How To Use CPT Code 81194

CPT 81194 refers to the NTRK (neurotrophic receptor tyrosine kinase 1, 2, and 3) translocation analysis, a specialized laboratory test used to detect genetic rearrangements associated with certain solid tumors. This analysis is crucial for identifying patients who may benefit from targeted therapies, particularly those involving tropomyosin receptor kinase (TRK) inhibitors. By examining specimens such as formalin-fixed paraffin-embedded tissue (FFPE), healthcare providers can determine the presence of NTRK gene fusions that contribute to tumor growth and proliferation.

1. What is CPT code 81194?

CPT code 81194 represents a laboratory procedure that analyzes translocations in the NTRK genes (NTRK1, NTRK2, and NTRK3) within solid tumors. This test is essential for understanding the genetic underpinnings of certain cancers, as NTRK gene fusions can lead to the activation of TRK proteins, which promote uncontrolled cell proliferation. The identification of these genetic alterations allows clinicians to tailor treatment strategies, particularly with the use of TRK inhibitors like larotrectinib (Vitrakvi®). The test is performed using advanced techniques such as RNA-based next-generation sequencing (NGS) to detect specific gene rearrangements that may indicate the presence of a fusion gene.

2. Qualifying Circumstances

This CPT code can be utilized when there is a clinical suspicion of NTRK gene fusions in patients with solid tumors. It is particularly relevant for tumors that may respond to TRK inhibitor therapies. The test is appropriate when a healthcare provider orders it based on the patient’s clinical presentation and the potential for targeted treatment. However, it is not suitable for use in cases where other methods, such as immunohistochemistry (IHC) or DNA fluorescence in situ hybridization (FISH), are employed to evaluate NTRK translocations. Additionally, the test should not be used if the specimen does not meet the necessary criteria for analysis, such as being derived from FFPE tissue.

3. When To Use CPT 81194

CPT 81194 is used when a healthcare provider suspects the presence of NTRK gene fusions in a patient with a solid tumor. The test is typically ordered after initial evaluations suggest the possibility of such genetic alterations. It is important to note that this code should not be reported alongside other codes for NTRK translocation analysis, such as 81191, 81192, or 81193, as each code corresponds to different methodologies or specific gene targets. If the analysis involves other techniques, the appropriate codes for those methods should be utilized instead. Additionally, if a physician interpretation of the test results is requested, it may be reported separately using G0452 with modifier 26, provided that the interpretation is performed by a qualified physician.

4. Official Description of CPT 81194

Official Descriptor: NTRK (neurotrophic receptor tyrosine kinase 1, 2, and 3) (eg, solid tumors) translocation analysis.

5. Clinical Application

The clinical application of CPT 81194 lies in its ability to identify NTRK gene fusions that are implicated in the pathogenesis of various solid tumors. By detecting these genetic alterations, healthcare providers can make informed decisions regarding the use of targeted therapies, which can significantly improve patient outcomes. The test is particularly valuable in the context of precision medicine, where treatment is tailored to the individual genetic profile of the tumor. The identification of NTRK fusions not only aids in diagnosis but also opens up therapeutic options that may not be available for tumors without these specific genetic changes.

5.1 Provider Responsibilities

The provider’s responsibilities during the procedure include collecting an appropriate specimen, such as FFPE tissue, and ensuring that it is processed correctly for analysis. The lab analyst performs several technical steps, starting with the extraction of nucleic acids from the specimen through methods like cell lysis and digestion. Following this, the nucleic acids are amplified using polymerase chain reaction (PCR) techniques to increase their quantity for analysis. Finally, the analyst employs RNA-based next-generation sequencing (NGS) to detect any gene rearrangements or fusions associated with the NTRK genes.

5.2 Unique Challenges

One of the unique challenges associated with CPT 81194 is ensuring the quality and integrity of the specimen used for analysis. The process of extracting nucleic acids can be sensitive to degradation, and any compromise in specimen quality may lead to inconclusive results. Additionally, the complexity of interpreting the results requires skilled personnel who are knowledgeable about the nuances of genetic testing and the implications of various gene fusions. The rapid evolution of genetic testing technologies also necessitates continuous education and training for laboratory staff to stay current with best practices.

5.3 Pre-Procedure Preparations

Before performing the NTRK translocation analysis, the provider must ensure that the specimen is suitable for testing. This includes verifying that the tissue is properly preserved (e.g., FFPE) and that it meets the necessary criteria for nucleic acid extraction. The provider may also need to conduct preliminary evaluations to determine the appropriateness of the test based on the patient’s clinical history and presentation. Proper documentation of the specimen collection process is essential for accurate billing and coding.

5.4 Post-Procedure Considerations

After the NTRK translocation analysis is completed, the results must be interpreted by a qualified physician, typically a pathologist. The interpretation involves assessing the presence of any NTRK gene fusions and determining their clinical significance. Follow-up care may include discussing the results with the patient and considering potential treatment options based on the findings. If the test indicates the presence of actionable genetic alterations, the healthcare provider may refer the patient for targeted therapy or clinical trials.

6. Relevant Terminology

Amplification: The process of making multiple copies of a specific gene sequence for analysis, often using techniques like polymerase chain reaction (PCR).

Breakpoint: The specific location on a chromosome where breakage occurs during a translocation event.

Gene: A segment of nucleic acid that encodes a specific protein or function within the body.

Lysis: The breakdown of cells or tissues, often used in laboratory settings to extract nucleic acids.

Nucleic acid: Biological molecules, such as DNA and RNA, that carry genetic information.

Polymerase chain reaction (PCR): A laboratory technique used to amplify specific DNA or RNA sequences for further study.

Translocation: A genetic abnormality where segments of chromosomes are rearranged, potentially leading to the formation of fusion genes.

7. Clinical Examples

1. A patient diagnosed with a rare solid tumor undergoes NTRK translocation analysis to determine eligibility for TRK inhibitor therapy.

2. A clinician suspects NTRK gene fusions in a patient with metastatic cancer and orders the test to guide treatment decisions.

3. Following a biopsy, a pathologist analyzes the FFPE tissue for NTRK translocations to assess the tumor’s genetic profile.

4. A patient with a history of lung cancer is tested for NTRK fusions to explore targeted therapy options.

5. A healthcare provider discusses the implications of NTRK translocation results with a patient considering participation in a clinical trial.

6. A laboratory technician prepares a specimen for NTRK analysis, ensuring proper nucleic acid extraction and amplification.

7. A physician interprets the results of an NTRK translocation analysis and recommends a specific TRK inhibitor based on the findings.

8. A patient with a solid tumor receives genetic counseling after testing positive for NTRK gene fusions.

9. A multidisciplinary team reviews NTRK analysis results to develop a personalized treatment plan for a cancer patient.

10. A researcher studies the prevalence of NTRK fusions in various solid tumors to better understand their role in cancer biology.