Implications of leaf fluence opening factors on transfer of plans between matched helical tomotherapy machines

Abstract

When helical tomotherapy plans are transferred between two matched machines, the leaf opening times are changed. A published method of checking these is based on the differences in leaf latency between the two machines. We have extended this method to account also for the differences in leaf fluence opening factors (LFOF) between the two machines. When LFOF is not taken into account, the number of false negatives (with under 95% of opening times agreeing within 5 ms or under 99% agreeing within 10 ms) is approximately 10% of patients. After correcting for LFOFs, all transfers meet the criteria.

Statistical Analysis of Treatment Planning Parameters for Prediction of Delivery Quality Assurance Failure for Helical Tomotherapy

“…9 Several studies have presented the optimal planning parameters between pitch, FW, and MF to maintain the optimal plan quality and treatment time for clinical cases using HT, and they have studied the correlation between planning parameters and DQA results. [9][10][11][12][13][14][15][16][17][18] However, to the best of our knowledge, there is no published report using comprehensive statistical analyses such as logistic regression, receiver operating characteristic (ROC) curves, and the Classification and Regression Tree (CART) algorithm for the impact of the various planning parameters on DQA failure, to date.…”