Radiation therapy, a localized treatment, directs high-energy radiation beams at a tumor to destroy its DNA. Consequently, patients typically experience hair or hair-like loss only in the specific area targeted by the radiation. For brain cancer or head and neck cancers, hair loss can occur as radiation beams pass through the scalp, damaging hair follicles. The extent of hair loss, whether partial or complete, depends on the angle and width of the radiation field. Hair usually begins to fall out two to three weeks after the initial radiation treatment.

For radiation therapy performed outside the head, face, or neck region, patients might experience hair loss on the irradiated skin. However, if a patient undergoes a combined chemoradiation protocol, any hair loss is primarily a side effect of the chemotherapy drugs, not the radiation itself.

A technician prepares and adjusts the patient's correct lying position before radiation therapy. Illustration: Tam Anh General Hospital

The time it takes for hair to regrow after radiation therapy varies depending on the radiation dose and treatment duration. In cases of prophylactic or palliative radiation involving low doses and short durations, hair follicles are temporarily suppressed and damaged. Hair typically starts to regrow approximately three to six months after completing radiation therapy. The new hair may have slight changes in texture, often appearing thinner, curlier, or lighter in color than before.

In some instances, patients may experience permanent hair loss after radiation therapy due to specific medications and the radiation dose applied to the scalp. It is advisable to consult your doctor about your particular radiation therapy protocol for tailored guidance. Modern, high-tech radiation therapy aims to minimize side effects. Patients undergoing radiation therapy to the head and neck, especially the scalp, often report sensitive, dry, peeling, irritated, and reddened skin.

Beyond hair loss, radiation exposure can cause the scalp to become dry, darkened, sensitive, and easily irritated. Therefore, patients receive prophylactic treatment to prevent radiation-induced dermatitis. During and for six months after radiation therapy, patients should avoid perming or bleaching their hair with chemicals. Patients may consider cutting their hair short or shaving it to reduce tangling and alleviate psychological distress from seeing significant daily hair loss. It is recommended to use a mild, natural-scented shampoo designed for infants. When washing hair, gently massage the scalp with the pads of your fingertips and dry with a soft towel. Additionally, patients should avoid direct sunlight exposure to the scalp. When going outside, wear a hat for protection. Use soft, sweat-absorbent scarves or hats. If using a wig, ensure the inner lining is soft and free of stiff seams that could rub against the irradiated skin.

Master, Doctor. Second-Degree Specialist Le Thi Thanh Hong

Department of Radiation Oncology, Oncology Center

Tam Anh General Hospital, TP HCM