Radiotherapy: Basic Concepts and Recent Advances.

Radiation therapy (RT) is a clinical modality dealing with the use of ionizing radiations to treat malignant neoplasias (and occasionally benign diseases). Since its inception, the goal of RT has been to cure cancer locally without excessive side effects. The most important factors affecting the results of RT are the tumor type, its location and regional extent, the anatomic area of involvement and the geometric accuracy with which a calculated radiation dose is delivered. Although higher doses of radiation can produce better tumor control, the dosage which can be given is limited by the possibility of normal tissue damage. Approximately 60-65% of all cancer patients require RT as the sole treatment modality and / or in combination with surgery or chemotherapeutic drugs. There is a huge gap between demand and supply of radiotherapy facilities and infrastructure. Most of the oncocentres are located in urban areas in private sector and are beyond the reach of the common man.