Talks
Presentation Type
Oral Presentation
Discipline Track
Clinical Science
Abstract Type
Research/Clinical
Abstract
Background: Radiation therapy for breast cancer has evolved from conventional to 3-dimentional radiation therapy (3-DCRT) and through more precise IMRT and VMAT. 3-DCRT is preferred for ca breast treatment as it reduces low dose area in contra lateral lung but with the advances in radiotherapy image guided techniques can deliver precise and lower doses to OARs with better coverage. This study is aimed to evaluate the doses of PTV, heart and ipsi-lateral lung with contra lateral lung doses delivered by VMAT technique.
Method and material: Total 10 patients of carcinoma left breast with mastectomy were selected for VMAT planning with prescription of 45 Gy/20#. Eclipse 16.1 treatment planning system was used and treatment was delivered by True Beam with 6 MV photon energy with image guidance. The VMAT technique includes the non-continuous partial arc and continuous partial arc to deliver the dose. Dose volume histogram (DVH) was used to analyze for doses of planning target volume (PTV) and organs at risk (OARs).
Results: PTV was covered with average 94.96% of prescribed dose. The average homogeneity index was found 0.02 and average conformity index was found 0.97 for VMAT plans. Mean doses for heart were measured 14.49±2.11Gy and for V25Gy 11.16±1.97Gy. Ipsilateral lung mean doses were observed 16.23±1.01 Gy, V20Gy doses were 28.73±1.52Gy, V30Gy doses were 14.78±2.5Gy and V40Gy doses were 5.59±1.98Gy. The contralateral lung mean doses were reported 7.69±1.79Gy and V10Gy 19.05±2.05Gy. Average planning target volume was 1710.98cc. The average homogeneity index was 0.02 and conformity index was 0.96.
Conclusion: OARs doses with the use of VMAT with continuous and partial arcs are within limit and PTV coverage was also satisfactory. The contralateral lung doses were also within limit. For more precise treatment and low doses of heart and contra lateral lung VMAT technique can be preferred for carcinoma left breast treatment.
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Recommended Citation
Bisht, Jyoti; Gupta, Meenu; Kant, Ravi; Nautiyal, Vipul; Kumar, Viney; Dobhal, Rishabh; Ahmad, Mushtaq; and Saini, Sunil, "Dosimetric study for mastectomy carcinoma left breast cases with volumetric modulated arc therapy (VMAT)" (2023). Research Symposium. 15.
https://scholarworks.utrgv.edu/somrs/theme1/track1/15
Included in
Dosimetric study for mastectomy carcinoma left breast cases with volumetric modulated arc therapy (VMAT)
Background: Radiation therapy for breast cancer has evolved from conventional to 3-dimentional radiation therapy (3-DCRT) and through more precise IMRT and VMAT. 3-DCRT is preferred for ca breast treatment as it reduces low dose area in contra lateral lung but with the advances in radiotherapy image guided techniques can deliver precise and lower doses to OARs with better coverage. This study is aimed to evaluate the doses of PTV, heart and ipsi-lateral lung with contra lateral lung doses delivered by VMAT technique.
Method and material: Total 10 patients of carcinoma left breast with mastectomy were selected for VMAT planning with prescription of 45 Gy/20#. Eclipse 16.1 treatment planning system was used and treatment was delivered by True Beam with 6 MV photon energy with image guidance. The VMAT technique includes the non-continuous partial arc and continuous partial arc to deliver the dose. Dose volume histogram (DVH) was used to analyze for doses of planning target volume (PTV) and organs at risk (OARs).
Results: PTV was covered with average 94.96% of prescribed dose. The average homogeneity index was found 0.02 and average conformity index was found 0.97 for VMAT plans. Mean doses for heart were measured 14.49±2.11Gy and for V25Gy 11.16±1.97Gy. Ipsilateral lung mean doses were observed 16.23±1.01 Gy, V20Gy doses were 28.73±1.52Gy, V30Gy doses were 14.78±2.5Gy and V40Gy doses were 5.59±1.98Gy. The contralateral lung mean doses were reported 7.69±1.79Gy and V10Gy 19.05±2.05Gy. Average planning target volume was 1710.98cc. The average homogeneity index was 0.02 and conformity index was 0.96.
Conclusion: OARs doses with the use of VMAT with continuous and partial arcs are within limit and PTV coverage was also satisfactory. The contralateral lung doses were also within limit. For more precise treatment and low doses of heart and contra lateral lung VMAT technique can be preferred for carcinoma left breast treatment.