One of the principal objectives of radiotherapy in the treatment of deep cancer tumors is to deliver a uniform dose distribution. Use of compensators in radiotherapy solves the problem of irregular dose distribution.
What is tissue compensator in radiotherapy?
ABSTRACT. A radiation beam incident on an irregular or sloping surface produces the non-uniformity of absorbed dose. The use of a tissue compensator can partially correct this dose inhomogeneity. The tissue compensator is designed based on the patient’s three dimensional contour.
What is a radiotherapy mask made of?
Masks are usually made using a type of mesh plastic. This is moulded to fit the shape of your head and neck. Less often, wet plaster bandages are used to make a mould, which is then used to make a clear plastic (Perspex®) mask.
What are wedges and compensators radiotherapy?
In radiation oncology, wedge filters are commonly used to improve the dose uniformity in the target volume. They can be used as missing tissue compensators or wedge pairs to alter the shape of isodose curves so that two beams can be angled with a small hinge angle at a target volume without creating a hotspot.
What is penumbra in radiation therapy?
Penumbra. The rapid decrease at the edges of the radiation beam is called the penumbra region. Usually defined as the space between the 80% and 20% isodose lines.
Why compensators are generally used?
The compensator must compensate not only for the reduction of the primary beam attenuation due to tissue deficit, but also for the loss of scattering by the missing tissues.
What is the use of bolus in radiation therapy?
In radiation therapy, bolus is a material which has properties equivalent to tissue when irradiated. It is widely used in practice to reduce or alter dosing for targeted radiation therapy.
What mask protects from radiation?
/RADIATION EVENTS/ /HOSPITAL WORKERS/ Ordinary surgical facemasks provide good protection against inhaling particulates, and allow excellent air transfer for working at high breathing rates. If available, high efficiency particulate air (HEPA) filter masks such as the NIOSH “N-95” mask provide even better protection.
What is virtual wedge in radiotherapy?
Virtual Wedge (VW) is a Siemens treatment modality which generates wedge-shaped dose distributions by moving a collimator jaw from closed to open at a constant speed while varying the dose rate in every 2 mm jaw position.
Why are wedges used in radiotherapy?
In radiation therapy, wedge filters are commonly used to improve dose uniformity toward the target volume [2]. A physical wedge is usually constructed from a high-density material, such as lead or steel, which attenuates the beam progressively across the entire field.
How can we reduce penumbra?
Using submegavoltage x-rays in radiosurgery, lead to reduction of radiological penumbra. Penumbra width is decreased using compensating filter and intensity modulation technique. Penumbra width is improved by removing the flattening filter of linac. Increasing SDD results in decreasing geometric penumbra width.
Why do you wear a mask during radiotherapy?
During most types of radiotherapy to the brain, head or neck, you wear a mask to help you lie still. What is a radiotherapy mask? What is a radiotherapy mask? For most types of radiotherapy to your brain, head or neck area, you wear a mask during each treatment. This is sometimes also called a mould, head shell or cast.
How long does it take to make a radiotherapy mask?
A technician or radiographer usually makes the mask in the radiotherapy department. The process of making the mask can be different depending on the hospital, but it usually takes about 30 minutes. You may need to take off some of your clothes and wear a hospital gown while it is being made.
How does radiotherapy treatment take place?
When you have the radiotherapy treatment, you lie in exactly the same position on a couch below a radiotherapy machine. The mask is gently placed over your head and neck and fixed to the couch. Treatment can take 10 to 30 minutes and is not painful. Again, the team can see, hear and talk to you and are close by if you need them at any time.
Can I Shave during radiotherapy?
Wet shaving can irritate the skin during radiotherapy. Use an electric shaver if you need to shave. A technician or radiographer usually makes the mask in the radiotherapy department. The process of making the mask can be different depending on the hospital, but it usually takes about 30 minutes.
