Related Experiment Video
Updated: Apr 7, 2026
Proton Therapy Delivery and Its Clinical Application in Select Solid Tumor Malignancies
Published on: February 6, 2019
Dosimetric Comparison of Tangential Beam and Equally Spaced Beam Intensity-modulated Radiation Therapy in Right
E Rajadurai1,2, A Saravana Kumar1, K N Govindarajan1
1Department of Medical Physics, PSG Institute of Medical Sciences Research and Hospitals, Coimbatore, Tamil Nadu, India.
Objective:
This study aimed to evaluate and compare the dosimetric performance and treatment efficiency of two intensity-modulated radiation therapy (IMRT) techniques - tangential field IMRT (Tan_IMRT) and equally spaced beam IMRT (Esb_IMRT) - in patients with right-sided breast cancer following breast-conserving surgery (BCS).
Materials And Methods:
A total of 25 female patients who underwent BCS for right-sided breast cancer and received adjuvant radiotherapy were included in this retrospective study. All patients were treated with whole-breast hypofractionated radiotherapy, delivering 40.05 Gy in 15 fractions. Each patient's treatment plans were generated using the Eclipse Treatment Planning System, employing Tan_IMRT and Esb_IMRT techniques on a TrueBeam SVC linear accelerator equipped with a high-definition multileaf collimator. Various dosimetric parameters were evaluated, including the conformity index (CI), homogeneity index (HI), dose-volume histogram metrics for organs at risk, and monitor units (MUs).
Results:
In right-sided breast radiotherapy following BCS, Esb_IMRT demonstrated a superior CI and HI compared to Tan_IMRT. In addition, Esb_IMRT achieved lower ipsilateral lung doses, as reflected by reduced V20%, V5%, and mean dose (Dmean). However, Tan_IMRT resulted in a lower Dmean for the contralateral breast.
Conclusion:
Tan_IMRT shows reduced radiation exposure to the heart, contralateral lung, and contralateral breast. Furthermore, Tan_IMRT delivers doses with fewer MUs. In contrast, Esb_IMRT gives superior CI and HI while achieving lower doses to the ipsilateral lung and liver. Hence, Tan_IMRT can be suitable for younger patients.
