Respiratory motion has significant effects on abdominal and lung tumor position, and incorporation of this uncertainty
increases volumes for focal cancer treatments. Respiratory correlated CT, obtained by oversampling images throughout
the respiratory cycle based on an external surrogate, is increasingly being used for radiation therapy planning.
Respiratory correlated CT is dependant on a fixed relationship between the external surrogate and the tumor, which may
change based on weight loss, breathing pattern changes or non-respiratory motion. Moreover, the process decouples
localization of the tumor (which is the goal of tumor directed therapy) with respiratory motion management. Recently,
implantable passive transponders (Calypso Medical Technologies) have been developed which can be tracked via an
external electromagnetic array in real-time and without ionizing radiation. We aimed to integrate wireless
electromagnetic tracking with multislice CT, and create volumetric datasets that are correlated to tumor position, as
opposed to an external surrogate. We call this process 'tumor correlated CT' (TCCT). Use of these images for
treatment planning will allow localization of the tumor to predict the position of other organs during treatment delivery.
We show the preliminary work in the integration of electromagnetic tracking and CT imaging.