Antimicrobial Agents and Chemotherapy

Biography

Biography: Marcos d’Ávila Nunes

Abstract

More than 100,000 patients have been treated with particle beams around the world, of which about 13% were treated with C-ion RT. In 1946, Wilson R proposed the use of proton for cancer therapy, and the first patient was treated at the Lawrence Berkeley National Laboratory in the USA (1954). In 1994, clinical trial on C-ion RT was launched at the National Institute of Radiological Sciences in Japan. Protons have a better dose distribution but a lower RBE (1.0-1.1) than carbon ions (1.5-3.4). However, RBE depends on radiation quality, LET, fraction size, and the biological aspects of the target. Higher RBE is good for tumor control, but it is bad for normal tissue toxicity. The biological benefits of C-ion RT have been demonstrated in inoperable cases with various types of sarcoma, adenocarcinoma, adenoid cystic carcinoma and malignant melanoma arising from various sites that are well known as photon-resistant tumors (and/or located close to critical structures). At HIT, Heidelberg, there is the Cleopatra and Pinocchio trial, both with a primary endpoint of toxicity. All studies on both proton and carbon ion therapy are small and therefore difficult to compare, also, assessment of the efficacy of proton therapy vs C-ion RT is not feasible, mainly due to the dose fractionation differences. The use of C-ion RT is recommended, when the advantages of using carbon ions outweigh the therapeutic advantages that can already be obtained by fractionated photon RT.