Improved Algorithm for Estimation of Linear Energy Transfer in Carbon Ion Radiotherapy Plans.

Abstract

This study aimed to develop an improved algorithm for linear energy transfer (LET) estimation in carbon ion radiotherapy (CIRT) using relative biological effectiveness (RBE) and to establish a clinical pipeline for LET assessment. New approximation functions for LET versus RBE were developed for the overkill region. LET estimation performance was examined at two facilities (A and B) using archival- and Monte Carlo simulation-derived LET data, respectively, as a reference. A clinical pipeline for LET assessment was developed using Python and treatment planning systems (TPS). In dataset A, LET estimation accuracy in the overkill region was improved by 80.0%. In dataset B, estimation accuracy was 2.3%±0.67% across 5 data points examined. LET distribution and LET-volume histograms were visualized for multiple CIRT plans. The new algorithm showed a greater LET estimation performance at multiple facilities using the same TPS. A clinical pipeline for LET assessment was established.