Publications by authors named "Hans S Jans"

Theragnostic pairs of isotopes are used to infer radiation dosimetry for a therapeutic radiopharmaceutical from a diagnostic imaging study with the same tracer molecule labelled with an isotope better suited for the imaging task. We describe the transfer of radiation dosimetry from the diagnostic radioiodine isotope I, labelled for the hypoxia tracer molecule iodoazomycin arabinoside ([I]IAZA), to isotopes I (therapeutic) and I (PET imaging). Uncertainties introduced by the dissimilar isotope half-lives are discussed in detail.

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Purpose: The response of well-type ionization chambers used, for example, in brachytherapy and nuclear medicine, depends on the location of the source. In cases where the source length is variable (typically in nuclear medicine), it is also dependent on length of the source. Here, the combined effect on chamber sensitivity of both source position and length is investigated in detail.

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6-Deoxy-6-[(18)F]fluoro-D-fructose (6-[(18)F]FDF) is a promising PET radiotracer for imaging GLUT5 in breast cancer. The present work describes GMP synthesis of 6-[(18)F]FDF in an automated synthesis unit (ASU) and dosimetry calculations to determine radiation doses in humans. GMP synthesis and dosimetry calculations are important prerequisites for first-in-human clinical studies of 6-[(18)F]FDF.

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6-Deoxy-6-[(18)F]fluoro-D-fructose (6-[(18)F]FDF) is a promising PET radiotracer for imaging GLUT5 in breast cancer. The present work describes GMP synthesis of 6-[(18)F]FDF in an automated synthesis unit (ASU) and dosimetry calculations to determine radiation doses in humans. GMP synthesis and dosimetry calculations are important prerequisites for first-in-human clinical studies of 6-[(18)F]FDF.

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Interest has been growing in recent years in the development of radiation treatment planning (RTP) techniques based solely on Magnetic Resonance (MR) images. However, it is recognized that MR images suffer from scanner-related and object-induced distortions that may lead to an incorrect placement of anatomical structures. This subsequently may result in a reduced accuracy in delivering treatment dose fractions in RTP.

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Post-implant dosimetry for permanent prostate brachytherapy is typically performed using computed tomography (CT) images, for which the clear visualization of soft tissue structures is problematic. Registration of CT and magnetic resonance (MR) image volumes can improve the definition of all structures of interest (soft tissues, bones, and seeds) in the joint image set. In the present paper, we describe a novel two-stage rigid-body registration algorithm that consists of (1) parallelization of straight lines fit to image features running primarily in the superior-inferior (Z) direction, followed by (2) normalized mutual information registration.

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