Systemic Chemotherapy or Combined Modality Therapy

Chemotherapy is usually indicated for the more aggressive histologic subtypes of orbital lymphoma with potential for future systemic involvement or with existing disseminated disease.

Indolent lymphomas are very sensitive to both single-agent and combination chemotherapy. Single-agent therapy is carried out with alkylating agents such as cyclophosphamide. For intermediate- to high-grade lymphomas, initial combination chemotherapy is usually with a doxorubicin-containing regimen such as cy-clophosphamide, doxorubicin, vincristine, and pred-nisone (CHOP) or cyclophosphamide, vincristine, dox-orubicin, and dexamethasone (CVAD). The most common life-threatening toxic effect from chemotherapy is myelosuppression, resulting in anemia, infection, and abnormal bleeding. Congestive heart failure secondary to decreased left ventricular function is another significant toxicity of these regimens.

Combined chemotherapy and radiation therapy may be an appropriate option for intermediate- to high-grade lymphomas.23 The rationale for combined modality therapy originates from observations that systemic extranodal sites of relapse are common following radiation therapy alone. Single-institution and cooperative group series, in which chemotherapy was combined with radiotherapy, have reported 5-year rates of relapse-free survival of 94 to 100% for stage I lymphomas and 72 to 78% for stage II disease.23,30,31 Furthermore, overall life-threatening toxicity and cardiac toxicity are significantly lower in patients receiving combined chemotherapy and radiation because fewer cycles of chemotherapy may be required.23

Aggressive chemotherapy induction regimens followed by stem cell transplantation have been investigated at the M. D. Anderson Cancer Center.32 Hyper-CVAD, with escalated doses of cyclophosphamide, high-dose methotrexate, and cytarabine followed by autologous or allogenic stem cell transplantation, can result in improved rates of remission for the more aggressive lymphomas.

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