R-CHOP Dosing After Prephase Regimen
On day 0 after completing prephase, initiate standard R-CHOP-21 with the following doses: rituximab 375 mg/m² IV on day 1, cyclophosphamide 750 mg/m² IV on day 1, doxorubicin 50 mg/m² IV on day 1, vincristine 1.4 mg/m² (maximum 2 mg) IV on day 1, and prednisone 100 mg orally on days 1-5, repeated every 21 days. 1
Standard Dosing Regimen
The established R-CHOP-21 protocol consists of:
- Rituximab: 375 mg/m² intravenously on day 1 1
- Cyclophosphamide: 750 mg/m² intravenously on day 1 1, 2
- Doxorubicin (Hydroxydaunorubicin): 50 mg/m² intravenously on day 1 1, 2
- Vincristine (Oncovin): 1.4 mg/m² intravenously on day 1 (maximum total dose of 2 mg) 1, 2
- Prednisone: 100 mg orally on days 1-5 1, 2
Cycles are repeated every 21 days. 1
Number of Cycles
For most patients with diffuse large B-cell lymphoma, administer 6-8 cycles of R-CHOP-21. 1 Specifically:
- Patients aged 60-80 years: 6-8 cycles of R-CHOP-21 with eight total doses of rituximab is the current standard 1
- Young patients with low-intermediate risk (aaIPI = 1): 6 cycles of R-CHOP-21 1
- Young patients with high/high-intermediate risk (aaIPI ≥2): 6-8 cycles of R-CHOP-21 1
Alternative Dosing Schedule
R-CHOP-14 (every 14 days) has been studied but does not demonstrate survival advantage over R-CHOP-21 and therefore R-CHOP-21 remains the standard. 1, 2 If R-CHOP-14 is used, 6 cycles of CHOP with 8 cycles of rituximab are sufficient. 1
Critical Supportive Care Measures
Avoid dose reductions due to hematological toxicity whenever possible. 1
Use prophylactic granulocyte colony-stimulating factor (G-CSF) for febrile neutropenia in patients treated with curative intent, especially those older than 60 years. 1
Common Pitfalls to Avoid
- Do not reduce chemotherapy doses unless absolutely necessary, as this compromises outcomes 1
- Ensure cardiac function assessment (left ventricular ejection fraction) before initiating doxorubicin-containing regimens 1
- The prephase treatment you completed (typically prednisone for 7 days ± vincristine 1 mg) was appropriate to reduce tumor lysis syndrome risk 1