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Generally, converting irradiation plans between C-arm linacs (C-linac) when the linac fails is possible without recalculating the dose distribution using a treatment planning system (TPS), because they have similar mechanical structure. However, the O-ring-type linac (O-linac) differs from the C-linac in forming the dose distribution. Therefore, if O-linac breaks down, it is necessary to formulate a treatment plan from scratch. In this study, we investigated a method for converting irradiation from an O-linac to a C-linac. Thirty patients with lung cancer who underwent volumetric-modulated arc therapy with an O-linac were included in this study. The O-linac dose distribution was converted into energy fluence by the function of the TPS. The alternative linac multi-leaf collimator (MLC) was then optimized to achieve energy fluence. The homogeneity index, conformity index, and planning treatment volume (D95%, D2%) of the converted plan were compared with the original plan. For organ at risk (OAR), the dose-volume histograms (DVHs) of the lung, esophagus, heart, and spinal cord were evaluated. Additionally, the shapes of the isodose curves were compared using the Dice similarity coefficient (DSC). There was no significant difference between the target and OARs (p > 0.05). The mean DSCs of 30% to 100% isodose curves of the prescribed dose and the isodose ≥ 105% and ≤ 20%were > 0.8 and

Additional file 6.

Objectives The correlation of XRCC-1 Gene Arg194Trp polymorphism with alcohol and tobacco substance user and with loco-regionally progressed squamous cell cancer of the larynx (LSCC) was assessed in this research study. The result of this research study is described herein. Material and methods A tertiary hospital-based observational case-control research was carried out. DNA segregation and Genotype examination were done from the blood sample of the control group and cases to know the correlation between XRCC-1 gene polymorphism with loco-regionally progressed LSCC and with hazard factors tobacco and alcohol. Results In the cases, the existence of DNA repair XRCC-1 gene polymorphic variants (Hetero CT and Mutant TT) was recognizable in contrary to the control group arm. The XRCC-1 gene polymorphic hetero (CT) genotype (O.R-1.96; 95% C.I: 1.23-3.13; P