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.

No abstract