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Purpose: The aim of this study is to quantify the potential benefits of a flattening filter‐free (FFF) beam and implement a dose‐computation algorithm for cervical radiotherapy through dosimetric and radiobiological analyses using RapidArc. Methods: Thirty‐three patients were enrolled, and four RapidArc plans were created for each patient using a dual‐arc flattening filter and 6‐MV FFF photon beams for the two calculation algorithms. Homogeneity index (HI), conformity index (CI), target coverage, monitor units (MUs), and organ‐at‐risk (OAR) dosimetric characteristics were compared between the plans. Radiobiological characteristics and normal tissue complication probability (NTCP) scores were computed for the OAR using different biological models. Results: No significant differences were observed in the Dmax, D98%, and CI in the planning target volume (PTV). Both computations estimated a significant difference in V95%, D2%, and HI for the PTV. Furthermore, the FFF beam showed a significant increase in the MUs and a significant reduction in V30% for the femoral heads. The NTCP score showed a significant increase in the late effects on the bladder, rectum, and bowel with FFF beams. Conclusion: The current study recommends FFF beams for better conformity, comparable dose coverage for the target, and OAR sparing invariable to the dose computation algorithm. The difference in the NTCP score for OAR was minimal with the FFF beam. [ABSTRACT FROM AUTHOR]

A genotype 'Sujata' developed earlier at CSIR-CIMAP from its parent 'Sampada' is considered to be the latex-less variety of Papaver somniferum. These two genotypes are contrasting in terms of latex and stem strength. Earlier we have carried out microarray analysis to identify differentially expressing genes from the capsules of the two genotypes. In this study, the peduncles of the two genotypes were compared for the anatomy revealing less number of laticifers in the cortex and vascular bundles. One of the important cell wall-related genes (for laccase) from the microarray analysis showing significantly higher expression in 'Sampada' capsule was taken up for further characterization in the peduncle here. It was functionally characterized through transient overexpression and RNAi suppression in 'Sujata' and 'Sampada'. The increase in acid insoluble lignin and total lignin in overexpressed tissue of 'Sujata', and comparable decrease in suppressed tissue of 'Sampada', along with corresponding increase and decrease in the transcript abundance of laccase confirm the involvement of laccase in lignin biosynthesis. Negligible transcript in phloem compared to the xylem tissue localized its expression in xylem tissue. This demonstrates the involvement of P. somniferum laccase in lignin biosynthesis of xylem, providing strength to the peduncle/stem and preventing lodging. [ABSTRACT FROM AUTHOR]