Therapeutic techniques applied in the heavy-ion therapy at IMP

Superficially-placed tumors have been treated with carbon ions at the Institute of Modern Physics (IMP), Chinese Academy of Sciences (CAS), since November 2006. Up to now, 103 patients have been irradiated in the therapy terminal of the heavy ion research facility in Lanzhou (HIRFL) at IMP, where carbon-ion beams with energies up to 100 MeV/u can be supplied and a passive beam delivery system has been developed and commissioned. A number of therapeutic and clinical experiences concerning heavy-ion therapy have been acquired at IMP. To extend the heavy-ion therapy project to deep-seated tumor treatment, a horizontal beam line dedicated to this has been constructed in the cooling storage ring (CSR), which is a synchrotron connected to the HIRFL as an injector, and is now in operation. Therapeutic high-energy carbon-ion beams, extracted from the HIRFL-CSR through slow extraction techniques, have been supplied in the deep-seated tumor therapy terminal. After the beam delivery, shaping and monitoring devices installed in the therapy terminal at HIRFL-CSR were validated through therapeutic beam tests, deep-seated tumor treatment with high-energy carbon ions started in March 2009. The therapeutic techniques in terms of beam delivery system, conformal irradiation method and treatment planning used at IMP are introduced in this paper