Which of the following is a common treatment modality for cancer?

Radiation therapy is a well-established and widely used treatment modality for cancer that employs high doses of radiation to kill cancer cells or slow their growth. This technique works by damaging the DNA within cancer cells, making it difficult for them to continue dividing and proliferating. Radiation therapy can be utilized in various settings, including as a primary treatment for localized tumors, to shrink tumors before surgery (neoadjuvant therapy), or to eliminate remaining cancer cells after surgical resection (adjuvant therapy).

It is particularly effective for certain types of cancer, such as breast, prostate, and head and neck cancers, and can be administered externally through external beam radiation or internally via brachytherapy. The decision to use radiation therapy is often guided by factors such as the type and stage of the cancer, its location, and the individual patient's overall health.

In contrast, clinical observation is typically used for patients with low-risk tumors that may not require immediate treatment and is often part of an active surveillance strategy rather than a definitive treatment modality. Exercise therapy and behavioral therapy may complement cancer treatment by improving overall well-being and managing symptoms but do not serve as primary treatment modalities for cancer itself. Hence, the prominence of radiation therapy as a direct intervention to treat cancer solidifies its