Session B4: Health and Biological Physics

Proton therapy for cancer: A superior method for the treatment of localized tumors.

About 50{\%} of all cancer patients receive radiation, besides other forms of treatment. Conventionally, X-ray (photon) radiation is used, because it is cheap to generate. However, photon radiation is difficult to focus on a localized area at a certain depth in the human body. Thus, in X-ray therapy, also wide areas of healthy tissue are damaged leading to potentially severe side effects. In contrast, proton radiation, by its nature, causes destruction that is mainly confined to a localized area known as the Bragg peak, which can be focused on the tumor. Thus, in proton therapy, healthy tissue is less affected resulting in a much lower rate of severe side effects as compared to photons. Recently published follow-up studies have shown that the long-term cure rate of proton therapy is a high or even higher than with other forms of cancer treatment. Unfortunately, proton facilities are expensive, which is why, until the year of 2000, we had only two such facilities in the country. This is changing now and four more facilities have been finished or are under construction.   

Biocompatible magnetic nanoparticles with high magnetic moment for cancer treatment

Non-toxic iron oxide naoparticles have extended the boundary in medical world; with size range form 2 to 400 nm they can be compiled with most of the small cells and tissues in living body. We have prepared monodispersive iron-iron oxide core-shell nanoparticles in our novel cluster deposition system. The nanoparticles have very high magnetic moment up to 200 emu/g. To test the nontoxicity and uptake we incubated the nanoparticles coated with dextrin and non-coated iron naoparticles with LXI SCLC lung cancer cells found in rats. Results indicate that both coated and noncoated cells were successfully untaken by the cells indicating that the core-shell nanoparticles are not toxic. Due to the high magnetic moment offered by the nanoparticles we propose that even in low applied external alternating field desired temperature can be reached for hyperthermia treatment in comparison to the commercially available iron oxide nanoparticles (magnetic moment less than 20 emu/g). We also found that our ferromagnetic nanoparticles were uptaken by the cancer cells without adding protamine sulfate, which is normally needed to prevent the coagulation of cells for the commercial nanoparticles.