Document Type : Original Paper
Authors
1
1.Department of Physics, Institute of Applied Science and Humanities, GLA University, Mathura-281406 (U.P.), India. 2.Department of Radiotherapy, Chief Medical Physicist, Saroj Gupta Cancer Centre and Research Institute, Kolkata, India.
2
Chief Medical Physicist, Department of Radiotherapy, Apollo Multispeciality Hospitals, Kolkata, India
3
Department of Mathematics, Institute of Applied Science and Humanities, GLA University, Mathura -281406 (U.P.), India
Abstract
Introduction: IMRT and VMAT increase PTV coverage, compliance, and homogeneity while minimising heart and ipsilateral lung exposure (IL). However, these methods may increase the number of OARs getting a low dosage and requiring additional MUs, raising cancer recurrence risk. The hybrid treatment planning technique is ideal for ca-breast treatments since it yields excellent outcomes with less sophisticated treatment planner skills.
Material and methods: Retrospectively, 15 Patients of Ca- breast were taken for this study from our institute’s patient database. Three different planning strategies were created, namely 3DCRT, IMRT and Hybrid IMRT plans. Different ratios of 3DCRT and IMRT treatment plans were kept while creating the Hybrid IMRT treatment plans. All treatment plans were created in Eclipse (V16.1), with a prescription dose of 40.05 Gy per 15 fractions.
Result: Hybrid IMRT80%, 60%, 40%, and 20% had UDI scores of 0.989 ±0.022, 0.997±0.256, 0.0999±0.026, and 0.9958±0.0291. The hybrid IMRT80% treatment plan had the lowest Total MU of 497.33±45.36, and V20Gy of Ipsilateral lung was 16.93±3.50%, compared to 17.14±3.39%, 17.51±3.14%, and 17.73±3.0% in IMRT60%, IMRT40%, and IMRT20%. Heart mean dose was lowest in IMRT80% (4.13±1.47Gy) and increased insignificantly from 4.426±1.344 Gy to 4.51±1.344 Gy in 3DCRT and IMRT100%.
Conclusion: The present dosimetry analysis recommends that hybrid IMRT should be 80% 3DCRT open field and 20% IMRT plan to spare the lungs and heart and cover the planning target volume.
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