A comparative planning study of step -and -shoot IMRT versus helical tomotherapy IMRT in the treatment of craniospinal tumor

OBJECTIVES In this study, we compared the plan qualities of craniospinal IMRT plans created in the Prowess Panther, Eclipse and tomotherapy treatment planning systems, and analyzed the doses received by critical organs. METHODS IMRT plans created in tomotherapy treatment plannin stations of the previously treated patients using Prowess Panther DAO (V5.01, Prowess Inc., USA) planning system were compared. The prescription dose of 36Gy was delivered in 20 fractions to the target volume planned. The optimization was performed so as to deliver at least the 95% of the predetermined dose (V95%) to the total volume of each PTV. DHI (dose homogeneity index) values of all planesare comparable. RESULTS Although a significant difference was not observed between planning systems as for conformity indices tomotherapy has a relatively better conformity index is relatively better. Whole body integral dose was found to be much higher in the tomotherapy planning. CONCLUSION Although tomoterapy IMRT plan is easy to perform when compared with eclipse, and prowess IMRT plans, treatment time is longer. Prolonged radiation time in tomotherapy can induce intrafraction motion.