Combined MV + kV inverse treatment planning for optimal kV dose incorporation in IGRT

摘要: Despite the existence of real-time kV intra-fractional tumor tracking strategies for many years, clinical adoption has been held back by concern over excess imaging dose cost to patient when in continuous fluoroscopic mode. This work aims solve this problem investigating, first time, use convex optimization tools optimally integrate into MV therapeutic order make clinically feasible. Phase space files modeling both a 6 treatment beam and on-board-imaging commercial LINAC were generated with BEAMnrc, used generate influence matrices DOSXYZnrc ten previously treated lung cancer patients. The IMRT, formulated as quadratic problem, was modified include additional constraints required tracking. An interior point optimizer problem. It found that using large apertures during tracking, combined MV + kV lead 0.5%-5.17% reduction total number monitor units assigned due inclusion accompanied up 42% compared standard IMRT For all field sizes considered, provided prescription volume coverage equal no-imaging case, yet superior non-optimized With optimization, it is possible quantify specific way dosimetric effect on patient. Such information necessary substantial performed.