AbstractID: 7448 Title: An Investigation of Deliverability Complexity in Intensity Modulated
Radiotherapy
An investigation has been undertaken to parameterize the deliverability of two-dimensional fluence profiles obtained from an inverse plan. The
deliverability is a measure of the desirability of a produced inverse plan for a delivery with the use of a multileaf collimator. Two scoring indices
are introduced to evaluate the complexity of the profiles in terms of delivery characteristics such as dosimetric accuracy. The fraction of a profile
that is planned to receive less than the minimum level of transmission radiation is scored as a Baseline Index (BI) and Cumulative Monitor Unit
Index (CMUI) is the ratio of an average fluence level and the Cumulative Monitor Units (CMU). The formulations of the deliverability scoring
indices are introduced.
Then, through dosimetric investigations, validity of the indices as a measure of predictability of dosimetric accuracy is
shown. The results of dosimetric investigations suggest that there is a clear correlation between the deliverability indices and the accuracy of a
delivered dose distribution.