Radiation biology implications and issues for the design of light ion beam therapy ( LIBT ) clinical trials

The main purpose of this meeting was to discuss radiation biology implications and issues for the design of light ion particle therapy (LIBT) clinical trials. This is a sequence of IAEA’s Consultant Meeting on Particle Therapy in the 21 Century, held in November 2014, on which the IAEA report “Particle Therapy in the 21 Century: Relevance to Developing Countries” was based. Light ion therapy (LIBT) currently includes the therapeutic application of protons and carbon ions in radiation oncology. It is considered an excellent tool for highly precise, conformal dose delivery. Importantly, not much is known about the radiobiological basis of LIBT, particularly with ions other than protons. In vitro radiobiological studies on the RBE of charged particles regarding clonogenic cell killing demonstrated a bell-shaped dependence on LET with significant dependence also on the particle charge (Durante, M., New challenges in high-energy particle radiobiology. Br J Radiol, 2014. 87(1035): p. 201306262014). However, little is known about other “classical” effects, such as DNA damage and repair, or even on so called non-targeted radiation effects or most importantly on in vivo pathobiological mechanisms and individual radiosensitivity to LIBT. This also applies to OER. Based on these considerations, the IAEA Technical Meeting (TM) on “Radiation biology implications and issues for the design of light ion therapy (LIBT) clinical trials” was organized in November 2015. The detailed program of the meeting and the list of participants are attached. This meeting was covering various aspects of LIBT, regarding radiobiology, clinical radiooncology, and implementation in low-and-middle-income countries (LMIC).