ABSTRACT
Introduction: In head and neck cancer the location, size, shape of disease, and normal anatomy change in 6-7 weeks radiotherapy. As a result, steep dose gradients move across target and critical structures resulting in underdose to target and overdose to critical structures. Aim: comparison of target coverage in initial IMRT plan and replan and to quantify dose changes to normal structures in two plans. Methods and Material: 30 patients with locally advanced head and neck cancer patients planned for curative radiotherapy were selected and treated with 3DCRT plan. For dosimetric comparison IMRT plan was created for pre-treatment and repeat CT, which was done after 40Gy. Statistical analysis used: Statistical methods (student’s paired t-test) were applied. Results: Both PTV coverage (V95 from 96.29±1.12 to 97.33±0.80) and dose (D95 from 66.64±0.87 to 67.57±0.74) increased in replanned CT. Both max and mean doses to the brainstem and spinal cord along with mean dose to parotid glands increased in replanned CT. Conclusions: Replanning is necessary during mid-treatment to accommodate anatomical and dosimetric changes during curative radiotherapy.
ABSTRACT
Sesame (Sesamum indicum L.) is an important crop known for its high-quality edible oil. Molecular markers are useful to explore highly diverse genotypes and relationships among populations for crossbreeding programs. In the present investigation, the genetic fidelity of 9 sesame cultivars of Tamil Nadu was assessed by 10 RAPD (Random Amplified Polymorphic DNA) and SSR (Simple Sequence Repeats) markers. A total of 102 DNA bands were obtained with RAPD primers, of which 46 were polymorphic. SSR primers generated 19 bands, of which 8 were polymorphic. The genetic relationships of nine varieties were inferred using the average linkage method. The cultivars were grouped into 2 clusters from RAPD and 3 clusters from SSR markers. Among the two RAPD clusters, cluster I comprised of TMV 4, TMV 5, TMV 6, TMV 7, SVPR 1, VRI 1, VRI 2, and CO 1 and cluster II comprised of TMV 3 cultivar. In SSR clusters, cluster I consisted of CO 1 and VRI 2, cluster II consisted of TMV 5, TMV 6, TMV 7, VRI 1, and SVPR 1 and cluster III consisted of TMV 3 and TMV 4 cultivars. The experimental results showed that mono-geographical separation of cultivars generally did not result in the greater genetic distance. This study demonstrated that RAPD and SSR markers were appropriate for evaluation of low diversified sesame varieties. Understanding of these characteristics of sesame cultivars in Tamil Nadu will provide a theoretical foundation for further development of variation among the sesame cultivars.