Orthovoltage X-rays

Orthovoltage X-rays are a form of radiation therapy used in the treatment of certain types of cancer. This method employs X-rays with energies in the range of 200 to 500 kilovolt peak (kVp), which distinguishes it from megavoltage X-rays used in modern linear accelerators for more penetrating treatments. Orthovoltage X-rays, also known as deep therapy X-rays or superficial X-rays, are primarily used for treating superficial tumors due to their limited penetration depth, making them less effective for treating deep-seated tumors.

Overview

Orthovoltage X-ray therapy works by directing high-energy X-ray beams at a tumor, with the aim of destroying cancer cells while sparing the surrounding healthy tissue. The energy range of orthovoltage X-rays allows for optimal penetration of the body's tissues to reach and treat tumors. However, due to their relatively lower energy compared to megavoltage X-rays, orthovoltage X-rays are more likely to be absorbed by bone and other dense tissues, which can limit their effectiveness for treating tumors located deep within the body.

Applications

Orthovoltage X-ray therapy is particularly useful for treating cancers located near the surface of the body, such as skin cancer, and certain types of head and neck cancers. It is also used in the treatment of keloids, basal cell carcinoma, and squamous cell carcinoma. Due to its characteristics, orthovoltage therapy can be a preferred option for patients for whom deep tissue penetration is not necessary or for those who cannot tolerate more invasive treatments.

Advantages and Disadvantages

The main advantage of orthovoltage X-ray therapy is its ability to treat tumors located near the surface of the body with a high degree of precision. It is also relatively cost-effective compared to more advanced radiation therapy techniques. However, the disadvantages include a higher risk of damage to the skin and other superficial tissues, and its limited effectiveness for treating deep-seated tumors. Additionally, the use of orthovoltage X-rays has declined with the advent of more advanced radiation therapy technologies that offer deeper tissue penetration with less damage to surrounding tissues.

Technique

The technique for delivering orthovoltage X-ray therapy involves positioning the patient and using various shields and cones to focus the X-ray beam on the tumor while protecting surrounding healthy tissue. The treatment is typically delivered in multiple sessions over a period of weeks to allow healthy tissues to repair while maximizing the dose to the tumor.

History

Orthovoltage X-ray therapy was a common form of radiation therapy before the development of megavoltage X-ray machines in the mid-20th century. Its use has declined with the advent of more advanced technologies, such as linear accelerators and gamma knife radiosurgery, which offer more precise targeting and deeper tissue penetration.

Current Use

While the use of orthovoltage X-rays in radiation therapy has decreased, it remains an important tool in certain clinical situations. Its use is often dictated by the specific type and location of the tumor, as well as the overall condition of the patient.

See Also

• Radiation therapy
• Linear accelerator
• Gamma knife
• Cancer treatment