Lymphoma PET scan
One of the most important uses of Positron Emission Tomography (PET) technology is its use in diagnosing and treating lymphoma. Lymphoma is a form of cancer that originates in the lymphatic system. There are two main types of lymphoma: Hodgkin’s lymphoma (Hodgkin’s disease) and non-Hodgkin’s lymphomas (NHL). Lymphoma is the fifth most common cancer in the United States of America, and the American Cancer Society estimates that approximately 7,600 new cases of Hodgkin’s disease and approximately 53,400 new cases of NHL will be diagnosed in 2004. The American Cancer Society estimates that lymphoma will cause 24,700 deaths in the United States in 2004.About Lymphoma
Lymphoma is the fifth most common cancer in the United States of America and refers to a form of cancer that originates in the lymphatic system. The lymphatic system is a part of the body’s immune system that is used to fight infections. Comprised of lymphatic vessels, a series of thin tubes, these lymphatic vessels collect fluid (lymph) from the different parts of the body to transport back to the heart. Lymph is a colorless, watery fluid that is rich in white blood cells and especially lymphocytes.
Lymphocytes are a vital in the immune system and are used to protect the body against infection and tumor growth. Lymphocytes form lymph nodes that can be found in different groups throughout different areas in the lymphatic system. Lymphocytes can be classified under two groups:
There are two main types of lymphoma: Hodgkin’s lymphoma (Hodgkin’s disease) and non-Hodgkin’s lymphoma (NHL). Hodgkin’s lymphoma occurs when cells in the lymph nodes become abnormal and form more cells in an uncontrolled manner. A tumor, which is a mass of tissue, forms in the lymphatic system in Hodgkin’s disease where it is mainly located in the lymph nodes (glands), spleen, and sometimes in other organs. Hodgkin’s disease is unique because only a minority of the cells in an involved lymph node is malignant. The American Cancer Society estimates that approximately 7,600 new cases of Hodgkin’s disease will be diagnosed in 2004.
The other form of lymphoma is NHL, which cannot be defined in a singular description as it describes a collection of diseases. For the most part, most Non-Hodgkin’s lymphomas originate within a lymph node, but increasing numbers of NHL have originated in other areas such as the jaw or brain. This is particularly true among children and individuals with AIDS.
Lymphoma can originate from nearly anywhere in the body as lymph tissue is found in many parts throughout the body. In lymphoma, the lymph nodes become enlarged and can spread throughout the lymph system to nearly anywhere in the body.
Although Hodgkin’s disease and non-Hodgkin’s lymphoma are different diseases that originate from the lymph node tissues in the body, early diagnosis and the appropriate treatment are both vital in the treatment of both types of lymphoma.Symptoms of Lymphoma
The symptoms of lymphoma depend on which type the person has. However there are some generally apply to both Hodgkin’s lymphoma and non-Hodgkin’s lymphoma:
Positron Emission Tomography is an effective procedure used in the staging and treatment of both forms of lymphoma. PET scans for Hodgkin’s lymphoma and non-Hodgkin’s lymphoma are effective in cases where lymphoma has been found detected. Lymphoma is a difficult disease to detect as they produce very little symptoms in their early stages. A biopsy is usually required to confirm the presence of lymphoma in the body.
From there, PET imaging can play an effective role in lymphoma staging. Staging commences following lymphoma diagnosis and is used to determine the extent of cancer spread. The staging component of lymphoma treatment is critical as it provides the necessary information for physicians in determining an appropriate medical course of action.
Through PET imaging, a physician is able to determine whether or not cancerous cells have spread from the lymphatic system to other parts of the body. Positron Emission Tomography involves the administration of a radioactive tracer that combines a radioisotope, a radioactive compound that is detected by a PET scanner, with a natural body compound, which the body is able to integrate into its system without any negative effects. In lymphoma screening, the radioactive tracer used is Fluorodeoxyglucose (FDG) that combines the natural body compound glucose with the radioisotope Fluorine-18. Although many patients have concerns about the radioactive component contained in PET imaging, Fluorine-18 contains a short half-life and disappears from the body within hours. Consequently, the PET procedure is a safe one for patients.
In the staging process, PET scans are one of the most effective imaging tools in determining the spread of cancerous cells. Lymphoma is able so spread nearly anywhere in the body through the various lymph modes that are present throughout the body. However, PET is able to comprehensively determine cancer spread as it traces the spread of FDG in a patient’s body. PET imaging is able to establish patterns of cancer spread based on the body’s chemical reactions to FDG. As it is similar in structure to glucose, PET determines cancer spread by studying the absorption of FDG by the patient’s organs and tissues. FDG is absorbed at a faster rate by cancerous organs and tissues than healthy organs and tissues. By studying the biochemical reaction of the patient’s body, PET scan is able to produce the most accurate analysis of whether lymphoma has spread to other areas of the body.PET and Lymphoma Follow-Up
Another valuable function of Positron Emission Tomography in lymphoma treatment is its role in studying the patient’s recovery. Following staging, a physician will recommend a medical course of action that they feel are the most appropriate and effective. In most instances, chemotherapy, radiation therapy, or a combination of both is used to treat lung cancer. Although these treatments are usually effective, an important component of lymphoma treatment is determining whether active cancer cells have remained in the body following treatment.
Prior to the clinical use of PET scan, physicians applied radiation therapy and chemotherapy according to standard rules. However, with PET imaging, it is now possible for physicians to specifically cater lymphoma treatment to your particular situation. This is because Positron Emission Tomography allows a physician to view the location, extent, and resilience of a patient’s lymphoma.
Additionally, PET imaging is the most effective diagnostic tool in detecting lymphoma tumor response to therapy. PET scans study the chemical function of the body and is able to produce images that show visual biochemical changes in the body caused by lymphoma. Unlike such anatomic imaging tools as x-rays, computed tomagraphy (CT), and magnetic resonance imaging (MRI) that detail changes in body structure such as the presence of tumors, PET imaging is able to determine whether a tumor is benign (alive tissue and non-cancerous) or malignant (dead tissue and cancerous).
PET scans involve the administration of the radioactive tracer, Fluorodeoxyglucose (FDG) that combines the natural body compound glucose with the radioisotope Fluorine-18. FDG safely travels through the body where a PET scanner monitors its movement within the body. A radioactive tracer that disappears from the body within hours, FDG is able to detect cancer recurrence in successfully treated lesions as well as determine whether tumors identified in an anatomic imaging scan are cancerous or not.
This is because FDG is similar in structure to glucose, which cancerous cells absorb at a faster rate than healthy cells. By tracing the absorption rates of FDG by the targeted cells, a physician is able to determine whether successfully treated lesions are showing signs of cancer recurrence. Additionally, PET imaging is able to detect cancer recurrence in lymph nodes and/or scar tissue from surgery from surgery or another lesion sooner than an anatomical imaging procedure. PET scans are also able to distinguish between cancerous and non-cancerous tumors that are detected by anatomical imaging and are still present despite lymphoma treatment.