Surgery – Diagnostic testing – Detecting nuclear – electromagnetic – or ultrasonic radiation
Reexamination Certificate
2001-04-25
2004-10-12
Robinson, Daniel (Department: 3742)
Surgery
Diagnostic testing
Detecting nuclear, electromagnetic, or ultrasonic radiation
C250S302000
Reexamination Certificate
active
06804549
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method of detecting sentinel lymph nodes, into which tumor cells first enter from the primary nidus of a tumor, and a system therefor.
2. Description of the Related Art
In recent years, the rate of early detection of cancer has been on the rise, and early surgical removal of cancerous growths is frequently performed. Generally, the objective of early surgical removal of cancerous growths is the complete arresting of the disease, and frequently, in addition to the diseased tissue, a plurality of lymph nodes in the area surrounding the diseased tissue, from which there is a suspected danger of transferal of the disease, are also removed. In addition, after removal of the lymph nodes an examination to determine the cause of the disease and whether or not the disease has been transferred thereto is conducted thereon, and the course of post-surgical treatment is determined.
Due to the fact that it is not known whether or not the disease has been transferred to the lymph nodes during performance the surgical removal thereof, a plurality of lymph nodes in the surrounding vicinity of the diseased tissue is removed, and the burden on the patient is therefore great. Further, in the early stages of breast cancer, for example, the rate of transfer of the disease to lymph nodes is 20 percent, for the 80 percent of the patients in whom the disease has not been transferred to the lymph nodes, the removal thereof is unnecessary.
In recent years, there has been a movement to obtain both the complete arresting of cancer attained through surgical removal of the cancerous tissue while preserving the QOL (Quality of Life) of the patient. To this end, one surgical method that has received much attention, which is aimed at preventing unnecessary removal of lymph nodes, is sentinel node navigation surgery. Hereinafter, a simple explanation of sentinel node navigation surgery will be given.
For cases in which cancer has been transferred to lymph nodes, it has recently become clear, in light of recent research, that it is not transferred randomly, but is transferred through the lymph system to the lymph nodes according to a set pattern. The first lymph node into which cancer cells enter from the primary nidus of a cancer is called a sentinel lymph node. It is believed that for cases in which cancer has been transferred to the lymph nodes, the cancer has definitely been transferred to a sentinel lymph node.
Accordingly, by finding and excising the sentinel lymph node in a cancer removal surgery performed in the early stages of the disease and performing a biopsy on the excised sentinel lymph node, and expediently diagnosing the cause of the disease, it can be determined whether or not the cancer has been transferred to the lymph nodes.
For cases in which the cancer is found to not have been transferred to the lymph nodes, it is unnecessary to remove the remaining lymph nodes. For cases in which the cancer is found to have been transferred to the lymph nodes, depending upon the conditions, a plurality of lymph nodes are surgically removed from the vicinity surrounding the diseased tissue.
By performing sentinel node navigation surgery, it becomes unnecessary to remove lymph nodes of patients for whom it has been determined that cancer has not been transferred to their lymph nodes, and the burden on such patients is reduced. Moreover, this type of surgery is not limited to breast cancer, but can be employed in conjunction with open gastrointestinal tract surgery or procedures utilizing a laparoscope.
There is a strong demand for a method of accurately and easily detecting the sentinel lymph node when performing sentinel node navigation surgery. One conventional method of detecting the lymph node is the colorant method, employing a blue colorant. According to this method, a blue colorant is locally injected, endermically or by use of an endoscope, into the vicinity surrounding the diseased area directly preceding the performance of cancer removal surgery. The injected blue colorant advances from the position at which it was injected toward the lymph nodes, and reaches the sentinel lymph node 5-15 minutes after injection.
The examiner visually detects the sentinel lymph node, which has been dyed blue. However, lymph nodes are often covered with fatty tissue, etc., and the sentinel lymph node must be searched for while such tissue is peeled away, which makes for a time consuming detection process. Moreover, while such searching and peeling away of tissues obstructing view of the sentinel lymph node is being performed, there are incidences in which the blue colorant advances beyond the sentinel lymph node and reaches other lymph nodes, whereby a problem arises in that it becomes difficult to detect the sentinel lymph node.
In addition, a method employing radioisotopes an, RI method, has also been developed. According to the Ri method, a radioisotope is locally injected, endermically or by use of an endoscope, on the day prior to surgery into the vicinity surrounding the diseased area. The injected radioisotope advances from the position at which it was injected towards the lymph nodes and stays for a set duration at the sentinel lymph node. A few hours after the radioisotope is injected a lymphosynthography is performed, and the approximate position is marked. When the surgery to remove the cancer is performed, the marked position is cut open, and employing a cancer gamma-probe, the gamma radiation emitted by the lymph nodes in the vicinity of the opened position is detected; the lymph node emitting the most gamma radiation is detected as the sentinel lymph node. According to the RI method, because the tracer reaches the lymph nodes beyond the sentinel lymph node in a short time and detection of the sentinel lymph node does not become difficult, and the sentinel lymph node can be detected even though it is covered with fatty, etc. tissue, although the detection rate is improved, because radiation is employed, management of the surgical procedure is complicated, and because a gamma probe is used, problems arise in that the detection process must be performed point-by-point and the information obtained cannot be made into an image, and the procedure is expensive.
On the other hand, in recent years a method employing fluorescent colorants, the fluorescent colorant method, for detecting diseased tissue has been proposed; a method as disclosed in PCT International Publication No. WO98/48845 for example, wherein a cyanine colorant is thrown onto a living tissue, and by irradiation thereof by stimulating light, the diseased tissue is detected.
According to the fluorescent colorant method disclosed in aforementioned WO98/48845, a photosensitive material that emits fluorescent light upon stimulation thereof by a stimulating light is applied in advance as a fluorescent diagnostic agent to the tissue that is the subject of an examination. Stimulating light in the wavelength band to which the fluorescent diagnostic agent is sensitive is irradiated onto the diseased tissue, causing fluorescent light to be emitted from the fluorescent diagnostic agent accumulated thereon, and the area into which the fluorescent diagnostic agent has permeated, which contains the diseased tissue, is detected by reception of this fluorescent light. In addition, it is indicated that the fluorescent diagnostic agent is also accumulated on the sentinel lymph node, and that detection thereof is possible.
However, in aforementioned PCT International Publication No. WO98/48845, there is no mention of a definite sentinel lymph node detection method or system. Further, regardless of the fact that the fluorescent colorant method disclosed therein suffers the same difficulty in detecting the sentinel lymph node due to the covering thereof by fatty, etc. tissues, as in the normal detection method, there is a problem in that no consideration is addressed therein to this difficulty.
SUMMARY OF THE INVENTION
The present invention has been developed in consideration of
Fuji Photo Film Co. , Ltd.
Robinson Daniel
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