Journal of Medical Physics
ORIGINAL ARTICLE
Year
: 2017  |  Volume : 42  |  Issue : 1  |  Page : 14--17

Comparison of rapid arc and intensity-modulated radiotherapy plans using unified dosimetry index and the impact of conformity index on unified dosimetry index evaluation


Jayapalan Krishnan1, Jayarama Shetty2, Suresh Rao1, Sanath Hegde1, C Shambhavi1 
1 Department of Radiation Oncology, Mangalore Institute of Oncology, Mangalore, Karnataka, India
2 Department of Radiation Oncology, K. S. Hegde Medical Academy, Mangalore, Karnataka, India

Correspondence Address:
Jayapalan Krishnan
Department of Radiation Oncology, Mangalore Institute of Oncology, Mangalore, Karnataka
India

The aim of this study was to evaluate the impact of conformity index in the unified dosimetry index (UDI) score for two different planning techniques namely intensity-modulated radiotherapy (IMRT) and Rapid Arc. Rapid Arc and IMRT plans of 57 patients were evaluated and compared using UDI score which incorporates four indices. To determine the impact of conformity index on the IMRT and Rapid Arc plans, UDI at conformity index one of all plan (UDIunit_CI) score was calculated by assuming conformity index is equal to one. Mean and standard deviations of all indices were calculated. Rapid Arc technique plans of different treatment sites of all patients scored lesser UDI than IMRT plans, and the conformity index of Rapid Arc plan was significantly better than IMRT plan. The average dose gradient, homogeneity, coverage, and conformity index of all sites with Rapid Arc plans were 0.212 ± 0.05, 1.123 ± 0.03, 0.959 ± 0.03, and 1.056 ± 0.09; with IMRT plans were 0.190 ± 0.05, 1.113 ± 0.04, 0.950 ± 0.04, and 1.172 ± 0.16, respectively. UDI score value with actual conformity index of Rapid Arc and IMRT plans differed significantly (P < 0.001). However, UDIunit_CIscore values with assumed conformity index equal to one did not differ significantly (P = 0.528). In the comparison of IMRT and Rapid Arc plans using the UDI score, the impact of conformity index was significant.


How to cite this article:
Krishnan J, Shetty J, Rao S, Hegde S, Shambhavi C. Comparison of rapid arc and intensity-modulated radiotherapy plans using unified dosimetry index and the impact of conformity index on unified dosimetry index evaluation.J Med Phys 2017;42:14-17


How to cite this URL:
Krishnan J, Shetty J, Rao S, Hegde S, Shambhavi C. Comparison of rapid arc and intensity-modulated radiotherapy plans using unified dosimetry index and the impact of conformity index on unified dosimetry index evaluation. J Med Phys [serial online] 2017 [cited 2017 May 23 ];42:14-17
Available from: http://www.jmp.org.in/article.asp?issn=0971-6203;year=2017;volume=42;issue=1;spage=14;epage=17;aulast=Krishnan;type=0