Sentinel lymph node identification and biopsy typically involves a multidisciplinary approach. A nuclear medicine procedure called lymphoscintigraphy may be performed in advance of the surgical procedure to locate and mark the sentinel node(s) for the surgeon. Briefly, a radioactive tracer is injected under the skin, flows toward and into the sentinel node and its lymphatic chain, and is imaged by a gamma camera that produces a map of the path of the radioactive tracer and its first appearance in the sentinel node. When performed, the injection and lymphoscintigraphy procedures are coded and reported separately by the radiologist.
The procedure may be performed under general or monitored anesthesia care (MAC). The patient is positioned on the operating table so that the planned injection site and the previously marked sentinel node site are accessible to the surgeon. The injection site is generally located around the periphery of the primary tumor or, in some cases, the primary tumor excision site (excised at a previous operative session).
To facilitate visualization of the sentinel node, the surgeon may inject a vital dye-isosulfan blue-which is selectively taken up by the lymphatic vessels that drain the tumor site and stains them blue. Absorption usually requires rarely more than 15 minutes. Four injections are usually made at equidistant points around the primary lesion.
The skin is then prepped and draped and an incision is made carefully to allow access to the now-dyed lymphatic chain. If a gamma probe is not used, the dissection will begin along the blue-stained vessels that are closest to the primary dye injection site, and proceed toward the regional lymphatic basin along these vessels until the blue-stained sentinel node is identified. The surgeon may use a portable, hand-held gamma-ray detection instrument to aid in identification and confirmation of a sentinel node previously identified by nuclear medicine lymphoscintigraphy. The highly sensitive instrument detects radioactivity. When held to the sentinel node, the level of radioactivity registers at very high levels compared to surrounding tissue or background radiation in the operating room. (Note: Both the injection of the dye and the intraoperative lympho-scintigraphy are included in the biopsy procedure and are not reported separately.) Once located, the sentinel node is removed and may be sent for frozen section. If a second sentinel node has been identified, it is removed as well. If each sentinel node is negative for tumor, the procedure is terminated and the lymphatic vessels are ligated. The wound is closed in layers.
Sentinel node excision should be report by the using the appropriate CPT code (38500-38542). Open biopsy or excision of sentinel lymph node(s) should be reported as follows: axillary (CPT codes 38500 or 38525), deep cervical (CPT code 38510), internal mammary (CPT code 38530). CPT code 38740 (axillary lymphadenectomy; superficial) should not be reported for a sentinel lymph node biopsy. Sentinel lymph node biopsy of superficial axillary lymph node(s) is correctly reported as CPT code 38500 (biopsy or excision of lymph node(s), superficial) which includes the removal of one or more discretely identified superficial lymph nodes.
If a second sentinel node is excised from a different lymphatic chain through a separate incision at the same operative session, report the appropriate CPT code for the second incision and append the –59 modifier.
Sentinel lymph node biopsy performed prior to but during the same operative session of an axillary node dissection may not be reported separately unless the results change the planned procedure. However, if the decision to perform a more comprehensive procedure is based on the biopsy result, the biopsy is diagnostic and the biopsy service may be reported separately using a 59 modifier.
Injection of vital dye (Isosulfan Blue Dye or similar agents) to visualize the sentinel node may not be reported separately.
The radiopharmaceutical is payable only when billed with the imaging code (CPT code 78195).
The diagnosis code(s) must be representative of the patient’s condition.