Estimation of tumor control probability model parameters from 3-D dose distributions of non-small cell lung cancer patients

Tumor control probability (TCP) model calculations may be used in a relativ e manner to evaluate and optimize three-dimensional (3-D) treatment plans. Using a mathematical model which makes a number of simplistic assumptions, TCPs can be estimated from a 3-D dose distribution of the tumor given the d ose required for a 50% probability of tumor control (D-50) and the normaliz ed slope (gamma) of the sigmoid-shaped dose-response curve at D-50 The purp ose of this work was to derive D-50 and gamma from our clinical experience using 3-D treatment planning to treat non-small cell lung cancer (NSCLC) pa tients. Our results suggest that for NSCLC patients, the dose to achieve si gnificant probability of tumor control may be large (on the order of 84 Gy) for longer (> 30 months) local progression-free survival. (C) 1999 Elsevie r Science Ireland Ltd. All rights reserved.