Radiology Coding Alert

Sentinel node biopsies are becoming an increasingly common tool to determine the staging and progression of cancer in oncology patients throughout the country. In many instances, lymphoscintigraphy a nuclear medicine imaging and localization procedure that often accompanies sentinel node biopsies is performed. Yet many radiology coders express confusion about the appropriate way to report this service.

At the core of the confusion are two codes used to describe lymphoscintigraphy: CPT 78195 (lymphatics and lymph glands imaging) and 38792 (injection procedure; lymphangiography; for identification of sentinel node). Each is assigned in distinct and clearly defined circumstances. But the two cannot be reported together by the same physician.

The confusion is exacerbated when coders realize that, sometimes, the nuclear radiologist performs the injection of the radioisotope, but does no imaging. Instead, the surgeon reads the progression of the radioactive material through the lymphatic system in the operating room with special Geiger counter-type instruments. And, in other situations, the surgeon can report the injection code, if he or she uses special dyes to help visualize the targeted node.

Use Code 78195 for Entire Imaging Procedure

According to Kenneth McKusick, MD, FACR, who is retired from the Massachusetts General Hospital and now a member of the American Medical Association CPT Advisory Committee representing the Society of Nuclear Medicine, lymphoscintigraphy is performed on patients who have had a tumor biopsy or lesion excision that confirms the presence of cancer. Surgeons and oncologists often then will conduct a sentinel node biopsy to find out if the cancer has spread or metastasized, he explains.

A sentinel node is described as the first node in the lymphatic network that drains lymphatic fluid from a tumor site. As a general rule, the lymphatic system cleanses the bodys tissues by draining and transporting fluid from the tissues back to the blood. If one or more malignant cells from a primary tumor site migrate into the lymphatic network, they usually lodge in the node closest to the site. Oncologists will biopsy this sentinel node to determine if the cancer has spread or is contained at the primary location.

Lymphoscintigraphy is used to help the surgeon map the lymphatic network emanating from the tumor site and locate the sentinel node, McKusick explains. During lymphoscintigraphy, the nuclear radiologist injects a radionuclide under the patients skin in the region of the malignant tumor or lesion. This tracer takes approximately 15 to 30 minutes to flow toward and into the sentinel node.

Then, using a gamma camera, the nuclear radiologist obtains dynamic, real-time images to localize the specific sentinel node that needs to be biopsied. A map will be drawn directly on the patients skin to indicate where the sentinel node is positioned. In addition, the physician will review the images, interpret the findings and write a report. Immediately following the imaging procedure, the patient usually is taken to surgery, McKusick says, and the biopsy subsequently is performed.

The nuclear radiologist would report code 78195, which covers the entire imaging procedure, as well as the injection of the radionuclide, McKusick says. In addition, radiology coders may report the radiopharmaceutical isotope, if the practice has provided the material.

Correct Use of CPT Code 38792

In some cases, however, the patient is injected with the radionuclide, but imaging is not done by the nuclear physician, says Donna Richmond, CPC, of Acadiana Computer Systems Inc., a medical billing management company based in Lafayette, La., which serves more than 200 radiologists, pathologists and anesthesiologists. There is an alternative approach that is being used more and more frequently, she says. The radiopharmaceutical is injected by the nuclear radiologist, but then the patient is sent directly to surgery. Instead of the nuclear physician taking images, the surgeon uses a hand-held gamma probe to locate the sentinel node and guide the procedure. The radiologist would code 38792 to reflect that he or she performed the injection but did not provide imaging services.

Under these circumstances, Richmond says, the surgeon moves a portable gamma-ray detection instrument over the region where the sentinel node is assumed to be. The device detects radioactivity and (when held over the sentinel node where the radionuclide has pooled) registers the increased levels relative to the surrounding tissue. Once the surgeon has located the node through this method, he or she removes it and sends it to pathology.

McKusick notes that the surgeon would choose an appropriate code from the CPT 38500-38542 (biopsy or excision of lymph node[s]) series to report the biopsy. Use of the hand-held gamma detector is bundled into the biopsy code, and therefore the surgeon should not report it separately. Coders should be aware, however, that some surgeons inject the tumor site with a vital dye isosulfan blue that stains the lymphatic chain blue and allows them to visualize the nodes, he says. This may be done instead of, or in addition to, the injection of radiopharmaceuticals. Surgeons who perform this dye-injection procedure may report 38792 in addition to the biopsy code.

Case Study #1: Injection and Imaging

During a routine mammogram, a lump is found in the right breast of a 64-year-old woman. The mass is biopsied, found to be malignant and removed (174.0-174.9, malignant neoplasm of the female breast). To determine if the cancer metastasized, the surgeon schedules a sentinel node biopsy. Prior to the procedure, the patient is sent to nuclear medicine and injected with a radioisotope near the site of the tumor. After 20 minutes, the nuclear radiologist takes images (lymphoscintigraphy) to localize the sentinel node. Using a surgical marking pen, he maps the nodes location on the patients body. The patient is sent to same-day surgery, where the surgeon removes the node and sends it to pathology.

The radiologist would use code 78195, and the surgeon would assign a code from the 38500-38542 series.

Case Study #2: Injection

A 74-year-old retired construction worker is diagnosed with cutaneous melanoma (172.0-172.9, malignant melanoma of skin), and a sentinel node biopsy is ordered to determine malignant staging. Shortly before the surgery, a nuclear physician injects the patient with a radiopharmaceutical diagnostic imaging agent. The patient is sent to surgery, where his physician uses a hand-held gamma probe to localize the sentinel node for biopsy.

The radiologist would use code 38792, and the surgeon would assign a code from the 38500-38542 series.
Case Study #3: Injection of Dye

A young male has a cancerous lump removed from breast tissue (175.0-175.9, malignant neoplasm of male breast), and his surgeon recommends a sentinel node biopsy to determine if the disease has spread into the lymphatic system. A physician from nuclear medicine injects the patient with a radioisotope but does no imaging. The surgeon uses a gamma detection instrument to locate the sentinel node into which the radioactive material has flowed but also injects vital dye so he can more easily visualize the affected node (which normally is transparent).

The radiologist would use code 38792, and the surgeon would assign a code from the 38500-38542 series. In addition, the surgeon would report 38792 to reflect the blue dye injection procedure.

Case Study #4: Entire Procedure Plus Dye

A young mother is diagnosed with an aggressive form of breast cancer (174.0-174.9, malignant neoplasm of female breast). After the lesions in her left breast have been excised, a sentinel node biopsy is scheduled. The nuclear radiologist performs lymphoscintigraphy (injection of radionuclide material and subsequent imaging) and maps the location of the tumor on the womans skin. The patient is transported to surgery, where the surgeon uses the nuclear radiologists report and injects vital dye to help in visualization of the sentinel node to be removed.

The radiologist would use code 78195, and the surgeon would assign a code from the 38500-38542 series. In addition, the surgeon would report 38792 to reflect the blue dye injection procedure.

Note: Because lymphoscintigraphy is relatively new and is expected to grow rapidly, radiology coders should stay abreast of local payer guidelines and policies. At least one local Medicare carrier in the Northeast, for instance, does not consider 38792 and 78195 bundled and allows radiologists to code both. Check with insurers in your area, and get their policies in writing. Be sure to update this information at least once a year because policies affecting lympho-scintigraphy may change.