Radiotherapy DICOM packet sniffing

Abstract

The Digital Imaging and Communications in Medicine (DICOM) standard is meant to allow communication of medical images between equipment provided by different vendors, but when two applications do not interact correctly in a multi-vendor environment it is often first necessary to demonstrate non-compliance of either the sender or the receiver before a resolution to the problem can be progressed. Sometimes the only way to do this is to monitor the network communication between the two applications to find out which one is not complying with the DICOM standard. Packet sniffing is a technique of network traffic analysis by passive observation of all information transiting a point on the network, regardless of the specified sender or receiver. DICOM packet sniffing traps and interprets the network communication between two DICOM applications to determine which is non compliant. This is illustrated with reference to three examples, a radiotherapy planning system unable to receive CT data from a particular CT scanner, a radiotherapy simulator unable to print correctly on a DICOM printer, and a PACS unable to respond when queried about what images it has in its archive by a radiotherapy treatment planning system. Additionally in this work it has been proven that it is feasible to extract DICOM images from the intercepted network data. This process can be applied to determine the cause of a DICOM image being rendered differently by the sender and the receiver.

Clinical accuracy of ExacTrac intracranial frameless stereotactic system

“…The shift tolerances were chosen based on phantom measurements that indicated they provided sufficient spatial localization for stereotaxy. 19 The primary treatment techniques are dynamic conformal arcs and static shaped beams. A manual adjustment of the couch longitudinal and lateral position is used to restore patient positioning found to be out of optical tolerance after couch rotation; only very rarely is the motorized couch vertical movement utilized.…”

“…Table II lists the standard deviations of the distributions of the ExacTrac reported coordinates about the actual coordinates inferred from the full clinical data set under the standard pass conditions of 0.7 mm and 0.5 , which phantom based measurements indicated provided sufficient spatial localization for stereotaxy. 19 The quoted interval is the 95% confidence interval. We define the derived value q as the difference in quadrature between the average of the r values in the plane of couch rotation and the value of r perpendicular to the plane, which is calculated according to Eq.…”

Aktuelle Anforderungen an das Bildmanagement in der Strahlentherapie

“…Diese mögli-chen Variationen des Standards bereits auf Bilddatenebene können besonders beim Datenaustausch bzw. bei der herstellerunabhängigen Visualisierung Probleme bereiten[1].…”