SENTINEL NODE BIOPSY

Introduction

Sentinel node biopsy is a recent development in the evaluation of cancers that are capable of spreading to other parts of the body (metastasizing), including melanoma, certain squamous cell carcinomas (especially those that are recurrent, or that are located on the lips, genitals, mucous membranes), Merkel cell carcinoma, and some others. Sentinel node biopsy is also useful for the evaluation of breast cancer.

This booklet is written to help you understand the concept of sentinel node biopsy; why it may be recommended as part of the treatment of your cancer; and why a "team approach" to your treatment is so important. At most there are a relatively small number of physicians in the United Stated trained and experienced in sentinel node biopsy.

Depending upon the location of the sentinel nodes, some patients may be able to have their sentinel node biopsy performed using local anesthesia in Dr. Gross's office; other patients may need their sentinel node biopsy performed in an outpatient hospital operating room or surgi-center under conscious sedation or general anesthesia.

Dr. Gross and his staff encourage patients to be as informed as possible about the surgical procedure they are considering. He and his staff are available to answer any additional questions you may have.

What is sentinel node biopsy?

All parts of the body have drainage channels (lymph channels) that empty into the body filter areas (lymph nodes). These filters can trap and process bacteria, virus, and tumor cells (among many other things). When a cancer occurs on the skin, breast, or other body areas, malignant cells can travel through the lymph channels to the lymph nodes. It has been discovered that both the direction of flow, and the individual lymph node(s) to which these cells flow is often unpredictable; what is predictable, however, is that once the cells reach a lymph node basin (a group of lymph nodes) they filter through that group of lymph nodes starting first with the sentinel node.

Since this has been proven to be true, if we can locate the correct basin or basins that drain the area in which a cancer is growing, and if we can locate this first sentinel lymph node, and if we can remove and carefully analyze this lymph node, then we can get extremely important information for the treatment of your cancer.

If the sentinel node(s) have no cancer, then we can predict that all the non-sentinel nodes in that same basin will also not have cancer, and we can say with a high degree of confidence that the cancer has a very low risk of metastasis (spreading).

We know we can control the local cancer by surgically removing the cancer with a margin of normal tissue (with or without additional radiation or chemotherapy, depending on the cancer type). Now we have a way of telling if the lymph nodes need treatment without having to remove all of the lymph nodes in the basin(s) draining the skin area where the cancer is located.

How is sentinel node biopsy done?

Your doctor will have done a skin biopsy and diagnosed a cancer that he/she knows has some risk for metastasis.

You have been referred to Dr. Gross or another member of the "melanoma team" usually before having a wider re-excision of your cancer. The sentinel node biopsy is best done before the wide re-excision of the cancer because wide re-excision may disrupt the lymph channels, making it harder to find the sentinel node(s).

Lymphoscintigraphy

The first procedure is to determine which lymph node basin or basins drain the area of your cancer. Even extremity cancers (hands, arms, feet and legs) need this done, because even though their lymph channel drainage is predictable, lymph node basins or individual lymph nodes may be seen between the cancer and main lymph node basin(s).

99 technetium sulfur colloid is carefully injected around the cancer by a nuclear medicine physician. This material has a radioactive dye so safe that it is approved for pregnant women, and tissue containing this dye may be handled by laboratory personnel with no special precautions. At 2 to 4 hours after the material is injected, a special camera is used by the nuclear medicine physician (radiologist) to locate which nodal basin(s) drain the area where your cancer is located. The radiologist can also show the approximate location of the sentinel node(s) in each basin. He/she takes pictures and marks the sentinel node(s) with special ink that will stay in the skin for many days. The radiologist also estimates how "deep" sentinel the lymph node(s) is from the surface of the skin.

The procedure just described is called "lymphoscintigraphy;" - it is easy and painless and always done with the patient awake. The patient should try to remember the position he/she was in when the lymphoscintigraphy was done, so that this position can be duplicated for the surgeon during sentinel node biopsy.

Once it is determined which nodal basin(s) drain the lymph channels from the cancer area, the information is forwarded to Dr. Gross and/or other members of the "melanoma team."

Depending upon which nodal basins need sentinel node(s) removed, a decision is made to either do the sentinel node biopsy in the office using local anesthesia, or in an outpatient surgery center with the patient "asleep." On the day the sentinel node biopsy is to be done, the nuclear medicine physician again injects around the cancer area with 99 technetium sulfur colloid. After 2 to 3 hours, the surgeon injects a special deep blue dye called Lymphazurin® around the cancer area; this blue dye travels to the same lymph node basin(s) in about 20 minutes and can help in the localization of the sentinel node, which becomes bright blue. With the patient either asleep or using local anesthesia, the surgeon uses this combined approach to localize the sentinel node: Lymphoscintigraphy with 99 technetium sulfur colloid and lymphangiography with blue dye.

Sentinel Node Biopsy

An incision is made over the lymph node basin and using a high tech machine called a "Neoprobe 1500" the node is localized by "reading" the amount of 99 technetium sulfur colloid in the sentinel node (HIGH) compared to other node(s) and background material (LOW). The blue dye further confirms that this is the correct node(s).

The sentinel node(s) is removed and sent to the pathologist.

What does the pathologist do?

The pathologist (physician) makes many slides of the sentinel node(s) and carefully looks for cancer cells through the microscope. He/she may also do special immunohistochemistry stains to help find these cells. For melanoma, these stains include S-100 and HMB-45; the results from these special stains can take a while to be completed.

What happens when the pathologist is done?

If the sentinel nodes are all located and do not show cancer cells, the cancer itself can be removed by wide re-excision, but the lymph node(s) do not need to be removed. This is usually done by the referring physician with concurrence of the patient. Melanoma patients need long term follow-up to make sure there is no local recurrence and that a second new melanoma does not occur (less than 10% risk). Family members are also advised to have their skin checked.

If cancer cells are found in the sentinel node(s), then the node basins containing cancer should be completely removed as a "therapeutic regional lymph node dissection" (TRLND) by the general surgeon member of the melanoma team. At that point, patients with melanoma will be offered high dose interferon α-2b (Intron-A); this is a new immunologic treatment, shown by recent studies to improve patient outcome in melanoma. The melanoma team member who gives the interferon is called a medical oncologist.

What is the melanoma team concept?

Ken Gross, M.D., a dermatologist surgeon, has had a long standing interest in melanoma and other skin cancers. He ran a large melanoma tumor board for five years before entering private practice. Realizing that sentinel node biopsy was a powerful new tool for the evaluation for treatment of melanoma and other aggressive types of skin cancer, he sought out special training in this technique. He then assembled a team of independent private practice physicians with strong similar interests in cancer treatment in order to offer state of the art evaluation to patients in the San Diego area.

Jeffrey Mazin, M.D., is a general and vascular surgeon with a strong interest in breast cancer and melanoma. Dr. Mazin and Dr. Gross trained together in the technique of sentinel node biopsy. Removal of node(s) from deep nodal basins and therapeutic regional lymph node dissection (TRLND) are part of Dr. Mazin's special expertise.

Dr. Gross and Dr. Mazin co-own the Neoprobe 1500--state of the art equipment for sentinel node(s) localization and biopsy.

John Campbell, M.D., surgical pathologist, is a physician specializing in the analysis of body tissues. He processes and interprets the sentinel node(s) removed by the surgeon(s).

Nuclear medicine radiology at Mission Bay Hospital has the expertise and equipment to do lymphoscintigraphy to determine lymph basin drainage of cancer.

Medical oncology involves training and experience in the treatment of high risk cancer and in the use of high dose interferon α-2b (Intron A).

Other interested physicians, including psychiatry, internal medicine, and others, may be involved in the "team."

What is the "melanoma team?"

The melanoma team is a concept. It is a group of independent private practice physicians working as a team to independently provide each cancer patient with their expertise in treating cancer. This is modeled on the tumor board concept being used by hospitals to provide multi-disciplinary expertise for difficult and/or complex cancer problems.

Why is sentinel node biopsy such a big deal?

For many years there has been debate among doctors treating melanoma (and some other tumors) about the value of removing lymph node basins that were presumed to drain the melanoma skin cancer site. This was often done without being able to feel any lymph node enlargement and was called prophylactic regional lymph node dissection (PRLND). In the recent past, two large prospective studies of melanoma patients have shown that such PRLND surgery does not improve the outcome for melanoma patients, but the debate has continued.

Sentinel node biopsy gives us several new abilities. First, we can now predict which lymph node basin(s) drain the cancer site. A mid back melanoma can drain to any or all of four lymph node basins!

Second, if we can locate and remove the sentinel node(s) in each basin that drains the cancer, we can look more thoroughly at these very few nodes (more thoroughly than if we removed all the nodes and tried to look at all of them).

If cancer is present microscopically, then we can do a therapeutic removal of these nodes when few cells are present and start immunotherapy (interferon α-2b) and/or other therapy very early — when we have the best possible chance for curing the cancer.

Now that effective therapy is available (interferon α-2b) this becomes even more important.

It is also important that we can now more accurately "stage" patients with melanoma and other cancers; this allows us to give patients a better indication as to how they may expect their cancer to behave over time.

What do I need to do to get ready for my sentinel node biopsy?

If it is done in the office you may eat and drink immediately before the procedure; no smoking within 2 hours of surgery; wear warm old clothes and bring a blanket to the office. Stop all alcohol one week before surgery; stop aspirin one week before surgery if the doctor prescribing the aspirin agrees it is safe to stop. If you are using coumadin or heparin, please discuss this with your surgeon well before your surgery.

If the procedure is being done under general anesthesia you must have nothing to eat for eight hours before the procedure and nothing to drink for six hours before the procedure. What you wear to the hospital is irrelevant, as you will be wearing a very fashionable hospital gown. In all cases, arrange for someone to drive you to and from the procedure.

What happens after the procedure?

You will have bandages in place. Leave them on and do not get them wet. As directed by your doctor, be physically quiet/inactive for 48 hours or longer to let the blood vessels seal. The wounds are strong enough at 25 days after surgery to permit contact sports.

Expect preliminary results within one week, but final results with special immunohistochemistry stains may take more than one week.

If any problems or questions occur, communicate with Dr. Gross; the answering service should be able to reach Dr. Gross or a doctor on call for him 24 hours per day, seven days per week.

How long will sentinel node biopsy take?

The actual surgical procedure takes 30 minutes to 3 hours depending on what basin or basins are being treated, how deeply the sentinel node is located, and how many sentinel nodes are present. Remember that the 99 technetium sulfur colloid needs to be injected approximately 2 hours before beginning the sentinel node biopsy.

Will sentinel node biopsy cure me?

Sentinel node biopsy is a test that gives information vital to your plan of treatment, but is not itself a treatment.

When will my post surgical plan be developed?

When all the results of the sentinel node biopsy are established, the results will be discussed with you and your doctor(s) and a treatment plan formulated. Remember that for melanoma, long-term close follow-up by a dermatologist is essential. There is always a risk of a new unrelated melanoma occurring, and only complete regular skin checks will catch this early. Patients with melanoma also have an increased risk of a family member (1st degree relative) having melanoma; therefore, ask parents, brothers, sisters, and children to have at least one skin exam by a dermatologist.

Important reminders
What About …?

We want you to be as comfortable, relaxed and informed about your sentinel node biopsy as possible. If you have other question, feel free to call us at (858) 292-5101.