Modern radiation oncology demands attention to classic principles of cancer patient management. The availability of new techniques in radiotherapy treatment planning and precise dose delivery tools has posed a tempting argument that higher doses can be delivered to larger volumes of tissues while maintaining a safe outcome for the patient. Adding toxic chemotherapeutic drugs and biological response modifiers to the modern radiotherapy approach further poses a challenge to stay within acceptable levels of normal tissue toxicity. More than ever, the radiation oncologist must collaborate closely with surgeon, medical oncologist and all physicians caring for the cancer patient to ensure that a safe therapeutic dose is delivered with minimal toxicity. Studies of the late effects of radiotherapy in cancer survivors continues to provide evidence of radiotherapeutic induction of new malignancies. Examples include a detection of breast cancer in patients cured of Hodgkin’s disease and a detection of lung cancer in breast cancer patients cured of their breast cancer. The radiation induction of soft tissue sarcomas in previously high dose treated areas has been known for decades. Modulation of radiotherapy techniques to minimize normal tissue malignant transformation as well as acute toxicity will be a persistent goal for the future.