Patent Number: 051480409
Section: summary

BACKGROUND OF THE INVENTION This invention relates generally to detecting radiation in a living being for medical applications, and more particularly to detecting, localizing, and imaging or mapping of radiation in a portion of the body of a being by means of a radiation detecting probe and an associated radiation blocking shield. The use of radioactive materials to tag tissue within a patient for effecting its localization and demarcation by radiation detecting devices has been disclosed in the medical literature for at least forty years. Significant developments in the localization and demarcation of tissue bearing radioactive isotope tags for diagnostic and/or therapeutic purposes have occurred since that time. Thus, it is now becoming an established modality in the diagnosis and/or treatment of certain diseases, e.g., cancer, to introduce monoclonal antibodies tagged with a radioactive isotope (e.g., Indium 111, Technetium 99m, Iodine 123, and Iodine 125) into the body of the patient. Such monoclonal antibodies tend to seek out particular tissue, such as the cancerous tissue, so that the gamma radiation emitted by the isotope can be detected by a hand-held radiation detecting probe. Such a probe is disposed or held adjacent portion of the patient's body where the cancerous tissue is suspected to be in order to detect if any radiation is emanating from that site, thereby indicating that cancerous tissue is likely to be found there. Prior art, hand-held, radiation detecting probes are commercially a available from the assignee of this invention, Care Wise Medical Products, Inc. under the trademark OncoProbe. In copending U.S. patent applications Ser. Nos. 07/363,243 and 07/491,390, filed on Jun. 8, 1989 and Mar. 9, 1990, respectively, and assigned to the same assignee as this invention there are disclosed hand-held radiation detecting probes having collimating means to establish the field of view of the probe. In U.S. Pat. No. 4,801,803 (Denen et al) there is also disclosed a hand-held radiation detecting probe. In some cases background activity (i.e., radiation emanating from portions of the body other than the portion being investigated) may interfere with sensitive and accurate surgical radiation detecting probe localization of radiolabeled tissues within body cavities. OBJECTS OF THE INVENTION It is a general object of this invention to provide simple means and a method of use for minimizing the problem of background activity interference with sensitive and accurate localization of radiolabeled tissues within body cavities. It is a further object of this invention to provide a means for use with a radiation detecting probe to block background radiation emanating from sources other than the tissue being examined by the probe within the probe's field of view. It is still a further object of this invention to provide means which may be readily inserted into the body of a being interposed between the tissues being examined by a radiation detecting probe and the remainder of the body cavity in the field of view of the probe. It is yet a further object of this invention to provide a radiation blocking shield which is simple in construction and easy to use. SUMMARY OF THE INVENTION These and other objects of this invention are achieved by providing a shield for use with a radiation detecting probe to effect the detection, localization, imaging or mapping of radiation in a first, internal, portion of the body of a living being by use of the probe. The shield comprises a sheet formed of a radiation blocking material which is sized to be readily located within a space within the body of the being so that the first portion of the body of the being is interposed between it and the probe, whereupon the shield fills up a substantial portion of the field of view of the probe, thereby blocking radiation from sources behind the shield. In one embodiment the shield is mounted on the probe by an adjustable yoke assembly. In another embodiment the shield is separate from the probe.