Short- distance radiotherapy or brachytherapy, Physics

Short- distance radiotherapy or brachytherapy:


The advantage:  it gives a very large dose to the tumor with a minimum  radiation to the surrounding normal tissue.
Disadvantage : The no uniformity of the dose and the radiation safety.


- The radiation source is radium but it replaced by 222Rn (radon gas) which is obtained by placing radium in a solution. Radon  also by radioactive gold 198Au .There is also 125I which is used for permanent implants.

-Brachytherapy is also use beta particles ,fast electrons emitted certain radionucleus.

- The (Yttrium 90)  90Y  is the most common  source of beta particles ,it is continuously being formed by the decay of strontium 90Sr which emits beta ray with energy of 0.54 Mev and 90Y emits β-ray with energy of up to 2.22Mev ,these rays can penetrate about 4mm and almost ideal for treating lesions on the eye.


Electrons in radiotherapy :


-    Electrons ,unlike gamma rays and x-rays ,have a fixed range.
-    The radiation at low electron energies is relatively uniform over most of its travel and this advantage is gradually lost in going to higher electron energies .
-    Disadvantage : there is some skin sparing since the maximum dose occur below the surface but its  amount is small compared to that from high energy x-ray beams.

 π-(Pi minus) mesons in radiotherapy:

-    Disadvantage: there life time is 10-8sec, high cost ,and protection problems.

-    Advantage: eliminate some or all of the oxygen effect

Posted Date: 10/1/2012 7:51:54 AM | Location : United States







Related Discussions:- Short- distance radiotherapy or brachytherapy, Assignment Help, Ask Question on Short- distance radiotherapy or brachytherapy, Get Answer, Expert's Help, Short- distance radiotherapy or brachytherapy Discussions

Write discussion on Short- distance radiotherapy or brachytherapy
Your posts are moderated
Related Questions
How many types of illuminators are there? As there are no standards inside the industry, the term "type" is slightly confusing. Regading to power usage, the lamp illuminators c

Compared with an atom of atomic weight 12 and atomic number 6, the atom of atomic weight 13 and atomic number 6: (1) Contains more neutrons         (2) Contains more electro

A rigid object is a body with a exact and unchanged size and shape i.e. a body is said to be rigid if the distance among any two particles of the body remains invariant.


During some kind of process the pressure of 2 mol of nitrogen gas linearly depends on the volume: p = p 0 + kV here p 0 and k are constants. What are the values fo

How nicol prism can be used as a polariser and an Analyser

what type of charge carriers are involved in conduction?

Define Space Station Pressure (MIT)? A space station consists of a huge cylinder of radius Ro filled with air. The  cylinder revolve about its symmetry axis at an angular  spee

The intermolecular forces (F) of attraction can be described as given: 1)   Cohesion. The force of attraction among molecules of the same substance is known as the force of cohe

what do you mean by nuclear fusion and fusion? explain briefly giving certain examples.