New Cancer Screening Technique (Unfinished Idea)

If I do become a doctor which I now want to do I might see if this idea is worth entertaining.
The problem with cancer screening is first that it has to be cost effective and those forms of screening are usually invasive(breast/prostate) and ineffective for some types of cancer(such as medical imaging of lung cancer legions).
The best way to cure cancer at the moment is to catch it early and to use modern chemotherapy and radiation to kill it. So to catch it early will save a lot of lives.
So me as an inventor, I like to find solutions to a problem.
I was thinking if you used:

Monoclonal antibody therapy is another strategy in which the therapeutic agent is an antibody which specifically binds to a protein on the surface of the cancer cells
-This quoted from wiki under "Cancer"

And combined it with a easily detectable material, which is also very cheaply produced and detected. Then you would give someone the detectable substance which is attached to the antibodies and introduce them into the blood stream. Most likely being a cheap and detectable solid(nano-sized, and sphere shaped) which is then coated with the antibodies, or peptides(also being cheap).
Take the pill filled with this material the night before and in the morning see the doctor and it will have spread throughout the body attaching to anything cancerous. Then you run through the full body scanning machine where it takes a quick picture and gives absolutely positive or absolutely negative results. Then you're done with your check-up.
This would be done maybe once a year for early diagnosis of all kinds of cancer. But may need different types of antibodies for different types of cancer proteins. Which may be a problem if we never find all of the antibody types for all of the types of cancerous proteins. And another problem is of you can't get the antibody particles to the cancer, from maybe blood flow not carrying the particles to that location.
The detector would actually probably be the most complex part of this idea because it has to detect very small anomalies trough the body tissue. maybe if the substance were metal it could be detected with a modified x-ray machine that ignored most organic tissue such as bones.
But Both the type of detector and the type of material to be detected are still up in the air.


Also research: Jellyfish green fluorescent proteins combined into a mammals DNA to make the animals skin luminescent under ultraviolet light.(It works also)
Also research: The new technique that uses the same metal particles surrounded by antibodies, but instead uses microwaves to then kill the cancer cells. And is now supposedly doing animal trials. Called the "Kanzius machine"
But in the end the ealier you get to the cancer the better no matter what the treatment. Also it's always less invasive for smaller tumors.