Four-dimensional (4D) image verification in respiratory gated radiation therapy

US7570738B2 · kind B2 · utility

Assignees

• Siemens Medical Solutions USA, Inc. · US
• Siemens Aktiengesellschaft · DE

Inventors

• Ali Khamene · Princeton, US
• Charles Florin · Lawrenceville, US
• Juan Carlos Celi · Heidelberg, DE
• Barbara Ofstad · Weinheim, DE
• Mikael Rousson · Préaux, FR
• Frank Sauer · Princeton, US
• Christian Schaller · Teublitz, DE

Key dates

• Filing date: Jul 31, 2007
• Grant date: Aug 4, 2009
• Expiry date: Jan 21, 2028

Classification

• Technology area (CPC A): Human Necessities
• CPC primary: A61N2005/1062
• WIPO field: Medical technology
• WIPO sector: Instruments

Abstract

A method for four-dimensional (4D) image verification in respiratory gated radiation therapy, includes: acquiring 4D computed tomography (CT) images, each of the 4D CT images representing a breathing phase of a patient and tagged with a corresponding time point of a first surrogate signal; acquiring fluoroscopic images of the patient under free breathing, each of the fluoroscopic images tagged with a corresponding time point of a second surrogate signal; generating digitally reconstructed radiographs (DRRs) for each breathing phase represented by the 4D CT images; generating a similarity matrix to assess a degree of resemblance in a region of interest between the DRRs and the fluoroscopic images; computing a compounded similarity matrix by averaging values of the similarity matrix across different time points of the breathing phase during a breathing period of the patient; determining an optimal time point synchronization between the DRRs and the fluoroscopic images by using the compounded similarity matrix; and acquiring a third surrogate signal and turning a treatment beam on or off according to the optimal time point synchronization.