Radiomaskering

Radiomaskering is a term used in Swedish clinical practice to describe the use of physical masks and shielding to control exposure to ionizing radiation. The concept covers techniques to limit dose to non-target tissues, to immobilize patients during treatment, and to shape radiation fields in both diagnostic and therapeutic settings.

In external beam radiotherapy, immobilization masks—often made of thermoplastic materials—are molded to the patient's head, neck, or other regions to ensure reproducible positioning across treatment sessions. These masks help maintain accuracy of dose delivery and can be combined with other immobilization devices. Dose-modifying devices such as boluses, compensators, and field-shaping elements are also used to achieve the desired dose distribution and spare nearby organs.

In diagnostic radiology and interventional radiology, masking includes the use of shielding (for example, lead aprons and gonadal shields) and collimation to limit the X-ray beam to the region of interest, thereby reducing scatter and protecting radiosensitive tissues. Masking in this context supports dose optimization and image quality while meeting safety requirements.

Materials commonly used include thermoplastic polymers for patient masks and lead or equivalent shielding for protection. The process typically begins with planning images (such as CT simulations) to design the mask or shield, followed by fabrication, fitting, and quality assurance. Masks are usually assigned to a single patient, with cleaning or replacement according to local regulations and guidelines.

Radiomaskering is governed by national and international radiation safety standards. Quality assurance verifies fit, reproducibility, and dosimetric accuracy, while patient comfort and clear communication are emphasized to ensure compliance and safety.