There are a couple of misleading statements in the article.
First of all you DO NOT use high concentration of ozone internally EVER. High concentrations internally will hemolyze red blood cells, which can be quite serious if not deadly. The maximum amount of ozone used in internal use is only 0.1% with the rest being pure oxygen.
Secondly it makes absolutely no difference whatsoever if the person has had previous chemotherapy. Same with radiation therapy. These do not change the chemistry of cancer cells in any way to make them ozone resistant.
Activated charcoal does not need to be taken with ozone treatments, and I actually advise against it since the charcoal absorbs valuable nutrients.
As far as whether or not IV injection is best, that is very debatable. Each form of administration has its pros and cons. Tumors readily accessible by a needle can actually be injected directly with ozone. Overall though for most internal applications I feel insufflation is best. And studies have shown after a few treatments to be just as effective as autohemotherapy, which is slightly below IV and IA injections. The big advantage of insufflation though is that it can be done easily at home with a little training and it does not carry the risks associated with injections that people often do too rapidly. Having a unit at home also allows a person to easily do multiple treatments a day and at a much lower cost.
It should also be noted that it is EXTREMELY important to not destroy large tumors too rapidly. It would be very easy to destroy a 20cm malignant tumor with ozone in one shot. But all this dead cellular debris constitutes an infection to the body, and that large of an amount of cellular debris could kill the patient from sepsis.