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Background and purpose: The delineation of the gross tumor volume (GTV) is a critical step for radiation therapy treatment planning. The delineation procedure is typically performed manually which exposes two major issues: cost and reproducibility. Delineation is a time-consuming process that is subject to inter- and intra-observer variability. While methods have been proposed to predict GTV contours, typical approaches ignore variability and therefore fail to utilize the valuable confidence information offered by multiple contours. Materials and methods: In this work we propose an automatic GTV contouring method for soft-tissue sarcomas from X-ray computed tomography (CT) images, using deep learning by integrating inter- and intra-observer variability in the learned model. Sixty-eight patients with soft tissue and bone sarcomas were considered in this evaluation, all underwent pre-operative CT imaging used to perform GTV delineation. Four radiation oncologists and radiologists performed three contouring trials each for all patients. We quantify variability by defining confidence levels based on the frequency of inclusion of a given voxel into the GTV and use a deep convolutional neural network to learn GTV confidence maps. Results: Results were compared to confidence maps from the four readers as well as ground-truth consensus contours established jointly by all readers. The resulting continuous Dice score between predicted and true confidence maps was 87% and the Hausdorff distance was 14 mm. Conclusion: Results demonstrate the ability of the proposed method to predict accurate contours while utilizing variability and as such it can be used to improve clinical workflow.

Intermittent ureteropelvic junction obstruction, or Dietl crisis, is a rare entity with sparse reports in published literature. Establishing the diagnosis is challenging given its intermittent nature. We report a case of Dietl crisis, focusing on ultrasound (US) and magnetic resonance urography (MRU) findings in a 7-year-old boy with recurrent episodes of colicky abdominal pain prompting multiple visits to the emergency department. Severe left hydronephrosis was visualized on US during one episode with complete resolution on follow-up US. MRU demonstrated severe left hydronephrosis with delayed calyceal transit time, time-to-peak enhancement, and excretion. There was no aberrant blood vessel. Surgical pyeloplasty provided complete symptomatic resolution. MRU can be a valuable tool in eliciting and dynamically confirming the diagnosis of Dietl crisis., (© 2020 Published by Elsevier Inc. on behalf of University of Washington.)