Year: 2024
Type: article
Abstract: Purpose To facilitate the use of quantitative modeling of biological effects in treatment planning by introducing a simpler function equivalent to the Lyman formula for calculating normal tissue complication probability (NTCP). Methods We first provide an approximation of the Lyman‐Kutcher‐Burman (LKB) formula using three parameters ( n , m , TD 50 ) as a function of equivalent uniform dose (EUD). The parameters for the new formula are defined in terms of the Lyman model's m and TD 50 . Conversely, m and TD 50 are expressed in terms of the parameters of the new equation. The role of the Lyman volume‐effect parameter n remains unchanged from its role in the Lyman model. Results The new formula, which exhibits a sigmoidal shape, demonstrates symmetry about TD 50 , akin to the LKB model. The difference in NTCP between the two formulas is less than 0.1%. The parameters ( n , m , TD 50 ) are preserved through rigorous mathematical deduction and have been recalibrated to the tolerance data of Emani et al. using the proposed formula. This new model provides a better fit to these data than the model by Burman et al. , which was fitted “by eye” rather than using statistical methods. Conclusion We have developed a formula that represents NTCP as a function of EUD, which proves to be potentially useful. The parameters derived in this study are mathematically robust and offer a superior fit to the data compared to previous efforts. Additionally, the new model fits brain data as well as, if not better than, the LKB model.
Source: Precision Radiation Oncology
DOI: 10.1002/pro6.1240
Authors: Tingting Cao, Qingqing Yuan, Zhitao Dai
Language: English
Subfield: Radiation
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W4402694526