Radiant energy – Invisible radiant energy responsive electric signalling – Semiconductor system
Reexamination Certificate
1998-10-06
2001-04-17
Hannaher, Constantine (Department: 2878)
Radiant energy
Invisible radiant energy responsive electric signalling
Semiconductor system
C250S336100, C250S370010
Reexamination Certificate
active
06218669
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
Not applicable.
BACKGROUND OF THE INVENTION
The involvement of the lymph system in tumor metastasis has been the subject of extensive investigation and is well established. Lymphatic systems are present as widely dispersed tissues, fluids, and cells concerned in a variety of interrelated functions of the mammalian body including the circulation and modification of tissue fluid formed in the capillary beds, and the removal by mononuclear phagocytes of cell debris and foreign matter. The lymphatic system is importantly involved in participation with the blood vascular system in developing the immune response of die lymphocytes and other cells. Lymph flows within the system as a consequence of a variety of perceived mechanisms of organ and tissue dynamics. For certain cancers, metastasis occurring in consequence of lymph drainage will result in an initial location or positioning of neoplastic cells at certain lymph nodes typically deemed “regional nodes” within a pertinent lymph drainage basin. Some cancers, for example, melanomas, have been observed to exhibit variability in lymphatic drainage patterns emanating from different portions of the body. Other cancers, such as those encountered in the breast, will evidence somewhat more predictable nodal involvement. In designing forms of cancer disease management, therefore, efforts are directed to the identification of affected lymph nodes. For melanomnas, it has been a more recent practice to identify the pertinent drainage basin or regional nodes along with an evaluation of the extent of lymph involvement with micrometastasis. A pre-surgical step undertaken in about 20% of investigational procedures concerning melanomas looks to carrying out of a gamma camera generated form of lymphoscintigraphy which gives the clinician a gross two-dimensionally limited image, generally showing the tumor site injection of sulfur colloid labeled with Technetium 99-m (
99m
Tc) and, spaced therefrom, a region of radioactivity at the pertinent regional lymph nodes. The latter information at least confirms the path of drainage and the location of the proper drainage basin. Regional nodes then are removed and submitted for pathology evaluation.
For cancers such as breast cancer, the sites of lymph node involvement are commonly encountered at axillary, internal mammary, and supraclavicular lymph node regions. Of these, the axillary lymph node region is the principal site of regional metastasis from carcinoma of the breast, and approximately 40% of patients have evidence of spread to the axillary nodes. In early approaches to the disease, these axillary nodes were removed as a form of therapy. Presently, however, their positive involvement, or lack thereof, has become the subject of diagnostics as opposed to therapy. In this regard, the combination of the presence and extent of metastasis to the axilla represents the single most important prognostic factor for the management of patients with breast cancer. See generally “Cancer, Principles and Practice of Oncology,” vol. 1, 4th ed. DeVita, Jr., et al., chapter 40, Harris, et al., J.P. Lippincott Co., Philadephia, Pa. (1993).
The axilla is a triangular region bounded by the axillary vein superiorly, the latissimus dorsi laterally, and the serratus anterior medially. With more current diagnostic procedures, essentially all axillary nodes at the axilla assumed to represent the drainage basin are removed during surgery for analysis. In general, somewhere between 10 and 30 nodes will be removed in the course of dissection with, of course, the attendant risks. In this regard, these nodes are generally surrounded by investment or fatty tissue and visualization of them necessarily is limited. Such dissection will pose risks of cutting the long thoracic nerve, the thoracic-dorsal nerve, the nerve to the pectoralis major or the axillary vein. Morbidity may occur in some cases due to regional node removal and patients are frequently known to discuss a numbing of the arm region following the procedure.
While this form of somewhat radical axillary lymph node dissection has been the conventional approach to determining nodal metastatic involvement, more recent data suggests that less radical axillary node evaluation procedures may generate equivalent information for staging and patient management, but with far more limited dissection and resultant trauma, as discussed below.
Patient management for staging purposes for the case of cutaneous melanoma is highly predicated upon determinations of lymph involvement. A number of factors are involved in the prognosis of the disease, including, inter alia, location, tumor thickness, level of invasion, growth patterns, and of particular importance the identification of regional node metastatic involvement. Generally, surgical excision of metastatic nodes within the drainage basin of a lesion has been considered the only effective treatment for cure or disease control. Some investigators have preferred to excise only clinically demonstrable metastatic nodes associated with the lesion, while others have chosen to excise the nodes even where they may appear normal because of the risk of the presence of occult (clinically undetectable) metastasis. A substantial dialog has been carried on by investigators as to whether or not elective lymph node dissection, or lymphadenectomy, is an appropriate therapy. Elective lymphodenectomy has the major advantage of treating a nodal metastasis at a relatively early stage in its natural history when the tumor burden is low. On the other hand, such an approach may subject patients to surgery which would otherwise have been unnecessary. In particular, where patients exhibit a clinical Stage I level of the disease, there will be no nodal metastasis present and no benefit then can be realized from regional lymphadenectomy.
Morton, et al., undertook an investigation of a procedure designed to identify that lymph node nearest the site of a melanoma and within the pertinent lymph drainage basin. Such a node, being on the most direct drainage pathway will present the most likely site of early metastasis and is referred to as the “sentinel node.” Thus, by carrying out only a limited dissection specific to this node and performing pathologic analysis of it, staging can be achieved without at least initial resort to more radical lymphadenectomy. With the approach, once the drainage basin from a lesion is identified, for example, by lymphoscintigraphy, an intraoperative mapping of the cutaneous lymphatics with vital dye is carried out at the time of surgical removal of the primary lesion. The vital dye, for example of blue color, is injected at the site of the lesion and tracked by blunt dissection until the sentinel node is reached. That node is now exclusively of blue color and readily identified. Thus, the sentinel draining lymph node of each primary melanoma is isolated and removed. By examining the sentinel nodes, for example by frozen section using routine hematoxylin-eosin histopathological techniques, as well as rapid immunohistochemical techniques, only those patients who have evidence of micrometastasis in the sentinel draining node are subject to subsequent lymphodenectomy. See generally, Morton D., Wen D-R, Wong J., et al. “Technical Details of Intraoperative Lymphatic Mapping for Early Stage Melanoma,”
Arch. Surg.
1992: 127:392-399; and R. F. Uren, et. al, “Lymphoscintigraphy in High-Risk Melanoma of the Trunk: Predicting Draining Node Groups, Defining Lymphatic Channels and Locating the Sentinel Node,”
J. Nucl Med
1993; 34:1435-1440.
The approach of Morton, et al., also has been undertaken to moderate the otherwise somewhat radical axillary lymph node dissection common in staging breast cancer. Through the utilization of the noted vital dyes in conjunction with the lymph drainage system from primary breast tumor, less radical sentinel node based procedures may result in adequate axillary staging and regional control. With the procedure, in general, a
Hannaher Constantine
Israel Andrew
Mueller and Smith LPA
Neoprobe Corporation
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