Absorbed dose estimates for 131I-labelled monoclonal antibody therapy in patients with intraperitoneal pseudomyxoma

Intraperitoneal radioimmunotherapy: Auger electron emitters for solid tumors

Evaluation of: Boudousq V, Ricaud S, Garambois V et al.: Brief intraperitoneal radioimmunotherapy of small peritoneal carcinomatosis using high activities of noninternalizing 125I-labeled monoclonal antibodies. J. Nucl. Med. 51, 1748–1755 (2010). Mesothelioma, pseudomyxoma peritonei, ovarian and colon cancers, and several other malignancies produce peritoneal carcinomatosis in their advanced stages. This condition is typically managed with curative intention by means of a radical cytoreductive surgery and intraperitoneal hyperthermic chemotherapy. The method has been shown to improve the survival of some patients with peritoneal dissemination. However, the intracavitary instillation of chemotherapy results in a nonuniform drug distribution and allows penetration of the drug only into the outermost layer of the cancer nodule. Authors of the current study demonstrate that 125I-radiolabeled monoclonal antibody, 35A7, which recognizes anti-carcinoembryonic antigen, can be used effectively and safely with low toxicity in the therapy of small volume peritoneal carcinomatosis after cytoreductive surgery.

A software tool for specifying voxel models for dosimetry estimation

Many dose estimation problems can be conveniently formulated in terms of finding the energy emitted and absorbed by a set of homogeneous volume elements (voxels) arranged in a rectilinear grid. The solution of these problems requires an accurate model of the source and target geometry to be established, whereupon conventional Monte Carlo simulation of radiation transport can be employed to determine energy deposition. A software application ("MrVoxel") has been developed to assist in the specification of the source and target models. This application includes tools for image segmentation and image registration (2D and 3D, intra- and inter-modality, interactive, and automatic). It employs a plug-in architecture to facilitate customization and future expansion: plug-ins can be written to perform image import and export as well as to implement specialized image processing routines. Using plug-ins, the package can, for example, import DICOM 3.10 files and export input files for a voxel-based Monte Carlo package. Standard dosimetric tools such as the geometric mean method, transmission based attenuation correction, and MIRD-style voxel dose kernel convolution are also implemented as plug-ins. MrVoxel was implemented on a Macintosh computer using a commercial software framework to produce a conventional document-centric application. Hence it includes useful features such as the ability to undo an operation or to save a processed image set at any point. This latter feature enables the production of a processing trail, to allow post-hoc auditing of the analysis process. This paper describes the MrVoxel application and its role in the analysis of a particular dosimetry problem.