Sentinel Node Scintigraphy (Lymphoscintigraphy)

Sentinel Node studies are relatively new to Nuclear Medicine. The procedure provides a "road map" showing the direction of lymphatic drainage from around the site of a cancer. Before this procedure was available, the surgeon would make the best guess about the direction of lymph drainage from a tumor to the lymph nodes. The surgeon would then take out many lymph nodes in the area estimated to be the drainage pathway. Those lymph nodes would then be examined microscopically for signs of spread of the tumor.

The Sentinel Node study, however, demonstrates more clearly and precisely the path of lymphatic drainage. This allows the surgeon to take out the specific node (or nodes) that are the first to receive lymphatic drainage from the area around the tumor. If these "sentinel" node(s) do not show any microscopic evidence of tumor, it is very unlikely that any other nodes would contain any tumor cells. Since fewer nodes are removed, the surgery is less extensive and recovery is faster.


The procedure involves no preparation on the part of the patient, other than the usual pre-operative instructions provided by the surgeon.

During the Exam

In Nuclear Medicine, the physician will inject a small amount of radioisotope in the region of the tumor. There are usually 4 to 8 injections, depending on the type of tumor. The injections can feel like bee stings, but the pain usually subsides after a few seconds.

The rest of the exam consists of taking pictures. The technologist and the doctor will work together to look for lymph nodes draining the region around the tumor. If lymph nodes are seen, the doctor will probably use a pen to put a mark on the skin overlying the lymph node to help the surgeon find the nodes.

In the operating room, the surgeon has a probe that detects the radioactivity in the lymph nodes. The probe is used in conjunction with the pictures and skin marks from Nuclear Medicine to identify the sentinel node(s). Once the nodes are removed, they are sent to pathology for microscopic examination for evidence of spread of the tumor.

Safety Issues

As with most Nuclear Medicine studies, the radiation dose from this test is very small. In addition, the surgeon will likely remove much of the skin and the lymph nodes that contain the greatest amount of the injected radioactivity. The rest of the radioactivity will decay quickly. Following surgery, no special precautions are necessary.

Making an Appointment

When you call, we'll ask you for basic information such as your Social Security number. We'll ask you what type of test you need to schedule, and will schedule you for the best possible time. If you need to reschedule your exam, you can call us back and we'll be happy to arrange a better time for you.

When you call to schedule your exam, we'll also give you important information about preparing for the exam. If your doctor has scheduled the exam for you, and you have questions regarding the preparation or the procedure itself, you can call the imaging department where your procedure is being performed (please refer to our 'Locations' page for exact phone numbers).

Your physician will have several tasks to perform:

Complete the necessary paperwork to order the test (similar to writing a prescription for medication)

Fax, mail, or place the order in our computer system

Call us to schedule a test for you or have your physician call us directly

Obtaining Your Images

Exam Image Availability

DRC's state-of-the-art PACS technology offers you immediate access to the images of your radiologic exam. No longer does your physician have to wait to have copies of your films made. Although we can still print your X-ray on film for you with just 24 hours notice, your physician can now review your exam images immediately via the Internet. We offer safe and secure web access for your physician through Specialty Networks. Your privacy and HIPAA compliance is assured.

Images on a CD

If your physician prefers, the digital images from your study can be written to a CD-ROM, giving him/her a permanent record that can be accessed easily and quickly via a computer. CDs hold multiple studies and take up significantly less space than the traditional film in the brown envelope. A 24-hour notice is also requested to create this digital record for you.

Versatile Image Viewing Options

Internet access to your studies for your doctor is available immediately after your pictures are taken. Copies of your images can be obtained on a CD or on film with 24 hours notice.

Both Internet and CD viewing offer your physician the ability to digitally adjust your images in ways not possible with traditional X-ray film. Using the computer, the image can be made lighter or darker or zoomed for better visualization of a particular portion, for example. Your physician can fine-tune the images to accommodate his or her preferences.

Obtaining Copies of Your Images

To receive a CD or film copies of exam images, please follow these steps:

1. Call the location where your examination was performed (please refer to the locations page). Please provide your name and other identifying information along with the study being requested. With 24 hours notice, we can either create a CD-ROM or print a film for you. Our representative at the imaging center will provide you with the times available to pick up the exam.

2. To protect your privacy, please be sure to bring a picture ID when you pick up your CD/films, you will have to sign a Medical Images Release form when receiving your CD/films. If anyone else picks up your CD/films for you, please be sure to give him or her your written authorization to release your information to him or her.

3. If you would like us to send a copy of your study to a physician outside the DRC system, we will need a signed release from you along with the study you would like sent and the receiving doctor's name and address. You can fax or deliver us that release in the form of a signed letter at the fax number listed on the locations page. Please allow us plenty of time to send your films.

Any Costs

Currently the first set of films is provided at no cost to the patient. There is no charge for CD-ROM's and, of course, the Internet is always free.


For the convenience of our patients, we offer Imaging Scans at several DRC locations:

Battlefield Imaging
Chattanooga Outpatient Center
Diagnostic Center
Diagnostic PET/CT of Chattanooga
Hutcheson Medical Center
Tennessee Imaging & Vein Center