Radiotherapy dactinomycin

Wilms tumor Vincristine plus dactinomycin after surgery and radiotherapy Methotrexate, cyclophosphamide, doxorubicin... 

Dactinomycin is an antineoplastic agent that is the principal component of the mixture of actinomycins produced by Streptomyces parvullus. It inhibits messenger RNA synthesis. Dactinomycin (0.5 mg/day IV for 5 days), in combination with vincristine, radiotherapy, and surgery, is used in Wilms tumor in conjunction with vincristine, cyclophosphamide, and doxorubicin, it is used in choriocarcinoma in combination with methotrexate, it is used in testicular carcinoma and in combination with cyclophosphamide and radiotherapy, it is used in Ewing s sarcoma. Dactinomycin inhibits messenger RNA synthesis by anchoring to a purine-pyrimidine (DNA) base pair by intercalation (see Figure 15). The toxicity of dactinomycin increases when combined with radiation therapy. 

The most important clinical use of dactinomycin is in the treatment of rhabdomyosarcoma and Wilms tumor in children, where it is curative in combination with primary surgery, radiotherapy, and other drugs, particularly vincristine and cyclophosphamide. Antineoplastic activity has been noted in Ewing s tumor, Kaposi s sarcoma, and soft-tissue sarcomas. Dactinomycin can be effective in women with advanced cases of choriocarcinoma in combination with methotrexate. Dactinomycin also has been used as an immunosuppressant in renal transplants. 

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