Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Megavoltage therapy:
Kerst developed the betatron which accelerates electrons to high energy .It open a new radiation therapy era-the supervoltage or megavoltage era.Another development in the radiation therapy is the application of man made radioactive source .
One of the radioactive sources:
Cobalt 60: it emits penetrating gamma rays of about 1.25 Mev energy.60Co units (also called cobalt teletherapy and cobalt bomb units)
-The high energy gamma rays emitted by 60Co are absorbed by tissue and produce high energy electrons .- Most of electrons move in the same direction as the original beam .- As the gamma ray beam penetrates the first few mm beneath the skin ,the no. of electrons increases and the energy deposited by them increases.- The dose maximum occurs about 5 mm below the skin .-The relatively low dose at the skin from high energy x-rays of gamma rays is referred to as the skin –sparing effect.-The radiation from 60Co teletherapy unit is emitted continuously ,the unit is turned on by rotating the source wheel until the source is over the beam port in the large lead shield .It is turn off by rotating the source wheel until the source shielded by the wheel fig (1).
Mega voltage therapy has three major advantages :
- The maximum dose occurs below the skin and the skin sparing effect greatly reduces the pain from the treatment.- The high energy is almost completely in the Compton effect region and doses not give a large doses to the bone .- The greater penetrating ability permits better treatment of tumors deep inside the body.
The discovery of neutron becomes very late because: (1)Neutrons are present in nucleus (2)Neutrons are highly unstable particles (3)Neutrons are chargeless (4)Neutrons
Q. What is band emission spectrum? Give an example. It consists of a numerous bright bands with a sharp edge at one end but fading out at the other end. Band spectra are acquir
A jogger runs at a constant rate of 10.0 m every 2.0 s. The jogger starts at the origin, and runs in the positive direction for 3600.0 s.The figure below is a position-time graph s
Magnetic monopole A hypothetical particle that sinks of the magnetic field & constitutes sources. Magnetic monopoles have never been determined, but would cause fairly minor m
What are the non- medical uses for endoscopy? Non-medical uses for endoscopy are as follows: a. The planning and architectural community have determine the endoscope helpful
when a soft iron piece is buried under the surface of earth in the north south direction why the iron piece show properties of a magnet
Kirkwood gaps (Kirkwood): Gaps in the asteroid belt, caused through resonance effects from Jupiter. Identical gaps exist in Saturn's rings, because of the resonance effects of
Is there any experiment to tell that water can move from lower concentration to higher Which means flows back to mountain without reversing time Could water flow upward by itself w
1. What are multipoint constraints? 2. What is the difference between an RBE2 and RBE3? When is one use over the other? 3. What is the difference between an isotropic, othrot
deflection magnetometer
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd