When using conventional (photon) irradiation, the patient is exposed to the excessive irradiation of healthy tissues. This poses a risk of late and very late toxicity. This means, in the long term, that the consequences of unwanted radiation delivered to the healthy tissues and organs, such as damage to the heart or lungs or secondary tumors, are often manifested long after the end of treatment.
Especially in the treatment of lymphomas, conventional photon therapy has already reached its limits and there is no possibility of reducing doses to the high-risk organs; in fact, when using advanced IMRT photon radiation therapy, there is an increased risk of developing secondary tumors.
In other words, conventional irradiation provides no room for improvement in results and the elimination of the above-mentioned risks.