Why is our technology going to be more effective and more productive
than today’s proton therapy ?
Having analyzed scientific evidence concerning beam therapy we came to the fundamental conclusion that the main reason of the efficiency of modern beam therapy which is less than 100% is insufficient irradiation doses received by tumor. For instance, in the work of Zietman AL, Bae K, Slater JD, et al. (2010) Randomized trial comparing conventional-dose with high-dose conformal radiation therapy in early-stage adenocarcinoma of the prostate: Long-term results from Proton Radiation Oncology Group/American College of Radiology 95-09. J Clin Oncol 28:1106–1111. Here the treatment efficiency using different doses was studied. (70,2 Gr and 79,2 Gr)
It is obvious that when dose is increased the treatment efficiency rises from 68% to 82,6% (the fact that irradiation was performed by means of mixture of protons and Gamma irradiation we do not consider to be of principle).
Even higher doses were applied in the work of Cahlon O, Zelefsky MJ, Shippy A, et al.(2008) Ultra-high dose (86.4 Gy) IMRT for localized prostate cancer: Toxicity and biochemical outcomes. Int J Radiat Oncol Biol Phys 71:330–337.
Here Gamma quant irradiation based on IMRT technology was applied which allowedusage of such high doses. The treatment efficiency increased considerably and such figures as 99% for the early stage of disease and 70% for the late one appeared.
Even higher doses were used at brachytherapy in the work of Morris WJ. & Pickles T. (Morris WJ, Keyes M, Palma D, et al. Population-based study of biochemical and survival outcomes after permanent 125I brachytherapy for low- and intermediate-risk prostate cancer. Urology 2009;73:860-865.)
Isotope 125I was used for irradiation and the absorbed dose in the tumor reached 144 Gr.
Extremely good indicators of relapse-free survivability were achieved as a result of 95,6%+/- 1,6% for 5 years and 94,0% +/- 2,2% for 7 years.
Thus, having considered all the scientific evidence listed above we can conclude that to make treatment more effective it is necessary to increase the doses received by the tumor, however, with today’s technology the increased tumor dose causes unacceptable irradiation to healthy tissue.
Our installation compared to the existing proton centers allows irradiating the tumor from different directions (36 or more). Obviously the beam of protons penetrates into the tumor through different areas of healthy tissue. Due to this we have the following: the dose in healthy tissue is lower than threshold of its sensitivity and the tumor dose is much higher as a result of summation of irradiation from different directions.
Another important circumstance is that irradiation is carried out using a new system of dose field planning – optimized IMPT. As a result of this algorithm we get bigger difference between doses received by tumor and healthy tissue. So, our new irradiation technology allows increasing irradiation dose in tumor with simultaneous decrease of dose in healthy tissue that (as it follows from medical evidence listed below) should result in recovery efficiency up to 90% and more.
A considerable increase of tumor dose for one irradiation session leads to decrease of total irradiation dose necessary to destroy the tumor, that is to say to reduce the amount of irradiation sessions which means the growth of carrying capacity of our installation.
Of course this technology should be medically tested that means it should be studied in medical circles.
There is a list of comparative pictures of dose fields below used in existing technologies and in our high performance technology.