What are the major side effects of radiotherapy?

Radiotherapy is a common treatment for cancer that uses high doses of radiation to kill or damage cancer cells. One of the most prominent side effects experienced by patients undergoing radiotherapy is localized skin irritation and damage in the area being treated, which aligns with the symptoms listed in the correct response.

Pruritis, or itching, is a typical reaction as the skin becomes inflamed and irritated. Erythema, or redness of the skin, often occurs due to the radiation's effect on the superficial layers. Burning sensations are also commonly reported and can range from mild discomfort to severe pain, depending on the radiation dose and treatment area. In some cases, skin sloughing, where the top layers of skin peel off, may occur, leading to open wounds and increased risk of infection. The other options provided contain side effects that are not directly associated with radiotherapy, making the chosen response the most accurate regarding the typical adverse effects patients may experience during treatment.