2Department of Radiation Oncology, Istanbul University, Institute of Oncology, Istanbul-Türkiye DOI : 10.5505/tjo.2022.3491 OBJECTIVE
There may be differences between optimized dose distributions and calculated dose distributions in the treatment planning system. The intermediate dose calculation (IDC) module, which was developed to eliminate this difference, provides better dose distribution, especially in inhomogeneous structures such as the lung. In the study, it was aimed to investigate the effect of IDC module for esophagus cancer patients.
METHODS
The treatment plans were prepared with the volumetric modulated arc technique (VMAT), with and
without IDC module, for ten thoracic and ten abdominal esophagus patients. The conformity index
(CI), homogeneity index (HI) values, and critical organ doses obtained from the dose volume histograms
of the prepared plans were compared.
RESULTS
The treatment plans created with IDC module give better results for CI and HI values. Especially in
patients with thoracic esophagus where inhomogeneity is more intense due to the presence of the lungs,
it has been observed that the IDC module provides a more significant decrease in CI (1.256±0.042 vs.
1.233±0.038, p=0.009) and HI (0.126±0.014 vs. 0.086±0.018, p=0.005) values. Heart V30, Spinal Cord
Dmax, and D1cc values were found to be significantly lower.
CONCLUSION
The use of IDC module in VMAT treatment plans of esophagus cancer patients improves the plan quality.