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Last modified on
Tue Mar 11 2008 03:02:57 PDT
3.9 Blood tests
3.10 MUGA Scan
The primary diagnosis of HD should be based on histologic examination of abnormal tissue, such as lymph nodes. The diagnosis is based on the identification of Reed-Sternberg (RS) cells. The classic RS cell measures about 20-30 micrometer in diameter and has a large bilobed nucleus in which the two lobes are connected by a thin nuclear bridge. Each lobe has a large, usually eosinophilic nucleolus.
Does the fact that I have no symptoms mean that my Hodgkin's is not very advanced?
3.2 Gallium / Thallium scan (Scintigraphy)
Gallium scans are used in some centers if mediastinal or hilar nodes are involved and as a baseline in patients with bulky disease for better determination of response during or after therapy.
In general, Gallium scans often are used to diagnose and follow the progression of tumors or infections. Gallium scans also can be used to evaluate the heart, lungs, or any other organ that may be involved with inflammatory disease.
What does a gallium scan entail? A gallium scan requires at least two visits to the Nuclear Medicine Department. On the first day, you will receive an injection in a vein in your arm. Your visit should take about fifteen minutes and the injection will cause no more discomfort than having blood drawn. The injection is slightly radioactive. Some nuclear medicine technicians recommend that you stay a few feet away from children for the first 48 hours after injection.
You will be scheduled to return for imaging between two and five days later. Your scan(s) is the longest part of the procedure and may take up to two hours. For most gallium scans, you will lie on a stretcher or imaging table with the camera positioned above or below you. Multiple images may be taken, or the camera may move slowly, scanning the entire length of your body. A SPECT (tomographic) study may be done to look at a particular area of your body in detail. This involves lying on a narrow imaging table while the camera rotates 360 degrees around you.
Many centers do a delayed scan 5-7 days after the initial scan. This delayed scan is usually better for viewing the abdomen area. The bowel has a high concentration of gallium during the initial scan and can mask a tumor. Some centers utilize food restrictions and enemas to address this problem.
What is a Gallium scan? Is this something my husband should have?
The archives are full of information about Gallium scans so I won't go into great detail. Basically a gallium scan is used to identify places which may indicate active cancer. This is done by giving the patient an injection of a radioactive material and then scanning the body a day or two later. Spots which "light up" tend to indicate cancer. The scan is useful when done prior to treatment and then again at the end of treatment. If the scan shows activity before treatment, but shows no activity after treatment, there is a good possibility that the treatment has eradicated the cancer. However, gallium scans can show both false positives and false negatives. I had one done and it showed no activity, even though I had a substantial chest mass. It's a potentially useful tool, particularly if you are likely to have substantial scar tissue remaining at the end of treatment. In this case (assuming your disease was "gallium avid") you can use the post-treatment test to see if there is any activity within the scar tissue. -- Jim Howe <email@example.com>
3.3 Computed Tomography (CT)
A CT scanner uses X-rays and massive computer processing to image the chest and abdomen in cross sectional slices. CT can detect intrathoracic sites of disease not detected on chest X-ray in up to 20% of patients. However, CT can not distinguish between scar tissue left after treatment and active disease.
In order to increase the quality of the images patients are often required to drink contrast fluid (yummy Barium) and iodine dye is injected into a vein during the scan.
3.4 Magnetic Resonance Imaging (MRI)
On MRI, lymphoma typically demonstrates a homogeneous low signal intensity similar to muscle on T1 images, and high (greater than fat) or mixed signal on T2.
3.5 Positron Emission Tomography (PET)
FDG-PET is a noninvasive imaging method which may contribute to improve the staging with HD, particularly by detecting previously unknown lesions in spleen and bone marrow. Equipment consists of scanner, computer and cyclotron.
Glucose uptake increases in cancer when cell proliferation is in progress. FDG (2-deoxy-2-(18F)fluoro-deoxyglucose) is a radioactive glucose analog.
PET imaging has demonstrated high sensitivity for the detection of abnormal lymph nodes in patients with lymphoma. There were false positives associated with inflammatory lymph nodes.
Lack of FDG uptake in residual masses four weeks after completion of treatment may predict high probability of long term disease-free survival.
A biopsy is normally a removal of a small piece of lymph tissue from one of the affected lymph nodes. This minor operation may be done under local or general anaesthetic. Hodgkin's disease must be diagnosed by removing a sample of tissue from the patient and sending it to a pathologist for examination.
There are several types of biopsies:
It is important to note, however, that normal sized spleens, as examined by MRI or CT, may harbor HD. For this and other reasons, patients staged first by non-invasive procedures sometimes may be staged higher when subsequently re-staged at laparotomy.
Staging laparotomy (most definitive technique) and splenectomy are controversial because of the extra treatment delay and risk of complications from surgery. (see 5.9 long term effects)
3.7 Bone marrow biopsy (BMB)
In adults, the sample is usually taken from the pelvic bone. With the patient lying on his/her stomach, the skin over the biopsy site is deadened with a local anesthetic. The needle is then inserted deeper to deaden the surface membrane covering the bone. A larger rigid needle with a very sharp point is then introduced into the marrow space. A syringe is attached to the needle and suction is applied. The marrow cells are then drawn into the syringe. This suction step is occasionally uncomfortable, since it is impossible to deaden the inside of the bone. The contents of the syringe, which to the naked eye looks like blood with tiny chunks of fat floating around in it, is the bone marrow sample.
This part of procedure, the aspiration, is usually followed by the core biopsy, in which a slightly larger needle is used to extract core of bone. The calcium is removed from the bone to make it soft, the tissue is processed and tissue sections are made. Even though the core biopsy procedure involves a bigger needle, it is usually less painful than the aspiration.
This test gives a very accurate picture of abdominal and pelvic lymph involvement. It is a long and uncomfortable procedure involving the injection of dye into the skin of the feet to show up the lymphatics using X-ray imaging.
3.9 Blood tests
What exactly is a "sed rate" and what kinds of numbers would be considered normal and what kind would be considered elevated?
This topic was discussed before, probably about 1 year ago, here is a small recap, but I suggest digging through the archives.
SED rate, or ESR, or erythrocyte sedimentation rate is a test to see how much inflammation is in your system. In some cases, cancer growth can increase SED rate, while there are a host of other reasons that a SED rate can be elevated. The method by which your SED rate is calculated is your blood is timed on how long it takes to travel down a certain amount of space in a test tube. The most common methods used today are the Westergen and modified Westergen (probably named after the person who discovered it). In men, the normal is below 8-12 (depends who you ask). For women, they usually exhibit a higher SED rate and their normal is something under about 20. When diagnosed with HD SED rate is sometimes used to determine if you are truly a b-symptom stager if your SED rate is above 50. -- Alex T.
3.10 MUGA Scan
I have to get a MUGA scan. What is this test?
Essentially what happens is they inject a very low level radioactive material which sticks to the muscles of your heart and spleen. From this point they use a machine that reads radiation to measure the amount of blood your heart pumps (also know as ejection fraction). The reason for this test is to ensure your heart muscle has not been damaged too much by Adriamycin. All in all the test is painless and only takes about 15 minutes. What is really cool is that you get to watch the test happen right in front of you because the technicians don't need to leave the room because the radiation levels are not that high. -- Jonathan Foster