External beam radiation therapy uses high-energy beams, often X-rays, aimed precisely at a tumor to destroy cancer cells. Patients often wonder about safety protocols regarding common items like jewelry. Clear guidelines are necessary because the interaction between powerful radiation beams and metallic objects affects patient safety and treatment accuracy.
The General Rule for Removable Jewelry
A universal protocol in radiation oncology departments is the removal of all metallic jewelry located in or near the intended treatment area before each session. This requirement applies to items such as necklaces, earrings, watches, bracelets, and removable body piercings. Even a belt buckle or a zipper can pose an issue if it falls within the path of the radiation beam.
This safety measure ensures the therapeutic dose reaches the target accurately. Staff will provide specific instructions, but the general rule is to arrive free of metal near the treatment field.
The Science Behind the Requirement
The necessity of removing metal stems from how high-energy radiation beams interact with dense materials. When powerful X-ray photons strike a metal object, the metal’s high atomic number causes dose scattering. This process involves metal atoms emitting secondary electrons that scatter back toward the patient’s skin.
This backscattering significantly increases the radiation dose absorbed by the skin immediately surrounding the jewelry. This can intensify the skin reaction, potentially leading to severe irritation, redness, or ulceration.
Furthermore, dense metallic objects interfere with imaging scans, such as the daily X-rays or CT scans, used to precisely position the patient. This interference creates artifacts on the images, making it harder to confirm the exact tumor location and compromising treatment accuracy.
Addressing Non-Removable Items
Items that cannot be easily taken out, such as permanent piercings, dental fillings, surgical metal plates, or pacemakers, require special consideration. The radiation oncology team must be informed about all non-removable metal during the initial consultation and treatment planning phase. The presence of these fixed objects must be accounted for before treatment begins, as they can affect the dose distribution.
The planning team can often adjust treatment angles or use specialized shielding to minimize the effect of internal metal on dose delivery. Modern planning software utilizes advanced algorithms, such as metal artifact reduction techniques, to correct for image distortions caused by implants.
If a permanent piercing falls directly within the treatment field, the patient may need to consult a professional. They can replace the metal jewelry with a non-metallic alternative, such as a glass or plastic retainer, to eliminate the scattering risk.