Patients sometimes get burns from radiation therapy because the treatment, while targeting cancer cells, also affects normal skin and underlying tissues in the treated area. Radiation therapy uses high-energy rays or particles to destroy cancer cells by damaging their DNA, but this energy can also harm healthy cells nearby. The skin is often the first layer of tissue exposed to radiation beams, making it vulnerable to injury that manifests as a burn.
Radiation burns differ from common sunburns in several ways. Sunburn results mainly from ultraviolet (UV) light damaging the outermost skin layers (epidermis), causing redness and peeling due to inflammation triggered by DNA damage. Radiation therapy involves ionizing radiation such as X-rays or electron beams that penetrate deeper into the skin and even underlying tissues, potentially causing more complex damage including delayed reactions like moist desquamation (skin peeling with oozing) and chronic ulcers[1][3].
The mechanism behind these burns involves direct DNA damage in healthy skin cells leading to cell death or premature aging of keratinocytes—the main cell type in the epidermis—and triggering an inflammatory response. This inflammation causes symptoms such as redness, pain, swelling, blistering, itching, and sometimes ulceration depending on severity[6]. The damaged tissue may also produce reactive oxygen species (ROS), which cause oxidative stress further harming cellular structures and delaying healing.
Several factors influence why some patients experience more severe radiation burns:
– **Radiation dose:** Higher doses increase risk since more energy is deposited into tissues.
– **Treatment area:** Skin folds or areas with thin skin are more susceptible.
– **Individual sensitivity:** Some people’s skin reacts more strongly due to genetics or pre-existing conditions.
– **Concurrent treatments:** Chemotherapy can make skin more sensitive.
– **Technical errors:** Rarely but importantly, equipment malfunctions or operator mistakes can deliver excessive doses locally causing severe burns[5].
In some historical cases like those involving Therac-25 machines in the 1980s, software faults caused massive overdoses of beta radiation focused on small areas of patients’ bodies resulting in intense electric shock sensations followed days later by serious radiation burns with tissue necrosis requiring surgery[5].
The progression of a radiation burn typically follows stages: initial erythema (redness), dry desquamation where dead cells peel off without moisture loss; then moist desquamation where deeper layers break down releasing fluid; finally chronic wounds if healing is impaired. Healing can be slow because irradiated tissue has reduced blood supply due to damaged capillaries impairing oxygen delivery needed for repair.
Modern approaches aim not only at preventing these injuries through careful planning but also at improving healing when they occur. Experimental therapies involve using growth factors combined with specialized cell clusters derived from fat tissue that promote collagen formation and new blood vessel growth while reducing oxidative stress—helping regenerate damaged skin after irradiation[2].
In summary: Radiation therapy causes patient burns because its high-energy rays intended for killing cancer cells inevitably affect surrounding normal tissues including sensitive skin layers. This leads to cellular damage through DNA breaks and oxidative stress triggering inflammation and impaired wound repair processes manifesting as painful burning injuries ranging from mild redness up to deep ulcers depending on dose intensity and individual susceptibility.