The incidence of these patients is seen more frequently in males vs. females, 2:1, and the median age is 55 years old.1 The number of cases has risen steadily since the end of the 20th century to approximately 51 cases per 10,000,000 per year, and 6-20% of human immunodeficiency virus (HIV) patients.1
Etiology:
Immunocompromised patients are at a higher risk for this disease. Risk is dependent on the nature, intensity, and duration of immune suppression.1 The overwhelmingly common risk factor is related to HIV infection from intravenous drug use.1
Signs & Symptoms:
Headaches2
Partial paralysis on one side of the body
Seizures
Cognitive or speech disorders
Vision problems
Diagnostic Procedures:
Central nervous system (CNS) lymphoma diagnostic tests examine the eyes, brain, and spinal cord. The following tests and procedures may be used:3
Physical exam: Check for signs of disease, such as lumps or anything else unusual. A history of the patient’s health habits and past illnesses and treatments is recorded.
Neurological exam: Checks a person’s mental status, coordination, ability to walk normally, and how well the muscles, senses, and reflexes work.
Slit-lamp eye exam: A special microscope with a bright, narrow slit of light is used to check the outside and inside of the eye.
MRI (magnetic resonance imaging): A magnet, radio waves, and a computer make a series of detailed images to assist with diagnosis. In nuclear magnetic resonance imaging (NMRI), a substance called gadolinium is injected into the patient through a vein. The gadolinium collects around the cancer cells so they show up brighter in the picture.
PET (positron emission tomography) scan: Radioactive glucose (sugar) is injected into a vein. The PET scanner detects where the radioactive glucose is being used in the body. Malignant tumor cells show up brighter in the images because they are more active and take up more glucose than normal cells do.
Stereotactic biopsy: A biopsy procedure that uses a computer and a three-dimensional (3-D) scanning device to find a tumor site and guide the removal of tissue so it can be viewed under a microscope to check for signs of cancer.
Lumbar puncture: After numbing an area of the patient’s lower back, a spinal needle is inserted into the lower part of the spinal column to remove cerebrospinal fluid (CSF). The fluid may be sent to a laboratory for testing.
Reprinted from National Cancer Institute, 2013.3
The following tests may be done on the samples of tissue that are removed:
Flow cytometry: A laboratory test that measures the number of cells in a sample, the percentage of live cells, and certain characteristics of cells, such as size, shape, and the presence of tumor markers on the cell surface. The cells are stained with a light-sensitive dye, placed in a fluid, and passed in a stream before a laser or other type of light. The measurements are based on how the light-sensitive dye reacts to the light.
Immunohistochemistry study: A laboratory test in which a substance such as an antibody, dye, or radioisotope is added to a sample of cancer tissue to test for certain antigens. This type of study is used to tell the difference between different types of cancer.
Cytogenetic analysis: A laboratory test in which cells in a sample of tissue are viewed under a microscope to look for certain changes in the chromosomes. Other tests, such as fluorescence in situ hybridization (FISH), may also be done to look for certain changes in the chromosomes.
Complete blood count (CBC) with differential: A procedure in which a sample of blood is checked for red blood cells, platelets, white blood cells, and the amount of hemoglobin (the protein that carries oxygen) in the red blood cells. The portion of the blood sample made up of red blood cells.
Blood chemistry studies: A procedure in which a blood sample is checked to measure the amounts of certain substances released into the blood by organs and tissues in the body. An unusual (higher or lower than normal) amount of a substance can be a sign of disease in the organ or tissue that makes it.
Histology:
*Most CNS lymphomas are metastatic.4 The histologic types are similar to those occurring outside of the nervous system. The most common being: B-Cell (most common) T-Cell
Lymph node drainage:
This is a tough question to answer for CNS lymphomas. By looking at their name, we can tell lymphomas stem from the lymph nodes. Therefore, the lymph node drainage can be anywhere in the body. The most common areas for lymph nodes to be involved includes the neck, groin, chest, and abdomen.5
Metastatic spread:
Tumors affecting the central nervous system rarely develop extraneural metastasis, probably because of inherent biologic characteristics of these tumors and also because the brain does not have a well-developed lymphatic drainage system. CNS lymphomas spread through CSF along the craniospinal axis and sometimes exhibit intraocular dissemination.6
Grading:
Most of the primary CNS lymphomas are high grade non-Hodgkin’s lymphoma. This cancer cells tend to be fast growing, look very abnormal (are poorly differentiated), tend to be more aggressive, and are more likely to spread quickly.6
Staging:
Primary CNS lymphomas do not have a standard staging system.7
Radiation side effects:
Nausea and vomiting8
Radiation dermatitis is usually mild
Alopecia
6 to 12 weeks after irradiation , neurological deterioration may occur.
Neuropsychological changes such as a decrease in learning abilities. Deficits in short-term memory, and difficulties with problem solving, particularly in older adults.
Prognosis:
The prognosis of a CNS lymphoma is dependent on a variety of different factors.7 The age of the patient, the type and grade of their tumor, the symptoms they present with and the length to which those symptoms have been occurring all have a part in the prognosis of this disease. Tumors recur relatively quickly, often times within a few months of treatment causing the median survival length of a year.
Treatments:
Chemotherapy drugs such as doxorubicin, vincristine, prednisone, dexamethasone, methotrexate, cytarabine, cyclophosphamide have all proven to be effective, especially when combined with radiation.7 Whole brain irradiation which includes the posterior orbits is taken to 40-50 Gray (Gy) without a boost, or 60-65Gy with a boost. Any patients presenting with CSF involvement should undergo craniospinal radiation, and eye involvement will need radiation to the entire orbit. There is also some cases that use corticosteroids in order to slow symptoms temporarily.
TD 5/5:
Organs in which radiation lesions result in severe to fatal morbidity:7 Brain: Infarction, necrosis 5000-6000 cGy Retina: Blindness 5500 cGy Cornea: Blindness 5000 cGy Lens: Cataracts 500 cGy Spinal cord: Infarction, necrosis 4500 cGy
Additional Images:
Reprinted from Radiation Oncology Notes, 2013.9
Craniospinal irradiation technique: Image B: Lateral view showing cranial field rotated to align with the diverging border of the spinal field. Image C: Couch rotated to provide match between the spinal field and the diverging border of the cranial-field. Image D: Elimination of cranial field divergence by using an independent jaw as a beam splitter (alternative to couch rotation in image C).
Reprinted from National Cancer Institute, 2013.3
The following tests may be done on the samples of tissue that are removed:
The histologic types are similar to those occurring outside of the nervous system. The most common being:
B-Cell (most common)
T-Cell
Brain: Infarction, necrosis 5000-6000 cGy
Retina: Blindness 5500 cGy
Cornea: Blindness 5000 cGy
Lens: Cataracts 500 cGy
Spinal cord: Infarction, necrosis 4500 cGy
Reprinted from Radiation Oncology Notes, 2013.9
Craniospinal irradiation technique:
Image B: Lateral view showing cranial field rotated to align with the diverging border of the spinal field.
Image C: Couch rotated to provide match between the spinal field and the diverging border of the cranial-field.
Image D: Elimination of cranial field divergence by using an independent jaw as a beam splitter (alternative to couch rotation in image C).
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