Isobio software: biological dose distribution and biological dose volume histogram from physical dose conversion using linear-quadratic-linear model.
OBJECTIVE
To develop an in-house software program that is able to calculate and generate the biological dose distribution and biological dose volume histogram by physical dose conversion using the linear-quadratic-linear (LQL) model.


METHODS
The Isobio software was developed using MATLAB version 2014b to calculate and generate the biological dose distribution and biological dose volume histograms. The physical dose from each voxel in treatment planning was extracted through Computational Environment for Radiotherapy Research (CERR), and the accuracy was verified by the differentiation between the dose volume histogram from CERR and the treatment planning system. An equivalent dose in 2 Gy fraction (EQD2) was calculated using biological effective dose (BED) based on the LQL model. The software calculation and the manual calculation were compared for EQD2verification with pairt-test statistical analysis using IBM SPSS Statistics version 22 (64-bit).


RESULTS
Two and three-dimensional biological dose distribution and biological dose volume histogram were displayed correctly by the Isobio software. Different physical doses were found between CERR and treatment planning system (TPS) in Oncentra, with 3.33% in high-risk clinical target volume (HR-CTV) determined by D90%, 0.56% in the bladder, 1.74% in the rectum when determined by D2cc, and less than 1% in Pinnacle. The difference in the EQD2between the software calculation and the manual calculation was not significantly different with 0.00% atp-values 0.820, 0.095, and 0.593 for external beam radiation therapy (EBRT) and 0.240, 0.320, and 0.849 for brachytherapy (BT) in HR-CTV, bladder, and rectum, respectively.


CONCLUSIONS
The Isobio software is a feasible tool to generate the biological dose distribution and biological dose volume histogram for treatment plan evaluation in both EBRT and BT.
Medical Physics Master Degree Program, Department of Radiology, Faculty of Medicine.
Tanwiwat
T
Jaikuna
Medical Physics Master Degree Program, Department of Radiology, Faculty of Medicine.
Phatchareewan
P
Khadsiri
Division of Therapeutic Radiology and Oncology, Faculty of Medicine.
Nisa
N
Chawapun
Department of Radiologic Technology, Faculty of Associated Medical Sciences; Biomedical Engineering Center, Chiang Mai University, Chiang Mai, Thailand.
Suwit
S
Saekho
Division of Therapeutic Radiology and Oncology, Faculty of Medicine.
Ekkasit
E
Tharavichitkul
EQD2 software; LQL model; biological dose