient management were collected and compared between PET/CT and EUS.Results: Eighty-one patients (65 male, 16 female) were identified with mean age of 63.5 years who underwent EUS and PET/CT to stage known ECA. PET/CT identified the primary tumor in 74/81 (91.4%) of cases, compared to 81/81 (100%) with EUS. Locoregional adenopathy was seen by PET/CT in 29/81 (35.8%) of cases, compared to 49/81 (60.5%) by EUS (p = 0.0001). PET/CT identified celiac axis adenopathy in 8/81 (9.9%) of cases, compared to 11/81 (13.6%) with EUS (p = 0.5050). PET/CT identified 17/81 (21.0%) of patients with distant metastases who subsequently did not undergo attempt at curative surgical resection.Conclusions: In ECA, EUS is superior to PET/CT for T staging and in identifying locoregional nodes, while PET/CT provides M staging. EUS and integrated PET/CT appear to independently affect treatment decisions, indicating complimentary and necessary roles in the staging of ECA. [ABSTRACT FROM AUTHOR]