Clinical Context
A typical adult patient with HER2-positive breast cancer presents to an outpatient oncology infusion center for systemic therapy. The patient has been prescribed intravenous trastuzumab for either adjuvant therapy following surgery or for metastatic disease management. Prior to infusion, a nurse performs pre-infusion assessment including vital signs, weight for dose calculation, review of prior echocardiogram results to document acceptable left ventricular ejection fraction (LVEF), and confirmation of informed consent and allergy history. Pharmacy prepares J9355 (trastuzumab, excludes biosimilar, 10 mg) in an appropriate diluent and concentration according to institutional and manufacturer guidelines. The infusion is administered via peripheral IV or implanted port over the recommended infusion time with cardiac monitoring as clinically indicated. Post-infusion monitoring includes observation for infusion-related reactions, documentation of lot number and expiration, and recording of the administered units of J9355 in the medical record and on the claim. Typical sites of service are hospital outpatient infusion centers, physician office infusion suites, and ambulatory infusion centers. Common clinical workflow interactions include baseline and interval cardiac monitoring (echocardiogram or MUGA), administration of pre-medications if prior reactions occurred, and coordination of chemotherapy agents when given in combination with trastuzumab.
Related Diagnoses
| ICD-10 Code | Description | Clinical Relevance |
|---|
C50.911 | Malignant neoplasm of unspecified site of right female breast | Represents HER2-positive invasive breast cancer that can be treated with trastuzumab |
| C50.912 | Malignant neoplasm of unspecified site of left female breast | Represents HER2-positive invasive breast cancer for left-sided disease indicated for trastuzumab
| C50.919 | Malignant neoplasm of unspecified site of unspecified female breast | Used when laterality is not specified but trastuzumab is indicated
| C79.51 | Metastasis to breast | Indicates metastatic involvement where trastuzumab may be part of systemic therapy
| Z08 | Encounter for follow-up examination after completed treatment for malignant neoplasm | Used for surveillance visits in patients receiving ongoing trastuzumab maintenance
| Z85.3 | Personal history of malignant neoplasm of breast | Used in problem lists and surveillance contexts when ongoing targeted therapy is provided
| I50.9 | Heart failure, unspecified | Relevant as a contraindication/monitoring code since trastuzumab can cause cardiotoxicity and LVEF must be monitored
Related CPT Codes
| CPT Code | Description | Relationship to This Procedure |
|---|
96413 | Chemotherapy administration, intravenous infusion technique; therapy up to 1 hour, single or initial substance/drug | Common code for administering an initial IV infusion of a chemotherapeutic or biologic agent such as trastuzumab when infusion time is up to one hour |
| 96365 | Intravenous infusion, therapeutic, prophylactic, or diagnostic; initial, up to 1 hour | Used for infusion administration services in some outpatient settings when chemotherapy-specific codes are not applicable
| 93306 | Echocardiography, transthoracic, real-time with image documentation (complete) | Baseline and surveillance cardiac imaging to monitor left ventricular function prior to and during trastuzumab therapy
| 99213 | Office or other outpatient visit for established patient, typically 15 minutes | Used for interim oncology follow-up visits related to therapy tolerance, toxicity assessment, and prescription management
| 96417 | Chemotherapy administration, each additional hour (List separately in addition to code for primary infusion) | Used when infusion time for trastuzumab exceeds the base hour and additional infusion time must be reported
| 96367 | Intravenous infusion for therapy, prophylaxis, or diagnosis; each additional hour (List separately in addition to code for primary infusion) | Used in conjunction with initial infusion codes when additional infusion time is billed