Cancer Therapy – Radiotherapy and Chemotherapy

The aim of therapy is to reduce the tumor mass within the shortest possible time and to destroy the remaining cells and prevent them from multiplying and disseminating. This ideal is possibly achieved only in the case of very few cancers but in the majority of cases this is not possible due to:

1. late diagnosis
2. presence of secondaries early in the disease
3. surgical risk, and
4. toxic effects of radiation and chemotherapeutic agents.

Surgery and radiotherapy are most effective to reduce the initial tumor load. These are the prime modalities of treatment in solid tumors. In the case of disseminated neoplasms like leukemia rad140 before and after and myeloma and in the case of some rapidly growing tumors like trophoblastic tumors, chemotherapy has to be employed as the first line of treatment.

Radiotherapy
Tumor cells are more radiosensitive as they proliferate faster than normal cells. Radio-therapy may be given as the only modality of treatment or combined with surgery and chemotherapy. With the advent of highly sophisticated equipment such as the linear accelerator, large doses (5000-6000 rads) may be focused on deep seated tumors with only minimal injury to adjacent tissues. Therapeutic efficacy of radiation is enhanced by exposure to hyperbaric oxygen and radiosensitizing drugs such as metronidazole.

Chemotherapy
Chemotherapy is the sheet anchor of therapy in leukemia, advanced lymphomas, chorio-carcinoma and other widely disseminated malignancies. It is combined with surgery in embronal tumors and used as the primary treatment in advanced cancers not amenable to surgery or radiation. The effectiveness of cytotoxic drugs is directly proportional to the inversely proportional to the number of cancer cells. Prior reduction of tumor mass by veness of chemotherapy. Cytotoxic drugs are nonselective and affect all cells which are in certain phases of their proliferative activity.