# Student of master degree need help in solving problems in radiotherapy

HI everyone,

I am a student. My master degree topic is - Finding the optimal position of irradiation isocenters in an irregularly shaped large volume tumor. So the problem in radiotherapy is when tumor is longer than 40 cm (lung tumor). So when tumor is bigger need to mark two isocenters. So came with the idea, if you draw any irregular shape and draw from each vertex a very thin line to all vertex; example: in the center where the lines croses most, there will be visible line. After that all I need is to gain all those dots in center, mark them, count the distance, divide it in for equal parts, and I will have two isocenters. After that I still have to do some countings, but first things first. Is it possible? Or I need to look for other tools? Can someone help me? (p.s. It would be great if someone told me how to export all coordinates of each vertices, at leats what i can do is draw a shape, get coordinates of vertices and export them to *.csv file, after that I can yous matlab to draw a lines) By the way, maybe there is an easier way to draw a middle line in any 3D irregular shape?

irregular ??
are all objects volume convex or got some manifold ?
if with manifold might have to split object in 2 may be !

so you would need the center of the convex volume ?

why 2 centers ?
got some example of volume like that
show some 3D Volume to better understand the 3D shape and the 2 centres !

did you check the Image J site ?

happy bl

Irregular shape is - if you can google how tumor looks like that is irregular shape, so tumor looks like this

so i need a center of body like in the picture. Why two centers - linear accelerator used in radiotherapy can irradiate tumor only smaller than 40cm, because mechanism is made so. but lungs is longer than 40 cm, and very very rare patients has a tumor across all lung and that tumor cant get irradiate depending on one center (cause dose is counted from the center to sides of tumor) so what oncologys set two centers using there experience. Than they move a patient to another position, for finishing irradiation of tumor. But this practice can be better if machine would show where is two isocenters , than linear accelerator counts dose around one center, than doctors move patient to another position and linear accelerator counts dose for other center. The point of two isocenters is to safe as many healthy cells as possible. In video conference I would explain everything about radiotherapy and the whole idea.
I will check Image j site, did I answered all your questions? Explaining everything is hard when writing, but when people have live conversation than its easier to explain. So will you help me? ready for some challlenge?